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排序方式: 共有1319条查询结果,搜索用时 31 毫秒
871.
Hans Engler 《Journal of Differential Equations》2002,185(1):348-369
For a class of scalar partial differential equations that incorporate convection, diffusion, and possibly dispersion in one space and one time dimension, the stability of traveling wave solutions is investigated. If the initial perturbation of the traveling wave profile decays at an algebraic rate, then the solution is shown to converge to a shifted wave profile at a corresponding temporal algebraic rate, and optimal intermediate results that combine temporal and spatial decay are obtained. The proofs are based on a general interpolation principle which says that algebraic decay results of this form always follow if exponential temporal decay holds for perturbation with exponential spatial decay and the wave profile is stable for general perturbations. 相似文献
872.
在扩展的Brueckner-Hartree-Fock理论框架内,研究了同位旋非对称核物质中质子和中子的平均自由程,着重讨论了其同位旋依赖性.结果表明:随核物质同位旋非对称度的增大,质子平均自由程减小而中子的平均自由程增大.这表明中子滴线附近的原子核表面对中子比对质子更具透明度.还简单讨论了基态关联效应对平均自由程的影响. 相似文献
873.
We give generalizations of extended Poincaré supergravity with arbitrarily many supersymmetries in the absence of central charges in three dimensions by gauging its intrinsic global SO(N) symmetry. We call these 0 (Aleph-null) supergravity theories. We further couple a non-Abelian supersymmetric Chern-Simons theory and an Abelian topological BF theory to 0 supergravity. Our result overcomes the previous difficulty for supersymmetrization of Chern-Simons theories beyond N = 4. This feature is peculiar to the Chern-Simons and BF theories including supergravity in three dimensions. We also show that dimensional reduction schemes for four-dimensional theories such as N = 1 self-dual supersymmetric Yang-Mills theory or N = 1 supergravity theory that can generate 0 globally and locally supersymmetric theories in three dimensions. As an interesting application, we present 0 supergravity Liouville theory in two dimensions after appropriate dimensional reduction from three dimensions. 相似文献
874.
SHEN Shou-Feng PAN Zu-Liang ZHANG Jun 《理论物理通讯》2004,42(10)
The variable separation approach method is very useful to solving (2 1 )-dimensional integrable systems. But the (1 1)-dimensional and (3 1 )-dimensional nonlinear systems are considered very little. In this letter, we extend this method to (1 1) dimensions by taking the Redekopp system as a simple example and (3 1)-dimensional Burgers system. The exact solutions are much general because they include some arbitrary functions and the form of the (3 1 )-dimensional universal formula obtained from many (2 1 )-dimensional systems is extended. 相似文献
875.
M. Hărăguş 《Journal of Nonlinear Science》1998,8(4):353-374
Summary. For a certain class of partial differential equations in cylindrical domains, we show that all small time-dependent solutions
are described by a reduced system of equations on the real line, which contains nonlocal terms. As an application, we investigate
the system describing nonlinear water waves travelling on the free surface of an inviscid fluid. Two-dimensional gravity waves
are characterized by the parameter λ , the inverse square of the Froude number. For λ close to the critical value λ
0
=1 , we obtain a reduced system of four nonlocal equations. We show that the terms of lowest order in μ=λ-1 lead to the Korteweg—de Vries equation for the lowest-order approximation of the free surface.
Received February 23, 1994; final revision received October 13, 1997; accepted for publication October 16, 1997. 相似文献
876.
Mohammad Masjed-Jamei 《Journal of Mathematical Analysis and Applications》2007,325(2):753-775
In this research, by applying the extended Sturm-Liouville theorem for symmetric functions, a basic class of symmetric orthogonal polynomials (BCSOP) with four free parameters is introduced and all its standard properties, such as a generic second order differential equation along with its explicit polynomial solution, a generic orthogonality relation, a generic three term recurrence relation and so on, are presented. Then, it is shown that four main sequences of symmetric orthogonal polynomials can essentially be extracted from the introduced class. They are respectively the generalized ultraspherical polynomials, generalized Hermite polynomials and two other sequences of symmetric polynomials, which are finitely orthogonal on (−∞,∞) and can be expressed in terms of the mentioned class directly. In this way, two half-trigonometric sequences of orthogonal polynomials, as special sub-cases of BCSOP, are also introduced. 相似文献
877.
许晓革 《数学的实践与认识》2005,35(1):156-159
利用非线性发展方程的变系数均衡作用法 ,借助计算机符号计算 ,求出变系数 Burgers方程的一种形式的解析解 . 相似文献
878.
Ch. Srinivasa Rao P. L. Sachdev Mythily Ramaswamy 《Nonlinear Analysis: Real World Applications》2003,4(5):723-741
The nonlinear ordinary differential equation resulting from the self-similar reduction of a generalized Burgers equation with nonlinear damping is studied in some detail. Assuming certain asymptotic conditions at plus infinity or minus infinity, we find a wide variety of solutions—(positive) single hump, monotonic (bounded or unbounded) or solutions with a finite zero. The existence or non-existence of positive bounded solutions with exponential decay to zero at infinity for specific parameter ranges is proved. The analysis relies mainly on the shooting argument. 相似文献
879.
本文研究了一些拟线性Burgers型方程的波前解的存在性、稳定性,利用谱分析的方法,证明了光滑波前解在某些加权空间中的渐近稳定性。 相似文献
880.
Abstract. One-dimensional steady flows with heat conduction, treated by the 13-moment theory of extended thermodynamics are considered. The usual well-posed boundary conditions for the corresponding problems in the Navier-Stokes-Fourier (NSF) theory are insufficient to give unique solutions. In order to have unique physically sensible solutions, minimization of the deviation of iterative approximations from the exact solutions, proposed in [1], is used as a criterion. Moreover, the solutions are shown to be invariant with respect to change of consistent boundary conditions - a requirement abide by our physical intuition. In the problems of plane shearing flow and Couette flow, the minimization with respect to two uncontrollable parameters is involved. The examples are carried out numerically, and the results are compared with the classical results of NSF theory.Received: 16 August 2002, Accepted: 20 April 2003, Published online: 5 December 2003PACS:
83.20.Lr, 83.50.Ax
Correspondence to: I-S. Liu Dedicated to Professor Ingo Müller on the occasion of his 65th birthday 相似文献