Borel的一个定理的一个应用——纪念刘书琴先生逝世一周年

在这篇论文中,研究了一般形式的代数微分方程的亚纯解的增长性并得到一些结果,研究的方法是根据一个关于亚纯函数组的定理。这个定理是Borel的一个关于整函数组的定理的一个推广。     

Borel的一个定理的一个应用

在这篇论文中，研究了一般形式的代数微分方程的亚纯解的增长性并得到一些结果，研究的方法是根据一个关于亚纯函数组的定理。这个定理是Ｂｏｒｅｌ的一个关于整函数组的定理的一个推广。     

涉及复微分方程(组)解的多项式的零点问题

本文主要利用最大模原理,讨论一类复微分方程和一类复微分方程组在存在超越亚纯解时,涉及该类复微分方程或复微分方程组解的多项式的零点问题,得到两个结果,其中复微分方程组的讨论是推广了复微分方程的结论.     

复域内一般微分方程组的非允许解

在文［８］中,我们已给出了复域内微分方程组的ｍ分量－允许解之定义,在本文里,我们类似给出复域内微分方程组的ｍ分量－非允许解之定义并讨论了更广泛的复域内微分方程组的这种解的存在性,得到了一些结果。     

Cn 中一类复高阶偏微分方程组的允许解

本文研究了多复变中一类复高阶偏微分方程组的允许解的存在性问题,利用多复变值分布理论和技巧,获得一类复高阶偏微分方程组在给定条件下,其允许解的性质.并将单复微分方程组中的一些结果推广到多复变中.     

具有允许解的代数微分方程组的形式

本文以不同于以往研究复微分方程组的方法,讨论了一类具有允许解的代数微分方程组的形式,得到了一个主要结果。     

一类非线性微分方程解的有界性

本文从探讨与函数密切相关的定性函数入手，研究了微分方程组解的有界性质，并由此给出某些高阶及２阶非线性微分方程解的有界性的一些结论，它们包合并推广了［３～８］的有关结果     

非线性Volterra积分微分方程组的扰动定理

本文讨论非线性Volterra积分微分方程组的解在经常作用干扰之下的渐近性质,所获结果包含和推广了Brauer-Strauss,Pachpatte以及,Brauer关于常微分方程组的已知扰动定理。     

正对称型偏微分方程组的可微分解

<正> 正对称型偏微分方程组的系统理论是 K.O.Friedrichs 在1958年的论文中建立的.这是一项具有相当普遍性的理论,大量的古典的偏微分方程的问题,如二阶双曲型方程的柯西问题和混合问题,自共轭椭圆型方程和某些抛物型方程的各项标准边界问题,混合     

关于微分方程组解的m-非允许分量

在本文里，我们给出了微分方程组解的非允许分量之定义，探讨了一类微分方程组解的m-非允许分量的存在性问题，得到了几个结果。它是文[9]的进—步讨论．     

A research into the numerical method of Dirichlet's problem of complex Monge-Ampère equation on Cartan-Hartogs domain of the third type

Monge-Ampère equation is a nonlinear equation with high degree, therefore its numerical solution is very important and very difficult. In present paper the numerical method of Dirichlet's problem of Monge-Ampère equation on Cartan-Hartogs domain of the third type is discussed by using the analytic method. Firstly, the Monge-Ampère equation is reduced to the nonlinear ordinary differential equation, then the numerical method of the Dirichlet problem of Monge-Ampère equation becomes the numerical method of two point boundary value problem of the nonlinear ordinary differential equation. Secondly, the solution of the Dirichlet problem is given in explicit formula under the special case, which can be used to check the numerical solution of the Dirichlet problem.     

A method of solving a nonlinear boundary value problem with a parameter for a loaded differential equation

A nonlinear loaded differential equation with a parameter on a finite interval is studied. The interval is partitioned by the load points, at which the values of the solution to the equation are set as additional parameters. A nonlinear boundary value problem for the considered equation is reduced to a nonlinear multipoint boundary value problem for the system of nonlinear ordinary differential equations with parameters. For fixed parameters, we obtain the Cauchy problems for ordinary differential equations on the subintervals. Substituting the values of the solutions to these problems into the boundary condition and continuity conditions at the partition points, we compose a system of nonlinear algebraic equations in parameters. A method of solving the boundary value problem with a parameter is proposed. The method is based on finding the solution to the system of nonlinear algebraic equations composed.     

带色散项的高阶非线性Schrdinger方程的精确解

对一类带色散项的高阶非线性Schrdinger方程的精确解进行研究.通过行波约化,将一类带色散项的高阶非线性Schrdinger方程化为一个高阶非线性常微分方程.再借助于计算机代数系统Mathematica通过构造非线性常微分方程的精确解,成功获得了一系列含有多个参数的包络型精确解,当精确解中参数取特殊值时可以得到两种新型的复合孤子解.并讨论了这两种孤子解存在的参数条件.     

Exact Solutions and Integrability of the Duffing – Van der Pol Equation

The force-free Duffing–Van der Pol oscillator is considered. The truncated expansions for finding the solutions are used to look for exact solutions of this nonlinear ordinary differential equation. Conditions on parameter values of the equation are found to have the linearization of the Duffing–Van der Pol equation. The Painlevé test for this equation is used to study the integrability of the model. Exact solutions of this differential equation are found. In the special case the approach is simplified to demonstrate that some well-known methods can be used for finding exact solutions of nonlinear differential equations. The first integral of the Duffing–Van der Pol equation is found and the general solution of the equation is given in the special case for parameters of the equation. We also demonstrate the efficiency of the method for finding the first integral and the general solution for one of nonlinear second-order ordinary differential equations.     

The Sinc-collocation method for solving the Thomas–Fermi equation

A numerical technique for solving nonlinear ordinary differential equations on a semi-infinite interval is presented. We solve the Thomas–Fermi equation by the Sinc-Collocation method that converges to the solution at an exponential rate. This method is utilized to reduce the nonlinear ordinary differential equation to some algebraic equations. This method is easy to implement and yields very accurate results.     

微分特征列法在拟微分算子和Lax表示中的应用

微分特征列法用于拟微分算子和非线性发展方程Lax表示的计算.首先,利用微分特征列法和微分带余除法计算拟微分算子的逆和方根,由于不必求解常微分方程组,并将解代入,因此,使得计算得以简化.其次,利用微分特征列法,约化从广义Lax方程和Zakharov-Shabat推出的非线性偏微分方程,并得到相应的非线性发展方程.在Mathematica计算机代数系统上,编写了相关程序,从而可以利用计算机辅助完成一些非线性发展方程Lax表示的计算.     

F-展开法的扩展及应用

对F-展开法中的辅助常微分方程进行了改进,并利用改进后的常微分方程的解求得了一些重要的非线性发展方程(组)的新的Jacobi椭圆函数解,从而得到了新的孤波解.     

Symmetries and Large Time Asymptotics of Compressible Euler Flows with Damping

Large time asymptotics of compressible Euler equations for a polytropic gas with and without the porous media equation are constructed in which the Barenblatt solution is embedded. Invariance analysis for these governing equations are carried out using the classical and the direct methods. A new second order nonlinear partial differential equation is derived and is shown to reduce to an Euler–Painlevé equation. A regular perturbation solution of a reduced ordinary differential equation is determined. And an exact closed form solution of a system of ordinary differential equations is derived using the invariance analysis.     

An observation on the periodic solutions to nonlinear physical models by means of the auxiliary equation with a sixth-degree nonlinear term

It is a fact that in auxiliary equation methods, the exact solutions of different types of auxiliary equations may produce new types of exact travelling wave solutions to nonlinear equations. In this manner, various auxiliary equations of first-order nonlinear ordinary differential equation with distinct-degree nonlinear terms are examined and, by means of symbolic computation, the new solutions of original auxiliary equation of first-order nonlinear ordinary differential equation with sixth-degree nonlinear term are presented. Consequently, the novel exact solutions of the generalized Klein–Gordon equation and the active-dissipative dispersive media equation are found out for illustration purposes. They are also applicable, where conventional perturbation method fails to provide any solution of the nonlinear problems under study.     

Stability in the almost everywhere sense: A linear transfer operator approach

The problem of almost everywhere stability of a nonlinear autonomous ordinary differential equation is studied using a linear transfer operator framework. The infinitesimal generator of a linear transfer operator (Perron-Frobenius) is used to provide stability conditions of an autonomous ordinary differential equation. It is shown that almost everywhere uniform stability of a nonlinear differential equation, is equivalent to the existence of a non-negative solution for a steady state advection type linear partial differential equation. We refer to this non-negative solution, verifying almost everywhere global stability, as Lyapunov density. A numerical method using finite element techniques is used for the computation of Lyapunov density.