GLOBAL EXISTENCE OF POSITIVE PERIODIC SOLUTION FOR A NEUTRAL DELAY COMPETITIVE SYSTEM

In this paper, by means of Mawhin's coincidence degree theory and somenew techniques, sufficient conditions for the global existence of positive periodicsolution to a class of neutral type competitive system with delays are obtained.     

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。     

EXISTENCE OF POSITIVE PERIODIC SOLUTION OF MUTUALISM SYSTEM WITH INFINITE DELAYS

In this paper, by using Mawhin coincidence degree, some sufficient conditions are obtained for the global existence of positive periodic solution of a mutualism system with infinite delays. Our results generalize those of Yang etc. [8] and Gopalsamy and He [7].     

EXISTENCE OF POSITIVE PERIODIC SOLUTION OF A DISCRETE TIME MUTUALISM SYSTEM WITH DELAYS

Discrete-time analogue of mutualism model is introduced. The discrete-time analogues is considered to be numerical discretization of the continuous-time models and we study their dynamical characteristics. It is shown that the discrete-time analogues preserve the periodicity of the continuous-time models.     

EXISTENCE OF POSITIVE PERIODIC SOLUTION TO A CLASS OF NEUTRAL DELAY COMPETITION MODEL

By means of the theory of coincidence degree, sufficient condition for the existence of positive periodic solution to certain neutral delay competition model is obtained.     

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.     

具有偏差变元的捕食者-食饵系统全局周期解的存在性

利用重合度理论中的延拓定理讨论了一类具有偏差变元的捕食者-食饵系统全局周期解的存在性,得到了一些新结果。     

EXISTENCE OF MULTIPLE PERIODIC SOLUTIONS TO THREE-SPECIES DELAYED LOTKA-VOLTERRA MODEL WITH DISPERSION AND HARVESTING

The positive periodic solutions to a three-species delayed Lotka-Volterra model with dispersion and harvesting terms are studied in this paper. By the coincidence degree theory, the sufficient conditions for existence of eight positive periodic solutions to the model are obtained.     

EXISTENCE AND GLOBAL ATTRACTIVITY OF POSITIVE PERIODIC SOLUTION OF A LOGISTIC GROWTH SYSTEM WITH FEEDBACK CONTROL AND DEVIATING ARGUMENTS

1 IntroductionIn recent years5 the application of theories of functional differential equationsin mathematical ecology has been developed rapidIy. Various mathematicalmodels have been proposed in the study of population dynarnics, ecology andepidemic. Some of them are described as non-autonomous delay differentialequations. Many authors studied the dynamics of population with deIays whichis usefuI for the control of the population of the mankind, animals and theenvironment. One of the famous…     

具有偏差变元的三种群食物链系统的全局正周期解的存在性

利用重合度理论研究一类具有偏差变元的三种群食物链系统的全局正周期解的存在性，得到了一些新的结果。     

一类中立型时滞多物种生态竞争系统的周期正解

利用重合度理论和某些新技巧建立了一类中立型时滞多物种生态竞争系统的周期正解存在的充分条件.     

一类非线性项前系数可变号的高阶Duffing方程的周期解存在性问题

利用Fourier级数理论,伯努利数理论和重合度理论研究了一类具偏差变元的高阶泛函微分方程$x^{(m)}(t)+\beta (t)g(x(t-\tau(t)))=p(t)$的周期解问题,得到了周期解存在性的新结论,有意义的是非线性项前的系数$\beta(t)$可变号,但是,周期解先验界估计方法与已有工作不同.     

周期捕食与被捕食系统正周期解的稳定性

本文研究具周期系数的Ｌｏｔｋａ－Ｖｏｌｔｅｒｒａ捕食与被捕食系统，建立了系统正周期解渐近稳定和全局稳定的新的判别准则。     

EXISTENCE OF POSITIVE PERIODIC SOLUTION FOR A DELAYED PERIODIC PREDATOR-PREY MODEL OF IVLEV TYPE

A periodic coefficients predator-prey system of Ivlev type with both discrete and continuous time delay is investigated. A sufficient condition of the existence of positive periodic solution is established for the system by using the continuation theorem of coincidence degree theory.     

POSITIVE PERIODIC SOLUTIONS OF A CLASS OF DISCRETE TIME SYSTEM WITH DELAYS AND A FEEDBACK CONTROL

With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, sufficient conditions are established for the existence of periodic solutions of a class of discrete differential system with delays and feedback control.     

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.     

PERIODIC SOLUTIONS FOR A CLASS OF DELAYED NONLINEAR DIFFERENCE EQUATIONS

With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree,some sufficient conditions are established for the global existence of positive periodic solutions of a class of delayed nonlinear difference equations.     

具有多个时滞的周期Lotka-Volterra系统(英文)

1 IntroductionThe LotkaVOlterra system is a rudimentary model on mathematical ecologyand has been studied extensively; one can see that the two--species predator-prey nonautonomous LotkaVolterra system and the two-predator and one-prey periodic Lotka-VOlterra system have been investigated, respectively, in[21 and [31. Some sufficient conditions are obtained for the (unifOrm) persi-stence, existence and uniqueness, and asymptotic stability of periodic solu-tions. Furthermore, the similar re…     

THE EXISTENCE OF POSITIVE PERIODIC SOLUTIONS IN A LOGISTIC DIFFERENCE MODEL WITH A FEEDBACK CONTROL

Consider the following nonautonomous delayed periodic logistic difference model with feedback control termwhich describes the evolution of a single species. The existence of a positive periodic solution is established by using the method of Mawhin's coincidence degree. This work has important significance in both theory and applications.     

PERIODIC SOLUTIONS FOR A DISCRETE TIME RATIO-DEPENDENT TWO PREDATOR-ONE PREY SYSTEM

In this paper, we consider a three-species ratio-dependent predator-prey model governed by difference equations with periodic coefficients. By using the method of coincidence degree, we discuss the existence of positive periodic solutions of this system, a set of easily verifiable sufficient conditions are derived.