两种生物相互作用的反应扩散模型及解的讨论

本文综合[1]和[2]的特点,给出以下相互作用的双种群模型:     

一类时滞反应扩散方程的周期解和概周期解

通过构造上、下控制函数，结合上、下解方法及相应的单调迭代方法研究了一类时滞反应扩散方程，证明了在反应项非单调时，如果一雏边值问题存在一对周期（或概周期）上、下解，则方程一定存在唯一的周期（或概周期）解．并给出了二维边值问题周期（或概周期）解存在唯一性的充分条件．推广了已有的一些结果。     

非单调时滞反应扩散方程的周期解和概周期解

通过构造上、下控制函数,结合上、下解方法及不动点理论,研究了一类反应项不具任何单调性的时滞反应扩散方程,证明了此方程对应的边值问题存在唯一的周期(或概周期)解.并通过一个经典的化学模型说明了所得结果的意义.     

一类反应扩散方程解的爆破性

本文讨论反应扩散方程的定态解的存在性以及依赖时间的解的爆破性．     

非局部反应扩散方程的奇摄动问题

本文研究了一类非局部反应扩散方程的奇摄动问题．利用上、下解，讨论了相应问题解的存在唯一性及其渐近性态．     

一类非局部反应扩散问题

本文研究了一类非局部反应扩散问题．利用上、下解，讨论了相应问题解的存在唯一性及其渐近性态．     

时滞反应扩散方程初边值问题奇摄动

本文考虑了在生物数学、生物化学等应用问题中常见的较广泛的一类奇摄动时滞反应扩散方程初边值问题。应用合成展开法构造了所述问题的形式渐近解，借助上、下解理论证明了形式解的一致有效性和原问题的解的存在性。     

一类反应扩散方程的行波解

1　引　　言由于反应扩散方程涉及的大量问题来自物理学、化学、生物学和人口动力学中众多的数学模型,因而有广阔的实际背景.其行波解引起了人们的兴趣,行波解是某个常微分方程的解,对某些传播速度,利用几何方法可以建立其解的存在性(见[1][2][3]).在文[4]中J.Canosa讨论了Fisher方程ut=2u2x+u(1-u)(1)行波解的存在性、逼近解和误差估计.所谓方程(1)的行波解是指形为u(x,t)=u(x-ct)=u(z)的解.众所周知,行波解u(x,t)=u(x-ct)=u(z)是方程(1)的行波解的充要条件是d2udz2+cdudz+u(1-u)=0(2)若u(z)是单调有界且不恒为常数,则u(z)叫做(1)的波前…     

On the Interior Smoothness of Solutions to Second-Order Elliptic Equations

We study the interior smoothness properties of solutions to a linear second-order uniformly elliptic equation in selfadjoint form without lower-order terms and with measurable bounded coefficients. In terms of membership in a special function space we combine and supplement some properties of solutions such as membership in the Sobolev space W _{2, loc} ¹ and Holder continuity. We show that the membership of solutions in the introduced space which we establish in this article gives some new properties that do not follow from Holder continuity and the membership in W _2,loc ¹ .     

On the Solutions of an Equation Involving the Smarandache Power Function SP（n）

For any positive integer n,the famous Smarandache power function SP(n) is defined as the smallest positive integer m such that n|mm,where m and n have the same prime divisors.The main purpose of this paper is using the elementary methods to study the positive integer solutions of an equation involving the Smarandache power function SP(n) and obtain some interesting results.At the same time,we give an open problem about the related equation.     

非线性四阶方程正解存在问题

本文讨论了一个四阶非线性方程在二类不同边界条件下正解的存在问题，即多点边值问题和积分型的边值问题．采用的方法是锥拉伸和压缩不动点定理，这里的结果推广了这类四阶方程边值问题的结果．     

On the Minimal Nonnegative Solution of Nonsymmetric Algebraic Riccati Equation

We study perturbation bound and structured condition number about the minimal nonnegative solution of nonsymmetric algebraic Riccati equation, obtaining a sharp perturbation bound and an accurate condition number. By using the matrix sign function method we present a new method for finding the minimal nonnegative solution of this algebraic Riccati equation. Based on this new method, we show how to compute the desired M-matrix solution of the quadratic matrix equation X^2 - EX - F = 0 by connecting it with the nonsymmetric algebraic Riccati equation, where E is a diagonal matrix and F is an M-matrix.     

二阶差分方程的奇性边值问题

主要采用上下解方法,研究了一类带有奇性的二阶差分方程的两点边值问题,给出了一系列正解的存在条件.     

On a Solution of the Gross--Pitaevskii Equation for a Condensate Wave Function

In this paper, we consider an approximate solution of the Gross--Pitaevskii equation in the one-dimensional case in the form of the eigenfunction of the ground state of the harmonic oscillator. A numerical experiment shows that the approximate solution obtained satisfies, with high accuracy, the Gross--Pitaevskii equation for the interatomic-interaction potential in the form of the superposition of Gaussian functions.     

On some new analytical solutionsforthe (2+1)-dimensional burgers equation and the special type of dodd_bullough_Mikhailov equation

Some new travelling wave transform methods are very importantfor obtaining analytical solutions of special type of nonlinear partial differentialequations (NLPDEs). Some of these solutions of NLPDEs may be inthe different forms such as rational function solutions, trigonometric functionsolutions, hyperbolic function solutions, exponential function solutions andJacobi elliptic function solutions. These forms tell us the various propertiesof the NLPDEs from scientifical applications to engineering.In this research, we have studied to obtain the analytical solution ofthe nonlinear (2+1)-dimensional Burgers equation which is named from JohannesMartinus Burgers and the nonlinear special type of the Dodd-Bullough-Mikhailov equation introduced to the literature by Roger Dodd, Robin Bullough,and Alexander Mikhailov.     

A Note on Singular Solution of the Matukuma Equation in Higher Dimensional Space

We revise one case of theM-solutions of [1, B.Wang, Z. C. Zhang, Y. Li, The radial positive solutions of the Matukuma equation in higher dimensional space: Singular solution, J. Differential Equations 253 (2012), 3232-3265.] and obtain more precise form of the singular term and the regular term.     

两个数论函数及其方程

对于任意给定的自然数n,著名的Eu ler函数φ(n)定义为不大于n且与n互素的正整数的个数.ω(n)表示n的所有不同素因子的个数.本文研究了方程φ(n)=2ω(n)的可解性,并给出了该方程的所有正整数解.     

RLW-Burgers方程的一类解析解

本文给出了 RLW-Burgers方程及 Kd V-Burgers方程的一类解析解 ,且可得到 RLW-Burgers方程的振荡激波解 .这些解可以表示为 Burgers方程和 Kd V方程解的线性组合 ,文末还对文 [8]作了讨论 .