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991.
992.
We investigate the long-time behavior of solutions to the classical mean-field model for coarsening by Lifshitz–Slyozov and Wagner (LSW). In the original work (Lifshitz and Slyozov, 1961; Wagner 1961) convergence of solutions to a uniquely determined self-similar solution was predicted. However, it is by now well known (Giron et al., 1998; Niethammer and Pego 1999 2001) that the long-time behavior of solutions depends sensitively on the initial data. In Niethammer and Pego (1999 2001) a necessary criterion for convergence to any self-similar solution which behaves like a finite power at the end of its (compact) support is given. It says that the data have to be regularly varying at the end of their support with the same power. This criterion is also shown to be sufficient if the power is sufficiently small and for data which are close to self-similar. In this article we extend the local stability result to the whole range of self-similar solutions with compact support. Our first main result establishes global stability of self-similar solutions with not too large power. The proof relies on a global contraction argument for the spreading of characteristics. In addition, we also establish upper and lower bounds for the coarsening rates of the system for a suitable class of initial data whose variation is bounded at the end of the support but not necessarily regular. 相似文献
993.
Kwangseok Choe 《偏微分方程通讯》2013,38(11):1465-1507
We study the asymptotic behavior for the condensate solutions of the self-dual Chern–Simons–Higgs equation as the Chern–Simons parameter tends to zero. By using these estimates, we establish existence results for solutions of non-topological type. 相似文献
994.
We investigate the large-time behavior of three types of initial-boundary value problems for Hamilton–Jacobi Equations with nonconvex Hamiltonians. We consider the Neumann or oblique boundary condition, the state constraint boundary condition and Dirichlet boundary condition. We establish general convergence results for viscosity solutions to asymptotic solutions as time goes to infinity via an approach based on PDE techniques. These results are obtained not only under general conditions on the Hamiltonians but also under weak conditions on the domain and the oblique direction of reflection in the Neumann case. 相似文献
995.
996.
《偏微分方程通讯》2013,38(7-8):1385-1408
The purpose of this paper is to study the limit in L 1(Ω), as t → ∞, of solutions of initial-boundary-value problems of the form ut ? Δw = 0 and u ∈ β(w) in a bounded domain Ω with general boundary conditions ?w/?η + γ(w) ? 0. We prove that a solution stabilizes by converging as t → ∞ to a solution of the associated stationary problem. On the other hand, since in general these solutions are not unique, we characterize the true value of the limit and comment the results on the related concrete situations like the Stefan problem and the filtration equation. 相似文献
997.
Zhong-Zhong Jiang Shu-Cherng Fang Zhi-Ping Fan Dingwei Wang 《European Journal of Operational Research》2013
The advancement of Internet technology has enabled new formats for selling products in the B2C online auctions. At present, on the major online auction sites, there exist three popular selling formats, namely, the posted price, pure auction and buy-price auction formats. It is an important decision problem for a firm to select the most profitable format to sell its products through the Internet. The customer behavior is of course a crucial element of the decision process. To the best of our knowledge, most models available today assume that customers are perfectly rational. To better understand the decision process, in this paper, we incorporate the concept of bounded rationality into consideration. We first present a “behavior choice function” to characterize the behavior of the customers with bounded rationality. Then corresponding to each selling format, we construct a revenue model based on the bounded rationality for analysis. Finally, we conduct some elaborate computational experiments to investigate the performance of each revenue model for developing new managerial insights. Our computational results clearly demonstrate how the bounded rationality of customer behavior affects the choice of a preferable selling format for a B2C firm in an online auction. 相似文献
998.
Yeping Li 《Mathematical Methods in the Applied Sciences》2013,36(11):1409-1422
In this paper, we discuss a bipolar transient quantum hydrodynamic model for charge density, current density, and electric field in the quarter plane. This model takes the form of a classical Euler–Poisson system with the additional dispersion terms caused by the quantum (Bohn) potential. We show global existence of smooth solutions for the initial boundary value problem when the initial data are near the nonlinear diffusive waves, which are different from the steady state. We also show the asymptotical behavior of the global smooth solution towards the nonlinear diffusive waves and obtain the algebraic decay rates. These results are proved by elaborate energy methods. Finally, using the Fourier analysis, we obtain the optimal convergence rates of the solutions towards the nonlinear diffusion waves. As far as we known, this is the first result about the initial boundary value problem of the one‐dimensional bipolar quantum hydrodynamic model in the quarter plane. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
999.
青铜—石墨复合材料在干摩擦和水润滑下的摩擦磨损性能及磨损机理研究 总被引:17,自引:4,他引:17
对比考察了青铜 -石墨复合材料在水润滑和干摩擦两种状态下的摩擦磨损性能及磨损机理 .结果表明 :水润滑下青铜 -石墨复合材料的磨损率明显比干摩擦下的小 ,其最小磨损率为 1.0 1× 10 -6mm3 /N·m ,而摩擦系数比干摩擦下的大 ,复合材料在干摩擦下的磨损机理主要为粘着磨损、剥层磨损和犁削 ,磨损较严重 ;而在水润滑下 ,复合材料的磨损机理主要为磨粒磨损和疲劳磨损 ,磨损较小 .这是因为水有利于降低摩擦副接触表面的温度 ,有效地抑制了基体青铜的转移 ;同时水促进了不锈钢偶件的氧化 ,形成薄而致密氧化膜 ,从而降低了磨损 相似文献
1000.
Z. Kuntová Z. Chvoj M. C. Tringides M. Yakes 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,64(1):61-66
The growth of Pb islands on a Si(111) surface exhibits many interesting properties. For example, the self-assembled process
results in a homogeneous distribution of Pb islands with uniform height. The dependence of this height on coverage and temperature
can be expressed as a phase diagram [1]. In this paper we develop a model of the growth process that reflects the main features
of the experimental observations and determines the key processes of quantum dot formation in a Pb/Si(111) system. The growth
of islands is simulated by the Monte Carlo method. With suitably chosen parameters the model is able to reconstruct the phase
diagram, via the dependence of the dynamics of Pb atoms on area and height. These dependencies are attributed to stress energy
and quantum size effects. 相似文献