非线性中立抛物型偏微分方程系统的振动性定理

研究一类非线性中立抛物型时滞偏微分方程系统解的振动性质,利用积分不等式和泛函微分方程的某些结果,获得了该类系统在第一类边值条件下所有解振动的若干充分条件.结论充分表明振动是由时滞量引起的.     

具高阶Laplace算子的非线性脉冲时滞双曲型方程的振动性

研究一类具高阶Laplace算子的非线性脉冲时滞双曲型偏泛函微分方程,利用二阶脉冲时滞微分不等式,得到了该类方程在两类不同边值条件下所有有界解振动的若干充分判据.     

非线性中立抛物型时滞偏微分方程解的振动性质

讨论一类多滞量非线性中立抛物型时滞偏微分方程解的振动性质 ,应用积分不等式和泛函微分方程的某些结果 ,在第一类边界条件下获得了其一切解振动的一系列充分条件 .结论充分表明了时滞量的决定性作用 ,指出了其与普通抛物型偏微分方程质的差异 .     

具高阶Laplace算子的非线性脉冲时滞双曲型方程的振动判据

研究一类具高阶Laplace算子的非线性脉冲时滞双曲型偏微分方程的振动性,利用特征函数法和一阶脉冲时滞微分不等式,获得了该类方程在两类不同边值条件下所有解振动的若干充分性判据.所得结论充分反映了脉冲和时滞在振动中的影响作用.     

非线性中立双曲型时滞偏微分方程解的振动性质

讨论一类多滞量非线性中立双曲型时滞偏微分方程解的振动性质,应用积分不等式和泛函微分方程的某些结果,获得了其一切解振动的一系列充分条件。结论充分表明了时滞量的决定性作用,指出了其与普通双曲型偏微分方程质的差异。     

非线性中立双曲型时滞微分方程解的振动判据

讨论一类多滞量非线性中立双曲型时滞微分方程的振动性质，获得了其一切解振动的充分条件。     

脉冲时滞抛物型偏微分方程组解的振动性

研究一类脉冲时滞抛物型偏微分方程组解的振动性,利用一阶脉冲时滞微分不等式获得了该类方程组在两类不同边值条件下所有解振动的若干充分条件.所得结果充分反映了脉冲和时滞在振动中的影响作用.     

一类非线性脉冲中立抛物型分布参数系统的振动条件

研究一类带中立项及高阶Laplace算子的非线性脉冲抛物型分布参数系统在第一类边值条件下的振动性问题,利用处理中立项及高阶Laplace算子的技巧和积分平均方法,建立了该类系统所有解振动的若干新的充分性条件.所得结论充分表明系统振动是由脉冲量和时滞量引起的.     

脉冲时滞抛物型偏微分方程组的振动性定理

本文研究了一类脉冲时滞抛物型偏微分方程组的振动性, 利用一阶脉冲时滞微分不等式, 获得了该类方程组在两类不同边值条件下所有解振动的若干充分性判据. 它反映了脉冲和时滞在振动中的影响作用.     

带脉冲和时滞影响的非线性双曲型方程振动性的新准则

考虑一类具非线性扩散项的脉冲时滞双曲型偏微分方程的振动性,借助一阶脉冲时滞微分不等式,获得了该类方程在Dirichlet边值条件下所有解振动的若干充分判据.     

具有连续偏差变元的非线性双曲方程的振动准则(英文)

讨论了一类双曲偏泛函微分方程边值问题,给出了在两类边值条件下解振动的充分条件。     

Oscillations of higher order differential equations of neutral type

In this paper, sufficient conditions have been obtained for oscillation of solutions of a class of nth order linear neutral delay-differential equations. Some of these results have been used to study oscillatory behaviour of solutions of a class of boundary value problems for neutral hyperbolic partial differential equations.     

非线性二阶时滞微分不等式的性质及其应用

本文研究一类非线性二阶时滞微分不等式解的性质。应用这些性质,建立了一类含时滞的双曲偏微分方程边值问题解的若干新的振动准则。     

On the solution of an initial‐boundary value problem that combines Neumann and integral condition for the wave equation

Numerical solution of hyperbolic partial differential equation with an integral condition continues to be a major research area with widespread applications in modern physics and technology. Many physical phenomena are modeled by nonclassical hyperbolic boundary value problems with nonlocal boundary conditions. In place of the classical specification of boundary data, we impose a nonlocal boundary condition. Partial differential equations with nonlocal boundary specifications have received much attention in last 20 years. However, most of the articles were directed to the second‐order parabolic equation, particularly to heat conduction equation. We will deal here with new type of nonlocal boundary value problem that is the solution of hyperbolic partial differential equations with nonlocal boundary specifications. These nonlocal conditions arise mainly when the data on the boundary can not be measured directly. Several finite difference methods have been proposed for the numerical solution of this one‐dimensional nonclassic boundary value problem. These computational techniques are compared using the largest error terms in the resulting modified equivalent partial differential equation. Numerical results supporting theoretical expectations are given. Restrictions on using higher order computational techniques for the studied problem are discussed. Suitable references on various physical applications and the theoretical aspects of solutions are introduced at the end of this article. © 2004 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005     

一类时滞双曲方程的振动准则

本文考虑一类滞量为连续分布型的双曲偏泛函微分方程解的振动性质，给出了这类方程在三类边值条件下解的振动准则．     

Approximation of pseudodifferential operators in absorbing boundary conditions for hyperbolic equations

Summary Engquist and Majda [3] proposed a pseudodifferential operator as asymptotically valid absorbing boundary condition for hyperbolic equations. (In the case of the wave equation this boundary condition is valid at all frequencies.) Here, least-squares approximation of the symbol of the pseudodifferential operator is proposed to obtain differential operators as boundary conditions. It is shown that for the wave equation this approach leads to Kreiss well-posed initial boundary value problems and that the expectation of the reflected energy is lower than in the case of Taylor- and Padé-approximations [3, 4]. Numerical examples indicate that this method works even more effectively for hyperbolic systems. The least-squares approach may be used to generate the boundary conditions automatically.     

On the combination of some semi‐discretization methods and boundary integral equations for the numerical solution of initial boundary value problems

We consider initial boundary value problems for the homogeneous differential equation of hyperbolic or parabolic type in the unbounded two‐ or three‐dimensional spatial domain with the homogeneous initial conditions and with Dirichlet or Neumann boundary condition. The numerical solution is realized in two steps. At first using the Laguerre transformation or Rothe's method with respect to the time variable the non‐stationary problem is reduced to the sequence of boundary value problems for the non‐homogeneous Helmholtz equation. Further we construct the special integral representation for solutions and obtain the sequence of boundary integral equations (without volume integrals). For the full‐discretization of integral equations we propose some projection methods.     

Generalization of a Relaxation Scheme for Systems of Forced Nonlinear Hyperbolic Conservation Laws with Spatially Dependent Flux Functions

A generalization of a finite difference method for calculating numerical solutions to systems of nonlinear hyperbolic conservation laws in one spatial variable is investigated. A previously developed numerical technique called the relaxation method is modified from its initial application to solve initial value problems for systems of nonlinear hyperbolic conservation laws. The relaxation method is generalized in three ways herein to include problems involving any combination of the following factors: systems of nonlinear hyperbolic conservation laws with spatially dependent flux functions, nonzero forcing terms, and correctly posed boundary values. An initial value problem for the forced inviscid Burgers' equation is used as an example to show excellent agreement between theoretical solutions and numerical calculations. An initial boundary value problem consisting of a system of four partial differential equations based on the two-layer shallow-water equations is solved numerically to display a more general applicability of the method than was previously known.     

含连续滞量和阻尼项的非线性双曲偏微分方程组的振动性

研究了一类含连续分布滞量和阻尼项的非线性双曲型偏微分方程组运用黎卡提变换获得了该方程组在两类边值条件下解振动的充分条件.