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1.
本文研究了具有脉冲和时滞效应的Logistic模型.利用脉冲微分方程的比较定理,BohlBrower不动点定理和Lyapunov函数法,获得了系统持续生存,正周期解存在、唯一以及全局吸引的充分条件.结果表明正周期解的全局吸引性与时滞有关.  相似文献   

2.
In this paper we consider the nonlinear impulsive delay population model. The main objective is to systematically study the qualitative behavior of the model including existence of periodic solutions, global attractivity and oscillation. The main oscillation results are the results of the prevalence of the mature cells about the periodic solutions and the global attractivity results are the conditions for nonexistence of dynamical diseases on the population.  相似文献   

3.
本文研究平方 Logistic型时滞微分方程在脉冲条件下的全局吸引性 ,获得了保证方程每一解趋于 0的充分条件 .  相似文献   

4.
By using Mawhin continuation theorem,an important lemma and some analysis techniques,sufficient conditions ensuring the existence and global attractivity of positive periodic solutions for an impulsive differential equation with time varying delay are investigated.  相似文献   

5.
Sufficient conditions are obtained for the existence and global attractivity of positive periodic solution of an impulsive delay differential equation with Allee effect. The results of this paper improve and generalize noticeably the known theorems in the literature.  相似文献   

6.
The periodicity of an impulsive delay Lasota-Wazewska model is discussed. Sufficient and necessary condition for the existence of a positive periodic solution is established. Sufficient conditions for its global attractivity are also obtained via the methods of Lyapunov function and comparison.  相似文献   

7.
本文研究了一类具有时滞的脉冲抛物型方程在Neumann边值条件下解的存在性问题,利用定义上下解对的方法,给出了一个新的解的存在性定理和比较原理.作为例子,当把这种方法应用到一种群模型中时,得到了该系统正平衡点全局吸引的新结果.  相似文献   

8.
An impulsive differential equation with time varying delay is proposed in this paper. By using some analysis techniques with combination of coincidence degree theory, sufficient conditions for the permanence, the existence and global attractivity of positive periodic solution are established. The results of this paper improve and generalize some previously known results.  相似文献   

9.
讨论了与害虫管理相关的一类捕食者具脉冲扰动与相互干扰的阶段结构时滞捕食-食饵模型,得到了害虫灭绝周期解的全局吸引和系统持久的充分条件,也证明了系统的所有解的一致完全有界.我们的结论为现实的害虫管理提供了一定的理论依据.  相似文献   

10.
In this paper, a new stage-structured delay ecosystem with impulsive effect is formulated and some dynamical properties of this system is investigated.By using comparison theorem and the stroboscopic technique, we prove the existence of the predator-extinction periodic solution of this system and obtain some sufficient conditions to guarantee the global attractivity of the prey-extinction periodic solution. In the final, we also obtain the permanence of this system. It should be pointed out that the new mathematical method used in this paper can also be applied to investigate such other ecosystems corresponding to both impulsive and delay differential equations.  相似文献   

11.
Uncontrolled contribution of pollutant to the environment has led many species to extinction and several others are at the verge of extinction. This article deals with the dynamics of a single stage-structured population model with impulsive toxin input and time delays (including constant individual maturation time delay and pollution time delay) in a polluted environment, in which we assume that only the mature individuals are affected by pollutants. We obtain conditions for the global attractivity of the population-extinction periodic solution and the permanence of the population. We show that maturation time delay and impulsive toxin input can bring great effects on the dynamics of the system, and pollution time delay is harmless. Numerical simulations confirm our theoretical results.  相似文献   

12.
This paper studies the nonlinear delay impulsive respiratory dynamics model. The model describes the sudden changes of the concentration of CO2 in the blood of the mammal. It is proved that the model has a unique positive periodic solution. Some sufficient conditions for oscillation of all positive solutions about the positive periodic solution are established and also some sufficient conditions for the global attractivity of the periodic solution are obtained.  相似文献   

13.
In this paper, a new delay SIR epidemic model with pulse vaccination and incubation times is considered. We obtain an infection-free semi-trivial periodic solution and establish the sufficient conditions for the global attractivity of the semi-trivial periodic solution. By use of new computational techniques for impulsive differential equations with delay, we prove that the system is permanent under appropriate conditions. The results show that time delay, pulse vaccination and nonlinear incidence have significant effects on the dynamics behaviors of the model. Our results are illustrated and corroborated with some numerical experiments.  相似文献   

14.
In this paper, we consider a stage-structured pest management SI model with time delay and diseased pests impulsive transmission. We obtain the sufficient conditions of the global attractivity of pest-extinction boundary periodic solution and the permanence of the system. We also prove that all solutions of the system are uniformly ultimately bounded. Our results provide a reliable tactic basis for the practice of pest management.  相似文献   

15.
考虑了一类新的污染环境下具有时滞增长反应及脉冲输入的Monod恒化器模型.运用离散动力系统的频闪映射,获得了一个‘微生物灭绝’周期解,进一步获得了该周期解全局吸引的充分条件.运用脉冲时滞泛函微分方程新的计算技巧,证明了系统在适当的条件下是持久的,结论还表明该时滞是“有害”时滞.  相似文献   

16.
In this paper, we study the existence of almost periodic solutions of a delay logistic model with fixed moments of impulsive perturbations. By using a comparison theorem and constructing a suitable Lyapunov functional, a set of sufficient conditions for the existence and global attractivity of a unique positive almost periodic solution is obtained. As applications, some special models are studied; our new results improve and generalize former results.  相似文献   

17.
In this paper, an impulsive delay predator–prey model with stage structure and Beddington-type functional response is established. By using the discrete dynamical system determined by the stroboscopic map, we obtain the existence and global attractivity of the predator-extinction periodic solution. By use of the theory on delay and impulsive differential equation, we study the permanence of the system. Finally, an example is given to show the effectiveness of the main results.  相似文献   

18.
In this paper, we investigate a stage-structured predator-prey model with periodic harvesting (catching or poisoning) for the prey and stage structure for the predator with constant maturation time delay. Sufficient conditions which guaranteed the global attractivity of predator-extinction periodic solution and permanence of the system are obtained. Furthermore, influences of the impulsive perturbation on the inherent oscillation are studied, which exhibits a wide variety of dynamic behaviors by numerical simulations.  相似文献   

19.
This paper provides sufficient conditions that guarantee theglobal attractivity of the zero solution of a delay populationmodel under impulsive perturbations.  相似文献   

20.
A three-species Lotka-Volterra type food chain model with stage structure and time delays is investigated. It is assumed in the model that the individuals in each species may belong to one of two classes: the immatures and the matures, the age to maturity is presented by a time delay, and that the immature predators (immature top predators) do not have the ability to feed on prey (predator). By using some comparison arguments, we first discuss the permanence of the model. By means of an iterative technique, a set of easily verifiable sufficient conditions are established for the global attractivity of the nonnegative equilibria of the model.  相似文献   

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