二次微分系统的反射函数及其周期解

本文给出了二镒多项式微分系统具有满足特定关系式的反射函数和存在周期解的充要条件，以及在此条件下反射函数的具体表达式及周期解的稳定性态。     

广义反射函数的性态与应用

推广了Mironenko的反射函数的概念,给出了广义反射函数的概念并讨论了广义反射函数的性质,应用它研究了微分系统周期解的存在性和稳定性态.作为应用举例,研究了Riccati方程的反射函数.     

n阶线性微分系统的广义反射矩阵与周期解

利用Mironenko的反射函数理论,讨论了n阶线性微分系统的广义反射矩阵并由此得到n阶周期线性系统及与之等价的非线性微分系统的周期解的存在性和稳定性的判定方法.     

二次多项式微分系统的广义反射函数

利用广义反射函数理论,讨论多项式微分系统的广义反射函数的结构形式.并利用所得结论探讨二次多项式微分系统的周期解的几何性质.     

一类三次多项式微分系统的周期解

根据Mironenko的反射函数理论,给出一种利用多项式方程探讨三次多项式微分系统周期解的几何性质的新方法.该文首先研究一类系统具有满足特定关系式的反射函数的结构,由此建立三次多项式微分系统与多项式方程之间的解的对应关系,然后利用此对应关系探讨三次多项式微分系统的周期解的几何性质.     

多项式微分系统的周期解

给出了多项式微分系统的反射函数第一分量不依赖于第二变量的的充要条件,并应用所得结论研究了周期多项式系统周期解的几何性态.     

四维线性微分系统下三角反射矩阵的存在与计算

利用反射函数理论来讨论四阶线性微分系统的下三角反射函数的存在性,并计算出在不同情况下具体的反射矩阵.同时,利用反射矩阵来建立周期微分系统的庞加莱映射,进而该系统周期解的存在稳定性判定定理也相应地建立起来.最后,将以上结果推广应用到了非线性微分系统中.     

非线性微分系统的Poincare映射与周期解

采用一种新方法-反射函数法,建立了非线性非自治微分系统的Poincare映射, 给出了这些微分系统周期解存在及稳定的充要条件．     

微分系统的反射函数与周期解

本文主要介绍了微分系统反射函数与周期解理论的产生与发展动态．论述了一些基本问题，并提出了一些可供研究的新课题。     

二次多项式微分系统的反射函数

本文给出了二次多项式微分系统的反射函数的第一分量不依赖第二分量的充要条件，以及此时第二分量的表示式，及该系统存在周期解的条件。     

On the dynamics of a discrete reaction-diffusion system

We investigate various aspects of the dynamics of a discrete reaction-diffusion system. First, we examine the effect of the boundary conditions on the spatially uniform fixed point at locations far from the boundaries by using an asymptotic expansion. We show that, except for a few computational cells adjacent to the boundary, the fixed point practically coincides with the one calculated by using reflective boundary conditions (equivalent to an infinite domain). Next, we introduce a classification of the fixed points based on the wavelength in the infinite-medium approximation of the system. We use the symbolic manipulator MACSYMA to analytically calculate the amplitude of several such classes of fixed points and we generate bifurcation diagrams for their members. Also, we consider two special classes of periodic solutions; we calculate their amplitude analytically in the infinite-medium approximation, and generate bifurcation diagrams that shed new light on some previous confusing results. Finally, we present an analysis of fictitious periodic solutions that have been previously reported and incorrectly interpreted.     

On the qualitative behavior of periodic solutions of differential systems

This article deals with the reflective function of differential systems. The obtained results are applied to studying the existence and stability of the periodic solutions of some linear and nonlinear periodic differential systems.     

On the existence of periodic solutions for large-scale systems

In recent ten years or more, many scholars have engaged in the investigation concerning the stability of large-scale systems, but up to the present, the problem on the existence of periodic solutions for large-scale systems has yet been seldomly touched upon in the literature.In this paper, by means of the method of constructing Lyapunov function. We study the problem on the existence of periodic solutions for linear and nonlinear large-scale systems, and obtain several sufficient conditions which guarantee the existence of periodic solutions.     

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。     

Multiple positive periodic solutions of a delayed discrete predator–prey system with type IV functional responses

In this paper, a discrete periodic predator–prey system with type IV functional responses and time delay is investigated. Using Gaines and Mawhin’s continuation theorem from coincidence degree theory as well as some prior estimates, we get sufficient conditions for the existence of positive periodic solutions of the system. This is also the first time that the coincidence degree theory has been used to obtain multiple positive periodic solutions in discrete ecological systems.     

Period doubling cascades of prey–predator model with nonlinear harvesting and control of over exploitation through taxation

The present study investigates a prey predator type model for conservation of ecological resources through taxation with nonlinear harvesting. The model uses the harvesting function as proposed by Agnew (1979) [1] which accounts for the handling time of the catch and also the competition between standard vessels being utilized for harvesting of resources. In this paper we consider a three dimensional dynamic effort prey–predator model with Holling type-II functional response. The conditions for uniform persistence of the model have been derived. The existence and stability of bifurcating periodic solution through Hopf bifurcation have been examined for a particular set of parameter value. Using numerical examples it is shown that the system admits periodic, quasi-periodic and chaotic solutions. It is observed that the system exhibits periodic doubling route to chaos with respect to tax. Many forms of complexities such as chaotic bands (including periodic windows, period-doubling bifurcations, period-halving bifurcations and attractor crisis) and chaotic attractors have been observed. Sensitivity analysis is carried out and it is observed that the solutions are highly dependent to the initial conditions. Pontryagin’s Maximum Principle has been used to obtain optimal tax policy to maximize the monetary social benefit as well as conservation of the ecosystem.