同伦分析法求解Burgers方程的初边值问题

采用同伦分析法求解了Burgers方程的一初边值问题,得到了它的近似解析解.在不同粘性系数情形下,对近似解与精确解进行了比较,发现在粘性系数不是非常小的情况下,用此方法得到的解析解与精确解符合地很好.     

时滞脉冲微分方程三点边值问题解的存在性和唯一性

研究一类时滞与脉冲共存的微分方程三点边值问题,利用上下解与单调迭代方法获得了边值问题解的存在性定理和唯一性定理,给出求解该类问题解析近似解的迭代方法,得出了新的结论.     

一类非线性积分偏微分方程初边值问题的整体解

讨论初边值问题整体经典解的存在性．在P′（s）≥0,p′（s）─q′（s）|≤const．的条件下,用Galerkin方法证明了该问题整体经典解的存在唯一性．     

分数阶广义扰动热波方程的与泛函映射解

研究了一类分数阶广义非线性扰动热波方程.首先在典型分数阶热波方程情形下得到解,接着用泛函分析映射方法,求出了分数阶广义非线性扰动热波方程初始边值问题的任意次近似解析解.最后简述了它的物理意义.求得的近似解析解,弥补了单纯用数值方法得到的模拟解的不足.     

分数阶广义扰动热波方程

研究了一类分数阶广义非线性扰动热波方程.首先用奇异慑动方法,求出了分数阶广义非线性扰动热波方程初始边值问题的任意次近似解析解.然后利用泛函分析不动点定理证明了它的一致有效性,最后简述了它的物理意义.求得的近似解析解,弥补了单纯用数值方法求模拟解的不足.     

同伦摄动法在求解四阶边值问题中的应用

将同伦摄动法用于求解常微分方程四阶边值问题.通过将常微分方程边值问题转化为积分方程组,应用同伦摄动法求得近似解.给出同伦摄动法在两个具体的实例中的应用,并将近似解与精确解进行了比较,验证了同伦摄动法对求解线性、非线性常微分方程边值问题是一种非常有效的方法.     

一维非线性梁方程的摄动解

对于两端固定的一维非线性梁方程的初边值问题,用多重尺度法求得近似解的首项,并用能量方法结合非线性Gronwall不等式得出了近似解首项的误差的一致性估计.     

一类非线性双曲型发展方程的孤子解

研究了一类非线性发展方程.首先在无扰动情形下,利用待定函数和泛函同伦映射方法得到了非扰动发展方程的孤子精确解和扰动方程的任意次近似行波孤子解.接着引入一个同伦映射,并选取初始近似函数,再用同伦映射理论,依次求出非线性双曲型发展扰动方程孤子解的各次近似解析解.再利用摄动理论举例说明了用该方法得到的近似解析解的有效性和各次近似解的近似度.最后,简述了用同伦映射方法得到的近似解的意义,指出了用上述方法得到的各次近似解具有便于求解、精度高等优点.     

一类广义解析函数的Riemann边值逆问题

本文给出了一类有关广义解析函数Riemann边值逆问题的数学提法．在将此边值逆问题转化为边值问题的基础上，借助于广义解析函数边值问题的相关理论，分别获得了此边值逆问题在正则型和非正则型情况下的解．     

一类兰切斯特方程的广义变分迭代解

通过构造一组泛函,用变分迭代地方式研究了兰切斯特方程的各次近似解,这种近似解是解析解,还能继续进行各种解析运算.从而可进一步研究对兰切斯特方程进行定性及定量的研究.     

离子声波方程的初值问题

本文讨论由Ott E.等建立的机械模型,并给出了该模型初值问题存在整体性弱解的证明。     

用初等行变换求线性矩阵方程的通解

本文通过建立通解矩阵的概念 ,给出了用初等行变换求线性矩阵方程 Am× n Xn× s=Bm× s的通解的方法 .     

Oscillation of neutral delay difference equations of second order with positive and negative coefficients

This paper is concerned with a class of neutral difference equations of second order with positive and negative coefficients of the forms

Multiple periodic solutions for system of first-order differential equation

Sufficient conditions have been obtained for the existence of at least two non-negative periodic solutions to a system of first-order nonlinear functional differential equations. Applications to some ecological models are given.     

The existence and nonexistence of entire positive solutions of semilinear elliptic systems with gradient term

We show the existence and nonexistence of entire positive solutions for semilinear elliptic system with gradient term Δu+|∇u|=p(|x|)f(u,v), Δv+|∇v|=q(|x|)g(u,v) on RN, N?3, provided that nonlinearities f and g are positive and continuous, the potentials p and q are continuous, c-positive and satisfy appropriate growth conditions at infinity. We find that entire large positive solutions fail to exist if f and g are sublinear and p and q have fast decay at infinity, while if f and g satisfy some growth conditions at infinity, and p, q are of slow decay or fast decay at infinity, then the system has infinitely many entire solutions, which are large or bounded.     

A class of discrete time generalized Riccati equations

In this paper, a class of discrete-time backward non-linear equations defined on some ordered Hilbert spaces of symmetric matrices is considered. The problem of the existence of some global solutions is investigated. The class of considered discrete-time non-linear equations contains, as special cases, a great number of difference Riccati equations both from the deterministic and the stochastic framework. The results proved in the paper provide the sets of necessary and sufficient conditions that guarantee the existence of some special solutions of the considered equations as: the maximal solution, the stabilizing solution and the minimal positive semi-definite solution. These conditions are expressed in terms of the feasibility of some suitable systems of linear matrix inequalities (LMI). One shows that in the case of the equations with periodic coefficients to verify the conditions that guarantee the existence of the maximal or the stabilizing solution, we have to check the solvability of some systems of LMI with a finite number of inequations. The proofs are based on some suitable properties of discrete-time linear equations defined by the positive operators on some ordered Hilbert spaces chosen adequately. The results derived in this paper provide useful conditions that guarantee the existence of the maximal solution or the stabilizing solution for different classes of difference matrix Riccati equations involved in many problems of robust control both in the deterministic and the stochastic framework. The proofs are deterministic and are accessible to the readers less familiarized with the stochastic reasonings.     

Asympototic Behavior of Semilinear Periodic-Parbolic Boundary Value Problem

51.IntroductionInthispaper,westudythefollowingperiodicboundaryproblemwithNeumannboundaryconditionwhereO=RNisabounddomainwithC1 '(6>o)boundary.LetSuppose'm(x,t)eFandf.,.,$)eFforthe$beIongtoaboundsubsetofR,anditissat-isfiesForthesystem(1.1)',wesupposeitsati…     

渐近线性算子方程的四种类型的解

利用拓扑度理论及不动点指数理论,讨论了渐近线性算子方程的四种类型的解(即零解、正解、负解和变号解)的存在性,并将这一抽象结果应用于微分方程两点边值问题.