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141.
Interface equations are derived for both binary diffusive and binary fluid systems subjected to nonequilibrium conditions,
starting from coarse-grained (mesoscopic) models. The equations are used to describe thermocapillary motion of a droplet in
both purely diffusive and fluid cases, and the results are compared with numerical simulations. A mesoscopic chemical potential
shift owing to the temperature gradient, and associated mesoscopic corrections involved in droplet motion, are elucidated. 相似文献
142.
P. Chattopadhyay 《Applied Surface Science》2006,252(12):4055-4063
An energy distribution of interface states has been considered to study the electrical characteristics of an anisotype semiconductor heterojunction. Various electrical quantities such as the surface potential, current, conductance and ideality factor of the device have been studied. The current-voltage and conductance-voltage characteristics are found largely sensitive to the parameters controlling the distribution profile of interface states. A new expression for the ideality factor of the device has been derived, which predicts appreciable voltage dependence due to the distributive nature of the interface states. It has been found that the experimental I-V data of p-InP/n-CdS heterojunction reported by earlier workers can be satisfactorily explained with the help of the present model if the effect of shunt resistance of the device is included in the evaluation scheme. 相似文献
143.
Xiaofeng Ren 《Journal of Differential Equations》2005,209(2):266-301
We find nucleation solutions of N interfaces and K spikes to the one-dimensional FitzhHugh-Nagumo system. Each spike sits asymptotically in the middle between two interfaces. We use the Lyapunov-Schmidt reduction method, in which the problem is split into a finite-dimensional problem related to the translation of the K spikes and an infinite-dimensional complement problem. However the complement problem remains near degenerate due to the translation of the N interfaces. To overcome this difficulty we move the interfaces by a small distance and solve the complement problem with the help of a Newton iteration argument. 相似文献
144.
本文评述了各向同性和横向各向同性柱状分层固体声散射理论和实验研究进展介绍了描述圆柱状界面薄层特性的弹簧模型,也讨论了该领域中有待进一步研究的一些问题。 相似文献
145.
有机-无机复合质子交换膜的制备与界面特性 总被引:3,自引:0,他引:3
有机-无机复合质子交换膜的开发是燃料电池用质子交换膜的一个重要研究方向,本文综述了有机-无机复合质子交换膜的制备方法,分析了两相之间的界面特性,并对这种复合膜的研究前景进行了展望. 相似文献
146.
A finite element method for solution of the stream function formulation of Stokes flow is developed. The method involves complete cubic non-conforming (C0) triangular Hermite elements. This element fails the patch test. To correct the element and produce a convergent method we employ a penalty method to weakly enforce the desired continuity constraint on the normal derivative across the inter-element boundaries. Successful use of the method is demonstrated to require reduced integration of the inter-element penalty with a 1-point Gauss rule. Error estimates relate the optimal choice of penalty parameter to mesh size and are corroborated by numerical convergence studies. The need for reduced integration is interpreted using rank relations for an associated hybrid method. 相似文献
147.
A computationally efficient two-level iterative scheme is proposed for the solution of the interface problems with Lagrange multipliers, where the oscillatory part of the solution is resolved by means off smoothing using a new, efficient preconditioner whereas the smooth component of the solution is captured by the collocation-based problem on the auxilliary grid, that is solved directly using a sparse direct solver. A simple adaptive feature is built into the proposed solution method in order to guarantee convergence for ill-conditioned problems. Nmerical results presented for example problems including that of a Boeing crown panel show that the proposed tww-level solution technique outperfrmsnce the standard, single level iterative and direect solvers. 相似文献
148.
Y. J. Wang H. A. Nickel B. D. McCombe F. M. Peeters J. M. Shi G. Q. Hai X. -G. Wu T. J. Eustis W. Schaff 《Physica E: Low-dimensional Systems and Nanostructures》1998,2(1-4)
A detailed experimental study of electron cyclotron resonance (CR) has been carried out at 4.2 K in three modulation-doped GaAs/Al0.3Ga0.7As multiple quantum well samples in fields up to 30 T. A strong avoided-level-crossing splitting of the CR energies due to resonant magnetopolaron effects is observed for all samples near the GaAs reststrahlen region. Resonant splittings in the region of AlAs-like interface phonon modes of the barriers are observed in two samples with narrower well width and smaller doping concentration. The interaction between electrons and the AlAs interface optical phonon modes has been calculated for our specific sample structures in the framework of the memory-function formalism. The calculated results are in good agreement with the experimental results, which confirms our assignment of the observed splitting near the AlAs-like phonon region is due to the resonant magnetopolaron interaction of electrons in the wells with AlAs-like interface phonons. 相似文献
149.
Biofilms are complex microbial communities that are resistant to attack by bacteriophages and to removal by drugs and chemicals. Here we use atomic force microscopy (AFM) to image the attack on Escherichia coli biofilms by Bdellovibrio bacteriovorus 109J. Bdellovibrio is a small, predatory bacterium that invades and devours other Gram-negative bacteria. We demonstrate that under dilute nutrient conditions, bdellovibrios can prevent the formation of simple bacterial biofilms and destroy established biofilms; under richer conditions the prey bacteria persist and are not eradicated, but may be shifted toward solution populations. Using AFM we explore these bacterial interactions with more detail and accuracy than available by more traditional staining assays or optical microscopy. AFM also allows us to investigate the nanoscale morphological changes of the predator, especially those related to motility. This demonstration of Bdellovibrio's successful predation in a biofilm inspires us to consider ways that it might be used productively for industrial, medical, agricultural, and biodefensive purposes. 相似文献
150.
Heide Narnhofer 《Journal of statistical physics》1982,29(4):761-771
Under intuitively reasonable assumptions it is shown that in two dimensions different phases cannot exist locally. In three dimensions we discuss the possibility of local coexistence of districts with different magnetization for the Heisenberg ferromagnet and show that an interaction that breaks rotational invariance is necessary for this phenomenon. 相似文献