一类具有无穷时滞中立型非稠定脉冲随机泛函微分方程积分解的存在性

本文讨论了一类具有无穷时滞中立型非稠定脉冲随机泛函微分方程,利用Sadovskii不动点原理等工具得到了其积分解的存在性,给出其在一类二阶无穷时滞中立型非稠定脉冲随机偏微分方程积分解的存在性中的应用.     

OSCILLATIONS OF SECOND ORDER DIFFERENTIAL EQUATIONS WITH IMPULSES

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｐａｐｅｒ，ｗｅｃｏｎｓｉｄｅｒｔｈｅｓｅｃｏｎｄ－ｏｒｄｅｒｄｉｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｓｗｉｔｈｉｍｐｕｌｓｅｓａｓ（ｒ（ｔ）ｘ′）′＋ｆ（ｔ，ｘ）＝０，ｔ≥ｔ０，ｔ≠０，ｋ＝１，２，…，ｘ（ｔ＋ｋ）...     

二阶时滞微分方程非振动性质在脉冲扰动下的不变性

本文建立了一类二阶脉冲时滞微分方程解的一个整体存在唯一性定理,并讨论了脉冲扰动对脉冲线性时滞微分程非振动性质的影响,获得了脉冲扰动对时滞微分方程非振动性质没有影响的一般性脉冲条件,推广了最近某些文献中的结论.     

On SPDEs with Variable Coefficients in One Space Dimension

Stochastic second-order partial differential equations of evolution type are considered in one space dimension. Existence and uniqueness results are given in weighted Sobolev spaces of functions given on an interval in the space variable.     

Asymptotic behavior of solutions of second-order nonlinear impulsive differential equations

In this work, the asymptotic behavior of all solutions of second-order nonlinear ordinary differential equations with impulses is investigated. By impulsive differential inequality and Riccati transformation, sufficient conditions of asymptotic behavior of all solutions of second-order nonlinear ordinary differential equations with impulses are obtained. An example is also inserted to illustrate the impulsive effect.     

二阶微分方程的逆特征值问题

运用渐近分析的方法及Rayleigh商原理,将Sturm-Liouville问题的Ambarzumyan定理推广到具有Neumann边界条件或拟周期边界条件的二阶微分方程情形.同时,获得了二阶向量微分方程的有关Ambarzumyan型结果.     

二阶微分方程的逆特征值问题

运用渐近分析的方法及Rayleigh商原理,将Sturm-Liouville问题的Ambarzumyan定理推广到具有Neumann边界条件或拟周期边界条件的二阶微分方程情形.同时,获得了二阶向量微分方程的有关Ambarzumyan型结果.     

非线性泛函微分方程解的性态

本文给出了一类非线性泛函微分方程解的性态的若干充要条件,推广了[1]的某些结论.     

第二类Painlevé方程解的亚纯性

Painlevé方程是六类重要的二阶代数微分方程,它们的发展和性质一直受到人们的关注.本文给出第二类Painlevé方程解的亚纯性一个严格的证明.     

二阶非线性脉冲积分-微分方程初值问题的解

该文利用单调迭代技术讨论了Banach空间中含有非线性一阶微分项x'的二阶脉冲积分-微分方程初值问题的最大最小解的存在性问题. 作为该文主要结论的应用,作者给出了一个例子.     

用观察法求二阶变系数齐线性方程的非零特解

主要用观察法求二阶变系数齐线性方程的非零特解.首先推广了欧拉方程和另外一个关于求非零特解的结论,其次在已有结果的情形外增添一些可用观察法求特解的情形.     

“一类拟线性二阶微分方程解的振动与非振动的判定”的注记

本文给出了一类拟线性二阶微分方程解振动与非振动的新的判定准则,完善和改进了最近一些文献中的某些结论。     

Oscillation and Nonoscillation Criteria for Second-Order Linear Differential Equations

Sufficient conditions for oscillation and nonoscillation of second-order linear equations are established.     

DOMAIN DECOMPOSITION PRECONDITIONERS FOR SECOND-ORDER HYPERBOLIC EQUATIONS ON L-SHAPED REGIONS

Linear systems arising from implicit time discretizations and finite difference space discretizations of second-order hyperbolic equations on L-shaped region are considered. We analyse the use of domain deocmposilion preconditioner.s for the solution of linear systems via the preconditioned conjugate gradient method. For the constant-coefficient second-order hyperbolic equaions with initial and Dirichlet boundary conditions,we prove that the conditionnumber of the preconditioned interface system is bounded by 2+x2 2+0.46x2 where x is the quo-tient between the lime and space steps. Such condition number produces a convergence rale that is independent of gridsize and aspect ratios. The results could be extended to parabolic equations.     

DIRICHLET PROBLEM FOR THE IMPLICIT OBSTACLE PROBLEMS

In this paper the implicit obstac|e problem of fully nonlinear second-order elliptic equations associated with impulsive control problem are investigated. The comparlon principle for viscosity solutions is proved,the existence and uniqueness results are disscussed.     

Compact difference scheme for two-dimensional fourth-order nonlinear hyperbolic equation

High-order compact finite difference method for solving the two-dimensional fourth-order nonlinear hyperbolic equation is considered in this article. In order to design an implicit compact finite difference scheme, the fourth-order equation is written as a system of two second-order equations by introducing the second-order spatial derivative as a new variable. The second-order spatial derivatives are approximated by the compact finite difference operators to obtain a fourth-order convergence. As well as, the second-order time derivative is approximated by the central difference method. Then, existence and uniqueness of numerical solution is given. The stability and convergence of the compact finite difference scheme are proved by the energy method. Numerical results are provided to verify the accuracy and efficiency of this scheme.     

Fite–Hille–Wintner-type oscillation criteria for second-order half-linear dynamic equations with deviating arguments

We study oscillatory behavior of solutions to a class of second-order half-linear dynamic equations with deviating arguments under the assumptions that allow applications to dynamic equations with delayed and advanced arguments. Several improved Fite–Hille–Wintner-type criteria are obtained that do not need some restrictive assumptions required in related results. Illustrative examples and conclusions are presented to show that these criteria are sharp for differential equations and provide sharper estimates for oscillation of corresponding $q$-difference equations.     

三维与二维晶体生长控制方程的精确解

本文通过将未知函数展开成复数形式的Fourier级数,求出了一类二阶偏微分方程的三角级数形式的解析解,并严格证明了其收敛性．三维稳态与二维稳态和二维非稳态晶体生长控制方程都是这类二阶偏微分方程特例．利用这一特点,本文求出了三维稳态与二维稳态和二维非稳态晶体生长控制方程的解析解．理论结果有助于揭示稳态晶体生长的本质特性．本文还给出了三维非稳态晶体生长控制方程的解析解．     

Invariant Lagrangians and a new method of integration of nonlinear equations

A method for solving the inverse variational problem for differential equations admitting a Lie group is presented. The method is used for determining invariant Lagrangians and integration of second-order nonlinear differential equations admitting two-dimensional noncommutative Lie algebras. The method of integration suggested here is quite different from Lie's classical method of integration of second-order ordinary differential equations based on canonical forms of two-dimensional Lie algebras. The new method reveals existence and significance of one-parameter families of singular solutions to nonlinear equations of second order.