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91.
杨力平 《应用数学学报(英文版)》1994,10(3):233-251
FREEBOUNDARYPROBLEMARISINGFROMEVAPORATIONFROMPOROUSMEDIUMYANGLIPING(杨力平)(DepartmentofAppliedMathematics,TsinghuaUniversity,Be... 相似文献
92.
In this paper, a model of translation gateway is proposed. The communications between IPv4 network and IPv6 network are realized by using the Microsoft intermediate driver technology in environment of Windows 2000. 相似文献
93.
In a previous paper we considered an extension of the hard hexagon model to a solvable two-dimensional lattice gas with at most two particles per pair of adjacent sites. Here we use various mathematical identities (in particular Gordon's generalization of the Rogers-Ramanujan relations) to express the local densities in terms of elliptic functions. The critical behavior is then readily obtained.Supported in part by the National Science Foundation Grant MCS 8201733. 相似文献
94.
在正常金属铁磁绝缘层dx2-y2 idxy混合波超导隧道结中,考虑到铁磁绝缘层的磁散射和界面的粗糙散射效应,运用BogoliubovdeGennes(BdG)方程和BlonderTinkhamKlapwijk(BTK)理论,计算了隧道结中的准粒子传输系数和微分电导.研究表明:(1)磁散射和界面粗糙散射均可以压低电导峰,其中磁散射能使电导峰滑移,而粗糙界面散射却能阻止这种滑移,且两散射的共同作用可抑制由混合波两序参数的幅值比不同所导致的电导峰滑移;(2)随铁磁层离超导表面距离的增加,隧道谱在零偏压处由凹陷变成了零偏压电导峰,继而又演化为凹陷中的中心峰;(3)当铁磁层离开超导表面有若干相干长度时,隧道谱中将呈现一些子能级谐振峰. 相似文献
95.
Cynthia Kolb Whitney 《Foundations of Physics》2007,37(4-5):788-812
This paper revisits the historical sequence in which some of the major developments of 20th-century physics occurred, and
explores how theories could have turned out differently, if the sequence of developments had been different. It shows how
a delay in founding special relativity theory until after (1) at least one puzzling problem in electromagnetic theory could
be acknowledged, and (2) sat least some of the experimental observations pertinent to the development of quantum mechanics
had become well known, could have resulted in a larger theory that covers both domains in a manner quite different from that
of any of the theories we use today. The revised theory dispenses with a separate postulate introducing Planck’s constant
h, identifying instead a physical mechanism that implies the constant. Some important aspects of quantum chemistry then follow.
Editor, Galilean Electrodynamics, Proceedings of the Natural Philosophy Alliance; Visiting Industry Professor, Tufts University,
retired 相似文献
96.
The standard view of mechanical adhesive contact is as a competition between a reduction in free energy when surfaces with bonding potential come into contact and an increase in free energy due to elastic deformation that is required to make these surfaces conform. An equilibrium state is defined by an incremental balance between these effects, akin to the Griffith crack growth criterion. In the case of adhesion of biological cells, the molecules that tend to form surface-to-surface bonds are confined to the cell wall but they are mobile within the wall, adding a new phenomenon of direct relevance to adhesive contact. In this article, the process of adhesive contact of an initially curved elastic plate to a flat surface is studied for the case in which the binders that account for adhesion are able to migrate within the plate. This is done by including entropic free energy of the binder distribution in the total free energy of the system. By adopting a constitutive assumption that binders migrate at a speed proportional to the local gradient in chemical potential, the transient growth of an adhesion zone due to binder transport is analyzed. For the case of a plate of very large extent, the problem can be solved in closed form, whereas numerical methods are invoked for the case of a plate of limited extent. Results are presented on the rate of growth of an adhesion zone in terms of system parameters, on the evolution of the distribution of binders and, in the case of a plate of limited extent, on the long-term limiting size of the adhesion zone. 相似文献
97.
M. Reuhl P. Nielaba K. Binder 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(2):225-232
,Static and dynamic properties of the Potts model on the simple cubic lattice with nearest neighbor -interaction are obtained from Monte Carlo simulations in a temperature range where full thermal equilibrium still can be
achieved (). For a lattice size L
= 16, in this range finite size effects are still negligible, but the data for the spin glass susceptibility agree with previous
extrapolations based on finite size scaling of very small lattices. While the static properties are compatible with a zero
temperature transition, they certainly do not prove it. Unlike the Ising spin glass, the decay of the time-dependent order
parameter is compatible with a simple Kohlrausch function, , while a power law prefactor cannot be distinguished. The Kohlrausch exponent y
(
T
) decreases from at [0pt] to at [0pt] however. The relaxation time is compatible with the exponential divergence postulated by McMillan for spin glasses at their lower critical dimension,
but the exponent that can be extracted still differs significantly from the theoretical value, . Thus the present results support the conclusion that the Potts spin glass in d
= 3 dimensions differs qualitatively from the Ising spin glass.
Received: 8 October 1997 / Accepted: 27 November 1997 相似文献
98.
A new and rather trivial model is suggested with mechanism that implies simultaneous violation of the zeroth and the second
laws of thermodynamics. Mathematically rigorous quantum theory reduces to a trivial application of the Golden rule formula.
It yields exciton on-energy-shell diffusion caused by bath-nonassisted excitation hopping between tails of different exciton
site levels ε1 < ε2 broadened by bath-assisted finite life-time effects. The elastic character of the hopping implies 1 ↔ 2-symmetric transfer
rate W. Thus the net diffusion exciton flow W(P
1 - P
2) and also, as argued, the net energy flow are possible due to different near-to-equilibrium exciton populations P
1 > P
2. As the sites are provided with two different baths, the population imbalance and the flows survive even for slightly different
local bath temperatures T
1 < T
2 < T
1ε2/ε1. Thus spontaneous exciton and also energy flows against temperature step become possible, in contradiction with the Clausius
form of the second law. Violations of both the laws disappear in the high-temperature, i.e. classical limit
Received 16 May 2001 and Received in final form 20 September 2001 相似文献
99.
James B. Hartle 《International Journal of Theoretical Physics》2006,45(8):1390-1396
Familiar quantum mechanics assumes a fixed spacetime geometry. Quantummechanics must therefore be generalized for quantum gravity where spacetime geometry is not fixed but rather a quantum variable. This extended abstract sketches a fully fourdimensional generalized quantum mechnics of cosmological spacetime geometries that is one such generalization.This contribution to the proceedings of the Glafka Conference is an extended abstract of the author's talk there. More details can be found in the references cited at the end of the abstract expecially (Hartle, 1995). 相似文献
100.
A numerical technique is developed for the simulation of free surface flows and interfaces. This technique combines the strength on the finite element method (FEM) in calculating the field variables for a deforming boundary and the versatility of the volume-of-fluid (VOF) technique in advection of the fluid interfaces. The advantage of the VOF technique is that it allows the simulation of interfaces with large deformations, including surface merging and breaking. However, its disadantage is that is solving the flow equations, it cannot resolve interfaces smaller than the cell size, since information on the subgrid scale is lost. Therefore the accuracy of the interface reconstruction and the treatment of the boundary conditions (i.e. viscous stresses and surface tension forces) become grid-size-dependent. On the other hand, the FEM with deforming interface mesh allows accurate implementation of the boundary conditions, but it cannot handle large surface deformations occurring in breaking and merging of liquid regions. Combining the two methods into a hybrid FEM-VOF method eliminates the major shortcomings of both. The outcome is a technique which can handle large surface deformations with accurate treatment of the boundary conditions. For illustration, two computational examples are presented, namely the instability and break-up of a capillary jet and the coalescence collision of two liquid drops. 相似文献