一类二阶迭代泛函微分方程的周期解

本文研究一类二阶迭代泛函微分方程周期解的存在性问题.利用Schauder和Banach不动点定理,获得此类方程周期解的存在唯一性及稳定性的结果,推广了已有结论.     

一类积分微分方程概周期解的存在性和唯一性

考虑具无穷时滞的非线性积分微分方程概周期的存在性和唯一性问题,利用矩阵测度和不动点方法获得了一类方程的概周期的存在性和唯一性的充分条件,推广了相应文献的结果.     

一类具脉冲效应的p-Laplace系统周期解的存在性

通过利用临界点理论中的极小极大方法,考虑一类具脉冲效应的p-Laplace系统周期解的存在性,获得了一些新的存在性结果,所得结果推广并改进了某些已有的结果.     

具无穷时滞的中立型周期微分系统周期解的存在性

研究了一类具无穷时滞的中立型周期微分系统周期解的存在性问题.利用指数型二分性及Krasnoselskii不动点定理,建立了保证该系统的周期解的存在性的充分条件.所得结果推广了文[1-7]的有关结果.     

一类具有比率和单调功能反应的中立型捕食系统的正周期解

研究了一类具有比率和单调功能反应的中立型捕食系统.通过利用重合度理论获得了其正周期解存在性的充分条件,推广和改进了已有文献的相关结果.     

概周期解的存在性、唯一性与稳定性

本文给出了一些保证微分方程的周期解和概周期解的存在性、唯一性、稳定性与不稳定性的充分性条件及周期解的存在范围估计式.所得结果推广[1]的主要结果及[2-6]的有关结果.     

具有脉冲效应和功能反应的捕食系统的周期解

研究具有时滞、Holling-类功能反应和脉冲效应的捕食-食饵系统正周期解的存在性.利用Mawhin重合度理论和同伦性质,获得周期解存在的充分条件.结果推广和改进一些最近文献结论.     

Ezeilo概周期解存在的性定理的推广

本文利用指数型二分性理论讨论了一般高维概周期系统的概周期解的存在性和唯一性,所得结果推广了Ｅｚｅｉｌｏ的一个概周期解的存在性定理。     

二阶非线性中立型泛函微分方程周期解的存在性

利用κ-集压缩算子拓扑度抽象连续定理,研究了一类二阶泛函微分方程周期解的存在性,获得了方程周期解存在的充分条件,这些结果推广并改进了已有文献的相关结果.     

时滞细胞神经网络概周期解的存在性与全局指数稳定性

通过利用Banach 空间中的不动点定理和Lyapunov泛函的方法,获得了时滞细胞神经网络概周期解的存在性与全局指数稳定性的新结论. 所获结果在较大程度上改进和推广了已有文献中的相应结果.     

逐段常变量微分方程组概周期型解存在唯一性

通过差分方程指数二分法,我们研究了一类具有变系数逐段常变量微分方程组概周期与伪概周期解的存在唯一性与渐近稳定性,改进了已有文献的结果,并且得到了差分方程满足指数二分性的一个充分条件．     

Solution spaces of homogeneous linear difference systems with coefficient matrices from commutative groups

We analyse the solution spaces of limit periodic homogeneous linear difference systems, where the coefficient matrices of the considered systems are taken from a commutative group which does not need to be bounded. In particular, we study such systems whose fundamental matrices are not asymptotically almost periodic or which have solutions vanishing at infinity. We identify a simple condition on the matrix group which guarantees that the studied systems form a dense subset in the space of all considered systems. The obtained results improve previously known theorems about non-almost periodic and non-asymptotically almost periodic solutions. Note that the elements of the coefficient matrices are taken from an infinite field with an absolute value and that the corresponding almost periodic case is treated as well.     

EXISTENCE OF ALMOST PERIODIC SOLUTIONS FOR DIFFERENCE SYSTEMS

1IntroductionAsisknown,therehavebeenquiteafewresu1tsontheexistenceofalrilostperiodicsolutionsforordinaryanddelaydifferentialstystems.However,tothebestofourknowledge,therehavenotappearedanycorrespondingresu1tsfOrevenordinarydifferencesystemssofar.Todealwithsuchproblems,wewilldefinethenotionoftheso-calleduni-formlyalmostperiodicsequencesbesidesthealmostsequencesandasymptoti-callyalmostsequences.Thenweprovidethecriteriaandthebasicpropertiesofuniformlyalmostperiodicsequenceswhichareneededinestabl…     

Almost periodic transformable difference systems

We analyse almost periodic homogeneous linear difference systems whose coefficient matrices belong to the so-called transformable groups. We introduce the notion of weakly transformable groups and we use this notion to obtain generalizations of known results about non-almost periodic solutions of considered systems.     

Almost periodic linear differential equations with non-separated solutions

A celebrated result by Favard states that, for certain almost periodic linear differential systems, the existence of a bounded solution implies the existence of an almost periodic solution. A key assumption in this result is the separation among bounded solutions. Here we prove a theorem of anti-Favard type: if there are bounded solutions which are non-separated (in a strong sense) sometimes almost periodic solutions do not exist. Strongly non-separated solutions appear when the associated homogeneous system has homoclinic solutions. This point of view unifies two fascinating examples by Zhikov-Levitan and Johnson for the scalar case. Our construction uses the ideas of Zhikov-Levitan together with the theory of characters in topological groups.     

Bounded and almost periodic solutions of convex Lagrangian systems

We study some properties of bounded and almost periodic solutions of convex Lagrangian systems in the presence of almost periodic forcing

     

Convergence in almost periodic cooperative systems with a first integral

This paper is to investigate the asymptotic dynamics in almost periodic cooperative systems with a first integral. By appealing to the theory of skew-product semiflows we establish the asymptotic almost periodicity of bounded solutions to such systems, which extends the existing convergence results for time independent and periodic cooperative systems with a first integral and proves a conjecture of B. Tang, Y. Kuang and H. Smith in SIAM J. Math. Anal., 24 (1993), 1331-1339.

     

带梯度算子二阶方程的渐近概周期解

利用渐近概周期函数的性质得到带梯度算子二阶方程的渐近概周期解在C（R^-）中的存在性．同时利用迭代法和线性常微分方程的概周期解的存在性和唯一性,得到R上此方程渐近概周期解的存在和唯一性．     

具有阶段结构且食饵有避难所的模型分析

研究了捕食者具有阶段结构且食饵有避难所的非自治捕食系统.利用Lyapunov函数方法得到了系统持续生存的条件,以及在一定条件下存在唯一全局渐进稳定的周期正解.对于更广泛的概周期现象,也得到了存在唯一全局渐进稳定的概周期正解的充分条件.     

Recurrent solutions of the derivative Ginzburg–Landau equation with boundary forces

In this paper, we will establish the existence of the bounded solutions, periodic solutions, quasi-periodic solutions and almost periodic solutions for the derivative Ginzburg–Landau equation with time-dependent boundary external forces. A smoothing effect for the semigroup associated with linear Ginzburg–Landau operator is the crucial tool in establishing the main results.