ALBERT

Description: Author(s): Xun-Wei Xu, Yuan-Jie Li, and Yu-xi Liu In contrast to recent studies [Rabl,   Phys. Rev. Lett. 107 063601 (2011) ; Nunnenkamp et al. , Phys. Rev. Lett. 107 063602 (2011) ] on photon blockade that prevents subsequent photons from resonantly entering the cavity in optomechanical systems, we study the photon-induced tunneling that increase... [Phys. Rev. A 87, 025803] Published Fri Feb 08, 2013

Description: Author(s): Tao Zhu, Paolo E. Trevisanutto, Teguh Citra Asmara, Lei Xu, Yuan Ping Feng, and Andrivo Rusydi Recently, an anomalous generation of multiple plasmons with large spectral weight transfer in the visible to ultraviolet range (energies below the band gap) has been experimentally observed in the insulatinglike phase of oxygen-rich strontium niobium oxides ( SrNbO 3 + δ ). Here, we investigate the groun... [Phys. Rev. B 98, 235115] Published Fri Dec 07, 2018

Description: Author(s): Jun Zhou, Ming Yang, Lei Shen, Qing Yun Wu, Lei Xu, Yuan Ping Feng, and Andrivo Rusydi How to tune two-dimensional electron gas at interface of heterostructures is becoming an important question for both fundamental physics and electronic applications. Here, using density functional theory calculations, we find that the polarization state of BaTiO 3 in metal capped BaTiO 3 / SrTiO 3 hetero… [Phys. Rev. B 93, 155167] Published Fri Apr 29, 2016

Description: Materials, Vol. 11, Pages 744: Facile Fabrication of Magnetic Metal-Organic Framework Composites for the Highly Selective Removal of Cationic Dyes Materials doi: 10.3390/ma11050744 Authors: Huijun Li Qingqing Li Yaling He Ning Zhang Zhouqing Xu Yuan Wang In this work, we show a novel magnetic composite material Fe3O4@HPU-9 (HPU-9 = {[Cd(L)0.5(H2O)](DMA)(CH3CN)}n) (H4L = 1,1′-di(3,5-dicarbonylbenzyl)-2,2′bimidazoline, DMA = N,N-dimethylacetamide) constructed by in situ growth of HPU-9 on Fe3O4, which has excellent absorption of cationic dyes from aqueous solution. The Fe3O4@HPU-9 particle possesses a well-defined core-shell structure consisting of a Fe3O4 core (diameter: 190 nm) and a HPU-9 shell (thickness: 10 nm). In the composite, the HPU-9 shell contributes to the capsulation of cationic dyes through electrostatic attractions between HPU-9 and cationic dyes, while the Fe3O4 core serves as magnetic particle. The maximum absorption capacity of Fe3O4@HPU-9 for R6G was 362.318 mg·g−1. The absorption kinetics data were well described by a psedo-second-order model (R2 > 0.99), and the equilibrium data were also well fitted to Langmuir isotherm model (R2 > 0.99). Our data confirmed that the proposed magnetic composite could be recycled and reused several times without centrifugal separation, making it more convenient, economic and efficient than common adsorbents.

Description: Sustainability, Vol. 10, Pages 1528: Identifying the Impacts of Social, Economic, and Environmental Factors on Population Aging in the Yangtze River Delta Using the Geographical Detector Technique Sustainability doi: 10.3390/su10051528 Authors: Xin Xu Yuan Zhao Xinlin Zhang Siyou Xia Under the background of social transformation and space reconstruction, population aging in China is becoming more and more diverse and complex. “Aging before getting rich”, a notion in population and economic development, has been a serious threat to sustainable development in China. On the basis of town- and street block-scale data from the Fifth and Sixth National Census in the Yangtze River Delta, we studied spatial distribution characteristics of population aging using global Moran’s I and hotspot analysis, and applied the geographical detector technique to explain the spatial heterogeneity of population aging. Several conclusions were drawn. (1) The promotion and replacement of aging coexist. Cluster of aging degree exhibits an increasing trend. Population aging is more severe in suburban areas than urban areas. (2) Migration is the main factor affecting the spatial heterogeneity of population aging. Per capital GDP and road network density are the second most influential factors. By contrast, the relief degree of land surface and the air quality index minimally influence population aging. The mechanisms of aging in various regions are affected by varying development levels. (3) The interaction among social, economic, and environmental factors enhances their effects and, thus, interacting factors have a greater influence on population aging than any single factor. The findings of this study have significant implications for local inhabitants and policy makers to address the population aging challenge in achieving sustainability of society, economy, and environment.

Description: Author(s): Laipan Zhu, Wei Huang, Pierre Renucci, Xavier Marie, Yu Liu, Yuan Li, Qing Wu, Yang Zhang, Bo Xu, Yuan Lu, and Yonghai Chen Spin photodiodes pique interest for converting information carried by photon helicity into electrical current, or for solid-state information storage and readout by illuminating the device with circularly polarized light. To elucidate the influence of incident and azimuthal angles on helicity amplitude, the authors use a hybrid device for systematic measurements at room temperature, with no need for an external magnetic field. The results yield important insight on the angular dependence of spin-photodiode efficiency, indicating key parameters that must be optimized to use such systems for spin filters or polarization detectors in spin-optoelectronic applications. [Phys. Rev. Applied 8, 064022] Published Wed Dec 20, 2017

Description: Author(s): Lei Li, Jian Zou, Hai Li, Bao-Ming Xu, Yuan-Mei Wang, and Bin Shao We investigate the heat transport between two nonthermal reservoirs based on a microscopic collision model. We consider a bipartite system consisting of two identical subsystems, and each subsystem interacts with its own local reservoir, which consists of a large collection of initially uncorrelated... [Phys. Rev. E 97, 022111] Published Fri Feb 09, 2018

Description: Sensors, Vol. 18, Pages 639: Robust Rate Maximization for Heterogeneous Wireless Networks under Channel Uncertainties Sensors doi: 10.3390/s18020639 Authors: Yongjun Xu Yuan Hu Guoquan Li Heterogeneous wireless networks are a promising technology in next generation wireless communication networks, which has been shown to efficiently reduce the blind area of mobile communication and improve network coverage compared with the traditional wireless communication networks. In this paper, a robust power allocation problem for a two-tier heterogeneous wireless networks is formulated based on orthogonal frequency-division multiplexing technology. Under the consideration of imperfect channel state information (CSI), the robust sum-rate maximization problem is built while avoiding sever cross-tier interference to macrocell user and maintaining the minimum rate requirement of each femtocell user. To be practical, both of channel estimation errors from the femtocells to the macrocell and link uncertainties of each femtocell user are simultaneously considered in terms of outage probabilities of users. The optimization problem is analyzed under no CSI feedback with some cumulative distribution function and partial CSI with Gaussian distribution of channel estimation error. The robust optimization problem is converted into the convex optimization problem which is solved by using Lagrange dual theory and subgradient algorithm. Simulation results demonstrate the effectiveness of the proposed algorithm by the impact of channel uncertainties on the system performance.

Description: Satellite remote sensing data that lacks spatial resolution and timeliness is of limited ability to access urban thermal environment on a micro scale. This paper presents an unmanned airship low-altitude thermal infrared remote sensing system (UALTIRSS), which is composed of an unmanned airship, an onboard control and navigation subsystem, a task subsystem, a communication subsystem, and a ground-base station. Furthermore, an experimental method and an airborne-field experiment for collecting land surface temperature (LST) were designed and conducted. The LST pattern within 0.8-m spatial resolution and with root mean square error (RMSE) value of 2.63 °C was achieved and analyzed in the study region. Finally, the effects of surface types on the surrounding thermal environment were analyzed by LST profiles. Results show that the high thermal resolution imagery obtained from UALTIRSS can provide more detailed thermal information, which are conducive to classify fine urban material and assess surface urban heat island (SUHI). There is a significant positive correlation between the average LST of profiles and the percent impervious surface area (ISA%) with R2 around 0.917. Overall, UALTIRSS and the retrieval method were proved to be low-cost and feasible for studying micro urban thermal environments.

Description: To characterize atmospheric dissolved iron over Newark, a large metropolitan city on US east coast, size-segregated (0.056–18 μm in aerodynamic diameter) aerosols were collected in downtown Newark, New Jersey during August to October 2012. Aerosols samples were analyzed for Fe(II) and total dissolved iron (Fe(TD)) by UV/Visible spectroscopy, and water soluble compounds were analyzed by ion chromatograph (IC). Results from this study showed that Fe(II) concentrations were 2.1 ng m−3 (range: 1.2–4.2 ng m−3), Fe(TD) concentrations were 2.4 ng m−3 (range: 1.3–4.9 ng m−3). Dissolved iron (Fe(II) and Fe(TD)) in general appeared as bi-modal size distribution, was mainly accumulated in the fine mode. The highest concentration of dissolved iron displayed in the fine mode, which was associated with high concentrations of sulfate, oxalate and nitrate, suggesting the potential for Fe–acids interactions. Dissolved iron presented positive correlations with sulfate in the coarse mode, and with nitrate in the fine mode, further suggesting the importance of acid processing in aerosol iron solubility. However, as the oxalate concentration was so low, a good correlation between dissolved iron and oxalate in both the fine and coarse mode was not found.