ON THE PERSISTENCE AND POSITIVE PERIODIC SOLUTION FOR PLANAR COMPETING LOTKA-VOLTERRA SYSTEMS

1IntroductionLetusa;onsi~~l'tile2-(1llTlellsiollalco'ttipetit;ion1,of-,ha--\./O]1,'lrra,s:\,s(t()lcfl.r]=.r,(l)j(t)--a,1(-t)xl--a,,(lt)x,),,.(II)ac=ac(6~(t-)--a21(t)x,--a22(t);rZ),xvhere(J:,.:x'2)eR;,~{(;t:l,.xZ)la:l20,IZ.20},l),(l),ail(t)fi{~j:lar(>conti…     

非自治Lotka-Volterra竞争生态系统的绝灭性和持久性

研究一般n个竞争种群的非自治Lotka-Volterra生态系统．得到了该系统一致持续生存和绝灭性的新的判别准则，这些结果改进和推广了文献[1，2]中的主要结果．     

具有时滞和基于比率的三种群捕食系统的持久性与全局渐近稳定性

研究一类具有时滞和基于比率的三种群食物链捕食-被捕食动力学模型.证明了该系统在适当条件下的一致持久性;通过构造Lyapunov泛函,得到了该系统正平衡点全局渐近稳定的充分条件.     

STABILITY OF TIME VARYING SINGULAR DIFFERENTIAL SYSTEMS WITH DELAY

In this paper, stability of time varying singular differential systems with delay is considered. Based on variation formula and Gronwall-Bellman integral inequality, we obtain the exponential estimation of the solution and the sufficient conditions under which the considered system is stable and exponentially asymptotically stable. These results will be very useful to further research on Roust stability and control design of uncertain singular control systems with delay.     

PERSISTENCE OF NONAUTONOMOUS PREDATOR-PREY SYSTEMS WITH INFINITE DELAY

Nonautonomous predator-prey systems with infinite delay is considered at phase space Cg in this paper. Some suitable conditions of persistence of the populations are obtained. The results are different from ones of Wang Ke which was considered in phase space Ch     

PERSISTENCE AND GLOBAL STABILITY FOR TWO-SPECIES NONAUTONOMOUS PREDATOR-PREY SYSTEM WITH DIFFUSION AND TIME DELAY

In this paper, a non-autonomous predator-prey model with diffusion andcontinuous time delay is studied, where the prey can diffuse between two pat-ches of a heterogeneous environment with barriers between patches, but for thepredator, the diffusion does not involve a barrier between patches, further itis assumed that all the parameters are time-dependent. It is shown that thesystem can be made persistent under some appropriate conditions. Moreover,sufficient conditions that guarantee the existence of a unique periodic solutionwhich is globally asymptotic stable are derived.     

具有缓变系数的线性时滞系统的稳定性

关于滞后型泛函微分方程的稳定性，本文给出了更一般的判别准则，推广了Ｐａзｙмихин的结果。并将所得结论用于考察具有缓变系数的线性时滞系统的稳定性，放宽了通常的对系统系数矩阵特征值的限制，给出了直接由系统右端系数计算的简明的稳定性判据。     

PERSISTENCE AND STABILITY OF A DISCRETE PERIODIC PREDATOR-PREY MODEL

In this paper,we investigate the persistence and global asymptotic stability of a discrete predator-prey system.Based on Lyapunov functions,several crite- ria are established concerning the persistence and globally asymptotic stability of difference systems.     

PERSISTENCE AND GLOBAL STABILITY FOR A THREE-SPECIES RATIO-DEPENDENT PREDATOR-PREY SYSTEM WITH TIME DELAYS IN TWO-PATCH ENVIRONMENTS

A three-species ratio-dependent predator-prey diffusion model with time de-lays is investigated. It is shown that the system is uniformly persistent under some ap-propriate conditions, and sufficient conditions are obtained for the global stability of the positive equilibrium of the system.     

时变退化时滞微分系统的变易公式

本文将研究时变退化时滞微分系统.给出了该类系统的变易公式.这将在进一步研究退化时滞微分系统时十分有用.     

时变退化时滞微分系统的变易公式

本文将研究时变退化时滞微分系统.给出了该类系统的变易公式.这将在进一步研究退化时滞微分系统时十分有用.     

ON CRITERIA FOR GLOBAL STABILITY OF N-DIMENSIONAL LOTKA-VOLTERRA SYSTEMS

This paper gives the conditions for the existence of a globally stable equi-librium of rz-dimensional Lotka-Volterra systems in the following cases: Lotka-Volterra chain systems and Lotka-Volterra modei between one and multispecies. The conditions obtained in this paper are much weaker than those in [6] and more easily verifiable in application. So the results can be applied to more general Lotka-Volterra models. At the same time, the existence and stability conditions of positive equilibrium points of the above systems are given.     

GLOBAL ASYMPTOTIC STABILITY IN N-SPECIES NONAUTONOMOUS LOTKA-VOLTERRACOMPETITIVE SYSTEMS WITH DELAYS

A delayed n-species nonautonomous Lotka-Volterra type competitive system without dominating instantaneous negative feedback is investigated. By means of a suitable Lyapunov functional, sufficient conditions are derived for the global asymptotic stability of the positive solutions of the system. As a corollary, it is shown that the global asymptotic stability of the positive solution is maintained provided that the delayed negative feedbacks dominate other interspecific interaction effects with delays and the delays are sufficiently small.     

PERMANENCE OF ASYMPTOTICALLY PERIODIC MULTISPECIES LOTKA-VOLTERRA COMPETITION PREDATOR-PREY SYSTEM

In this paper, we consider the permanence of asymptotically periodic mul-tispecies Lotka-Volterra competition predator-prey system. By means of the standard comparison theorem, we improve or extend the corresponding results given by Peng and Chen [1], Teng and Li [2], Zhao and Chen [3]. Also, we obtain the conditions which ensure the permanence and global attractivity of asymptotically periodic multispecies competition predator-prey system.     

时变仿射非线性系统的动态补偿线性化

用微分几何方法讨论了时变仿射非线性系统的动态补偿线性化问题，给出了系统动态的反馈线性化的条件，它是状态反馈线性化的推广。     

具有扩散的捕食与被捕食系统的持续性和稳定性

本文研究了一类具有扩散和时滞的捕食与被捕食系统,证明了在适当条件下系统 是一致持续的,利用同伦技术证明了正平衡点的存在性,构造适当的Lyapunov函数获得 了正平衡点的局部和全局稳定的充分条件.     

带有干扰的线性时变系统变结构鲁棒控制器

对含有未知时变参数和系统干扰的单输入单输出线性时变系统,给出了一种输出跟踪变结构鲁棒控制器设计机制．系统参数只要求光滑有界,没有其它限制条件．通过引入辅助信号和带有记忆功能的正规化信号以及适当选择控制器参数,该变结构控制器能保证闭环系统所有信号有界,跟踪误差能被调整到任意小．     

GLOBAL ASYMPTOTIC STABILITY OF PERIODIC SOLUTION IN N-SPECIES COMPETITION SYSTEM WITH TIME DELAYS

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两种群非自治Lotka-Volterra竞争扩散系统的概周期解

本文讨论两种群概周期竞争扩散系统，利用微分不等式，证明了系统概周期解的存在、唯一性及其在壳扰动下的稳定性．     

POSITIVE ALMOST PERIODIC SOLUTIONS OF n DIMENSIONAL NONAUTONOMOUS LOTKA-VOLTERRA COMPETITIVE SYSTEMS

In this paper,we study some n dimensional nonautonomous Lotka-Volterra competitive ecological systems.We then obtain permanence of such systems, as well as the existence,uniqueness and global asymptotic stability of almost periodic positive solutions to these systems.