一类具有时滞的强身型捕食模型的稳定性与Hopf分支

研究一类具有时滞和阶段结构的捕食模型.分析了正平衡点的稳定性和Hopf分支的存在性.应用中心流形定理和规范型理论,得到了确定Hopf分支方向和分支周期解稳定性的计算公式.     

Chmostat系统中Hopf分支的存在性

应用Hopf分支理论研究了具有比例确定增长率的Chmostat系统存在Hopf分支的条件,同时得到周期解的存在性及稳定性的结果.     

一类具时滞和非线性发生率的生态流行病模型的稳定性和Hopf分支

研究一类具有时滞和非线性发生率的生态流行病模型.以滞量为参数,通过分析特征方程,得到了正平衡点局部稳定和Hopf分支存在的条件.同时,应用中心流形定理和规范型理论,得到了分支方向和分支周期解的稳定性计算公式.最后对所得理论结果进行了数值模拟.     

具性别结构时滞捕食系统的Hopf分支,混沌与脉冲控制

建立了具性别结构的时滞捕食系统,研究了平衡点的存在性及局部稳定性,给出了系统发生局部Hopf分支的充分条件,并应用中心流形定理研究了Hopf分支周期解的性质(分支类型,方向及稳定性).数值例子佐证了理论结果,并揭示了系统诸如高倍周期及拟周期振荡,混沌振荡,倍周期分岔等复杂的动力学行为;脉冲控制可以有效的改善系统的稳定性.     

非线性红松林生态系统的定性与分支研究(英文)

利用系统分析的方法研究了一类非线性红松林生态系统的稳定性,讨论了其鞍结分支和Hopf分支,且对Hopf分支周期解进行了详细的分析和计算,指出了红松林生态系统中松籽、鼠类和幼苗三种群数量具有周期波动的特征.     

含连续时滞的二维竞争系统的周期解和循环解

本文利用HOPf分支定理和Birkhoff定理给出了含连续时滞的二维Lotka-Volterra竞争系统存在周期解和循环解的条件。     

一类具有时滞的传染病模型的稳定性分析

研究了一类具有时滞的传染病生物模型．首先研究了该模型的线性稳定性,并给出了一列Hopf分支值,然后利用中心流形定理和正规型方法,给出了确定分支周期解的分支方向与稳定性的计算公式．     

具时滞Gilpin-Ayala型L-V系统产生多周期解和Hopf分支现象的条件

研究了具时滞Gilpin-Ayala型L-V系统中相应产生多周期解和Hopf分支的条件,得到了新的结果．     

具脉冲出生的Leslie-Gower捕食者-食饵系统的动力学分析

研究了一个具有脉冲出生的Leslie-Gower捕食者一食饵系统的动力学性质．利用频闪映射。得到了带有Ricker和Beverton-Holt函数的脉冲系统准确的周期解．通过Floquet定理和脉冲比较定理,讨论了该系统的灭绝和持久生存．最后,数值分析了以b（p）为分支参数的分支图,得到的结论是脉冲出生会带给系统倍周期分支、混沌以及在混沌带中出现周期窗口等复杂的动力学行为．     

一类时滞红松生态系统的稳定性和Hopf分支（英文）

本论文研究了一类高维时滞松籽,鼠类和幼苗的红松生态系统的动力学行为,讨论了时滞对平衡点的稳定性和Hopf分支影响,指出了随着时滞的变化,平衡点由稳定变为不稳定,产生Hopf分支现象且一定条件下会出现分支周期解.数值模拟例证了分析结果.     

具有阶段结构和群体防卫的脉冲捕食系统

讨论了食饵具有群体防卫和捕食者具有阶段结构的脉冲控制捕食系统,根据Floquet乘子理论和脉冲比较定理,获得了食饵（害虫）灭绝周期解局部稳定与系统持续生存的充分条件．利用Matlab软件对害虫灭绝周期解和害虫周期爆发现象进行了数值模拟,并揭示了诸如高倍周期振荡,混沌,吸引子突变等复杂的动力学现象．得出的结论为害虫治理提供了可靠的策略依据．     

非自治阶段结构合作系统的持久性与周期解

本文研究一类非自治阶段结构的合作系统,得到系统的最终有界性,对应周期系统正周期解的存在性,唯一性以及全局渐近稳定性的充分条件。     

Existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems with several deviating arguments.

In this paper, we study the existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems. By using the method of coincidence degree and Lyapunov functional, a set of easily verifiable sufficient conditions are derived for the existence of at least one strictly positive (componentwise) periodic solution of periodic n-species Lotka-Volterra competition systems with several deviating arguments and the existence of a unique globally asymptotically stable periodic solution with strictly positive components of periodic n-species Lotka-Volterra competition system with several delays. Some new results are obtained. As an application, we also examine some special cases of the system we considered, which have been studied extensively in the literature. Some known results are improved and generalized.     

Periodic solution of a chemostat model with Monod growth rate and impulsive state feedback control

In this paper, we develop a mathematical model concerning a chemostat with impulsive state feedback control to investigate the periodicity of bioprocess. By the existence criteria of periodic solution of a general planar impulsive autonomous system, the conditions under which the model has a periodic solution of order one are obtained. Furthermore, we estimate the position of the periodic solution of order one and discuss the existence of periodic solution of order two. The theoretical results and numerical simulations indicate that the chemostat system with impulsive state feedback control either tends to a stable state or has a periodic solution, which depends on the feedback state, the control parameter of the dilution rate and the initial concentrations of microorganisms and substrate.     

Almost periodic solution of non-autonomous Lotka-Volterra predator-prey dispersal system with delays

This paper studies a non-autonomous Lotka-Volterra almost periodic predator-prey dispersal system with discrete and continuous time delays which consists of n-patches, the prey species can disperse among n-patches, but the predator species is confined to one patch and cannot disperse. By using comparison theorem and delay differential equation basic theory, we prove the system is uniformly persistent under some appropriate conditions. Further, by constructing suitable Lyapunov functional, we show that the system is globally asymptotically stable under some appropriate conditions. By using almost periodic functional hull theory, we show that the almost periodic system has a unique globally asymptotical stable strictly positive almost periodic solution. The conditions for the permanence, global stability of system and the existence, uniqueness of positive almost periodic solution depend on delays, so, time delays are "profitless". Finally, conclusions and two particular cases are given. These results are basically an extension of the known results for non-autonomous Lotka-Volterra systems.     

具有时滞和基于比率的一类捕食者-食饵系统全局周期解的存在性

利用重合度理论研究一类具有时滞和基于比率的捕食者-食饵系统的全局周期解的存在性,得到了周期正解存在的充分条件。     

具有阶段结构的两种群竞争系统的周期解

本文研究了具有阶段结构的两种群竞争系统的渐近行为.我们得到了系统持续生存的条件.由Brouwer不动点定理和李亚普诺夫函数,我们证明相应的周期系统在满足一定的条件下,存在一个唯一的全局渐近稳定的正周期解.最后我们把没有阶段结构的系统与有阶段结构的系统进行了比较.     

关于一类非自治阶段结构捕食系统的持久性与周期解

本文研究了一类非自治阶段结构捕食系统的渐近性质,得到在适当的条件下系统的持久性,对应周期系统正周期解的存在性、唯一性以及全局渐近稳定性。     

状态依赖脉冲微分方程的周期解的存在性及其在害虫治理中的应用

在文献[1]中研究的状态依赖脉冲微分方程的基础上,推广了其中的判定一般性平面自治状态依赖脉冲微分方程的准则,并利用它得到了文献[1]中所没有涉及到的情况下的状态依赖脉冲微分方程的阶一周期解☆栌在性．之后本文以此为基础并结合数值模拟的手段讨论了系统在农业害虫治理中的一些应用意义．     

State-dependent impulsive models of integrated pest management (IPM) strategies and their dynamic consequences

A state-dependent impulsive model is proposed for integrated pest management (IPM). IPM involves combining biological, mechanical, and chemical tactics to reduce pest numbers to tolerable levels after a pest population has reached its economic threshold (ET). The complete expression of an orbitally asymptotically stable periodic solution to the model with a maximum value no larger than the given ET is presented, the existence of which implies that pests can be controlled at or below their ET levels. We also prove that there is no periodic solution with order larger than or equal to three, except for one special case, by using the properties of the LambertW function and Poincare map. Moreover, we show that the existence of an order two periodic solution implies the existence of an order one periodic solution. Various positive invariant sets and attractors of this impulsive semi-dynamical system are described and discussed. In particular, several horseshoe-like attractors, whose interiors can simultaneously contain stable order 1 periodic solutions and order 2 periodic solutions, are found and the interior structure of the horseshoe-like attractors is discussed. Finally, the largest invariant set and the sufficient conditions which guarantee the global orbital and asymptotic stability of the order 1 periodic solution in the meaningful domain for the system are given using the Lyapunov function. Our results show that, in theory, a pest can be controlled such that its population size is no larger than its ET by applying effects impulsively once, twice, or at most, a finite number of times, or according to a periodic regime. Moreover, our theoretical work suggests how IPM strategies could be used to alter the levels of the ET in the farmers' favour.