ALBERT

Beschreibung:    Based on the high flux synchrotron X-ray of the Shanghai Synchrotron Radiation Facility (SSRF), high precision 3D digital models of diesel nozzle tips have been established by X-ray micro-tomography technology, which reveal the internal surfaces and structures of orifices. To analyze the machining precision and characteristics of orifice processing methods, an approach is presented based on the parameters of the internal structures of nozzle orifices, including the nozzle diameter, the orifice inner surface waviness, the eccentricity distance and the angle between orifices. Using this approach, two kinds of nozzle orifice processing methods, computerized numerical control drilling and electric discharge machining, have been studied and compared. The results show that this approach enables a simple, direct, and comprehensive contrastive analysis of nozzle orifice processing methods. When processing a single orifice, the electric discharge machining method has obvious advantages. However, when there are multiple orifices, the error levels of the two methods are similar in relation to the symmetry of distribution of the orifices. Content Type Journal Article Pages 182-188 DOI 10.1631/jzus.A1100252 Authors Zhi-jun Wu, School of Automotive Studies, Tongji University, Shanghai, 201019 China Zhi-long Li, School of Automotive Studies, Tongji University, Shanghai, 201019 China Wei-di Huang, School of Automotive Studies, Tongji University, Shanghai, 201019 China Hui-feng Gong, School of Automotive Studies, Tongji University, Shanghai, 201019 China Ya Gao, School of Automotive Studies, Tongji University, Shanghai, 201019 China Jun Deng, School of Automotive Studies, Tongji University, Shanghai, 201019 China Zong-jie Hu, School of Automotive Studies, Tongji University, Shanghai, 201019 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    A type of hollow cylinder joints connected with H-shaped beams is proposed for spatial structures. Based on von Mises yield criterion and perfect elasto-plasticity model, a series of finite element models of the joints is established, in which the effect of geometric nonlinearity is taken into account. Then mechanical behavior and load-carrying capacity of the joints were investigated, which were subjected to axial load, in- and out-plane bending moments, and their combinations. The results show that the ultimate loads of the joints are determined by the maximum displacement. Furthermore, the case of one joint connected with multiple beams was discussed. Experiments on a set of typical full-scale joints were conducted to understand the structural behavior and the failure mechanism of joint, and also to validate the finite element models. Finally, the practical calculation method was established through finite elements analysis (FEA) results and numerical fitting. The results show that the joints are more ductile and materially economical than welded hollow spherical joints, and the practical calculation method can provide a reference for direct design and the revision of relevant design codes. Content Type Journal Article Pages 174-181 DOI 10.1631/jzus.A1100128 Authors Hui Wu, Finance and Economics of Zhejiang College, Hangzhou, 310018 China Bo-qing Gao, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Qiang Chen, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    Moisture adsorption-desorption tests (MATs) were conducted on simulated mural plaster specimens under different air temperatures (ATs) and relative humidity (RH) to investigate the possible effect of seasonal alteration and visitors’ breath on the deterioration of Mogao Grottoes, Dunhuang, China. Saturated salt solutions were used to maintain a constant RH, and plant growth cabinets were used to maintain a constant or varying temperature in the simulation test. The weight of specimen was periodically measured to determine the adsorbed or desorbed moisture. Test data illustrate that the desorption process is far quicker than the adsorption one, indicating that it is possible to inhibit the disadvantage effect from visitors, such as shortening the staying time in caves. In case of high humidity, an accumulated moisture adsorption was found to correspond to the varying temperature. On the other hand, in case of low humidity, accumulated moisture desorption corresponded. Test data imply that opening caves more often to visitors in humid seasons should be avoided so as to prevent continuous wetting of wall paintings. Content Type Journal Article Pages 208-218 DOI 10.1631/jzus.A1100204 Authors Hu-yuan Zhang, MOE Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou, 730000 China Geng-sheng Yan, MOE Key Laboratory of Mechanics on Disaster and Environment in Western China, Lanzhou University, Lanzhou, 730000 China Xu-dong Wang, National Engineering Research Center of Ancient Mural Protection, Dunhuang, 736200 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    This study presents and verifies a new idea for constructing a rotary traveling wave ultrasonic motor (USM) that uses the radial bending mode of a ring. In the new design, 20 trapezoid cross section slots are cut symmetrically in the outer surface of a thick duralumin alloy ring, where 20 PZT stacks are nested. In each slot, two wedging blocks are set between the PZT stack and the two sides of the slot respectively to apply preloading on the PZT ceramics. Two radial bending modes of the stator that have a phase difference of a quarter wavelength on space are generated by using the d33 operating mode of the PZT elements, and then a flexural traveling wave is formed by the superimposing of two standing waves whose amplitudes are equal and phases are different by 90° temporally. Two conical rotors are pressed to each end of the ring type stator by a coiled spring. The finite element method (FEM) simulation is developed to validate the feasibility of the proposed motor. The maximal speed and torque of the prototype are tested to be 126 r/min and 0.8 N·m, respectively. Content Type Journal Article Pages 189-196 DOI 10.1631/jzus.A1100225 Authors Ying-xiang Liu, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Jun-kao Liu, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Wei-shan Chen, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Xiao-hui Yang, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    In order to investigate the wind characteristics of coastal areas of China, a long-term field measurement of natural wind was carried out. Based on the field measurement results, this paper presents the natural wind characteristics of typhoons and strong monsoons at the site of Xi-hou-men Bridge, including mean wind speed, mean wind direction, mean wind elevation angle, turbulent intensity, gust factor, turbulence integral length scales, power spectrum of wind speed and spatial correlation of gusty wind, the profiles of mean wind speed and turbulent intensity, etc. The correlation among wind characteristics is analyzed in detail, and the similarities and differences of wind characteristics between typhoons and monsoons are analyzed. These results can provide detailed wind characteristics of coastal areas of China. Content Type Journal Article Pages 197-207 DOI 10.1631/jzus.A1100178 Authors Ming Liu, Research Center for Wind Engineering, Southwest Jiaotong University, Chengdu, 610031 China Hai-li Liao, Research Center for Wind Engineering, Southwest Jiaotong University, Chengdu, 610031 China Ming-shui Li, Research Center for Wind Engineering, Southwest Jiaotong University, Chengdu, 610031 China Cun-ming Ma, Research Center for Wind Engineering, Southwest Jiaotong University, Chengdu, 610031 China Mei Yu, Research Center for Wind Engineering, Southwest Jiaotong University, Chengdu, 610031 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    Hollow core slabs are becoming of increasing interest as the construction industry attempts to minimise the impact of its activities on the environment. By forming voids in the interior of a concrete slab, the amount of concrete used can be reduced without significantly altering the capacity of the structure. In this study, we examined the inner force transfer mechanism of a column-supported cast-in-situ hollow core slab using finite element analysis. Both a hollow core slab and the corresponding solid slab were analysed using ANSYS and the results were compared. The orientation of the tube fillers causes the stiffness of the hollow slab to be orthotropic, potentially changing the distribution of load carried in the two orthogonal directions. Both the cross-section’s moments in the column strip and near the columns in the hollow core slab become larger than that in the solid floor. As well, the cross-section’s stiffness along the tube arrangement direction is larger than that of the radial cross-section, which causes the direction along the hole of the hollow core slab to carry more moment than the radial direction. The conversion factors of the two directions are proposed from the comparison for four typical areas of the hollow core slab, as are the moment distribution coefficients. Content Type Journal Article Pages 165-173 DOI 10.1631/jzus.A1100170 Authors Hai-tao Li, Department of Building Engineering, Nanjing Forestry University, Nanjing, 210037 China Andrew John Deeks, Department of Building Engineering, Nanjing Forestry University, Nanjing, 210037 China Li-xin Liu, Department of Civil Engineering, Zhengzhou University, Zhengzhou, 450002 China Dong-sheng Huang, Department of Building Engineering, Nanjing Forestry University, Nanjing, 210037 China Xiao-zu Su, Department of Building Engineering, Tongji University, Shanghai, 200092 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    Population exposure to pollutants is important for studies on the exposure-response relationship. However, it is difficult to evaluate population exposure to non-conventional pollutants due to limited data on concentration levels and the movement patterns of inhabitants. In this study, an air dispersion model was used to simulate N, N-dimethylformamide (DMF) concentrations, as a proxy to monitoring concentrations. A total of 1289 randomly selected household representatives were surveyed to obtain information on movement characteristics. Subsequently, population movement patterns were combined with DMF concentration levels on maps of 100 m×100 m resolution to calculate population exposure. During 2008, the estimated population exposure to DMF ranged from 0.002 to 0.64 mg/m 3 . The highest level of population exposure to DMF was found in the north and northwest sub-districts of the study area, ranging from 0.42 to 0.64 mg/m 3 . The population exposure to DMF for different occupational groups indicated that retired people and farmers were vulnerable subpopulations among people highly exposed to DMF. This was mainly because they spent most time at home where the DMF concentration was high. As pollutant concentrations were divided into small grids, we found that exposure levels were substantially impacted by population movement characteristics. Content Type Journal Article Pages 794-806 DOI 10.1631/jzus.A11b0381 Authors Yu-mei Wei, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Wei-li Tian, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Qing-yu Zhang, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Ying-yue Zheng, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Yi-ke Yang, Management Office of the New Rural Cooperative Medical Service, Longwan District Health Bureau, Wenzhou, 325011 China Zu-cheng Wu, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Qi Zhu, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Lei Zhou, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310027 China Si-mai Fang, Department of Information Management, University of International Business and Economics, Beijing, 100029 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    The pressure increasing process within a twin screw multiphase pump, under the condition of high gas volume fractions (GVFs), induces large temperature and pressure changes that cause the rotors to deform. Rotor deformations heavily influence the backflow of the multiphase fluid through clearances within the twin screw multiphase pump and these deformations may even lead to pump failures. An accurate temperature and pressure distribution on the screw rotors need be obtained before the deformation analysis can be carried out. By means of small temperature and pressure sensors embedded into the groove at the root of the rotors, the temperatures of 12 points on the rotors and the pressure distributions of a twin screw multiphase pump under high GVFs conditions were recorded. Temperature test results were adopted to perform a heat transfer analysis for determining the temperature distribution on the screw rotors. Then deformation analyses, including thermal deformation, force deformation, and total deformation, were conducted according to the pressure and temperature distributions. Deformation analysis for different materials was also conducted under the same boundary conditions. A material was suggested for the manufacturing of rotors in a twin screw multiphase pump under the condition of high gas volume fractions. Content Type Journal Article Pages 720-730 DOI 10.1631/jzus.A1000485 Authors Tie-yu Gao, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Dong-fang Yang, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Feng Cao, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Jin-cheng Jiao, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    A preloading frame is firstly designed to accurately apply external flexural stress to concrete specimens. Then a method is developed to measure one and two dimensional (1D and 2D) chloride ion concentrations at different distances from the surface of concrete under flexural stress. Using this method and the preloading frame, 1D and 2D stress-diffusion is systematically investigated for fly ash concretes made with different fly ash contents (0%, 10%, 20%, 40%, and 60%), and water to binder ratios (0.3, 0.35, and 0.4). The stress accelerating effect on 1D and 2D chloride ion diffusion is also quantitatively analyzed through a comparison between stress-diffusion and nonstress-diffusion. A diffusion accelerating effect caused by external flexural stress can clearly be observed through the comparison. In order to quantify the stress accelerating effect, a stress accelerating factor is proposed in this paper. The relationship between stress accelerating factor and external stress-to-ultimate stress ratio is given as an exponential function. Finally, the process of the initiation, prorogation, and distribution of microcracks on the tensile face of specimen is observed in-situ by using a small-sized loading frame and scanning electron microscope (SEM). The above research provides an insight into chloride attack on the edge reinforcing bars of concrete structures under flexural stress, such as large-span beam and board in the field of civil engineering. Content Type Journal Article Pages 692-701 DOI 10.1631/jzus.A1100006 Authors Yun-sheng Zhang, Jiangsu Key Laboratory for Construction Materials, Southeast University, Nanjing, 211189 China Wei Sun, Jiangsu Key Laboratory for Construction Materials, Southeast University, Nanjing, 211189 China Zhi-yong Liu, Jiangsu Key Laboratory for Construction Materials, Southeast University, Nanjing, 211189 China Shu-dong Chen, Jiangsu Key Laboratory for Construction Materials, Southeast University, Nanjing, 211189 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    Simulation models of traction driver systems were established using SIMULINK, according to the actual structure and parameters of China Railway High-Speed 2 (CRH2) and China Railway High-Speed 3 (CRH3) trains. In these models, the traction motor adopts transient current control and an indirect rotor magnetic field orientation vector control strategy, and the traction converter uses sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) methods. After these models are transformed in VC++ program, and a friendly interface and data processing system are constructed, simulation software is obtained for CRH2 and CRH3 traction driver systems. On this basis, the operational performance of a traction converter was simulated and analyzed at different train speeds and in different conditions. The simulation results can provide a reference for the actual design and production of a traction converter. Content Type Journal Article Pages 945-949 DOI 10.1631/jzus.A11GT006 Authors Qin-fen Lu, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Bin Wang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Xiao-yan Huang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Ji-en Ma, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China You-tong Fang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Jin Yu, National Engineering Laboratory for System Integration of High-Speed Train (South), CSR Qingdao Sifang Co., Ltd., Qingdao, 266111 China Wen-ping Cao, Newcastle University, Newcastle Upon Type, NE1 7RU UK Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    It is essential to manage customers’ diverse desires and to keep manufacturing costs as low as possible for survival in competition and eventually in production. Sharing resources in manufacturing for different products is a vital method of accomplishing this goal. The advantages of using a common process in production are stated in the literature. However, the mathematical models as well as simulation or conceptual models are not sufficient. The main objective of this paper is to develop mathematical models for multiproduct and multistage production under quality and breakdown uncertainties. The idea of the process commonality is incorporated in the proposed models. The models are validated by primary data collected from a Malaysian company and comparison of the timely requirement schedules of earlier MRP II and the proposed models under stable and perfect production environments. An appreciable convergence of the outcomes is observed. However, the proposed models are carrying additional information about the available locations of the parts in a time frame. After validation, the effects of process commonality on cost, capacity and the requirement schedule under uncertainties are examined. It is observed that the use of common processes in manufacturing is always better than the non-commonality scenario in terms of production cost. However, the increase in capacity requirement for commonality designs is higher for an ideal system, while it is less when the system suffers from breakdowns and a quality problem. Content Type Journal Article Pages 837-848 DOI 10.1631/jzus.A1000477 Authors Mohammed Abdul Wazed, Department of Engineering Design and Manufacture, University of Malaya, Kuala Lumpur, 50603 Malaysia Shamsuddin Ahmed, Department of Engineering Design and Manufacture, University of Malaya, Kuala Lumpur, 50603 Malaysia Yusoff Bin Nukman, Department of Engineering Design and Manufacture, University of Malaya, Kuala Lumpur, 50603 Malaysia Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    Steel structures are widely used in railway infrastructures. Their stress state is the most important determinant of the safety of these structures. The elasto-magnetic (EM) sensor is the most promising for stress monitoring of in-service steel structures. Nevertheless, the necessity of magnetic excitation to saturation due to the use of a secondary coil for signal detection, keeps from its engineering application. In this paper, a smart elasto-magneto-electric (EME) sensor using magneto-electric (ME) sensing units to take the place of the secondary coil has been exploited for the first time. The ME sensing unit is made of ME laminated composites, which has an ultrahigh ME voltage coefficient and can measure the magnetic induction simply and precisely. Theoretical analysis and characterization experiments firstly conducted on the ME laminated composites showed that the ME sensing units can be applied in the EM sensor for improved performance in stress monitoring. A tension test of a steel bar was carried out to characterize our smart EME sensor and the results showed high accuracy and sensitivity. The present smart EME sensor is a promising tool for stress monitoring of steel structures in railway and other civil infrastructures. Content Type Journal Article Pages 895-901 DOI 10.1631/jzus.A11GT007 Authors Yuan-feng Duan, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Ru Zhang, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Yang Zhao, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Siu-wing Or, Department of Electrical Engineering, The Hong Kong Polytechnic University, Hong Kong, China Ke-qing Fan, School of Information Engineering, Wuyi University, Jiangmen, 529020 China Zhi-feng Tang, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    As a new kind of technology in retaining structures, the characteristics of double-row piles are significantly affected by spatial effects. In this paper, double-row piles as a retaining structure are simulated numerically in three-dimension by finite element software PLAXIS 3D FOUNDATION. The behavior differences of piles in different positions around the foundation pit are analyzed. By changing the parameters, including the length-width ratio, the excavation depth, the distance between rows and the diameter of piles, the variations of the lateral deformation, the bending moment and the earth pressure around the piles are determined. The reasonable values of parameters and some suggestions with consideration of earth pressure are proposed for the design of double-row piles as a retaining structure. The results show that the lateral deformation and bending moment are the largest in the middle of long side of the foundation pit, which is identified as the most unfavorable position. It is indicated that the earth pressure between rows above pit bottom is close to active earth pressure, while the earth pressure between rows under pit bottom is close to static earth pressure. It is suggested that 1/2–2/3 of pile length, 0.6–1.2 m, 3 d –6 d , and 2 d –2.5 d be chosen as embedded depth of piles, diameter of piles, distance between rows, and distance between piles, respectively, where d is the pile diameter. Content Type Journal Article Pages 758-770 DOI 10.1631/jzus.A1100067 Authors Zi-han Wang, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092 China Jian Zhou, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    Energy crisis make the effective use of low grade energy more and more urgent. It is still a worldwide difficult conundrum. To efficiently recover low grade heat, this paper deals with a theoretical analysis of a new power generation method driven by a low grade heat source. When the temperature of the low grade heat source exceeds the saturated temperature, it can heat the liquid into steam. If the steam is sealed and cooled in a container, it will lead to a negative pressure condition. The proposed power generation method utilizes the negative pressure condition in the sealed container, called as a condensator. When the condensator is connected to a liquid pool, the liquid will be pumped into it by the negative pressure condition. After the condensator is filled by liquid, the liquid flows back into the pool and drives the turbine to generate electricity. According to our analysis, for water, the head pressure of water pumped into the condensator could reach 9.5 m when the temperature of water in the pool is 25 °C, and the steam temperature is 105 °C. Theoretical thermal efficiency of this power generation system could reach 3.2% to 5.8% varying with the altitude of the condensator to the water level, ignoring steam leakage loss. Content Type Journal Article Category Energy and Power Engineering Pages 140-145 DOI 10.1631/jzus.A1100152 Authors Wei-feng Wu, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Xin-ping Long, School of Power and Mechanical Engineering, Wuhan University, Wuhan, 430072 China Xiao-ling Yu, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Quan-ke Feng, School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    The effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells is investigated through experimental and numerical buckling analysis using six welded steel cylindrical shell specimens. The relationship between the amplitude of weld reinforcement and the axial plastic buckling critical load is explored. The effect of the material yield strength and the number of circumferential welds on the axial plastic buckling is studied. Results show that circumferential weld reinforcement represents a severe imperfect form of axially compressed welded steel cylindrical shells and the axial plastic buckling critical load decreases with the increment of the mean amplitude of circumferential weld reinforcement. The material yield strength and the number of circumferential welds are found to have no significant effect on buckling waveforms; however, the axial plastic buckling critical load can be decreased to some extent with the increase of the number of circumferential welds. Content Type Journal Article Category Mechanics and Mechanical Engineering Pages 79-90 DOI 10.1631/jzus.A1100196 Authors Chu-lin Yu, Institute of Process Equipment, Zhejiang University, Hangzhou, 310027 China Zhi-ping Chen, Institute of Process Equipment, Zhejiang University, Hangzhou, 310027 China Ji Wang, Institute of Process Equipment, Zhejiang University, Hangzhou, 310027 China Shun-juan Yan, Institute of Process Equipment, Zhejiang University, Hangzhou, 310027 China Li-cai Yang, Institute of Process Equipment, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    Time domain analysis is an essential implement to study the buffeting behavior of long-span bridges for it can consider the non-linear effect which is significant in long-span bridges. The prerequisite of time domain analysis is the accurate description of 3D turbulence winds. In this paper, some hypotheses for simplifying the 3D turbulence simulation of long-span cable-stayed bridges are conducted, considering the structural characteristics. The turbulence wind which is a 3D multivariate stochastic vector process is converted into four independent 1D univariate stochastic processes. Based on recorded wind data from structural health monitoring system (SHMS) of the Sutong Bridge, China, the measured spectra expressions are then presented using the nonlinear least-squares fitting method. Turbulence winds at the Sutong Bridge site are simulated based on the spectral representation method and the Fast Fourier transform (FFT) technique, and the relevant results derived from target spectra including measured spectra and recommended spectra are compared. The reliability and accuracy of the presented turbulence simulation method are validated through comparisons between simulated and target spectra (measured and recommended spectra). The obtained turbulence simulations can not only serve further analysis of the buffeting behavior of the Sutong Bridge, but references for structural anti-wind design in adjacent regions. Content Type Journal Article Category Mechanics and Mechanical Engineering Pages 91-104 DOI 10.1631/jzus.A1100177 Authors Hao Wang, Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Zhou-hong Zong, Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Ai-qun Li, Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Teng Tong, Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Jie Niu, Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Wen-ping Deng, Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    A coupled discrete-continuum simulation incorporating a 3D aspect and non-circular particles was performed to analyze soil-pile interactions during pile penetration in sand. A self-developed non-circular particle numerical simulation program was used which considered sand near the pile as interacted particles using a discrete element method; the sand away from the pile was simulated as a continuous medium exhibiting linear elastic behaviors. The domain analyzed was divided into two zones. Contact forces at the interface between the two zones were obtained from a discrete zone and applied to the continuum boundaries as nodal forces, while the interface velocities were obtained from the continuum zone and applied to the discrete boundaries. We show that the coupled discrete-continuum simulation can give a microscopic description of the pile penetration process without losing the discrete nature of the zone concerned, and may significantly improve computational efficiency. Content Type Journal Article Pages 44-55 DOI 10.1631/jzus.A1100172 Authors Jian Zhou, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092 China Qi-wei Jian, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092 China Jiao Zhang, School of Civil Engineering and Transportation, Shanghai Technical College of Urban Management, Shanghai, 200432 China Jian-jun Guo, Sichuan Provincial Chuanjian Investigation and Design Institute, Chengdu, 610017 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    In the structural design of tall buildings, peak factors have been widely used to predict mean extreme responses of tall buildings under wind excitations. Vanmarcke’s peak factor is directly related to an explicit measure of structural reliability against a Gaussian response process. We review the use of this factor for time-variant reliability design by comparing it to the conventional Davenport’s peak factor. Based on the asymptotic theory of statistical extremes, a new closed-form peak factor, the so-called Gamma peak factor, can be obtained for a non-Gaussian resultant response characterized by a Rayleigh distribution process. Using the Gamma peak factor, a combined peak factor method was developed for predicting the expected maximum resultant responses of a building undergoing lateral-torsional vibration. The effects of the standard deviation ratio of two sway components and the inter-component correlation on the evaluation of peak resultant response were also investigated. Utilizing wind tunnel data derived from synchronous multi-pressure measurements, we carried out a wind-induced time history response analysis of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard tall building to validate the applicability of the Gamma peak factor to the prediction of the peak resultant acceleration. Results from the building example indicated that the use of the Gamma peak factor enables accurate predictions to be made of the mean extreme resultant acceleration responses for dynamic serviceability performance design of modern tall buildings. Content Type Journal Article Pages 18-32 DOI 10.1631/jzus.A1100136 Authors Ming-feng Huang, Institute of Structural Engineering, Zhejiang University, Hangzhou, 310058 China Chun-man Chan, Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong, China Wen-juan Lou, Institute of Structural Engineering, Zhejiang University, Hangzhou, 310058 China Kenny Chung-Siu Kwok, School of Engineering, University of Western Sydney, Sydney, NSW, Australia Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    With the development of high-speed railways in China, more than 2000 high-speed trains will be put into use. Safety and efficiency of railway transportation is increasingly important. We have designed a high availability quadruple vital computer (HAQVC) system based on the analysis of the architecture of the traditional double 2-out-of-2 system and 2-out-of-3 system. The HAQVC system is a system with high availability and safety, with prominent characteristics such as fire-new internal architecture, high efficiency, reliable data interaction mechanism, and operation state change mechanism. The hardware of the vital CPU is based on ARM7 with the real-time embedded safe operation system (ES-OS). The Markov modeling method is designed to evaluate the reliability, availability, maintainability, and safety (RAMS) of the system. In this paper, we demonstrate that the HAQVC system is more reliable than the all voting triple modular redundancy (AVTMR) system and double 2-out-of-2 system. Thus, the design can be used for a specific application system, such as an airplane or high-speed railway system. Content Type Journal Article Pages 926-935 DOI 10.1631/jzus.A11GT003 Authors Ping Tan, State Key Laboratory of Industrial Control Technology & Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027 China Wei-ting He, State Key Laboratory of Industrial Control Technology & Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027 China Jia Lin, State Key Laboratory of Industrial Control Technology & Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027 China Hong-ming Zhao, Zhejiang Insigma-Supcon Co., Ltd., Hangzhou, 310013 China Jian Chu, State Key Laboratory of Industrial Control Technology & Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    Understanding the pattern of phytoplankton and their dependence on water quality variables, can help the management of eutrophic lakes. The aim of this study was to determine water quality and environmental factors associated with cyanobacteria dominance and microcystin production in Qingshan Lake, a subtropical lake located in the headwater of the Taihu watershed, China. Water samples collected monthly from 10 study sites in Qingshan Lake were analyzed for the species distributions of freshwater algae and physico-chemical parameters including total nitrogen (TN), ammonia (NH 4 + -N), nitrate (NO 3 − -N), total phosphorus (TP), and chlorophyll a (Chl-a) from June, 2008 to May, 2009. Qingshan Lake was found to be eutrophic, based on the calculated trophic state index (TSI). The average TN of 4.33 mg/L during the study period exceeded the Surface Water Quality Standards of China. TP was significantly correlated with relative abundance of cyanobacteria and Microcystis biovolume, indicating its important role in regulating cyanobacteria. Microcystis, Anabaena , and Oscillatoria were dominant cyanobacteria in Qingshan Lake from June to November, 2008. Cyanobacteria dominance was regulated by water temperature and TP. Principal component analysis further indicated that microcystin production was most affected by water temperature, TP, and cyanobacteria biomass. Results suggest that the control of TP in summer can mitigate cyanobacteria dominance and microcystin production in Qingshan Lake, and close monitoring should be undertaken in summer. Content Type Journal Article Pages 311-322 DOI 10.1631/jzus.A1100197 Authors Wan-min Ni, Institute of Environmental Science, Zhejiang University, Hangzhou, 310058 China Jian-ying Zhang, Institute of Environmental Science, Zhejiang University, Hangzhou, 310058 China Teng-da Ding, Institute of Environmental Science, Zhejiang University, Hangzhou, 310058 China R. Jan Stevenson, Center for Water Sciences, Michigan State University, East Lansing, MI 48824, USA Yin-mei Zhu, Institute of Environmental Science, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 4

Beschreibung:    This laboratory study deals with the hydraulic jump properties for an artificially roughened bed with wedge-shaped baffle blocks. The experiments were conducted for both smooth and rough beds with a Froude number in the range of 3.06≤ F 1 ≤10.95 and a relative bed roughness ranging 0.22≤ K R ≤1.4. The data from this study were compared with those of rectangular baffle blocks. New experimental formulae were developed for determining the sequent depth ratio and the hydraulic jump length in terms of the inflow Froude number and relative bed roughness. Bélanger’s jump equation of a rectangular channel was extended to account for the implications of the bed shear stress coefficient attributable to channel bed roughness. It was found that, in comparison with the smooth bed, the wedge-shaped bed roughness reduced the sequent depth of the hydraulic jump by approximately 16.5% to 30% and the hydraulic jump length by approximately 30% to 53%. Content Type Journal Article Pages 519-525 DOI 10.1631/jzus.A1200037 Authors Ashraf Fathy Ellayn, Institute of Port, Coastal and Offshore Engineering, Zhejiang University, Hangzhou, 310058 China Zhi-lin Sun, Institute of Port, Coastal and Offshore Engineering, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    As a new technique in ground improvement, geosynthetic-encased columns (GECs) have promising applications in soft soil foundation. By assuming yielding occurs in the columns while the surrounding soil and the geosynthetic remain elastic, an elastoplastic analytical procedure for foundations improved by GECs is proposed. The radial stresses that the geosynthetic provides and the elastoplastic deformations of the foundation resting on a rigid base are derived. A comparison with finite element analysis shows that the proposed method is effective and can provide a reasonable prediction of a GEC’s deformation. Subsequent parametric analysis indicates that higher geosynthetic stiffness leads to better performance of the composite foundation. The optimum length of encasement is related to the load acting on the foundation and the permissible vertical and radial displacements of the column. Moreover, as the dilation angle of the column increases, the settlement decreases, especially under high loading. The influence of the encasement is more significant in soils with smaller elastic modulus. Content Type Journal Article Pages 506-518 DOI 10.1631/jzus.A1100334 Authors Yuan-yu Duan, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Yi-ping Zhang, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Dave Chan, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada Ya-nan Yu, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    Electromigration in porous media is enhanced by a new type of electrokinetic processing. Compared with a single-oriented electric field, a continuously reoriented electric field was proven to sharply enhance mass transport of several heavy metals in kaolin. The initial concentration of the metals was: Cd: 250 mg/kg; Cu: 250 mg/kg; Ni: 250 mg/kg; Zn: 900 mg/kg. Electric field reorientation was obtained by the use of a fixed anode and a cathode that rotated at different frequencies (0, 0.25, 1.00, 1.25, 2.00, 5.00 and 10.00 r/m). Mass transport evidently increased from 0 r/m to 1.25 r/m, and then decreased as the rotation speed reached 10 r/m. From 0 r/m to 1.25 r/m, mass transport increased 2.87 times for Cd, 3.17 times for Cu, 2.11 times for Ni, and 4.13 times for Zn. We suggest that continuous reorientation of the electric field facilitates the advance of ions through kaolin pores, minimizing the retardation effect caused by media tortuosity. Content Type Journal Article Pages 546-558 DOI 10.1631/jzus.A1200017 Authors Juan Almeira, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100 China Chang-sheng Peng, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100 China Ahmed Abou-Shady, College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    This paper deals with an improved bonding approach of surface-bonded fiber Bragg grating (FBG) sensors for airship envelope structural health monitoring (SHM) under the strain transfer theory. A theoretical formula is derived from the proposed model to predict the strain transfer relationship between the airship envelope and fiber core. Then theoretical predictions are validated by numerical analysis using the finite element method (FEM). Finally, on the basis of the theoretical approach and numerical validation, parameters that influence the strain transfer rate from the airship envelope to fiber core and the ratio of effective sensing length are analyzed, and some meaningful conclusions are provided. Content Type Journal Article Pages 538-545 DOI 10.1631/jzus.A1100336 Authors Hai-tao Zhao, School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, 200240 China Quan-bao Wang, School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, 200240 China Ye Qiu, School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, 200240 China Ji-an Chen, School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, 200240 China Yue-ying Wang, School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, 200240 China Zhen-min Fan, School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, 200240 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    This paper presents a type of vibration energy harvester combining a piezoelectric cantilever and a single degree of freedom (SDOF) elastic system. The main function of the additional SDOF elastic system is to magnify vibration displacement of the piezoelectric cantilever to improve the power output. A mathematical model of the energy harvester is developed based on Hamilton’s principle and Rayleigh-Ritz method. Furthermore, the effects of the structural parameters of the SDOF elastic system on the electromechanical outputs of the energy harvester are analyzed numerically. The accuracy of the output performance in the numerical solution is identified from the finite element method (FEM). A good agreement is found between the numerical results and FEM results. The results show that the power output can be increased and the frequency bandwidth can be improved when the SDOF elastic system has a larger lumped mass and a smaller damping ratio. The numerical results also indicate that a matching load resistance under the short circuit resonance condition can obtain a higher current output, and so is more suitable for application to the piezoelectric energy harvester. Content Type Journal Article Pages 526-537 DOI 10.1631/jzus.A1100344 Authors Hong-yan Wang, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Xiao-biao Shan, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Tao Xie, State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin, 150001 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    To investigate the fire endurance of wood beams exposed to three-side fire, we conducted bearing capacity tests of two wood beams and experiments of five wood beams exposed to three-side fire. The finite element software ANSYS was also used to predict the fire endurance of those beams with the indirect order coupling method. It was found that the fire endurance decreases as the load level increases, and the reduction ratio tends to decrease. In the case of a certain load level, the fire endurance is improved if the section size is increased or covered by the fire protection coating. The central deformation increases as the fire duration increases, and the ratio of increase tends to rise. On another note, an increase in the density of wood leads to a rise in the fire endurance of a given beam. From the finite element method (FEM) calculation results, the fire endurance decreases as the load level increases, and the reduction ratio tends to decrease. When the load level is greater than 0.5, the fire endurance is significantly reduced, and it does not change significantly when the load level changes. Lastly, for a load level magnitude below 0.5, the fire endurance and load level are proportional to one another. Content Type Journal Article Pages 491-505 DOI 10.1631/jzus.A1200022 Authors Jin Zhang, Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, Southeast University, Nanjing, 210096 China Qing-feng Xu, Shanghai Key Laboratory of New Technology Research on Engineering Structure, Shanghai Research Institute of Building Sciences, Shanghai, 200032 China Yi-xiang Xu, Department of Civil Engineering, Strathclyde University, Glasgow, G12 8QQ UK Bin Wang, Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, Southeast University, Nanjing, 210096 China Jing-xiang Shang, Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education, Southeast University, Nanjing, 210096 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    An intrusion of contaminants into the water distribution network (WDN) can occur through storage tanks (via animals, dust-carrying bacteria, and infiltration) and pipes. A sensor network could yield useful observations that help identify the location of the source, the strength, the time of occurrence, and the duration of contamination. This paper proposes a methodology for identifying the contamination sources in a water distribution system, which identifies the key characteristics of contamination, such as location, starting time, and injection rates at different time intervals. Based on simplified hypotheses and associated with a high computational efficiency, the methodology is designed to be a simple and easy-to-use tool for water companies to ensure rapid identification of the contamination sources, The proposed methodology identifies the characteristics of pollution sources by matching the dynamic patterns of the simulated and measured concentrations. The application of this methodology to a literature network and a real WDN are illustrated with the aid of an example. The results showed that if contaminants are transported from the sources to the sensors at intervals, then this method can identify the most possible ones from candidate pollution sources. However, if the contamination data is minimal, a greater number of redundant contamination source nodes will be present. Consequently, more data from different sensors obtained through network monitoring are required to effectively use this method for locating multi-sources of contamination in the WDN. Content Type Journal Article Pages 559-570 DOI 10.1631/jzus.A1100286 Authors Tao Tao, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 China Ying-jun Lu, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 China Xiang Fu, State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan, 430072 China Kun-lun Xin, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 7

Beschreibung:    The volume of influence of excavation at the right bank slope of Dagangshan Hydropower Station, southwest China, is essentially determined from microseismic monitoring, numerical modeling and conventional measurements as well as in situ observations. Microseismic monitoring is a new application technique for investigating microcrackings in rock slopes. A microseismic monitoring network has been systematically used to monitor rock masses unloading relaxation due to continuous excavation of rock slope and stress redistribution caused by dam impoundment later on, and to identify and delineate the potential slippage regions since May, 2010. An important database of seismic source locations is available. The analysis of microseismic events showed a particular tempo-spatial distribution. Seismic events predominantly occurred around the upstream slope of 1180 m elevation, especially focusing on the hanging wall of fault XL316-1. Such phenomenon was interpreted by numerical modeling using RFPA-SRM code (realistic failure process analysis-strength reduction method). By comparing microseismic activity and results of numerical simulation with in site observation and conventional measurements results, a strong correlation can be obtained between seismic source locations and excavation-induced stress distribution in the working areas. The volume of influence of the rock slope is thus determined. Engineering practices show microseismic monitoring can accurately diagnose magnitude, intensity and associated tempo-spatial characteristics of tectonic activities such as faults and unloading zones. The integrated technique combining seismic monitoring with numerical modeling, as well as in site observation and conventional surveying, leads to a better understanding of the internal effect and relationship between microseismic activity and stress field in the right bank slope from different perspectives. Content Type Journal Article Pages 445-460 DOI 10.1631/jzus.A1100131 Authors Nu-wen Xu, State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resources and Hydropower, Sichuan University, Chengdu, 610065 China Chun-an Tang, Institute of Rock Instability and Seismicity Research, Dalian University of Technology, Dalian, 116024 China Hong Li, Institute of Rock Instability and Seismicity Research, Dalian University of Technology, Dalian, 116024 China Feng Dai, State Key Laboratory of Hydraulics and Mountain River Engineering, College of Water Resources and Hydropower, Sichuan University, Chengdu, 610065 China Ke Ma, Institute of Rock Instability and Seismicity Research, Dalian University of Technology, Dalian, 116024 China Jing-dong Shao, HydroChina Chengdu Engineering Corporation, Chengdu, 610072 China Ji-chang Wu, China Guodian Dadu River Dagangshan Hydropower Development Co., Ltd., Ya’an, 625409 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 6

Beschreibung:    This paper describes one approach to the design of reinforced concrete (RC) bridge piers, using a three-hybrid multi-objective simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs), namely MOSAMO1, MOSAMO2 and MOSAMO3. The procedure is applied to three objective functions: the economic cost, the reinforcing steel congestion and the embedded CO 2 emissions. Additional results for a random walk and a descent local search multi-objective algorithm are presented. The evaluation of solutions follows the Spanish Code for structural concrete. The methodology was applied to a typical bridge pier of 23.97 m in height. This example involved 110 design variables. Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts. Further, the proposed procedure will help structural engineers to enhance their bridge pier designs. Content Type Journal Article Pages 420-432 DOI 10.1631/jzus.A1100304 Authors Francisco J. Martinez-Martin, Department of Geotechnical Engineering, Universitat Politècnica de València, 46022 Valencia, Spain Fernando Gonzalez-Vidosa, Department of Construction Engineering, ICITECH, Universitat Politècnica de València, 46022 Valencia, Spain Antonio Hospitaler, Department of Construction Engineering, ICITECH, Universitat Politècnica de València, 46022 Valencia, Spain Víctor Yepes, Department of Construction Engineering, ICITECH, Universitat Politècnica de València, 46022 Valencia, Spain Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 6

Beschreibung:    In the structures where long-term behavior should be monitored and controlled, creep and shrinkage effects have to be included precisely in the analysis and design procedures. Shrinkage varies with the constituent and mixture proportions, and depends on the curing conditions and the work environment as well. Self-compacting concrete (SCC) contains combinations of various components, such as aggregate, cement, superplasticizer, water-reducing agent and other ingredients which affect the properties of the SCC including shrinkage. Hence, the realistic prediction shrinkage strains of SCC are an important requirement of the design process for this type of concrete structures. This study reviews the accuracy of the conventional concrete (CC) shrinkage prediction models proposed by the international codes of practice, including CEB-FIP (1990), ACI 209R (1997), Eurocode 2 (2001), JSCE (2002), AASHTO (2004; 2007) and AS 3600 (2009). Also, SCC shrinkage prediction models proposed by Poppe and De Schutter (2005), Larson (2007), Cordoba (2007) and Khayat and Long (2010) are reviewed. Further, a new shrinkage prediction model based on the comprehensive analysis on both of the available models, i.e., the CC and the SCC is proposed. The predicted shrinkage strains are compared with the actual measured shrinkage strains in 165 mixtures of SCC and 21 mixtures of CC. Content Type Journal Article Pages 407-419 DOI 10.1631/jzus.A1100340 Authors Farhad Aslani, Centre for Built Infrastructure Research, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, Australia Shami Nejadi, Centre for Built Infrastructure Research, School of Civil and Environmental Engineering, University of Technology Sydney, Sydney, Australia Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 6

Beschreibung:    Air-driven boosters are widely used to obtain high-pressure gas. Through analysis of the boosting process of an air-driven booster, the basic mathematical model of working processes can be set up. By selecting the appropriate reference values, the basic mathematical model is transformed to a dimensionless expression. Using MATLAB/Simulink for simulation and studying the booster experimentally, the dimensionless outlet flow characteristics of the booster were obtained and the simulation results agree well with the experimental results. Through analysis, it can be seen that the dimensionless outlet flow of the booster is mainly determined by the dimensionless input pressure of the driving chamber, the dimensionless outlet condition pressure of the booster and the dimensionless area of the piston in the driving chamber. The dimensionless average outlet flow becomes larger with an increasing dimensionless input pressure of the driving chamber, but it becomes smaller with an increase in the dimensionless outlet condition pressure of the booster. Especially when the dimensionless outlet condition pressure is approximately 1.4, the dimensionless average outlet flow reaches zero. With an increase in the dimensionless area of the piston in the driving chamber, the dimensionless average outlet flow increases and peaks at approximately 1.89, and after this peak, it starts to decrease. This research can be referred to in the design of air-driven boosters. Content Type Journal Article Pages 481-490 DOI 10.1631/jzus.A1100176 Authors Yan Shi, School of Automation Science and Electrical Engineering, Beihang University, Beijing, 100191 China Mao-lin Cai, School of Automation Science and Electrical Engineering, Beihang University, Beijing, 100191 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 6

Beschreibung:    In a landfill, excessive tensile strains or failure of the liner system due to localized subsidence underneath the geosynthetic liner, is a concern in design and operation of the landfill. The localized subsidence can be commonly withstood by reinforcements such as geogrids. A total of nine model tests were carried out to study the influence of soil arching in overburden sandy soil on the geosynthetics and the interaction between the soil and the geosynthetics. The localized subsidence was modeled by a strip trapdoor under the geosynthetic reinforcements. The reinforcement includes several layers of polyvinylchlorid (PVC) membrane or both PVC membrane and a compacted clay layer. Test results show that the vertical soil pressure acting on the geosynthetics within the subsidence zone is strongly related to the deflection of the geosynthetics. The soil pressure acting on the deflected geosynthetics will decrease to a minimum value with respect to its deflection if the final deflection is large enough, and this minimum value is almost independent of the overburden height. Otherwise, the deflection of geosynthetics cannot result in a full degree of soil arching, and the soil pressure within the subsidence zone increases with the increase of overburden height. Deflections and strains of the geosynthetics obviously decrease with the increase of their tensile stiffness. The presence of a compacted clay layer buffer can therefore reduce both deflections and strains of the geosynthetics. Finally, a composite liner structure is recommended for landfills to withstand the localized subsidences. Content Type Journal Article Pages 433-444 DOI 10.1631/jzus.A1100315 Authors Bin Zhu, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Deng Gao, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Jun-chao Li, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Yun-min Chen, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 6

Beschreibung:    Steel plates are widely used in various structures, such as the deck and bodies of ships and bridges, and in the aerospace industry. In many instances, these plates are subjected to axial compression loads that predispose the sheets to instability and buckling. In this study, we investigate the buckling and post-buckling behaviors of steel plates having groove-shaped cutouts of various dimensions and angles using finite element method (FEM) (by ABAQUS software) and experimental tests (by an Instron servohydraulic machine). Boundary conditions were clamped by supports at upper and lower ends and free supports at the other edges. The results of both numerical and experimental analyses are compared, which show a very good agreement between them. Finally, based on the experimental findings, formulas are presented for the determination of the buckling load of such plates. Content Type Journal Article Pages 469-480 DOI 10.1631/jzus.A1100226 Authors Y. Faradjian Mohtaram, Mechanical Department, Islamic Azad University, Bostan Abad Branch, Iran J. Taheri Kahnamouei, Mechanical Department, Islamic Azad University, Bostan Abad Branch, Iran M. Shariati, Mechanical Department, Shahrood University of Technology, Shahrood, Iran B. Behjat, Mechanical Department, Sahand University of Technology, Tabriz, Iran Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 6

Beschreibung:    The effects of journal misalignment on the transient flow of a finite grooved journal bearing are presented in this study. A new 3D computational fluid dynamics (CFD) analysis method is applied. Also, the quasi-coupling calculation of transient fluid dynamics of oil film in journal bearing and rotor dynamics is considered in the analysis. Based on the structured mesh, a new approach for mesh movement is proposed to update the mesh volume when the journal moves during the fluid dynamics simulation of an oil film. Existing dynamic mesh models provided by FLUENT are not suitable for the transient oil flow in journal bearings. The movement of the journal is obtained by solving the moving equations of the rotor-bearing system with the calculated film pressure as the boundary condition of the load. The data exchange between fluid dynamics and rotor dynamics is realized by data files. Results obtained from the CFD model were consistent with previous experimental results on misaligned journal bearings. Film pressure, oil film force, friction torque, misalignment moment and attitude angle were calculated and compared for misaligned and aligned journal bearings. The results indicate that bearing performances are greatly affected by misalignment which is caused by unbalanced excitation, and the CFD method based on the fluid-structure interaction (FSI) technique can effectively predict the transient flow field of a misaligned journal bearing in a rotor-bearing system. Content Type Journal Article Pages 293-310 DOI 10.1631/jzus.A1100228 Authors Qiang Li, Institute of Chemical Machinery, Zhejiang University, Hangzhou, 310027 China Shu-lian Liu, Department of Electro-Mechanical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023 China Xiao-hong Pan, Institute of Modern Manufacture Engineering, Zhejiang University, Hangzhou, 310027 China Shui-ying Zheng, Institute of Chemical Machinery, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 4

Beschreibung:    An experimental and numerical investigation on the aeroengine blade/case containment analysis is presented. Blade out containment capability analysis is an essential step in the new aeroengine design, but containment tests are time-consuming and incur significant costs; thus, developing a short-period and low-cost numerical method is warranted. Using explicit nonlinear dynamic finite element analysis software, the present study numerically investigated the high-speed impact process for simulated blade containment tests which were carried out on high-speed spin testing facility. A number of simulations were conducted using finite element models with different mesh sizes and different values of both the contact penalty factor and the friction coefficient. Detailed comparisons between the experimental and numerical results reveal that the mesh size and the friction coefficient have a considerable impact on the results produced. It is shown that a finer mesh will predict lower containment capability of the case, which is closer to the test data. A larger value of the friction coefficient also predicts lower containment capability. However, the contact penalty factor has little effect on the simulation results if it is large enough to avoid false penetration. Content Type Journal Article Pages 239-259 DOI 10.1631/jzus.A1100294 Authors Qing He, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Zhejiang University, Hangzhou, 310027 China Hai-jun Xuan, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Zhejiang University, Hangzhou, 310027 China Lian-fang Liao, Department of Automation, Zhejiang University, Hangzhou, 310027 China Wei-rong Hong, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Zhejiang University, Hangzhou, 310027 China Rong-ren Wu, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 4

Beschreibung:    To provide physically based wind modelling for wind erosion research at regional scale, a 3D computational fluid dynamics (CFD) wind model was developed. The model was programmed in C language based on the Navier-Stokes equations, and it is freely available as open source. Integrated with the spatial analysis and modelling tool (SAMT), the wind model has convenient input preparation and powerful output visualization. To validate the wind model, a series of experiments was conducted in a wind tunnel. A blocking inflow experiment was designed to test the performance of the model on simulation of basic fluid processes. A round obstacle experiment was designed to check if the model could simulate the influences of the obstacle on wind field. Results show that measured and simulated wind fields have high correlations, and the wind model can simulate both the basic processes of the wind and the influences of the obstacle on the wind field. These results show the high reliability of the wind model. A digital elevation model (DEM) of an area (3800 m long and 1700 m wide) in the Xilingele grassland in Inner Mongolia (autonomous region, China) was applied to the model, and a 3D wind field has been successfully generated. The clear implementation of the model and the adequate validation by wind tunnel experiments laid a solid foundation for the prediction and assessment of wind erosion at regional scale. Content Type Journal Article Pages 274-283 DOI 10.1631/jzus.A1100231 Authors Zhuo-dong Zhang, Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF), Muencheberg, 15374 Germany Ralf Wieland, Institute of Landscape System Analysis, Leibniz-Centre for Agricultural Landscape Research (ZALF), Muencheberg, 15374 Germany Matthias Reiche, Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF), Muencheberg, 15374 Germany Roger Funk, Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF), Muencheberg, 15374 Germany Carsten Hoffmann, Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF), Muencheberg, 15374 Germany Yong Li, Institute of Agricultural Environment and Sustainable Development, Chinese Academy of Agricultural Sciences (CAAS), Beijing, 100081 China Michael Sommer, Institute of Soil Landscape Research, Leibniz-Centre for Agricultural Landscape Research (ZALF), Muencheberg, 15374 Germany Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 4

Beschreibung:    A first-order torsion theory based on Vlasov theory has been developed to investigate the restrained torsion of open thin-walled beams. The total rotation of the cross section is divided into a free warping rotation and a restrained shear rotation. In first-order torsion theory, St. Venant torque is only related to the free warping rotation and the expression of St. Venant torque is derived by using a semi-inverse method. The relationship between the warping torque and the restrained shear rotation is established by using an energy method. The torsion shear coefficient is then obtained. On the basis of the torsion equilibrium, the governing differential equation of the restrained torsion is derived and the corresponding initial method is given to solve the equation. The relationship between total rotation and free warping rotation is obtained. A parameter λ , which is associated with the stiffness property of a cross section and the beam length, is introduced to determine the condition, under which the St. Venant constant is negligible. Consequently a simplified theory is derived. Numerical examples are illustrated to validate the current approach and the results of the current theory are compared with those of some other available methods. The results of comparison show that the current theory provides more accurate results. In the example of a channel-shaped cantilever beam, the applicability of the simplified theory is determined by the parameter study of λ . Content Type Journal Article Pages 260-273 DOI 10.1631/jzus.A1100149 Authors Zhao-qiang Wang, Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Jin-cheng Zhao, Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Da-xu Zhang, Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Jing-hai Gong, Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 4

Beschreibung:    To analyze the stability of a shallow square tunnel, a new curved failure mechanism, representing the mechanical characteristics and collapsing form of this type of tunnel, is constructed. Based on the upper bound theorem of limit analysis and the Hoek-Brown nonlinear failure criterion, the supporting pressure derived from the virtual work rate equation is regarded as an objective function to achieve optimal calculation. By employing variational calculation to optimize the objective function, an upper bound solution for the supporting pressure and the collapsing block shape of a shallow square tunnel are obtained. To evaluate the validity of the failure mechanism proposed in this paper, the solutions computed by the curved failure mechanism are compared with the results calculated by the linear multiple blocks failure mechanism when the Hoek-Brown nonlinear failure criterion is converted into the Mohr-Coulomb linear criterion. The influences of rock mass parameters on the supporting pressure and collapsing block shape are discussed. Content Type Journal Article Pages 284-292 DOI 10.1631/jzus.A1100246 Authors Fu Huang, School of Civil Engineering, Central South University, Changsha, 410075 China Xiao-li Yang, School of Civil Engineering, Central South University, Changsha, 410075 China Lian-heng Zhao, School of Civil Engineering, Central South University, Changsha, 410075 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 4

Beschreibung:    Combustion kinetic parameters (i.e., activation energy and frequency factor) of coal have been proven to relate closely to coal properties; however, the quantitative relationship between them still requires further study. This paper adopts a support vector regression machine (SVR) to generate the models of the non-linear relationship between combustion kinetic parameters and coal quality. Kinetic analyses on the thermo-gravimetry (TG) data of 80 coal samples were performed to prepare training data and testing data for the SVR. The models developed were used in the estimation of the combustion kinetic parameters of ten testing samples. The predicted results showed that the root mean square errors (RMSEs) were 2.571 for the activation energy and 0.565 for the frequency factor in logarithmic form, respectively. TG curves defined by predicted kinetic parameters were fitted to the experimental data with a high degree of precision. Content Type Journal Article Pages 344-352 DOI 10.1631/jzus.A1100232 Authors Jian-guo Yang, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Xiao-long Zhang, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Hong Zhao, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Li Shen, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    The synthesis of methanol and dimethyl ether (DME) from CO hydrogenation has been investigated on Cu-based catalysts. A series of Cu/ZnO/Al 2 O 3 catalysts were prepared using a solvent-free routine which involved a direct blend of copper/zinc/aluminum salts and citric acid, followed by calcination at 450 °C. The calcination processes were monitored using thermogravimetry differential scanning calorimetry (TG-DSC). Catalysts were further characterized using N 2 adsorption, scanning electronic microscopy (SEM), X-ray diffraction (XRD), N 2 O oxidation followed by H 2 titration, and temperature-programmed reduction with H 2 (H 2 -TPR). The reduction processes were also monitored with in-situ XRD. The physicochemical properties of catalysts depended strongly on the types of precursor salts, and catalysts prepared using Al acetate and Cu nitrate as starting materials had a larger surface area, larger exposed metallic copper surface area, and lower reduction temperature. The CO hydrogenation performances of these catalysts were compared and discussed in terms of their structures. Catalysts prepared with copper nitrate, zinc and aluminum acetates exhibited the highest catalytic activity. Content Type Journal Article Pages 395-406 DOI 10.1631/jzus.A1100345 Authors Hong Lei, Institute of Catalysis, Department of Chemistry, Zhejiang University, Hangzhou, 310028 China Ren-feng Nie, Institute of Catalysis, Department of Chemistry, Zhejiang University, Hangzhou, 310028 China Jin-hua Fei, Institute of Catalysis, Department of Chemistry, Zhejiang University, Hangzhou, 310028 China Zhao-yin Hou, Institute of Catalysis, Department of Chemistry, Zhejiang University, Hangzhou, 310028 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    This paper deals with a multi-objective parameter optimization framework for energy saving in injection molding process. It combines an experimental design by Taguchi’s method, a process analysis by analysis of variance (ANOVA), a process modeling algorithm by artificial neural network (ANN), and a multi-objective parameter optimization algorithm by genetic algorithm (GA)-based lexicographic method. Local and global Pareto analyses show the trade-off between product quality and energy consumption. The implementation of the proposed framework can reduce the energy consumption significantly in laboratory scale tests, and at the same time, the product quality can meet the pre-determined requirements. Content Type Journal Article Pages 382-394 DOI 10.1631/jzus.A1100250 Authors Ning-yun Lu, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 China Gui-xia Gong, College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016 China Yi Yang, Department of Control Engineering and Science, Zhejiang University, Hangzhou, 310027 China Jian-hua Lu, School of Computer Science and Engineering, Southeast University, Nanjing, 210096 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    This paper presents the explosion cratering effects and their propagation laws of blast waves in dry standard sands using a 450 g -t geotechnical centrifuge apparatus. Ten centrifuge model tests were completed with various ranges of explosive mass, burial depth and centrifuge accelerations. Eleven accelerometers were installed to record the acceleration response in sand. The dimensions of the explosion craters were measured after the tests. The results demonstrated that the relationship between the dimensionless parameters of cratering efficiency and gravity scaled yield is a power regression function. Three specific function equations were obtained. The results are in general agreement with those obtained by other studies. A scaling law based on the combination of the π terms was used to fit the results of the ten model tests with a correlation coefficient of 0.931. The relationship can be conveniently used to predict the cratering effects in sand. The results also showed that the peak acceleration is a power increasing function of the acceleration level. An empirical exponent relation between the proportional peak acceleration and distance is proposed. The propagation velocity of blast waves is found to be ranged between 200 and 714 m/s. Content Type Journal Article Pages 335-343 DOI 10.1631/jzus.A1100227 Authors Yi-kai Fan, State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, 100044 China Zu-yu Chen, State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, 100044 China Xiang-qian Liang, State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, 100044 China Xue-dong Zhang, State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing, 100044 China Xin Huang, School of Transportation Science and Engineering, Beihang University, Beijing, 100191 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    Alternate path (AP) method is the most widely used method for the progressive collapse analysis, and its application in frame structures has been well proved. However, the application of AP method for other structures, especially for cable-stayed structures, should be further developed. The four analytical procedures, i.e., linear static, nonlinear static, linear dynamic, and nonlinear dynamic were firstly improved by taking into account the initial state. Then a cable-stayed structure was studied using the four improved methods. Furthermore, the losses of both one cable and two cables were discussed. The results show that for static and dynamic analyses of the cable-stayed bridges, there is large difference between the results obtained from simulations starting with either a deformed or a nondeformed configuration at the time of cable loss. The static results are conservative in the vicinity of the ruptured cable, but the dynamic effect of the cable loss in the area farther away from the loss-cable cannot be considered. Moreover, the dynamic amplification factor of 2.0 is found to be a good estimate for static analysis procedures, since linear static and linear dynamic procedures yield approximately the same maximum vertical deflection. The results of the comprehensive evaluation of the cable failure show that the tread of the progressive failure of the cable-stayed bridges decreases when the location of the failed cables is closer to the pylon. Content Type Journal Article Pages 323-334 DOI 10.1631/jzus.A1100296 Authors Jian-guo Cai, Key Laboratory of C&PC Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Yi-xiang Xu, Department of Civil Engineering, Strathclyde University, Glasgow, UK Li-ping Zhuang, Key Laboratory of C&PC Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Jian Feng, Key Laboratory of C&PC Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Jin Zhang, Key Laboratory of C&PC Structures of Ministry of Education, Southeast University, Nanjing, 210096 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    In this study, an experimental setup is designed and built to investigate the feasibility and performance of the proposed dual-mode cascade refrigeration cycle. The apparatus can be operated in two modes: dual-stage mode and single-stage mode such that the low temperature cycle (LTC) can be operated together with the high temperature cycle (HTC) or can run independently. Experimental results validate the feasibility of independent operation of LTC. The performance of the independent operation of LTC mode is theoretically investigated using experimental data as bases. Detailed suggestions are made for the improvement of the coefficient of performance (COP) of the experimental system. Theoretically, high COP of the cycle provides excellent application for the presented refrigeration cycle. Content Type Journal Article Pages 375-381 DOI 10.1631/jzus.A1100107 Authors Xiu-fang Liu, Institute of Refrigeration and Cryogenic Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Jiong-hui Liu, Institute of Refrigeration and Cryogenic Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Hong-li Zhao, Institute of Refrigeration and Cryogenic Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Qiao-yu Zhang, Institute of Refrigeration and Cryogenic Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Juan-li Ma, Institute of Refrigeration and Cryogenic Engineering, Xi’an Jiaotong University, Xi’an, 710049 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    Staggered pattern perforations are introduced to isolated isothermal plates, vertical parallel isothermal plates, and vertical rectangular isothermal fins under natural convection conditions. The performance of perforations was evaluated theoretically based on existing correlations by considering effects of ratios of open area, inclined angles, and other geometric parameters. It was found that staggered pattern perforations can increase the total heat transfer rate for isolated isothermal plates and vertical parallel plates, with low ratios of plate height to wall-to-wall spacing ( H/s ), by a factor of 1.07 to 1.21, while only by a factor of 1.03 to 1.07 for vertical rectangular isothermal fins, and the magnitude of enhancement is proportional to the ratio of open area. However, staggered pattern perforations are detrimental to heat transfer enhancement of vertical parallel plates with large H/s ratios. Content Type Journal Article Pages 353-360 DOI 10.1631/jzus.A1100222 Authors Zan Wu, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Wei Li, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Zhi-jian Sun, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Rong-hua Hong, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 5

Beschreibung:    The aim of this study was to perform computational fluid dynamics (CFD) simulations on the airflows at the Hong Kong International Airport (HKIA). In particular, the effects of hangar buildings and terrain were studied to explore the effects of turbulence on flying aircraft, especially during landing. The CFD simulation showed that significant differences in wind speeds may occur between the north and the south runways on the western part of the HKIA under typhoon conditions with a strong north to northwesterly wind. Simulation also showed that the hanger buildings between the two runways on the western side and the nearby terrain could be causing the observed difference in the wind speeds. The results also indicated that these obstacles could cause significant wind speed variations at the western end of the south runway. This may affect the operation of landing aircraft. The CFD results for a typical typhoon case were analyzed and found to match the wind data recorded by an aircraft landing that day. Content Type Journal Article Pages 1-8 DOI 10.1631/jzus.A1100293 Authors Dennis Y. C. Leung, Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China W. Y. Lo, Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China W. Y. Chow, Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, China P. W. Chan, Hong Kong Observatory, Hong Kong, China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X

Beschreibung:    The propulsive efficiency of a plunging NACA0012 airfoil is maximized by means of a simple numerical optimization method based on the response surface methodology (RSM). The control parameters are the amplitude and the reduced frequency of the harmonic sinusoidal motion. The 2D unsteady laminar flow around the plunging airfoil is computed by solving the Navier-Stokes equations for three Reynolds number values ( Re = 3.3×10 3 , 1.1×10 4 , and 2.2×10 4 ). The Nelder-Mead algorithm is used to find the best control parameters leading to the optimal propulsive efficiency over the constructed response surfaces. It is found that, for a given efficiency level and regardless of the considered Re value, it is possible either to obtain high thrust by selecting a high oscillation frequency or to reduce the input power by adopting a low plunging amplitude. Content Type Journal Article Category Mechanics and Mechanical Engineering Pages 105-120 DOI 10.1631/jzus.A1000502 Authors Mahmoud Mekadem, Fluids Mechanics Laboratory, Polytechnic Military School, Bordj el Bahri, Algiers, 16045 Algeria Taha Chettibi, Structural Mechnics Laboratory, Polytechnic Military School, Bordj el Bahri, Algiers, 16045 Algeria Samir Hanchi, Fluids Mechanics Laboratory, Polytechnic Military School, Bordj el Bahri, Algiers, 16045 Algeria Laurent Keirsbulck, TEMPO Laboratory, University of Valenciennes and Hainaut-Cambresis, 59313 Valenciennes Cedex 9, France Larbi Labraga, TEMPO Laboratory, University of Valenciennes and Hainaut-Cambresis, 59313 Valenciennes Cedex 9, France Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    In this paper, a new ternary non-azeotropic mixture of HFC-161/125/143a (0.15/0.45/0.40 in mass fraction), as a promising mixed refrigerant to R404A, is presented. The ozone depletion potential (ODP) of the new refrigerant is zero and its basic thermodynamic properties are similar to those of R404A, but its global warming potential (GWP) is much smaller than those of R507A and R404A. Meanwhile, theoretical calculations show that, under the working condition I (the average evaporation temperature: −23 °C, the average condensing temperature: 43 °C, the superheat temperature: 28 °C, the subcooling temperature: 5 °C), the volumetric refrigerating effect and specific refrigerating effect of the new mixture are 2.33% and 15.48% higher, respectively, than those of R404A. The coefficient of performance (COP) of the new mixture is 5.19% higher than that of R404A and the pressure ratio of the new mixture is 0.82% lower than that of R404A. Equally, under the working condition II (the average evaporation temperature: −40 °C, the average condensing temperature: 35 °C, the superheating temperature: 30 °C, the subcooling temperature: 5 °C), the volumetric refrigerating effect and specific refrigerating effect of the new mixture are 2.24% and 20.58% higher, respectively, than those of R404A. The COP of the new mixture is 4.60% higher than that of R404A and the pressure ratio of the new mixture is similar to that of R404A. The performances of the new mixture and R404A are compared in a vapor compressor refrigeration apparatus originally designed for R404A under several working conditions (condensing temperatures: 35–45 °C, evaporation temperatures: −40–−20 °C). Experimental results show that the new mixture can obtain a higher COP, by 6.3% to 12.1%, and a lower pressure ratio, by 1.8% to 6.6%, compared to R404A; although the discharge temperature of the new mixture is slightly higher than that of R404A. The advantages of the new mixture will be further verified in the actual system. Content Type Journal Article Category Energy and Power Engineering Pages 132-139 DOI 10.1631/jzus.A1100154 Authors Xiao-hong Han, State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027 China Yu Qiu, State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027 China Ying-jie Xu, State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027 China Men-yuan Zhao, State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027 China Qin Wang, State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027 China Guang-ming Chen, State Key Laboratory of Clean Energy Utilization, Institute of Refrigeration and Cryogenics, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    This paper discusses stress intensity factor (SIF) calculations for surface cracks in round bars subjected to combined torsion and bending loadings. Different crack aspect ratios, a/b , ranging from 0.0 to 1.2 and relative crack depths, a / D , ranging from 0.1 to 0.6 were considered. Since the loading was non-symmetrical for torsion loadings, a whole finite element model was constructed. Then, the individual and combined bending and torsion loadings were remotely applied to the model. The equivalent SIF method, F * EQ , was then used explicitly to combine the individual SIFs from the bending and torsion loadings. A comparison was then carried out with the combined SIF, F * FE , obtained using the finite element analysis (FEA) under similar loadings. It was found that the equivalent SIF method successfully predicted the combined SIF for Mode I. However, discrepancies between the results determined from the different approaches occurred when F III was involved. It was also noted that the predicted F * FE using FEA was higher than the F * EQ predicted through the equivalent SIF method due to the difference in crack face interactions. Content Type Journal Article Pages 1-8 DOI 10.1631/jzus.A1100040 Authors Al Emran Ismail, Faculty of Mechanical & Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Batu Pahat, 86400 Johor, Malaysia Ahmad Kamal Ariffin, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia Shahrum Abdullah, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia Mariyam Jameelah Ghazali, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia Mohammed Abdulrazzaq, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, Bangi, 43600 Selangor, Malaysia Ruslizam Daud, School of Mechatronic Engineering, Universiti Malaysia Perlis, Arau, 02600 Perlis, Malaysia Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    In this paper, the steady-state response of a saturated half-space with an overlying dry layer subjected to a moving rectangular load is investigated. The governing partial differential equations are solved using the Fourier transform. The solutions in time-space domain are expressed in terms of infinite Fourier type integrals, which can be evaluated only by numerical quadrature. Numerical results show that the influence of a drained or undrained interface on the response is related to the permeability of the underlying saturated soil. Moreover, the effect due to the upper dry layer is associated with the thickness of the layer. Content Type Journal Article Pages 33-43 DOI 10.1631/jzus.A1100184 Authors An-feng Hu, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058 China Bo Sun, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058 China Kang-he Xie, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    When aerodynamic braking works, the braking wings can change the flow field around the train, which may impact on the comfort and safety. Based on a sliding mesh, the pressure wave and flow field around high-speed trains with aerodynamic braking are analyzed. By comparing three typical intersection situations, the pressure wave of a high-speed train during braking (with or without aerodynamic braking) is studied. The analyses indicate that the pressure wave around the high-speed train body will change while using the aerodynamic braking, causing several pressure pulses on the surface of crossing high-speed trains. The distances between the pressure pulses are equal to the longitudinal distances of the brake wings, but the magnitudes of the fluctuations are less than those induced by the head of crossing trains. During the crossing, a train without aerodynamic braking will not impact the crossing train. Content Type Journal Article Pages 979-984 DOI 10.1631/jzus.A11GT011 Authors Meng-ling Wu, Research Institute of Railway & Urban Mass Transit, Tongji University, Shanghai, 200092 China Yang-yong Zhu, Research Institute of Railway & Urban Mass Transit, Tongji University, Shanghai, 200092 China Chun Tian, Research Institute of Railway & Urban Mass Transit, Tongji University, Shanghai, 200092 China Wei-wei Fei, Research Institute of Railway & Urban Mass Transit, Tongji University, Shanghai, 200092 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung: On China’s high-speed railway technology Content Type Journal Article Category Editorial Pages 883-884 DOI 10.1631/jzus.A11GT000 Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    Dynamic responses of track structure and wave propagation in nearby ground vibration become significant when train operates on high speeds. A train-track-ground dynamic interaction analysis model based on the 2.5D finite element method is developed for the prediction of ground vibrations due to vertical track irregularities. The one-quarter car model is used to represent the train as lumped masses connected by springs. The embankment and the underlying ground are modeled by the 2.5D finite element approach to improve the computation efficiency. The Fourier transform is applied in the direction of train’s movement to express the wave motion with a wave-number. The one-quarter car model is coupled into the global stiffness matrix describing the track-ground dynamic system with the displacement compatibility condition at the wheel-rail interface, including the irregularities on the track surface. Dynamic responses of the track and ground due to train’s moving loads are obtained in the wave-number domain by solving the governing equation, using a conventional finite element procedure. The amplitude and wavelength are identified as two major parameters describing track irregularities. The irregularity amplitude has a direct impact on the vertical response for low-speed trains, both for short wavelength and long wavelength irregularities. Track irregularity with shorter wavelength can generate stronger track vibration both for low-speed and high-speed cases. For low-speed case, vibrations induced by track irregularities dominate far field responses. For high-speed case, the wavelength of track irregularities has very little effect on ground vibration at distances far from track center, and train’s wheel axle weights becomes dominant. Content Type Journal Article Pages 885-894 DOI 10.1631/jzus.A11GT012 Authors Xue-cheng Bian, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Chang Chao, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Wan-feng Jin, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Yun-min Chen, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Department of Civil Engineering, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    The influence of sandstorms on train aerodynamic performance and safe running was studied in response to the frequent occurrence of sandstorm weather in north China. An Eulerian two-phase model in the computational fluid dynamic (CFD) software FLUENT, validated with published data, was used to solve the gas-solid multiphase flow of a sandstorm around a train. The train aerodynamic performance under different sandstorm levels and no sand conditions was then simulated. Results showed that in sandstorm weather, the drag, lift, side forces and overturning moment increase by variable degrees. Based on a numerical analysis of aerodynamic characteristics, an equation of train stability was also derived using the theory of moment balance from the view of dynamics. A recommended speed limit of a train under different sandstorm levels was calculated based on the stability analysis. Content Type Journal Article Pages 971-978 DOI 10.1631/jzus.A11GT005 Authors Hong-bing Xiong, Department of Mechanics, Zhejiang University, Hangzhou, 310027 China Wen-guang Yu, Department of Mechanics, Zhejiang University, Hangzhou, 310027 China Da-wei Chen, National Engineering Laboratory for System Integration of High-Speed Train (South), CSR Qingdao Sifang Co., Ltd., Qingdao, 266111 China Xue-ming Shao, Department of Mechanics, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    We present a new algorithm for nesting problems. Many equally spaced points are set on a sheet, and a piece is moved to one of the points and rotated by an angle. Both the point and the rotation angle constitute the packing attitude of the piece. We propose a new algorithm named HAPE (Heuristic Algorithm based on the principle of minimum total Potential Energy) to find the optimal packing attitude at which the piece has the lowest center of gravity. In addition, a new technique for polygon overlap testing is proposed which avoids the time-consuming calculation of no-fit-polygon (NFP). The detailed implementation of HAPE is presented and two computational experiments are described. The first experiment is based on a real industrial problem and the second on 11 published benchmark problems. Using a hill-climbing (HC) search method, the proposed algorithm performs well in comparison with other published solutions. Content Type Journal Article Pages 860-872 DOI 10.1631/jzus.A1100038 Authors Xiao Liu, School of Civil and Transportation Engineering, South China University of Technology, Guangzhou, 510640 China Jia-wei Ye, School of Civil and Transportation Engineering, South China University of Technology, Guangzhou, 510640 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    The objective of this work is to provide decision-making processes with an updated/real picture of the mobile resources in industrial environments through a constant feedback of information. The combination of identification technologies and wireless sensor networks (WSN) is proposed as a key development to guarantee an accurate and timely supply of online information regarding the localization and tracking of the mobile wireless devices. This approach uses a cooperative and distributed localization system, called ZigID, which is a WSN based on a Zigbee network with radio frequency identification (RFID) active tags as end nodes. The WSN can recover not only the ID information stored at the tags attached to mobile resources, but also any other useful data captured by specific sensors for acceleration, temperature, humidity and fuel status. This paper also shows the development of ZigID, including devices and information flows, as well as its implementation in ground handling operations at the Ciudad Real Central Airport, Spain. Content Type Journal Article Pages 849-859 DOI 10.1631/jzus.A1100024 Authors Pablo García Ansola, Autolog Labs, School of Industrial Engineering, University of Castilla-La Mancha, Ciudad Real, 13071 Spain Andrés García, Autolog Labs, School of Industrial Engineering, University of Castilla-La Mancha, Ciudad Real, 13071 Spain Javier de las Morenas, Autolog Labs, School of Industrial Engineering, University of Castilla-La Mancha, Ciudad Real, 13071 Spain Javier García Escribano, Autolog Labs, School of Industrial Engineering, University of Castilla-La Mancha, Ciudad Real, 13071 Spain Francisco Javier Otamendi, Applied Economic Department, University Rey Juan Carlos, Madrid, 28032 Spain Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    For the dynamic demand assessment of bridge structures under ship impact loading, it may be prudent to adopt analytical models which permit rapid analysis with reasonable accuracy. Herein, a nonlinear dynamic macro-element is proposed and implemented to quantify the demand of bridge substructures subjected to ship collisions. In the proposed nonlinear macro-element, a combination of an elastic-plastic spring and a dashpot in parallel is employed to describe the mechanical behavior of ship-bows with strain rate effects. Based on the analytical model using the proposed macro-element, a typical substructure under 5000 deadweight tonnage (DWT) ship collision is discussed. Our analyses indicate that the responses of the structure using the nonlinear macro-element agree with the results from the high resolution model, but the efficiency and feasibility of the proposed method increase significantly in practical applications. Furthermore, comparisons between some current design codes (AASHTO, JTGD60-2004, and TB10002.1-2005) and the developed dynamic analysis method suggest that these design codes may be improved, at least to consider the effect of dynamic amplification on structural demand. Content Type Journal Article Pages 826-836 DOI 10.1631/jzus.A1100187 Authors Wei Fan, State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai, 200092 China Wan-cheng Yuan, State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai, 200092 China Mi Zhou, Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation, Chang’an University, Xi’an, 710064 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    The flat dilatometer test (DMT) has the potential to be a useful tool in the evaluation of liquefaction potential of soils. In practice, it is necessary to carefully examine existing DMT-based methods for evaluating liquefaction potential. We conducted the DMT and cone penetration test (CPT) in high liquefaction potential areas to examine the existing DMT-based methods for liquefaction potential evaluation. Specifically, the DMT and CPT were conducted side-by-side at each of six in-situ sites, and thus it is feasible to utilize those test results to validate the existing DMT-based methods. The DMT parameter, horizontal stress index ( K D ), is used as an indicator for estimating liquefaction resistance of soils in terms of cyclic resistance ratio (CRR). The analysis results revealed that the existing K D -based liquefaction evaluation methods would overestimate the CRR of soils, which leads to overestimation of the factor of safety against liquefaction. Also, the estimations of DMT- K D values by using the CPT- q c as well as the correlation between DMT- K D and CPT- q c proposed by the previous studies would be significantly smaller than field measurements. The results reflected that further validation of the existing DMT-based methods for liquefaction evaluation is desirable. Content Type Journal Article Pages 807-817 DOI 10.1631/jzus.A1100015 Authors Gordon Tung-Chin Kung, Sustainable Environment Research Center, National Cheng Kung University, Taiwan, 701 Taiwan Der-Her Lee, Sustainable Environment Research Center, National Cheng Kung University, Taiwan, 701 Taiwan Pai-Hsiang Tsai, Department of Civil Engineering, National Cheng Kung University, Taiwan, 701 Taiwan Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    This study employs the random finite element method (RFEM) to analyze the wall deflection caused by excavation. The RFEM combined random fields of material properties with the FEM through the Monte Carlo simulation. A well-documented excavation case history is employed to evaluate the influence of uncertainty of analysis parameters. This study shows that RFEM can provide reasonable estimations of the exceedance probability of wall deflection caused by excavation, and has the potential to be a useful tool to account for the uncertainties of material and model parameters in the numerical analysis. Content Type Journal Article Pages 737-746 DOI 10.1631/jzus.A1100016 Authors Yu-geng Tang, Department of Architecture, Hwa-Hsia Institute of Technology, Taiwan 23568 Taipei Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    A 3D numerical model considering the soil-structure interaction is presented in this paper to examine the ground movement and internal force during the construction of Qingdao North Metro Station, China with a special focus on the convex effect of the crossing excavation. The influence of intersection angles and soil resilience characteristics on deformation behavior is discussed, and the suitability of two alternative constitutive models applied in excavation simulation is also considered. The analysis results show that a notable convex effect appears to be associated with the crossing excavation, and the intersection is the key area requiring special attention. The displacements at the corner decrease with increasing crossing angles. The axial loads of struts along the retaining pile wall are unequal, and the values near the cross section are generally larger than the average loads of the left-sided ones. The modified Cam-Clay (MCC) model, which is capable of describing the loading-unloading criterion and identifying the stiffness difference of strain hardening between loading and unloading, can yield a relatively high accuracy of estimation for the behavior of excavations in comparison to the Mohr-Coulomb (MC) model. Furthermore, slight soil deformation resilience after unloading can reduce the ground surface settlement and enhance the ground stability. Content Type Journal Article Pages 747-757 DOI 10.1631/jzus.A1100028 Authors Min Zhang, School of Civil Engineering, Central South University, Changsha, 410075 China Xing-hua Wang, School of Civil Engineering, Central South University, Changsha, 410075 China Guang-cheng Yang, School of Civil Engineering, Central South University, Changsha, 410075 China You Wang, School of Civil Engineering, Central South University, Changsha, 410075 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    In this paper, an integrated validation method and process are developed for multivariate dynamic systems. The principal component analysis approach is used to address multivariate correlation and dimensionality reduction, the dynamic time warping and correlation coefficient are used for error assessment, and the subject matter experts (SMEs)’ opinions and principal component analysis coefficients are incorporated to provide the overall rating of the dynamic system. The proposed method and process are successfully demonstrated through a vehicle dynamic system problem. Content Type Journal Article Category Mechanics and Mechanical Engineering Pages 121-131 DOI 10.1631/jzus.A1100073 Authors Zhen-fei Zhan, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Jie Hu, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Yan Fu, Research and Innovation Center, Ford Motor Company, Dearborn, MI 48124, USA Ren-Jye Yang, Research and Innovation Center, Ford Motor Company, Dearborn, MI 48124, USA Ying-hong Peng, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Jin Qi, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, 200240 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    In this paper, we developed a novel method of combining remote sensing tools at the sub-pixel level for accurate identification of impervious surface time series changes. We examined the use of the red-green-blue impervious surface model (RGB-IS) in detecting time series internal modification of urban regions by integrating Landsat data collected over four different periods between 1987 and 2009 (i.e., 1987, 2000, 2002, and 2009). The performance of this approach was compared with two conventional methods, namely standard RGB-normalized difference vegetation index (NDVI) and post-classification technique. In contrast to conventional techniques, RGB-IS could monitor between-class changes, within-class changes, and location of these modifications. The proposed method was independent of seasonal changes and was also able to serve as a useful alternative for quick mapping growth hotspots and updating transportation corridor map. The results also showed that Cixi County, Zhejiang Province, China experienced tremendous impervious surface changes, especially along the corridors of newly constructed highways and around urban areas over the past 22 years. Content Type Journal Article Category Environmental Engineering Pages 146-158 DOI 10.1631/jzus.A1100034 Authors Amirreza Shahtahmassebi, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Zhou-lu Yu, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Ke Wang, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Hong-wei Xu, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Jin-song Deng, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Jia-dan Li, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Rui-sen Luo, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Jing Wu, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Nathan Moore, Institute of Agriculture Remote Sensing and Information Technology, Zhejiang University, Hangzhou, 310029 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 2

Beschreibung:    This paper aims to present a comprehensive proposal for project scheduling and control by applying fuzzy earned value. It goes a step further than the existing literature: in the formulation of the fuzzy earned value we consider not only its duration, but also cost and production, and alternatives in the scheduling between the earliest and latest times. The mathematical model is implemented in a prototypical construction project with all the estimated values taken as fuzzy numbers. Our findings suggest that different possible schedules and the fuzzy arithmetic provide more objective results in uncertain environments than the traditional methodology. The proposed model allows for controlling the vagueness of the environment through the adjustment of the α -cut, adapting it to the specific circumstances of the project. Content Type Journal Article Pages 56-68 DOI 10.1631/jzus.A1100160 Authors José Luís Ponz-Tienda, School of Building Engineering, Universitat Politècnica de València, 46022 Valencia, Spain Eugenio Pellicer, School of Civil Engineering, Universitat Politècnica de València, 46022 Valencia, Spain Víctor Yepes, Department of Construction Engineering, ICITECH, Universitat Politècnica de València, 46022 Valencia, Spain Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    This paper presents an analytical layer-element method used to analyze the displacement of a multi-layered transversely isotropic elastic medium of arbitrary depth subjected to axisymmetric loading. Based on the basic constitutive equations and the HU Hai-chang’s solutions for transversely isotropic elastic media, the state vectors of a multi-layered transversely isotropic medium were deduced. From the state vectors, an analytical layer element for a single layer (i.e., a symmetric and exact stiffness matrix) was acquired in the Hankel transformed domain, which not only simplified the calculation but also improved the numerical efficiency and stability due to the absence of positive exponential functions. The global stiffness matrix was obtained by assembling the interrelated layer elements based on the principle of the finite layer method. By solving the algebraic equations of the global stiffness matrix which satisfy the boundary conditions, the solutions for multi-layered transversely isotropic media in the Hankel transformed domain were obtained. The actual solutions of this problem in the physical domain were acquired by inverting the Hankel transform. This paper presents numerical examples to verify the proposed solutions and investigate the influence of the properties of the multi-layered medium on the load-displacement response. Content Type Journal Article Pages 9-17 DOI 10.1631/jzus.A1100163 Authors Zhi-yong Ai, Key Laboratory of Geotechnical and Underground Engineering of MOE, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092 China Nai-rui Cang, Key Laboratory of Geotechnical and Underground Engineering of MOE, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092 China Jie Han, Department of Civil, Environmental, and Architectural Engineering, The University of Kansas, Lawrence, KS 66045, USA Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    Compared to the current eddy braking patterns using a single magnetic source, hybrid excitation rail eddy brakes have many advantages, such as controllability, energy saving, and various operating models. Considering the large braking power consumption of the high-speed train, a hybrid excitation rail eddy brake system, which is based on the principle of electromagnetic field, is proposed to fulfill the needs of safety and reliability. Then the working processes of the mechanical lifting system and electromagnetic system are demonstrated. With the electromagnetic system analyzed using the finite element method, the factors such as speed, air gap, and exciting current have influences on the braking force and attractive force. At last, the structure optimization of the brake system is discussed. Content Type Journal Article Pages 936-944 DOI 10.1631/jzus.A11GT002 Authors Ji-en Ma, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Bin Zhang, The Key State Lab of Fluid Power Transmission and Control, Zhejiang University, Hangzhou, 310027 China Xiao-yan Huang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China You-tong Fang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Wen-ping Cao, Newcastle University, Newcastle upon Type, NE1 7RU UK Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    The China’s high-speed railway is experiencing a rapid growth. Its operating mileage and the number of operating trains will exceed 45 000 km and 1500 trains by 2015, respectively. During the long range and constant high-speed operation, the high-speed trains have extremely complex and varied work conditions. Such a situation creates a huge demand for high-speed train on-board monitoring. In this paper, architecture for high-speed train on-board monitoring sensor network is proposed. This architecture is designed to achieve the goals of reliable sensing, scalable data transporting, and easy management. The three design goals are realized separately. The reliable sensing is achieved by deploying redundant sensor nodes in the same components. Then a hierarchal transporting scheme is involved to meet the second goal. Finally, an electronic-tag based addressing method is introduced to solve the management problem. Content Type Journal Article Pages 921-925 DOI 10.1631/jzus.A11GT013 Authors Xiao-fan Wu, College of Computer Science, Zhejiang University, Hangzhou, 310027 China Chun Chen, College of Computer Science, Zhejiang University, Hangzhou, 310027 China Jia-jun Bu, College of Computer Science, Zhejiang University, Hangzhou, 310027 China Gang Chen, College of Computer Science, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    The emission of dioxins from municipal solid waste incinerators (MSWIs) has become a widespread concern. The effect of meteorological parameters (wind speed, atmospheric stability and mixing height) on the hourly ground level concentration (GLC) of dioxins was estimated using air dispersion models. Moreover, the health risks of dioxin exposure were evaluated for children and adults using the Nouwen equation. The total environmental exposure via air inhalation and food ingestion was calculated, based on linear fit equations. The results indicate that potentially severe pollution from dioxins occurs at a wind speed of 1.5 m/s with atmospheric stability class F. In addition, local residents in the study area are exposed to severe weather conditions most of the time, and the risk exposures for children are far higher than those for adults. The total exposure for children far exceeds the tolerable daily intake of dioxin recommended by the World Health Organization (WHO) of 1–4 pg TEQ/(kg·d) under severe weather conditions. Results from modeling calculations of health risk assessment were consistent with dioxin levels obtained during actual monitoring of emissions. Content Type Journal Article Pages 69-78 DOI 10.1631/jzus.A1100201 Authors Xiao-jun Ma, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Xu-guang Jiang, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Yu-qi Jin, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Hong-mei Liu, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Xiao-dong Li, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Tong Chen, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Jian-hua Yan, State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 1

Beschreibung:    With the development of high-speed train, it is considerably concerned about the aerodynamic characteristics and operation safety issues of the high-speed train under extreme weather conditions. The aerodynamic performance of a high-speed train under heavy rain and strong crosswind conditions are modeled using the Eulerian two-phase model in this paper. The impact of heavy rainfall on train aerodynamics is investigated, coupling heavy rain and a strong crosswind. Results show that the lift force, side force, and rolling moment of the train increase significantly with wind speed up to 40 m/s under a rainfall rate of 60 mm/h. when considering the rain and wind conditions. The increases of the lift force, side force, and rolling moment may deteriorate the train operating safety and cause the train to overturn. A quasi-static stability analysis based on the moment balance is used to determine the limit safety speed of a train under different rain and wind levels. The results can provide a frame of reference for the train safe operation under strong rain and crosswind conditions. Content Type Journal Article Pages 964-970 DOI 10.1631/jzus.A11GT001 Authors Xue-ming Shao, Department of Mechanics, Zhejiang University, Hangzhou, 310027 China Jun Wan, Department of Mechanics, Zhejiang University, Hangzhou, 310027 China Da-wei Chen, National Engineering Laboratory for System Integration of High-Speed Train (South), CSR Qingdao Sifang Co., Ltd., Qingdao, 266111 China Hong-bing Xiong, Department of Mechanics, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    Three optimal linear attitude estimators are proposed for single-point real-time estimation of spacecraft attitude using a geometric approach. The final optimal attitude is represented by modified Rodrigues parameters (MRPs). After introducing incidental right-hand orthogonal coordinates for each pair of measured values, three error vectors are obtained by the use of dot or/and cross products. Corresponding optimality criteria are rigorously quadratic and unconstrained, which do not coincide with Wahba’s constrained criterion. The singularity, which occurs when the principal angle is close to π, can be easily avoided by one proper rotation. Numerical simulations show that the proposed three optimal linear estimators can provide a precision comparable with those complying with the Wahba optimality definition, and have faster computational speed than the famous quaternion estimator (QUEST). Content Type Journal Article Pages 873-882 DOI 10.1631/jzus.A1100146 Authors De-ren Gong, Institute of Aerospace Science & Technology, Shanghai Jiao Tong University, Shanghai, 200240 China Xiao-wei Shao, Institute of Aerospace Science & Technology, Shanghai Jiao Tong University, Shanghai, 200240 China Wei Li, Institute of Aerospace Science & Technology, Shanghai Jiao Tong University, Shanghai, 200240 China Deng-ping Duan, Institute of Aerospace Science & Technology, Shanghai Jiao Tong University, Shanghai, 200240 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    The effects induced by streamwise conduction on the thermal characteristics of forced convection for single-phase liquid flow in rectangular microchannel heat sinks under imposed constant wall temperature have been studied. By employing the fin approach in the first law of analysis, models with and without streamwise conduction term in the energy equation were developed for hydrodynamically and thermally fully-developed flow under local thermal non-equilibrium for the solid and fluid phases. These two models were solved to obtain closed form analytical solutions for the fluid and solid temperature distributions and the analysis emphasized details of the variations induced by the streamwise conduction on the fluid temperature distributions. The effects of the Peclet number, aspect ratio, and thermal conductivity ratio on the thermal characteristics of forced convection in microchannel heat sinks were analyzed and discussed. This study reveals the conditions under which the effect of streamwise conduction is significant and should not be neglected in the forced convective heat transfer analysis of microchannel heat sinks. Content Type Journal Article Pages 655-664 DOI 10.1631/jzus.A1000289 Authors Suhandran Muniandy, Faculty of Engineering and Technology, Multimedia University, 75450 Melaka, Malaysia Yew Mun Hung, School of Engineering, Monash University, 46150 Bandar Sunway, Malaysia Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    This paper deals with a mortality-weighted synthetic evaluation (MWSE) method for evaluating urban air risk. Sulphur dioxide (SO 2 ), nitrogen oxide (NO x ), and particulate matter (PM 10 ) were used as pollution indices. The urban area of Hangzhou, China is divided into 756 grid cells, with a resolution of 1 km×1 km, and is evaluated using the MWSE and the air quality index (AQI), a widely-used method to evaluate ambient air quality and air risk. In an evaluation of one day in April 2004, the surface areas categorized as levels I and III, as defined by the integrated air risk evaluation, were 27.3% and 3.3% lower, respectively, than grades I and III defined by the AQI evaluation. Meanwhile, the areas classified as level II or above level III by the integrated air risk evaluation were 55.1% and 101.1% higher, respectively, than grade II or above grade III when using the AQI evaluation. From this comparison, we find that the MWSE method is more sensitive than the AQI method. The AQI method uses a single index to assess integrated air quality and is therefore unable to evaluate integrated air risks due to multiple pollutants. The MWSE method overcomes this problem, providing improved accuracy in air risk assessment. Content Type Journal Article Pages 702-709 DOI 10.1631/jzus.A11b0043 Authors Qing-yu Zhang, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058 China Guo-jin Sun, Department of Chemical Engineering, Zhejiang University, Hangzhou, 310027 China Wei-li Tian, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058 China Yu-mei Wei, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058 China Si-mai Fang, College of Information, University of International Business and Economic, Beijing, 100029 China Jin-feng Ruan, Department of Environmental Engineering, Zhejiang University, Hangzhou, 310058 China Guo-rong Shan, Department of Chemical Engineering, Zhejiang University, Hangzhou, 310027 China Yao Shi, Department of Chemical Engineering, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    In this work, a systematic approach is presented to obtain the input-output equations of a single loop 4-bar spatial mechanisms. The dialytic method along with Denavit-Hartenberg parameters can be used to obtain these equations efficiently. A genetic algorithm (GA) has been used to solve the problem of spatial mechanisms synthesis. Two types of mechanisms, e.g., RSCR and RSPC (R: revolute; S: spherical; C: cylindrical; P: prismatic), have illustrated the application of the GA to solve the problem of function generation and path generation. In some cases, the GA method becomes trapped in a local minimum. A combined GA-fuzzy logic (GA-FL) method is then used to improve the final result. The results show that GAs, combined with an adequate description of the mechanism, are well suited for spatial mechanism synthesis problems and have neither difficulties inherent to the choice of the initial feasible guess, nor a problem of convergence, as it is the case for deterministic methods. Content Type Journal Article Pages 665-679 DOI 10.1631/jzus.A1000052 Authors Med Amine Laribi, Laboratoire de Génie Mécanique, LAB-MA-05, Ecole Nationale d’Ingénieurs de Sousse, 4000 Sousse, Tunisia Lotfi Romdhane, Laboratoire de Génie Mécanique, LAB-MA-05, Ecole Nationale d’Ingénieurs de Sousse, 4000 Sousse, Tunisia Saïd Zeghloul, Département Génie Mécanique et Systémes Complexes, SP2MI, Institut Pprime-UPR 3346, CNRS-Université de Poitiers-ENSMA, BP30179, 86962 Futuroscope, France Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    Ultrasonic wave testing was applied to investigate the quality and weathering status of rock specimens obtained in two borings situated in the Xishan Buddha rock slope in Taiyuan, China. This paper pays special attention to the distribution of bulk density, dynamic parameters and static parameters of rock specimens as well as the relationship between static and dynamic parameters. The results illustrate that the distribution of both parameters is identical along the depth of two drilled holes in the rock slope. When the hole depth increases, the density of rock mass, saturated compression strength and static elastic modulus, dynamic elastic modulus and wave velocity also show increase tendency. The weathering degree in the rock mass ranging from the surface of cliff to the depth of 2.5 m is the highest while the rock mass is unsalted and more rigid when the depth is larger than 3.0 m. The relationship between dynamic elastic modulus, sonic wave velocity and horizontal depth indicates that dynamic elastic modulus is more sensitive than sonic wave velocity. Conversely, by comparing quantity relationship between static elastic modulus and sonic wave velocity, it is found that the composition of rock has a great influence on the relationship between static and dynamic parameters, that is, inequality of rock composition will lead to dispersion and abnormality of the distribution of static and dynamic parameters. Content Type Journal Article Pages 771-781 DOI 10.1631/jzus.A1100003 Authors Jin Jiang, School of Civil and Environmental Engineering, Nanyang Technological University, 639798 Singapore, Singapore Jin-zhong Sun, School of Engineering and Technology, China University of Geosciences, Beijing, 100083 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    The buckle and collapse of offshore pipeline subjected to combined actions of tension, bending, and external pressure during deepwater installation has drawn a great deal of attention. Extended from the model initially proposed by Kyriakides and his co-workers, a 2D theoretical model which can successfully account for the case of simultaneous tension, bending, and external pressure is further developed. To confirm the accuracy of this theoretical method, numerical simulations are conducted using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. The model is then used to study the effects of several important factors such as load path, material properties, and diameter-to-thickness ratio, etc., on buckling behaviors of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which aims to provide the design guidelines for deepwater pipeline with solid theoretical basis. Content Type Journal Article Pages 627-636 DOI 10.1631/jzus.A1000489 Authors Shun-feng Gong, Institute of Structural Engineering, Zhejiang University, Hangzhou, 310058 China Lin Yuan, Institute of Structural Engineering, Zhejiang University, Hangzhou, 310058 China Wei-liang Jin, Institute of Structural Engineering, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 8

Beschreibung:    In this paper, a modeling method for a pantograph-catenary system is put forward to investigate the dynamic contact behavior in space, taking into consideration of the appearance characteristics of the contact surfaces of the pantograph and catenary. The dynamic performance of the pantograph-catenary system, including contact forces, accelerations, and the corresponding spectra, is analyzed. Furthermore, with the modeling method, the influences of contact wire irregularity and the vibration caused by the front pantograph on the rear pantograph for a pantograph-catenary system with double pantographs are investigated. The results show that the appearance characteristics of the contact surfaces play an important role in the dynamic contact behavior. The appearance characteristics should be considered to reasonably evaluate the dynamic performance of the pantograph-catenary system. Content Type Journal Article Pages 913-920 DOI 10.1631/jzus.A11GT015 Authors Ning Zhou, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, 610031 China Wei-hua Zhang, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, 610031 China Rui-ping Li, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu, 610031 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    In order to study the unsteady aerodynamics effects in railway tunnels, the 3D Reynolds average Navier-Stokes equations of a viscous compressible fluid are solved, and the two-equation k - ɛ model is used in the simulation of turbulence, while the dynamic grid technique is employed for moving bodies. We focus on obtaining the changing tendencies of the aerodynamic force of the train and the aerodynamic pressures on the tunnel wall and train surface, and discovering the relationship between the velocity of the train and the intensity of the micro pressure wave at the tunnel exit. It is shown that the amplitudes of the pressure changes in the tunnel and on the train surface are both approximately proportional to the square of the train speed, so are the microwave and the drag of the train. Content Type Journal Article Pages 957-963 DOI 10.1631/jzus.A11GT008 Authors Xin-hua Li, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, 310027 China Jian Deng, National Engineering Laboratory for System Integration of High-Speed Train (South), CSR Qingdao Sifang Co., Ltd., Qingdao, 266111 China Da-wei Chen, National Engineering Laboratory for System Integration of High-Speed Train (South), CSR Qingdao Sifang Co., Ltd., Qingdao, 266111 China Fang-fang Xie, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, 310027 China Yao Zheng, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    In this paper, an efficient model structure composed of a second-order resistance-capacitance network and a simply analytical open circuit voltage versus state of charge (SOC) map is applied to characterize the voltage behavior of a lithium iron phosphate battery for electric vehicles (EVs). As a result, the overpotentials of the battery can be depicted using a second-order circuit network and the model parameterization can be realized under any battery loading profile, without a special characterization experiment. In order to ensure good robustness, extended Kalman filtering is adopted to recursively implement the calibration process. The linearization involved in the calibration algorithm is realized through recurrent derivatives in a recursive form. Validation results show that the recursively calibrated battery model can accurately delineate the battery voltage behavior under two different transient power operating conditions. A comparison with a first-order model indicates that the recursively calibrated second-order model has a comparable accuracy in a major part of the battery SOC range and a better performance when the SOC is relatively low. Content Type Journal Article Pages 818-825 DOI 10.1631/jzus.A1100141 Authors Xiao-song Hu, National Engineering Laboratory for Electric Vehicles, Department of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081 China Feng-chun Sun, National Engineering Laboratory for Electric Vehicles, Department of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081 China Xi-ming Cheng, National Engineering Laboratory for Electric Vehicles, Department of Mechanical Engineering, Beijing Institute of Technology, Beijing, 100081 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 11

Beschreibung:    A switched-mode unit used in electric locomotive generates a strong high frequency conducted electromagnetic interference (EMI), which radiates electromagnetic energy through railway lines. Evaluation of magnetic field using analytical technique based on contour integral is presented, in order to assess the electromagnetic environment around a high-speed railway. Actual railway multiconductor finitely long overhead lines are represented by an infinitely long single line above two-layered earth, whose characteristic is different from homogeneous earth. Owing to the constraint of the GB/T 24338-2009 and the high frequency investigated (a few MHz), only the magnetic fields are examined. The magnetic fields consist of four components: the direct wave, the ideal reflected wave or image wave, the trapped surface wave, and the lateral wave. The calculation results proved that due to the presence of the trapped surface wave, the magnetic field of the observer point on the interface is strongly influenced, when the line is on or closed to the interface. Content Type Journal Article Pages 950-956 DOI 10.1631/jzus.A11GT004 Authors Yong-jian Zhi, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Bin Zhang, State Key Lab of Fluid Power Transmission and Control, Zhejiang University, Hangzhou, 310027 China Kai Li, Department of Information Science and Electronic Engineering, Zhejiang University, Hangzhou, 310027 China Xiao-yan Huang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China You-tong Fang, College of Electrical Engineering, Zhejiang University, Hangzhou, 310027 China Wen-ping Cao, Newcastle University, Newcastle upon Type, NE1 7RU UK Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    Line planning is the first important strategic element in the railway operation planning process, which will directly affect the successive planning to determine the efficiency of the whole railway system. A two-layer optimization model is proposed within a simulation framework to deal with the high-speed railway (HSR) line planning problem. In the model, the top layer aims at achieving an optimal stop-schedule set with the service frequencies, and is formulated as a nonlinear program, solved by genetic algorithm. The objective of top layer is to minimize the total operation cost and unserved passenger volume. Given a specific stop-schedule, the bottom layer focuses on weighted passenger flow assignment, formulated as a mixed integer program with the objective of maximizing the served passenger volume and minimizing the total travel time for all passengers. The case study on Taiwan HSR shows that the proposed two-layer model is better than the existing techniques. In addition, this model is also illustrated with the Beijing-Shanghai HSR in China. The result shows that the two-layer optimization model can reduce computation complexity and that an optimal set of stop-schedules can always be generated with less calculation time. Content Type Journal Article Pages 902-912 DOI 10.1631/jzus.A11GT016 Authors Li Wang, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, 100044 China Li-min Jia, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, 100044 China Yong Qin, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, 100044 China Jie Xu, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, 100044 China Wen-ting Mo, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong University, Beijing, 100044 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 12

Beschreibung:    In this paper, the vibration influence on a monument caused by Chengdu Subway Line 2 is analyzed. Due to its elaborate and unique design, both structural and architectural damages should be avoided. First, the allowable root mean square (RMS) velocity at the foundation of the monument is derived and a site measurement is performed to obtain the background vibrations induced by road traffic. In addition, a train-track coupled model and 3D tunnel-soil-structure coupled finite element models are built to predict the dynamic response of the monument. Prediction models are checked by site measurement in Beijing Subway Line 5. Different kinds of fasteners and train speeds are compared and discussed as well. Results show that: (1) At a train speed of 72 km/h, all the traffic vibrations exceed the low limit no matter what kind of fastener is used, which is mainly due to the contribution of road traffic. Slowing down train speeds can cause effective vibration attenuation; (2) Vibrations drop dramatically with the train speed from 65 to 58 km/h. When the train speed is lower than 58 km/h, vibrations are lower than allowable value even if the contribution of road traffic is considered. Content Type Journal Article Pages 782-793 DOI 10.1631/jzus.A1100088 Authors Meng Ma, School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044 China Valéri Markine, Section of Road and Railway Engineering, Department of Design and Construction, Delft University of Technology, Delft, 2600GA the Netherlands Wei-ning Liu, School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044 China Yang Yuan, School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044 China Feng Zhang, School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    This research was aimed at deriving average stress-average strain tension-stiffening relationships in accordance with the provisions of design codes for reinforced concrete (RC) members. Using a proposed inverse technique, the tension-stiffening relationships were derived from moment-curvature diagrams of RC beams calculated by different code methods, namely Eurocode 2, ACI 318, and the Chinese standard GB 50010-2002. The derived tension-stiffening laws were applied in a numerical study using the nonlinear finite element software ATENA. The curvatures calculated by ATENA and the code methods were in good agreement. Content Type Journal Article Pages 731-736 DOI 10.1631/jzus.A1100029 Authors Gintaris Kaklauskas, Department of Bridges and Special Structures, Vilnius Gediminas Technical University, Vilnius, 10223 Lithuania Viktor Gribniak, Department of Bridges and Special Structures, Vilnius Gediminas Technical University, Vilnius, 10223 Lithuania Rokas Girdzius, Department of Bridges and Special Structures, Vilnius Gediminas Technical University, Vilnius, 10223 Lithuania Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 10

Beschreibung:    A friction damper device (FDD) is used for vibration control of an existing steel jacket platform under seismic excitation. First, the damping is presented for vibration mitigation of structures located in seismically active zones. A new method for quick design of friction or yielding damping devices is presented. The effectiveness of the damping system employing such FDDs in a jacket platform is evaluated numerically. The influence of key parameters of the damping system on the vibration suppression of the offshore structure is studied in detail. To examine the vibration control effectiveness of the FDD for the jacket platform, performance of the controlled structure under the seismic forces is studied using numerical simulations. A parametric study is undertaken to discover the optimized slip load and brace area of the FDD. It is shown that the FDD is effective in mitigating the dynamic responses of the offshore platform structure. Content Type Journal Article Pages 680-691 DOI 10.1631/jzus.A1000381 Authors Y. Komachi, Department of Civil Engineering, Pardis Branch, Islamic Azad University, Pardis, Iran M. R. Tabeshpour, Faculty of Engineering, Sabzevar Tarbiat Moallem University, Sabzevar, Iran A. A. Golafshani, Department of Civil Engineering, Sharif University of Technology, Tehran, Iran I. Mualla, DAMPTECH Ltd., Denmark Technical University, Lyngby, Denmark Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    Despite widespread concerns and elevated policy debates, little is known about the Chinese public’s perceptions of water pollution and willingness to cooperate with government policies. Based on survey data, this study examined Lake Tai resident perception of water pollution, willingness to pay (WTP) for water quality improvements, and its influencing factors. Contingent valuation (CV) results showed that respondents would prefer to pay 141 CNY per household a year, approximately 0.70% of their annual per capita disposable income, as an environmental fee to improve water quality in Lake Tai. Aggregate WTP for all five lakeside cities of Lake Tai was estimated at about 3.8 billion CNY, without discounts, in the next ten years. WTP was found to increase with income and female respondents were willing to pay more than males. Those respondents who were dissatisfied with water quality were more likely to pay more. The usage of Lake Tai did not strongly affect WTP. Content Type Journal Article Pages 710-719 DOI 10.1631/jzus.A11b0157 Authors Wei-wen Zhang, Department of Land Management, Zhejiang University, Hangzhou, 310029 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 12 Journal Issue Volume 12, Number 9

Beschreibung:    Locating distribution centers optimally is a crucial and systematic task for decision-makers. Optimally located distribution centers can significantly improve the logistics system’s efficiency and reduce its operational costs. However, it is not an easy task to optimize distribution center locations and previous studies focused primarily on location optimization of a single distribution center. With growing logistics demands, multiple distribution centers become necessary to meet customers’ requirements, but few studies have tackled the multiple distribution center locations (MDCLs) problem. This paper presents a comprehensive algorithm to address the MDCLs problem. Fuzzy integration and clustering approach using the improved axiomatic fuzzy set (AFS) theory is developed for location clustering based on multiple hierarchical evaluation criteria. Then, technique for order preference by similarity to ideal solution (TOPSIS) is applied for evaluating and selecting the best candidate for each cluster. Sensitivity analysis is also conducted to assess the influence of each criterion in the location planning decision procedure. Results from a case study in Guiyang, China, reveals that the proposed approach developed in this study outperforms other similar algorithms for MDCLs selection. This new method may easily be extended to address location planning of other types of facilities, including hospitals, fire stations and schools. Content Type Journal Article Pages 782-798 DOI 10.1631/jzus.A1200137 Authors Yong Wang, School of Transportation, Southeast University, Nanjing, 210096 China Xiao-lei Ma, Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195-2700, USA Yin-hai Wang, Department of Civil and Environmental Engineering, University of Washington, Seattle, WA 98195-2700, USA Hai-jun Mao, School of Transportation, Southeast University, Nanjing, 210096 China Yong Zhang, School of Transportation, Southeast University, Nanjing, 210096 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 10

Beschreibung:    The Aircraft Integrated Meteorological Measuring System 20 Hz (AIMMS-20) has been used by the Hong Kong Observatory (HKO), China in data collection for tropical cyclone situations over the South China Sea and windshear and turbulence measurement at the Hong Kong International Airport (HKIA). This paper discusses possible methods for further enhancing the quality of the wind and temperature measurements from the system. For wind measurement, the enhancement methods include: error modelling of the accelerometer (e.g., bias offset and cross-axis rate sensitivity), global positioning system (GPS) phase lag consideration, better representation of the inertial measurement unit (IMU) velocity based on the GPS velocities and considering their location differences, consideration of the slower update of GPS velocity, and wing flexure. For temperature measurement, the methods include the consideration of the temperature sensor response and the sensor housing response. The results of typical flights using AIMMS-20 show that the accuracy of the wind and temperature data could be improved by 20%–30%. Though the discussion in the present paper is related mainly to a specific meteorological measuring system on a particular aircraft, the techniques so employed should be a useful reference for similar systems installed on other aircraft. Content Type Journal Article Pages 723-746 DOI 10.1631/jzus.A1100245 Authors Stephen Foster, Aventech Research Inc., Barrie, ON L4N 2E3, Canada P. W. Chan, Hong Kong Observatory, Kowloon, Hong Kong, China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 10

Beschreibung:    An exact analytical solution is obtained for convective heat transfer in straight ducts with rectangular cross-sections for the first time. This solution is valid for both H1 and H2 boundary conditions, which are related to fully developed convective heat transfer under constant heat flux at the duct walls. The separation of variables method and various other mathematical techniques are used to find the closed form of the temperature distribution. The local and mean Nusselt numbers are also obtained as functions of the aspect ratio. A new physical constraint is presented to solve the Neumann problem in non-dimensional analysis for the H2 boundary conditions. This is one of the major innovations of the current study. The analytical results indicate a singularity occurs at a critical aspect ratio of 2.4912 when calculating the local and mean Nusselt numbers. Content Type Journal Article Pages 768-781 DOI 10.1631/jzus.A1100122 Authors Mohammad Mohsen Shahmardan, Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran Mahmood Norouzi, Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran Mohammad Hassan Kayhani, Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran Amin Amiri Delouei, Department of Mechanical Engineering, Shahrood University of Technology, Shahrood, Iran Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 10

Beschreibung:    This paper studies the excavation collapse at the Xianghu subway station on Hangzhou metro line 1. The objective is to present an overview of this case study and discuss the cause of the failure. Through field investigation and preliminary analysis, the reasons for the excavation collapse were the misuse of the soil parameters, over excavation, incorrect installation of steel struts, invalid monitoring data, and inadequate ground improvement. Finally, a small strain constitutive model was used for further analysis. In order to estimate damage efficiently, the orthogonal array (OA) was introduced for screening the key factor in the numerical experiments. Six estimated indexes including deformations and internal forces of the excavation were taken, and the effectiveness of four factors which may cause the collapse was evaluated. Through numerical experiments and interaction analysis, it is found that the deformation and internal force can be well controlled by jet grouting of the subsoil under the final cutting surface, but increasing the improvement ratio of the jet grouting cannot help optimize the excavation behavior efficiently, and without jet grouting and the fourth level struts, the deformation and internal force of the excavation in this case will far surpass the allowable value. Content Type Journal Article Pages 760-767 DOI 10.1631/jzus.A1200120 Authors Xiao-nan Gong, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058 China Xue-chan Zhang, MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering, Zhejiang University, Hangzhou, 310058 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 10

Beschreibung:    The buckling of thin-walled structures is presented using the 1D finite element based refined beam theory formulation that permits us to obtain N -order expansions for the three displacement fields over the section domain. These higher-order models are obtained in the framework of the Carrera unified formulation (CUF). CUF is a hierarchical formulation in which the refined models are obtained with no need for ad hoc formulations. Beam theories are obtained on the basis of Taylor-type and Lagrange polynomial expansions. Assessments of these theories have been carried out by their applications to studies related to the buckling of various beam structures, like the beams with square cross section, I-section, thin rectangular cross section, and annular beams. The results obtained match very well with those from commercial finite element softwares with a significantly less computational cost. Further, various types of modes like the bending modes, axial modes, torsional modes, and circumferential shell-type modes are observed. Content Type Journal Article Pages 747-759 DOI 10.1631/jzus.A1100331 Authors Syed Muhammad Ibrahim, Specialty Units for Safety and Preservation of Structures, King Saud University, Riyadh, Saudi Arabia Erasmo Carrera, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Marco Petrolo, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Enrico Zappino, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 10

Beschreibung:    To determine the ash characteristics during fluidized bed combustion and gasification purposes, the investigation of the impacts of chemical composition of Jincheng coal ash on the sintering temperature was conducted. A series of experiments on the sintering behavior at 0.5 MPa was performed using the pressurized pressure-drop technique in the combustion and gasification atmospheres. Meanwhile, the mineral transformations of sintered ash pellets were observed using X-ray diffractometer (XRD) analyzer to better understand the experimental results. In addition, quantitative XRD and field emission scanning electron microscope/energy dispersive X-ray spectrometer (FE-SEM/EDS) analyses of ash samples were used for clarifying the detailed ash melting mechanism. These results show that the addition of Fe 2 O 3 can obviously reduce the sintering temperatures under gasification atmospheres, and only affect a little the sintering temperature under combustion atmosphere. This may be due to the presence of iron-bearing minerals, which will react with other ash compositions to produce low-melting-point eutectics. The FE-SEM/EDS analyses of ash samples with Fe 2 O 3 additive show consistent results with the XRD measurements. The CaO and Na 2 O can reduce the sintering temperatures under both the combustion and gasification atmospheres. This can be also contributed to the formation of low-melting-point eutectics, decreasing the sintering temperature. Moreover, the fluxing minerals, such as magnetite, anhydrite, muscovite, albite and nepheline, contribute mostly to the reduction of the sintering temperature while the feldspar minerals, such as anorthite, gehlenite and sanidine, can react with other minerals to produce low-melting-point eutectics, and thereby reduce the sintering temperatures. Content Type Journal Article Pages 230-238 DOI 10.1631/jzus.A1100206 Authors Ni-jie Jing, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Qin-hui Wang, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Yu-kun Yang, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Le-ming Cheng, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Zhong-yang Luo, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Ke-fa Cen, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    This paper investigated the static and fatigue behaviors of steel and composite multi-leaf spring using the ANSYS V12 software. The dimensions of an existing conventional leaf spring of a light commercial vehicle were used. The same dimensions were used to design composite multi-leaf spring for the two materials, E-glass fiber/epoxy and E-glass fiber/vinyl ester, which are of great interest to the transportation industry. Main consideration was given to the effects of material composition and its fiber orientation on the static and fatigue behaviors of leaf spring. The design constraints were bending stresses, deflection and fatigue life. Compared to the steel leaf spring, the designed composite spring has much lower bending stresses and deflections and higher fatigue life cycles. Content Type Journal Article Pages 159-164 DOI 10.1631/jzus.A1100212 Authors Joo-teck Jeffrey Kueh, Department of Mechanical Engineering, Universiti Tenaga Nasional, Selangor, 43000 Malaysia Tarlochan Faris, Department of Mechanical Engineering, Universiti Tenaga Nasional, Selangor, 43000 Malaysia Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    A sequencing batch reactor (SBR) seeded with activated sludge was established for landfill leachate treatment. Small bio-aggregates began to appear after 40-d operation, and gradually changed to mature aerobic granules, with a mean size of 0.36–0.60 mm. Their sludge volume index at 5 min (SVI 5 min ), mixed liquor volatile suspended solids (MLVSS), and wet density were around 35 ml/g, 3.4 g/L, and 1.062 g/cm 3 , respectively. The settling velocities of the granules in distilled water ranged from 0.3 to 1.3 cm/s, which were faster than those in landfill leachate with a salt content of 1.4% (w/v), and also slightly faster than those predicted by Stokes’ law for porous but impermeable particles. Microbial community evolution during the granulation process and stages under different nitrogen loading rates (NLRs) were monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), cloning, and sequencing of 16S ribosomal RNA (rRNA) fragments. Results revealed that some primary and dominant communities in inoculating activated sludge died out gradually; while a few common bacteria, inhabiting soils, municipal wastewater, or activated sludge systems, dominated in the SBR system throughout. In addition, some other dominant species, associated with the aerobic granulation process, were thought to play a significant role in the formation and growth of aerobic granular sludge. During the stable operation time under low NLR, a few species were present in abundance, and may have been responsible for the high organic removal efficiency at this time. Content Type Journal Article Pages 219-229 DOI 10.1631/jzus.A1100153 Authors Yan-jie Wei, Key Laboratory of Environmental Protection in Water Transport Engineering Ministry of Communications, Tianjin Research Institute of Water Transport Engineering, Tianjin, 300456 China Min Ji, School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072 China Guo-yi Li, Key Laboratory of Environmental Protection in Water Transport Engineering Ministry of Communications, Tianjin Research Institute of Water Transport Engineering, Tianjin, 300456 China Fei-fei Qin, Tianjin Tanggu Sino French Water Supply Co., Ltd., Tianjin, 300450 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 3

Beschreibung:    Analyzing the service behavior of high dams and establishing early-warning systems for them have become increasingly important in ensuring their long-term service. Current analysis methods used to obtain safety monitoring data are suited only to single survey point data. Unreliable or even paradoxical results are inevitably obtained when processing large amounts of monitoring data, thereby causing difficulty in acquiring precise conclusions. Therefore, we have developed a new method based on multi-source information fusion for conducting a comprehensive analysis of prototype monitoring data of high dams. In addition, we propose the use of decision information entropy analysis for building a diagnosis and early-warning system for the long-term service of high dams. Data metrics reduction is achieved using information fusion at the data level. A Bayesian information fusion is then conducted at the decision level to obtain a comprehensive diagnosis. Early-warning outcomes can be released after sorting analysis results from multi-positions in the dam according to importance. A case study indicates that the new method can effectively handle large amounts of monitoring data from numerous survey points. It can likewise obtain precise real-time results and export comprehensive early-warning outcomes from multi-positions of high dams. Content Type Journal Article Pages 687-699 DOI 10.1631/jzus.A1200122 Authors Xing Liu, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098 China Zhong-ru Wu, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098 China Yang Yang, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098 China Jiang Hu, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098 China Bo Xu, State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    Disk burst accidents sometimes happen in aeroengines. To avoid tragic consequences, aeroengine casings must have sufficient containment capability. Experiments and simulations need to be conducted to study the impact, distortion, and perforation caused by disk burst and which may give important clues to potential failure mechanisms. This paper presents some containment tests of high-speed rotating disk fragments, in which the original disks were burst into three equal fragments within a predetermined rotating speed range. The failure modes of the containment casing varied significantly with the thickness of the containment casing. Shearing, tearing, tensile fracture, and large plastic stretching deformation occurred in a thin-walled containment casing, while a thick-walled casing could contain disk fragments and withstand large plastic deformation. Numerical simulations were carried out to study the impact process and failure modes further. Good agreement was found between the results of the simulations and the tests. Content Type Journal Article Pages 665-673 DOI 10.1631/jzus.A1200047 Authors Hai-jun Xuan, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Faculty of Engineering, Zhejiang University, Hangzhou, 310027 China Lu-lu Liu, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Faculty of Engineering, Zhejiang University, Hangzhou, 310027 China Yi-ming Feng, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Faculty of Engineering, Zhejiang University, Hangzhou, 310027 China Qing He, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Faculty of Engineering, Zhejiang University, Hangzhou, 310027 China Juan-juan Li, High-Speed Rotating Machinery Laboratory, Institute of Chemical Machinery, Faculty of Engineering, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    The differential evolution (DE) algorithm has been received increasing attention in terms of optimizing the design for the water distribution systems (WDSs). This paper aims to carry out a comprehensive performance comparison between the new emerged DE algorithm and the most popular algorithm—the genetic algorithm (GA). A total of six benchmark WDS case studies were used with the number of decision variables ranging from 8 to 454. A preliminary sensitivity analysis was performed to select the most effective parameter values for both algorithms to enable the fair comparison. It is observed from the results that the DE algorithm consistently outperforms the GA in terms of both efficiency and the solution quality for each case study. Additionally, the DE algorithm was also compared with the previously published optimization algorithms based on the results for those six case studies, indicating that the DE exhibits comparable performance with other algorithms. It can be concluded that the DE is a newly promising optimization algorithm in the design of WDSs. Content Type Journal Article Pages 674-686 DOI 10.1631/jzus.A1200072 Authors Xiao-lei Dong, College of Environmental Science and Technology, Tongji University, Shanghai, 200092 China Sui-qing Liu, College of Environmental Science and Technology, Tongji University, Shanghai, 200092 China Tao Tao, College of Environmental Science and Technology, Tongji University, Shanghai, 200092 China Shu-ping Li, College of Environmental Science and Technology, Tongji University, Shanghai, 200092 China Kun-lun Xin, College of Environmental Science and Technology, Tongji University, Shanghai, 200092 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    The effects of journal misalignment on a journal bearing caused by an asymmetric rotor structure are presented in this study. A new model considering the asymmetric deflection is applied. Also, the thermo-hydrodynamic of the oil film in the journal bearing and straightforward elasticity theory are considered in the analysis. Based on the structure stiffness equivalent characteristic, a simple stepped shaft can reflect the entire complex structure model. The existing lubrication model, which does not consider this angle component, is not very precise for journal bearings. Film pressure, misalignment angle, velocity field, oil leakage, and temperature field were calculated and compared in the journal bearing analysis. The results indicate that bearing performances are greatly affected by misalignment caused by the asymmetric structure. A simple stepped shaft can effectively represent a misaligned journal bearing in a rotor-bearing system. Content Type Journal Article Pages 647-664 DOI 10.1631/jzus.A1200082 Authors Zhen-peng He, State Key Laboratory of Engine, Tianjin University, Tianjin, 300072 China Jun-hong Zhang, State Key Laboratory of Engine, Tianjin University, Tianjin, 300072 China Wei-song Xie, Deparment of Mathematics, School of Science, Tianjin University, Tianjin, 300072 China Zhou-yu Li, State Key Laboratory of Engine, Tianjin University, Tianjin, 300072 China Gui-chang Zhang, State Key Laboratory of Engine, Tianjin University, Tianjin, 300072 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    A multi-dimensional computational fluid dynamics (CFD) approach was proposed in this study aiming to calculate the transfer matrix of an engine exhaust muffler in the conditions with and without mean flow. The CFD model of the muffler with absorptive material defined as porous zone was calibrated with the measured noise reduction without mean flow, and was further employed to study the effect of the mean flow on the acoustic performance of the muffler. Furthermore, the exhaust acoustical source was derived from the calculated transfer matrices of six different additional acoustic loads obtained by the proposed CFD approach as well as the measured tail noise based on a multiload least squares method. Finally, the exhaust noise was predicted based on Thevenin’s theorem. The proposed CFD approach was suggested to be able to predict the acoustic performance of a complex muffler considering mean flow (without and with mean flow) and heat transfer, and provide reasonable results of the exhaust noise. Content Type Journal Article Pages 709-716 DOI 10.1631/jzus.A1200155 Authors Lian-yun Liu, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Zhi-yong Hao, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Chi Liu, Department of Energy Engineering, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    This paper presents an improved model for global sunshine duration estimation. The methodology incorporates geostationary satellite images by including snow cover information, sun and satellite angles and a trend correction factor for seasons, for the determination of cloud cover index. The effectiveness of the proposed methodology has been tested using Meteosat geostationary satellite images in the visible band with a temporal resolution of 1 h and spatial resolution of 2.5 km×2.5 km, for the Brue Catchment in the southwest of England. Validation results show a significant improvement in the estimation of global sunshine duration by the proposed method as compared to its predecessor ( R 2 is improved from 0.68 to 0.83, root mean squared error (RMSE) from 2.37 h/d to 1.19 h/d and the mean biased error (MBE) from 0.21 h/d to 0.08 h/d). Further studies are needed to test this method in other parts of the world with different climate and geographical conditions. Content Type Journal Article Pages 717-722 DOI 10.1631/jzus.A1100292 Authors Muhammad Ali Shamim, Department of Civil Engineering, University of Engineering and Technology, Taxila, 47050 Pakistan Renji Remesan, Department of Geography, University of Hull, Hull, HU6 7RX UK Da-wei Han, Department of Civil Engineering, University of Bristol, Bristol, BS8 1TR UK Naeem Ejaz, Department of Civil Engineering, University of Engineering and Technology, Taxila, 47050 Pakistan Ayub Elahi, Department of Civil Engineering, University of Engineering and Technology, Taxila, 47050 Pakistan Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    Elemental mercury capture on heat-treated activated carbon (TAC) was studied using a laboratory-scale fixed bed reactor. The capability of TAC to perform Hg 0 capture under both N 2 and baseline gas atmospheres was studied and the effects of common acid gas constituents were evaluated individually to avoid complications resulting from the coexistence of multiple components. The results suggest that surface functional groups (SFGs) on activated carbon (AC) are vital to Hg 0 capture in the absence of acid gases. Meanwhile, the presence of acid gas components coupled with defective graphitic lattices on TAC plays an important role in effective Hg 0 capture. The presence of HCl, NO 2 , and NO individually in basic gases markedly enhances Hg 0 capture on TAC due to the heterogeneous oxidation of Hg 0 on acidic sites created on the carbon surface and catalysis by the defective graphitic lattices on TAC. Similarly, the presence of SO 2 improves Hg 0 capture by about 20%. This improvement likely results from the deposition of sulfur groups on the AC surface and oxidation of the elemental mercury by SO 2 due to catalysis on the carbon surface. Furthermore, O 2 exhibits a synergistic effect on Hg 0 oxidation and capture when acid gases are present in the flue gases. Content Type Journal Article Pages 700-708 DOI 10.1631/jzus.A1200112 Authors Jian-ming Zheng, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Jin-song Zhou, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Zhong-yang Luo, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Ke-fa Cen, State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 9

Beschreibung:    The fuel dynamic transfer process, including fuel injection, fuel film deposition and evaporation in the intake port, was analyzed for spark ignition (SI) engines with port fuel injection (PFI). The influence of wall-wetting fuel film, especially its evaporation rate, upon the air-fuel ratio of in-cylinder mixtures was also discussed. According to the similarity principle, Fick’s law, the ideal gas equation and the Gilliland correlation, an evaporate prediction model of wall-wetting fuel film was set up and an evaporate prediction based dynamic fuel film compensator was designed. Through engine cold start tests, the wall-wetting temperature, which is the key input of the fuel film evaporate prediction model, was also modeled and predicted. Combined with the experimental data of the evaporation characteristics of ethanol-gasoline blends and engine calibration tests, all the parameters of the wall-wetting fuel film evaporate prediction model used in the fuel film compensator were identified. Square-wave disturbance tests of fuel injection showed that with the help of the fuel film compensator the response of the in-cylinder air-fuel ratio was significantly improved and the real air-fuel ratio always closely matched the expected ratio. The fuel film compensator was then integrated into the final air-fuel ratio controller, and the engine tests showed that the air-fuel ratio control error was less than 2% in steady-state conditions, and less than 4% in transient conditions. The fuel film compensator also showed good adaptability to different ethanol-gasoline blends. Content Type Journal Article Pages 610-619 DOI 10.1631/jzus.A1200068 Authors Dong-wei Yao, Institute of Power Machinery and Vehicular Engineering, Zhejiang University, Hangzhou, 310027 China Xin-chen Ling, Institute of Power Machinery and Vehicular Engineering, Zhejiang University, Hangzhou, 310027 China Feng Wu, Institute of Power Machinery and Vehicular Engineering, Zhejiang University, Hangzhou, 310027 China Journal Journal of Zhejiang University - Science A Online ISSN 1862-1775 Print ISSN 1673-565X Journal Volume Volume 13 Journal Issue Volume 13, Number 8