具有脉冲效应非自治捕食系统的研究

研究了具有脉冲效应的非自治捕食系统,该系统是两个具有互惠关系的食饵种群被一个捕食种群捕食.利用重合度理论证明系统正周期解的存在性.     

具阶段结构的非自治捕食模型的持久性

讨论了一类具有密度制约且食饵带有阶段结构和捕食者仅捕食成年食饵的捕食-食饵种群模型,,得到了持久生存以及非平凡周期解存在的充分条件.     

一个具有时滞和功能反应的非自治阶段结构的捕食模型

研究一个具有时滞和功能反应的非自治阶段结构的捕食模型,其中食饵种群分两个阶段——幼年和成年,且捕食种群只捕成年食饵.通过利用微分不等式、比较定理和构造适当的Lyapunov泛函,得到该模型的永久持续生存和绝灭的充分条件,同时也得到了周期系统存在唯一全局渐近稳定的周期解的充分条件.     

一类具有不育和脉冲投放的捕食模型

建立了一类具有不育控制和脉冲投放的捕食模型.判断了食饵灭绝周期解存在和全局渐近稳定的充分条件,还得到了种群一致持续生存的充分条件.     

具有分布时滞和捕食者非密度制约的捕食-食饵系统的动力学行为研究

研究了具有分布时滞和捕食者非密度制约的捕食-食饵系统的动力学性质.应用微分方程比较原理,叠合度定理和Lyapunov函数的方法,得到了捕食者种群的灭绝性以及系统正周期解的存在性和全局吸引性的充分条件.     

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.     

带有脉冲和Holling-Ⅳ型功能反应函数的中立型捕食-食饵模型的周期解

该文研究一类带有中立型脉冲时滞和Holling-Ⅳ型功能反应函数的捕食-食饵模型.通过运用Mawhin迭合度理论和分析技巧,得到了捕食-食饵模型正周期解存在性的充分条件.     

Holling Ⅳ捕食-食饵时滞系统的多个周期解

应用重合度定理研究了一类具有Holling Ⅳ类功能性反应时滞捕食-食饵系统的周期解的存在性问题,建立了该系统具有至少两个正周期解的充分条件.     

一类具有HollingⅢ型食饵—捕食系统的周期解存在性

利用重合度理论中的延拓定理研究非自治周期食饵—捕食系统的非平凡周期解存在性,给出了周期解存在的充分条件.     

多种群生态时滞系统正周期解的全局吸引性

利用比较定理结合Liapunov泛函, 讨论一类具有多个周期时滞的多种群生态竞争 捕食系统正周期解的存在性和全局吸引性. 最后, 利用一致持久性理论, 讨论捕食 食饵系统正周期解存在的充要条件.     

Existence and stability of almost periodic solutions of nonautonomous competitive systems with weak Allee effect and delays

In this paper, a class of nonautonomous Lotka–Volterra type multispecies competitive systems with weak Allee effect and delays are considered. By using Mawhin’s continuation theorem of coincidence degree theory, we obtain some sufficient conditions for the existence of almost periodic solutions for the Lotka–Volterra system. On the case of no delays of Allee effects, by constructing a suitable Lyapunov function, we get a sufficient condition for the globally attractivity of the almost periodic solution for the Lotka–Volterra system. Moreover, we also present an illustrative example to show the effectiveness of our results.     

Almost periodic solutions of a discrete Lotka–Volterra competition system with delays

In this paper, we consider a discrete almost periodic Lotka–Volterra competition system with delays. Sufficient conditions are obtained for the permanence and global attractivity of the system. Further, by means of an almost periodic functional hull theory, we show that the almost periodic system has a unique strictly positive almost periodic solution, which is globally attractive. Some examples are presented to verify our main results.     

Dynamics of a nonautonomous predator-prey system with the Beddington-DeAngelis functional response

In this paper, we systematically study the dynamics of a nonautonomous predator-prey system with the Beddington-DeAngelis functional response. The explorations involve the permanence, extinction, global asymptotic stability (general nonautonomous case); the existence, uniqueness and stability of a positive (almost) periodic solution and a boundary (almost) periodic solution for the periodic (almost periodic) case. The paper ends with some interesting numerical simulations that complement our analytical findings.     

PERIODIC SOLUTIONS AND ALMOST PERIODIC SOLUTIONS OF A NONAUTONOMOUS PREDATOR-PREY SYSTEM WITH STAGE-STRUCTURE AND DELAY

In this paper, by using the comparing theorem, Razumikhin-type theorem and V-function method, we consider a nonautonomous predator-prey system with stage-structure and time-delay. We get the sufficient conditions for the uniform persistence and the solutions global attractivity of this system. For a periodic system, we obtain the existence and uniqueness of a positive periodic solution of this system. For an almost periodic system, we prove the existence and the uniform asymptotic stability of the almost periodic solutions of this system.     

GLOBAL ATTRACTIVITY IN AN ALMOST PERIODIC PREDATOR-PREY-MUTUALIST SYSTEM

In this paper, the almost periodic predator-prey-mutualist model with Holling type II functional response is discussed. A set of sufficient conditions which guarantee the uniform persistence and the global attractivity of the system are obtained. For the almost periodic case, by constructing a suitable Lyapunov function, sufficient conditions which guarantee the existence of a unique globally attractive positive almost periodic solution of the system are obtained. An example together with its numerical simulations shows the feasibility of the main results.     

Bochner’s theorem and Stepanov almost periodic functions

Motivated by a renewed interest in generalizations of classical almost periodicity (originally due to Harald Bohr), we develop a theorem of Bochner within the framework of almost periodic functions in the sense of Stepanov. As a result we establish some conditions that guarantee the existence of Stepanov almost periodic solutions to differential equations with Stepanov almost periodic coefficients. Finally, we extend a now classic theorem of Favard originally stated for classical almost periodic functions to the Stepanov almost periodic case.      

Periodic and almost periodic solution for a non-autonomous epidemic predator-prey system with time-delay

In this paper, we studied a non-autonomous predator-prey system with discrete time-delay, where there is epidemic disease in the predator. By using some techniques of the differential inequalities and delay differential inequalities, we proved that the system is permanent under some appropriate conditions. When all the coefficients of the system is periodic, we obtained the existence and global attractivity of the positive periodic solution by Mawhin’s continuation theorem and constructing a suitable Lyapunov functional. Furthermore, when the coefficients of the system are not absolutely periodic but almost periodic, sufficient conditions are also derived for the existence and asymptotic stability of the almost periodic solution.     

Dynamic Behavior of a Logistic Type Equation with Infinite Delay

A non-autonomous Logistic type equation with infinite delay is investigated.For general nonau-tonomous case,sufficient conditions which guarantee the uniform persistence and globally attractivity of thesystem are obtained;For almost periodic case,by means of a suitable Lyapunov functional,sufficient conditionsare derived for the existence and uniqueness of almost periodic solution of the system.Some new results areobtained.     

Existence and exponential stability of positive almost periodic solution for Nicholson-type delay systems

In this paper, we study the existence and exponential convergence of positive almost periodic solutions for a class of Nicholson-type delay system. Under proper conditions, we establish some criteria to ensure that the solutions of this system converge locally exponentially to a positive almost periodic solution. Moreover, we give an example to illustrate our main results.     

The positive almost periodic solution for Nicholson-type delay systems with linear harvesting terms

In this paper, we study the existence and exponential convergence of positive almost periodic solutions for a class of Nicholson-type delay system with linear harvesting terms. Under appropriate conditions, we establish some criteria to ensure that the solutions of this system converge locally exponentially to a positive almost periodic solution. Moreover, we give an example to illustrate our main results.