具Ⅱ型Holling功能性反应强耦合椭圆系统的共存问题

本文研究带齐次Dirichlet边界条件的强耦合椭圆系统,首先证明了当食饵和捕食者的扩散率足够大,或者出生率足够小时,系统不存在共存现象,并给出半平凡解存在的充分条件．然后利用Schauder不动点定理,得到强耦合的椭圆问题至少有一个正解存在的充分条件．该条件说明只要捕食者的内部竞争强,物种的交叉扩散相对弱,或者捕获率足够小,物种的交叉扩散相对弱,强耦合系统就至少有一个正解存在．     

污染环境下毒素脉冲输入和心理效应对随机捕食-食饵系统的影响

文章研究了在污染环境下毒素脉冲输入和心理效应对随机捕食-食饵系统的影响.通过构造Lyapunov函数,证明了系统全局正解的存在性;利用随机微分方程比较定理得到系统平均持续生存与灭绝的充分条件;应用Has'minskii定理证明了系统至少存在一个非平凡的正周期解,并给出了数值模拟.     

带Ivlev反应项的捕食模型的全局分歧

在Dirichlet边界条件下研究一类带Ivlev反应项的捕食模型.利用谱分析和分歧理论的方法,证明了发自半平凡解的局部分歧正解的存在性,同时运用线性特征值扰动理论给出局部分歧解的稳定性.最后将局部分歧延拓为全局分歧,从而得到正解存在的充分条件.     

二阶三点边值问题正解的存在性

利用不动点指数定理研究了一类二阶非线性常微分方程的三点边值问题正解的存在性问题,得到了至少存在一个或无穷多个正解的几个充分条件.     

二阶Sturm-Liouville型边值问题正解的三解定理

利用Leggett-Williams不动点定理得到了一类二阶Sturm-Liouville型边值问题正解的存在性.得到了所研究问题至少存在三个正解的充分条件.     

一类无穷多点边值问题正解的存在性

研究一类二阶非线性常微分方程无穷多点边值问题正解的存在性,利用不动点指数理论得到了方程至少存在一个正解的若干充分条件.     

分数阶微分方程m点边值问题正解的存在性

应用凸锥上的不动点定理,讨论了一类分数阶微分方程m点边值问题正解的存在性,得到了这类边值问题至少存在一个正解的充分条件,并给出了一个实例.     

具有脉冲效应的周期三种群捕食-食饵系统

本文讨论一类具有脉冲效应和周期系数的两个食饵一个捕食者的捕食-食饵系统的动力学行为.利用脉冲微分方程比较定理和乘子理论,证明了系统的有界性,讨论了平凡周期解和半平凡周期解的稳定性,利用重合度的理论给出了系统存在周期正解的充分条件.     

带p-Laplace算子三点奇异边值问题对称正解的存在性

该文应用不动点指数理论,讨论了一类带p-Laplace算子三点奇异边值问题对称正解的存在性,分别得到了这类边值问题至少存在一个或两个对称正解的充分条件.     

一类含积分边界条件的分数阶微分方程的正解的存在性北大核心CSCD

本文研究了一类含积分边界条件的分数阶微分方程的边值问题,利用格林函数的性质和Krasnoselskii不动点定理,得到了至少有一个,两个正解存在以及正解不存在的充分条件.     

一类非线性算子方程的正解问题

研究算子方程X^s+A^*X^-tA=Q的正算子解的存在性问题,通过构造有效的迭代序列,给出了算子方程X^s+A^*X^-tA=Q有正算子解的一些充分条件和必要条件,同时给出了该方程有极大解和唯一解的条件.     

ON HERMITIAN POSITIVE DEFINITE SOLUTIONS OF MATRIX EQUATION X-A^＊X^-2 A=I

The Hermitian positive definite solutions of the matrix equation X-A^＊X^-2 A=I are studied. A theorem for existence of solutions is given for every complex matrix A. A solution in case A is normal is given. The basic fixed point iterations for the equation are discussed in detail. Some convergence conditions of the basic fixed point iterations to approximate the solutions to the equation are given.     

奇异四阶积分边值问题正解的存在唯一性

利用上下解方法结合极值原理研究了具有积分边值条件的奇异四阶微分方程正解的存在、唯-性,给出了C~2[0,1]和C~3[0,1]正解存在唯一的充分条件.非线性项f(t,χ)允许在t=0,1和χ=0处具有奇异性.     

非局部抛物型方程解的性质

In this short note, we investigate the properties of positive solutions for some non-local parabolic equations. The conditions on the global existence and blow-up in finite time of solution are given.     

On the Properties of ParabolicSolutions of Non-localEquations

In this short note, we investigate the properties of positive solutions for some non-local parabolic equations. The conditions on the global existence and blowup in finite time of solution are given.     

Strongly coupled elliptic systems and applications to Lotka–Volterra models with cross-diffusion

The aim of this paper is to investigate the existence and method of construction of solutions for a general class of strongly coupled elliptic systems by the method of upper and lower solutions and its associated monotone iterations. The existence problem is for nonquasimonotone functions arising in the system, while the monotone iterations require some mixed monotone property of these functions. Applications are given to three Lotka–Volterra model problems with cross-diffusion and self-diffusion which are some extensions of the classical competition, prey–predator, and cooperating ecological systems. The monotone iterative schemes lead to some true positive solutions of the competition system, and to quasisolutions of the prey–predator and cooperating systems. Also given are some sufficient conditions for the existence of a unique positive solution to each of the three model problems.     

Blow-up for a degenerate parabolic equation with nonlocal source and nonlocal boundary

In this article, we investigate the blow-up properties of the positive solutions for a doubly degenerate parabolic equation with nonlocal source and nonlocal boundary condition. The conditions on the existence and nonexistence of global positive solutions are given. Moreover, we give the precise blow-up rate estimate and the uniform blow-up estimate for the blow-up solution.     

奇异二阶微分方程积分边值问题正解的存在唯一性

利用上下解方法结合极值原理研究一类带积分边值条件的奇异二阶微分方程正解的存在性以及唯一性,给出了$C[0,1]$和$C^1[0,1]$正解存在唯一的一个充分条件.非线性项允许在$t=0,1$ 和$x=0$处具有奇异性.     

Globally asymptotical stability and periodicity for a nonautonomous two-species system with diffusion and impulses

Existence and globally asymptotical stability of positive periodic solutions for a nonautonomous two-species competition system with diffusion and impulses are studied in this paper. By employing Mawhin continuation theorem, a set of easily verifiable sufficient conditions are obtained for the existence of at least one positive periodic solution, and by means of a suitable Lyapunov functional, the globally asymptotical stability of positive periodic solution is presented. Finally, an illustrative example and simulations are given to show the effectiveness of the main results.     

Positive solutions of higher-order nonlinear fractional differential systems with nonlocal boundary conditions

The paper deals with the existence and multiplicity of positive solutions for a system of higher-order nonlinear fractional differential equations with nonlocal boundary conditions. The main tool used in the proof is fixed point index theory in cone. Some limit type conditions for ensuring the existence of positive solutions are given.