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  • 1
    Electronic Resource
    Electronic Resource
    Path integration of the time-dependent forced oscillator with a two-time quadratic action (1986)
    College Park, Md. : American Institute of Physics (AIP)
    Journal of Mathematical Physics 27 (1986), S. 767-771 
    Details
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: Using the prodistribution theory proposed by DeWitt-Morette [C. DeWitt-Morette, Commun. Math. Phys. 28, 47 (1972); C. DeWitt-Morette, A. Maheshwari, and B. Nelson, Phys. Rep. 50, 257 (1979)], the path integration of a time-dependent forced harmonic oscillator with a two-time quadratic action has been given in terms of the solutions of some integrodifferential equations. We then evaluate explicitly both the classical path and the propagator for the specific kernel introduced by Feynman in the polaron problem. Our results include the previous known results as special cases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.527181
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  • 2
    Electronic Resource
    Electronic Resource
    Regularized spherical harmonic analysis and the 3-D electromagnetic response of the Earth (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 116 (1994), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: A new form of electromagnetic tensor response function suitable for modelling the 3-D electrical conductivity structure of the spherical Earth was introduced by Zhang & Schultz (1992). The 3-D response tensor ζ can be directly estimated from coefficients of the spherical harmonic expansion of the time variations in the geomagnetic field. Physically, ζ depends both on the horizontal components of B, as well as the horizontal gradient of the vertical component. For conventional spherical harmonic analysis, the aggregate effects of sparse irregularly spaced observations, truncation of the expansion, and noise, results in potentially unbounded oscillatory field behaviour at locations in-between observation points. Such an effect destroys the reliability of estimates of the horizontal gradient in the geomagnetic field derived from resulting spherical harmonic coefficients and impacts our ability to calculate ζ with confidence. We present here a regularized inverse formulation for solving for the spherical harmonic coefficients such that the B field, and its horizontal gradient, are maximally smooth. We examine the l2 norms of the surface integrals of the Laplacian of vertical and horizontal components of B. We find the field that fits the data to a prescribed tolerance such that these norms are simultaneously minimized. The effects of noise and spacing of observation points on the stability of resulting field models and response functions are examined using a synthetic data set produced by the 3-D forward solution of Zhang & Schultz (1992). The trade-off between model misfit and smoothness is emphasized. This formulation involving both vertical and horizontal field components at the surface, termed ‘holomorphically regularized spherical harmonic analysis’ (HRSHA), is relatively insensitive to truncation level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1994.tb02133.x
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  • 3
    Electronic Resource
    Electronic Resource
    A 3-D perturbation solution for the EM induction problem in a spherical earth—the forward problem (1992)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical journal international 111 (1992), S. 0 
    Details
    ISSN: 1365-246X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: A solution of the three-dimensional forward problem for electrical conductivity in a spherical earth is considered. This work is based upon the standard decomposition which separates the magnetic field into toroidal magnetic (TM) mode and poloidal magnetic (PM) mode, and the assumption that the lateral inhomogeneity of the conductivity structure of the earth at mid-mantle depths is small. Under this restriction, we apply a perturbation method. The conductivity may be written as the summation of its major part, which is radially symmetric, and a perturbation term which is a function of all three variables, i.e. σ=σ(0)(r) +σ(1) (r, Θ, ϕ).It can be shown that the zeroth-order approximation of the problem is just the one-dimensional case in which the two modes TM and PM can be totally separated. Higher order solutions introduce lateral heterogeneity into the system and make the two modes couple into each other. A finite difference method is used to solve the zeroth-order equation. The first-order perturbation solution depends on the solution to the zeroth-order problem. The three-dimensional perturbation to the initial one-dimensional solution is obtained by expanding a function of conductivity in terms of spherical harmonics. The three-dimensional solution is calculated from the coefficients of this expansion by numerical integration.Preliminary results are compared with Wannamaker's flat earth two dimensional finite element model for a restricted set of conductivity models, and a reasonable agreement is obtained. A three-dimensional model has also been calculated up to second-order approximation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-246X.1992.tb00580.x
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  • 4
    Electronic Resource
    Electronic Resource
    Forced secondary resonances at the 3 : 1 commensurability (1994)
    Springer
    Celestial mechanics and dynamical astronomy 59 (1994), S. 313-325 
    Details
    ISSN: 1572-9478
    Keywords: Forced secondary resonance ; degenerate Hamiltonian system ; stochastic web ; adiabatic approximation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract For the 3 : 1 Jovian resonance problem, the time scales of the two degrees of freedom of the resonant Hamiltonian are well-separated [5]. With the adiabatic approximation, the solution for the fast oscillations can be found in terms of the slowly varying variables. Thus the rapidly oscillating terms in the slow oscillation equations can be treated as forced terms. We refer to the resonance between the forcing and intrinsic frequencies as a forced secondary one in this paper. We discuss the forced secondary resonances in asteroidal motion at the 3 : 1 commensurability by using Wisdom's method. The results show that the orbits situated originally near the resonance will leave the neighbourhood of resonance and tend to the separatrices and critical points for different energies, respectively. We have not found any stochastic web as expected in this case. Moreover, we study the problem of validity on the approximation of a system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00692100
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  • 5
    Electronic Resource
    Electronic Resource
    Realization of Silicon Nitride Template for Nanoimprint: A First Result (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 121-123 (Mar. 2007), p. 669-672 
    Details
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Notes: A first result of realization of silicon nitride templates on 100mm silicon wafer asnanoinprint mold using simple wet etching method is reported in this paper. The process is basedon traditional photolithograph and following buffer HF wet etching, which started from a p-typewafer with 400nm thermal silicon oxide, 200nm PECVD silicon nitride and 400nm PECVDsilicon oxide sandwich layer. After patterning with lithography, the patterned resist is used asmask for the isotropic underlayer wet etching of silicon dioxide with buffer HF solution. Usingthe obtained nanosacle silicon dioxide lines as RIE dry etching mask, silicon nitride template of100nm width with steep sidewalls is successfully realized
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/23/transtech_doi~10.4028%252Fwww.scientific.net%252FSSP.121-123.669.pdf
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  • 6
    Electronic Resource
    Electronic Resource
    Influence of Turning by Burnishing on Surface Integrity to Analyze Feasibility of Hybrid Process (2008)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 375-376 (Mar. 2008), p. 411-415 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Burnishing, an ultra-precision superficial plastic deformation process, is usedincreasingly as a surface enhancement finishing treatment after machining operations not only togive a mirror-like and work-hardened surface but also to impose favorable compressive residualstress in it. To analyze the feasibility of turning-burnishing hybrid process, the Taguchi’s L27(313)orthogonal array method with the analysis of variance (ANOVA) were used to analyze the influenceof the initial turning process on surface integrity of roller burnished AISI 1045 steel such as surfaceroughness, surface microhardness. three turning parameters, namely the cutting feed, cutting depthand cutting speed, three burnishing parameters, namely the burnishing feed, burnishing depth andburnishing speed were selected as the experimental factors in Taguchi’s design of experiments todetermine which one has the dominant influence and how it works on burnishing effects, namelythe surface roughness and surface microhardness, the interactions between cutting feed, burnishingfeed and burnishing depth were considered. The experimental results agreed well with thetheoretical analysis and the conclusion is cutting feed has dominant influence on burnished surfaceintegrity
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/57/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.375-376.411.pdf
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  • 7
    Electronic Resource
    Electronic Resource
    Synthesis of Glass Ceramic from Goldmine Tailings (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 336-338 (Apr. 2007), p. 1872-1873 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Glass ceramic was successfully synthesized using goldmine tailings as main raw material. Thefrit preparation and molding techniques, and the nucleation and crystallization processes were discussed.The results showed that only one crystalline phase, idiomorphic diopside, was formed in shapes of smallcolumns and grains. The optimum temperatures for melt, sintering, nucleation and crystallization were1350°C, 1160°C,[removed info]750°C,[removed info]and 860°C, respectively
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/53/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.336-338.1872.pdf
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  • 8
    Electronic Resource
    Electronic Resource
    Advanced Giant Magnetostrictive Alloys and Application in Actuators for Active Vibration Control (2007)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 546-549 (May 2007), p. 2143-2150 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Co and Si were selected as substitutes to improve performance of TbDyFe giantmagnetostrictive alloys for special purpose, respectively. The results showed that the Co-dopedTb0.36Dy0.64Fe2 alloys can possess giant magnetostriction over a wide temperature range from -80 to100 [removed info]. Optimum magnetostriction, high electrical resistivity and improved corrosion resistance wasobtained in Tb0.3Dy0.7(Fe1-xSix)1.95 system. High performance grain-aligned rods with 〈110〉 preferredorientation have been successfully prepared by zone melting unidirectional solidification. This paperalso presents the design and fabrication of Giant Magnetostrictive Actuator (GMA) for activevibration control with oriented TbDyFe rods. Experimental results showed that the GMA possessesgood static and dynamic performance. Excellent damping effect, 20-30 dB under the frequency rangefrom 10 Hz to 120 Hz was obtained
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/16/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.546-549.2143.pdf
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  • 9
    Electronic Resource
    Electronic Resource
    Numerical Computation of a Linear Friction Welding Process (2008)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 575-578 (Apr. 2008), p. 811-815 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Linear friction welding (LFW) has become a key manufacture and repair technology in theaeronautical engine manufacturing, especially in the blisk manufacturing. The kinematic equationduring LFW was built, based on which the friction heat in the whole process was computed. Withthermal- mechanical coupling technique, and considering the geometrical non-linearity, the materialproperty non-linearity and the interface frictional non-linearity, a Finite Element Model (FEM) oftemperature, stress and deformation fields were constructed. The distribution contour of temperature,plastic flow, stress and strain during LFW were plotted. The simulated temperature and axialshortening results were also validated by experimental data
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/18/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.575-578.811.pdf
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  • 10
    Electronic Resource
    Electronic Resource
    Giant Magnetostrictive Actuator and Its Application in Active Vibration Control (2005)
    s.l. ; Stafa-Zurich, Switzerland
    Materials science forum Vol. 475-479 (Jan. 2005), p. 2089-2094 
    Details
    ISSN: 1662-9752
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: TbDyFe is a rare earth-iron magnetostrictive alloy with “giant” magnetostrain, good magnetomechanical coupling factor and fast response. Giant magnetostrictive actuators (GMAs) are designed and fabricated with home-made TbDyFe rods. Their magnetostrain properties under varied operation are tested. The static output displacement up to 100μm and output force up to 1500N were obtained. The dynamic displacement increases with amplitude under fixed frequency and decreases with frequency under fixed amplitude generally. The maximum dynamic output displacement of 146µm was obtained at natural frequency around 5Hz. Active vibration control employing GMA was implemented in the flexible structure. The excellent damping effect, 20-30 dB under the frequency range from 10Hz to 100Hz was obtained. The dynamic phase delay of GMA has been analyzed. Anovel improved FSLMS algorithm is proposed to achieve a better control performance
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/02/09/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.475-479.2089.pdf
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