一类具有时滞功能反应的两种群捕食-食饵脉冲扩散系统的周期解

本文研究了一类具有脉冲的时滞功能反应的两种群捕食-食饵扩散模型的周期解存在性问题.应用重合度理论方法和不等式的分析理论,得到该系统正周期解存在的充分条件.     

Positive periodic solution for a neutral delay competitive system

In this paper we study the existence of positive periodic solutions for a class of neutral type competitive system with delay. Applying the continuation theorem of coincidence degree theory, a general criteria on the existence of positive periodic solutions are established. Some the related results are generalized and improved. It is shown that the arguments delays have no effect on the existence positive periodic solution of system.     

POSITIVE PERIODIC SOLUTION OF A PREDATOR-PREY SYSTEM WITH TIME DELAY

By using continuation theorem in coincidence degree theory,we study the existence of positive periodic solution for a delay and mutual interference predator- prey system with functional response,and obtain sufficient conditions for the existence of positive periodic solution.     

Existence and global attractivity of positive periodic solutions for impulsive predator–prey model with dispersion and time delays

In this paper, we study the existence and global attractivity of positive periodic solutions for impulsive predator–prey systems with dispersion and time delays. By using the method of coincidence degree theorem, a set of easily verifiable sufficient conditions are obtained for the existence of at least one strictly positive periodic solution, and by means of a suitable Lyapunov functional, the uniqueness and global attractivity of the positive periodic solution are presented. Some known results subject to the underlying systems without impulses are improved and generalized.     

Periodic solution of a two-species competitive system with toxicant and birth pulse

In this paper, we study the existence of positive periodic solution of two-species competitive system with toxicant and birth pulse. A set of easily verifiable sufficient conditions are derived for the existence of at least one positive periodic solution of the above system by using the method of coincidence degree. Numerical simulations are also presented to illustrate the feasibility of our main results.     

具脉冲效应的时滞周期捕食与被捕食系统正周期解的存在性

本文研究一类具脉冲效应的时滞周期捕食与被捕食系统，利用重合度理论中的方法，获得该系统至少存在一个正周期解的充分条件。     

Positive periodic solutions for impulsive predator-prey model with dispersion and time delays

In this paper, we study the existence and global attractivity of positive periodic solutions for impulsive predator-prey systems with dispersion and time delays. By using coincidence degree theorem, a set of easily verifiable sufficient conditions are obtained for the existence of at least one strictly positive periodic solutions, and by means of a suitable Lyapunov functional, the uniqueness and global attractivity of positive periodic solution is presented. Some known results subject to the underlying systems without impulses are improved and generalized.     

Positive Solutions for Nonlinear Periodic Problems with the Scalar p-Laplacian

We study the existence of positive solutions for a nonlinear periodic problem driven by the scalar p-Laplacian and having a nonsmooth potential. We impose a nonuniform nonresonance condition at +?∞ and a uniform nonresonance condition at 0^?+?. Using degree theoretic argument based on a fixed point index for multifunctions, we prove the existence of a strict positive solution.     

Existence of periodic solutions in predator-prey with Watt-type functional response and impulsive effects

In this paper, the existence of a periodic solution and the permanence of a periodic Watt-type predator-prey system where the prey disperses in patchy environment with two patches are investigated. With the continuation theorem of coincidence degree theory, we obtain the existence of a positive periodic solution for such a system. We assume the Watt-type functional response within-patch dynamics and provide a sufficient condition to guarantee the predator and prey species to be permanent. Furthermore, we give numerical analysis to confirm our theoretical results. It will be useful to ecosystem control.     

Existence and global attractivity of periodic solution for enterprise clusters based on ecology theory with impulse

In this paper, a competition and corporation impulsive model of two enterprises is investigated. Applying the continuation theorem of coincidence degree theory, we derive a set of sufficient conditions that guarantee the existence of at least a positive periodic solution, and by constructing a suitable Lyapunov functional, the uniqueness and global attractivity of the positive periodic solution are included.     

Existence and global attractivity of positive periodic solutions for a delayed competitive system with the effect of toxic substances and impulses

In this paper, a class of non-autonomous delayed competitive systems with the effect of toxic substances and impulses is considered. By using the continuation theorem of coincidence degree theory, we derive a set of easily verifiable sufficient conditions that guarantees the existence of at least one positive periodic solution, and by constructing a suitable Lyapunov functional, the uniqueness and global attractivity of the positive periodic solution are established.     

具有holling Ⅲ类功能反应的捕食者食系统差分方程周期解的存在性[英文]

本文利用重合度理论研究了一类具有holling Ⅲ类功能反应捕食者食差分方程的正周期解的存在性问题。     

Periodic solutions of a resonant third-order equation

We study the existence of periodic solutions for a third-order equation of resonant type. Under suitable conditions we prove the existence of at least one periodic solution of the problem applying Mawhin coincidence degree theory.     

Dynamic behavior of an eco-epidemic system with impulsive birth

In the paper, we investigate an eco-epidemic system with impulsive birth. The conditions for the stability of infection-free periodic solution are given by applying Floquet theory of linear periodic impulsive equation. And we give the conditions of persistence by constructing a consequence of some abstract monotone iterative schemes. By using the method of coincidence degree, a set of sufficient conditions are derived for the existence of at least one strictly positive periodic solution. Finally, numerical simulation shows that there exists a stable positive periodic solution with a maximum value no larger than a given level. Thus, we can use the stability of the positive periodic solution and its period to control insect pests at acceptably low levels.     

Global attractivity of a positive periodic solution for a nonautonomous stage structured population dynamics with time delay and diffusion

By employing the continuation theorem of coincidence degree theory, the existence of a positive periodic solution for a nonautonomous stage structured population dynamics with time delay and diffusion is established. Further, by constructing a Lyapunov functional and using the result of the existence of positive periodic solution, the attractivity of a positive periodic solution for above system is obtained.     

Dynamics of a periodic Watt-type predator–prey system with impulsive effect

In this paper, an impulsive periodic predator–prey system with Watt-type functional response is investigated. By using the Floquet theory of linear periodic impulsive equation, the stability conditions for the prey-eradication positive periodic solution are given, and the boundedness of the system is proved. By the method of coincidence degree, the sufficient conditions for the existence of at least one strictly positive periodic solution are obtained. Furthermore, we give numerical analysis to confirm our theoretical results. It will be useful for ecosystem control.     

一类三种群离散型捕食系统的周期解

本文研究了一类三种群离散型捕食者－食饵系统，利用重合度理论建立了这类系统正周期解的存在性判据。     

Positive solutions for nonlinear periodic problems

We consider a nonlinear periodic problem driven by the scalar p-Laplacian and with a nonsmooth potential. Using the degree map for multivalued perturbations of (S)₊-operators and the spectrum of a weighted eigenvalue problem for the scalar periodic p-Laplacian, we prove the existence of a strictly positive solution. Michael E. Filippakis: Researcher supported by a grant of the National Scholarship Foundation of Greece (I.K.Y.)     

具有时滞和基于比率的两种群捕食者-食饵扩散系统的周期解

本文研究了一类具有时滞和基于比率的两种群捕食者—食饵扩散系统，利用重合度理论建立了这类系统正周期解的存在性判据。     

n维变时滞Lotka-Volterra系统周期正解的存在性

基于非线性常微分方程泛函分析研究了一类变时滞n维非自治Lotka-Volterra系统周期正解的存在性,利用重合度理论建立了这类系统周期正解的存在性判据,得到了相应的充分性条件.同时对系统的持久性问题也作了分析,得到了相应的定理.最后,通过计算机仿真,对文中论述周期正解的存在性进行了佐证.