一类非线性泛函微分方程的渐近性

本文利用单调半流理论研究一类非线性泛函微分方程的渐近性态，发展了ＨｉｒｓｃｈＭ．Ｗ．和ＳｍｉｔｈＨ．Ｌ．关于常微分方程所得的某些结果．     

一类泛函微分方程生成的K型单调半流

我们在[5]中考察了形如(?)(t)=f(x(?))的泛函微分方程,其中 f 是互助映射(依 Smith[9]).本文在对 f 的更一般的假定下继续上述研究,新的假定使得方程(?)(t)=f(x(?))生成所谓 K 型单调半流,它以 Smith[8]所考察的 K 型单调系统作为其特款,本文的主要结果(定理4)给出了方程的解具有某种全局渐近稳定性的充分条件.     

一类泛函微分方程生成的K型单调半流

我们在[5]中考察了形如(?)(t)=f(x(?))的泛函微分方程,其中 f 是互助映射(依 Smith[9]).本文在对 f 的更一般的假定下继续上述研究,新的假定使得方程(?)(t)=f(x(?))生成所谓 K 型单调半流,它以 Smith[8]所考察的 K 型单调系统作为其特款,本文的主要结果(定理4)给出了方程的解具有某种全局渐近稳定性的充分条件.     

一次脉冲周期边值问题解的存在及收敛性

带有周期边值条件的脉冲泛函微分方程经常会出现在物理学等问题的研究中.本文用单调迭代技术和拟线性方法来探讨一类脉冲泛函微分方程周期边值问题解的存在性及收敛性.研究表明,方程上下解的单调序列快速收敛于方程的唯一解.     

非线性中立型泛函微分方程Runge-Kutta 法的稳定性和收敛性

本文涉及Runge-Kutta 法变步长求解非线性中立型泛函微分方程(NFDEs) 的稳定性和收敛性.为此, 基于Volterra 泛函微分方程Runge-Kutta 方法的B- 理论, 引入了中立型泛函微分方程Runge-Kutta 方法的EB (expanded B-theory)-稳定性和EB-收敛性概念. 之后获得了Runge-Kutta 方法变步长求解此类方程的EB - 稳定性和EB- 收敛性. 这些结果对中立型延迟微分方程和中立型延迟积分微分方程也是新的.     

脉冲泛函微分方程实用稳定性的一个比较定理

考虑一类脉冲泛函微分方程的实用稳定性，利用锥值李亚普诺夫函数方法，建立了脉冲泛函数微分方程与脉冲常微分方程的实用稳定性之间的比较定理。     

Banach空间中非线性刚性Volterra泛函微分方程稳定性分析

获得了Banach空间中非线性刚性Volterra泛函微分方程理论解的一系列稳定性、收缩性及渐近稳定性结果,为非线性刚性常微分方程、延迟微分方程、积分微分方程及实际问题中遇到的其他各种类型的泛函微分方程的解的稳定性分析提供了统一的理论基础.     

随机泛函微分方程的渐近稳定性

应用多个Liapunov函数讨论了随机泛函微分方程解的渐近行为，建立了确定这种方程解的极限位置的充分条件，并且从这些条件得到了随机泛函微分方程渐近稳定性的有效判据，使实际应用中构造Liapunov函数更为方便．同时也说明了该结果包含了经典的随机泛函微分方程稳定性结果为其特殊情况．最后给出的结果在随机Hopfield神经网络中的应用．     

含无限时滞的混合型偏泛函微分方程初边值问题解的稳定性

本文采用 Liapunov 方法,通过构造向量模与 L_2模混合形式的 Liapunov 泛函,对一类含无限时滞的混合型偏泛函微分方程初边值问题解的稳定性进行了讨论.获得了其平凡解渐近稳定的充分判别条件.     

一类脉冲随机泛函微分方程的分布稳定性分析

本文研究了一类脉冲随机泛函微分方程的分布稳定性问题.利用弱收敛方法、伊藤公式和一些常用的随机分析技巧,得到了一类脉冲随机泛函微分方程依分布稳定的一个充分条件,并且举例说明了结论的有效性,推广了随机泛函微分方程稳定性的相关结果.     

THEORY AND APPLICATIONS OF MONOTONE SEMIFLOWS FOR FUNCTIONAL DIFFERENTIAL EQUATIONS

The theory of monotone semiflows has been widely applied to functional differential equations (FDEs). The studies on the theory and applications of monotone semiflows for FDEs are very important and interesting. A brief des-cription of our recent works are as follows.By using general monotone semiflow theory, several results of positively invariant sets, monotone solutions and contracting rectangles of retarded functional differential equations(RFDEs) with infinite delay are gained under the assumption of quasimonotonicity; sufficient conditions for the existence, un-iqueness and global attractivity of periodic solutions are also established by combining the theory of monotone semiflows for neutral functional differential equations(NFDEs) and Krasnoselskii's fixed point theorem.     

具有时滞的高维生态系统的稳定性

本文引用了混合单调流的概念,利用其性质,我们得到了一类时滞生态系统的稳定性判别准则,推广了文[2][3]的结果。     

Global attractivity in monotone and subhomogeneous almost periodic systems

A global attractivity theorem is first proved for a class of skew-product semiflows. Then this result is applied to monotone and subhomogeneous almost periodic reaction-diffusion equations, ordinary differential systems and delay differential equations for their global dynamics.     

Stability and extensibility results for abstract skew-product semiflows

In this paper we present new stability and extensibility results for skew-product semiflows with a minimal base flow. In particular, we describe the structure of uniformly stable and uniformly asymptotically stable sets admitting backwards orbits and the structure of omega-limit sets. As an application, the occurrence of almost periodic and almost automorphic dynamics for monotone non-autonomous infinite delay functional differential equations is analyzed.     

Convergence for pseudo monotone semiflows on product ordered topological spaces

In this paper, we consider a class of pseudo monotone semiflows, which only enjoy some weak monotonicity properties and are defined on product-ordered topological spaces. Under certain conditions, several convergence principles are established for each precompact orbit of such a class of semiflows to tend to an equilibrium, which improve and extend some corresponding results already known. Some applications to delay differential equations are presented.     

Periodic Solutions of Neutral Functional Differential Equations

Periodic neutral functional differential equations are considered.Sufficient conditions for existence, uniqueness and global attractivityof periodic solutions are established by combining the theoryof monotone semiflows generated by neutral functional differentialequations and Krasnosel'skii's fixed-point theorem. These resultsare applied to a concrete neutral functional differential equationthat can model single-species growth, the spread of epidemics,and the dynamics of capital stocks in a periodic environment.     

Convergence and stability for essentially strongly order-preserving semiflows

This paper is concerned with a class of essentially strongly order-preserving semiflows, which are defined on an ordered metric space and are generalizations of strongly order-preserving semiflows. For essentially strongly order-preserving semiflows, we prove several principles, which are analogues of the nonordering principle for limit sets, the limit set dichtomy and the sequential limit set trichotomy for strongly order-preserving semiflows. Then, under certain compactness hypotheses, we obtain some results on convergence, quasiconvergence and stability in essentially strongly order-preserving semiflows. Finally, some applications are made to quasimonotone systems of delay differential equations and reaction-diffusion equations with delay, and the main advantages of our results over the classical ones are that we do not require the delicate choice of state space and the technical ignition assumption.     

Persistence and propagation of a discrete-time map and PDE hybrid model with strong Allee effect

Persistence and propagation of species are fundamental questions in spatial ecology. This paper focuses on the impact of Allee effect on the persistence and propagation of a population with birth pulse. We investigate the threshold dynamics of an impulsive reaction–diffusion model and provide the existence of bistable traveling waves connecting two stable equilibria. To prove the existence of bistable waves, we extend the method of monotone semiflows to impulsive reaction–diffusion systems. We use the methods of upper and lower solutions and the convergence theorem for monotone semiflows to prove the global stability of traveling waves and their uniqueness up to translation. Then we enhance the stability of bistable traveling waves to global exponential stability. Numerical simulations illustrate our theoretical results.