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1.
本文考虑单种群非自治缀块扩散的竞争系统,利用微分不等式,证明了系统存在唯一的正概周期解,它在壳的扰动下是稳定的.  相似文献   

2.
讨论了一类食饵具有性别结构,捕食者具有阶段结构的非自治捕食者.食饵系统,运用Liapunov函数方法,得到了该系统一致持续生存的充分条件.对于该模型的周期系统,在适当条件下,存在唯一、全局渐近稳定的周期解.对更具普遍意义的概周期现象,也得出了概周期正解唯一存在且全局渐近稳定的充分条件.  相似文献   

3.
具有时滞和功能反应的捕食者-食饵缀块系统的持久性   总被引:4,自引:2,他引:2  
研究了具有Michaelis-Menten类型功能反应的三种群捕食者-食饵缀块系统,得到持久性的条件。  相似文献   

4.
具有Holling Ⅳ类功能反应的三维顺环捕食者-食饵模型   总被引:8,自引:0,他引:8  
考虑具有Holling Ⅳ类功能反应三维顺环捕食者一食饵系统,利用常微分方程比较定理及Liapunov函数方法,得到了该系统持久性的充分条件,并且对于周期系统在一定条件下。系统存在唯一一个全局渐进稳定的周期正解,最后讨论了概周期解现象,得出了概周期正解的唯一存在性和全局渐进稳定性的充分条件。  相似文献   

5.
讨论了一类具有庇护所的自治三种群捕食者一食饵模型,运用Liapunov函数方法,得到了该模型持久性的充分条件.对于该模型的周期系统,在一定的条件下,将产生唯一一个全局渐近稳定的周期正解.对更具普遍意义的概周期现象,也得出了概周期正解唯一存在且全局渐近稳定性的充分条件.  相似文献   

6.
本文研究了一般的m缀块上n种群Lotka-Volterra合作系统的渐近性,在适当条件下证明了此系统能持续生存,对于周期系统其周期解是存在唯一的。  相似文献   

7.
本文研究了一类具有功能反应周期的捕食食饵模型,其中捕食者是非密度制约的.我们得到使系统持久灭绝,周期解存在的积分形式的充分条件.把一些关于捕食者密度制约的重要的结论推广到了捕食者非密度制约的情形.  相似文献   

8.
具有扩散和放养的时滞竞争系统的正周期解   总被引:1,自引:0,他引:1  
主要研究缀块环境下具有扩散和放养的时滞Lotka-Volterra竞争系统,得到了系统的周期解存在性,唯一性和全局渐近稳定性的充分条件.  相似文献   

9.
提出了一类具有时滞的一个捕食者一两个竞争被捕食者生态动力学模型.首先,利用Krasnoselskii不动点定理研究了系统的正周期解的存在性;然后通过构造Lyapunov函数方法获得了正周期解全局收敛的一个充分条件:最后.给出一个例子以验证理论结果的正确性.  相似文献   

10.
一类捕食者-食铒系统正周期解的存在性   总被引:5,自引:1,他引:4  
利用重合度理论中的延拓定理研究了一类具有HollingⅡ型功能性反应的捕食者-食铒系统非平凡周期解的存在性,其中食饵种群服从Smith增长,捕食者种群具有密度制约效应。得到了存在正周期解的充分性判据,推广并改进了已知的相关结果。  相似文献   

11.
具有扩散的非自治两种群Lotka-Volterra模型的概周期问题   总被引:9,自引:0,他引:9  
研究非自治两种群竞争系统,其中一种群可以在两个斑块之间扩散。而另一种群在一个斑块中,不能扩散。本文结合运用Liapunov函数,得到该系统唯一存在全局渐近稳定的正概周期解的条件.  相似文献   

12.
OneOfthemostintereStingquestionSintnathematiedbiologyconcernsthes~ofSpecsinecologicalmodels.Forautonomoussystemwhichhavenodiffusion,therearemanyliteraturesabout~istenceanddondnance[1,2,3j.R~ly,manyauthorsfindthatthediffusionpzocessineCOIOgitalsystemPlaysanimPOrtantrole.Infact,diffusionoftenoccursinnatural~icalenvironxnent,thatistosay,whenonepatchisnotvaluabletolivein-spotescan~tOanother.SoLevin[4)firsteStablishedthemedelabbotautonomousLDthe-VolterraSystemwithdiffusionprocess.AfterLevin…  相似文献   

13.
1IntroductionOneofthemOStnit~tingquestionsinrnathernaticalbiologyconcernsthesurvivalofspeCiesinecologiCalmodels.Perslstenceisanimportantconceptindabingwiththeseproblems.Therearemanyliteraturesaboutthedy'ndricsofdiffuSivecompetingspeCies,butthefunctionalresPOnseofthisfOITnhasnotbeenst'Udiedtoomuchyet.Inthispaper,weconsiderthepersistenceproblemforanonautonomoussystemoftwOcompetingspecieswithfunctionalreSPOnse,themodelweconsiderinthispaperishereallri(t),ail(t),D,(t)anda(t)areassumedtobecon…  相似文献   

14.
Persistence and periodic orbits of a three-competitor model with refuges.   总被引:5,自引:0,他引:5  
We consider a model composed of four patches. One patch has three competing species forming a heteroclinic cycle within the patch. The remaining patches are refuges for the three competitors, and each species can diffuse between the competitive patch and its refuge. It is proved that the model can be made persistent by the introduction of the refuges for the competitors even if the isolated competitive patch has an attracting heteroclinic cycle. Further it is shown that Hopf bifurcation is possible when we change the value of the diffusion constant and periodic orbits may exist in a specific case.  相似文献   

15.
具有分离扩散的两种群Lotka—Volterra模型的持久性   总被引:1,自引:1,他引:0  
本文考虑具有分离扩散的捕食-被捕食系统的持续性。此模型由两种群组成,其中被捕食种群可在两个生态环境中生存,而捕食种群仅能在一个生态环境中生存,两种群的动态行为都用Lotka-Volterra模型来描述。得到了系统强持续的充分必要条件,并证明了无论无扩散时系统是共存的,还是主导的都可以适当选择分离扩散系数使整个系统强持续。  相似文献   

16.
本文讨论有时滞的扩散系统,此系统有两个种群两个斑块,其中一种种群可以在两斑块中自由扩散,另一种群被限定在斑块中不能扩散,当系数数满足一定的条件时,得到系统有持续生存和全局稳定的解。  相似文献   

17.
In most models of population dynamics, diffusion between two patches is assumed to be either continuous or discrete, but in reality, many species diffuse only during a single period, and diffusion often occurs in regular pulses. Further, in forest habitats, the highest-level predator species are restricted to a specific territory, but prey can impulsively move between territories. Therefore, in this paper, we consider a delayed stage-structured predator–prey model with impulsively diffusive prey between two patches; in the model, patches represent the territories of two different predator populations. Here, we analytically obtain the global attractivity condition of predator-extinction periodic solutions for the system by using the concepts of Hui and Chen (2005); a numerical simulation is also included to illustrate this result. Further, we establish permanence conditions for the coexistence of the species using the theory of impulsive delayed differential equations. Finally, we explore the possibilities of the permanence of the system by using the growth rates of immature predators and the impulse period as critical parameters, and we also obtain the parameters’ threshold limits using numerical experimentation.  相似文献   

18.
We consider a model in which the need to forage and the need to avoid a competitor are in conflict. The model is composed of two Lotka-Volterra patches. The system has two competitors; one can diffuse between two patches, but the other is confined to one of the patches and cannot diffuse. It is proved that the system can be made persistent under appropriate diffusion conditions that ensure the instability of boundary equilibria, even if the competitive patch is not persistent without diffusion. Further it is shown that the system is globally stable for any diffusion rate if the competition between the two species is weak.  相似文献   

19.
结合运用Liapunov泛函数,研究二维Lotka-Volterra捕食系统周期正解的存在唯一性。  相似文献   

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