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1.
具有脉冲效应非自治捕食系统的研究   总被引:2,自引:2,他引:0  
研究了具有脉冲效应的非自治捕食系统,该系统是两个具有互惠关系的食饵种群被一个捕食种群捕食.利用重合度理论证明系统正周期解的存在性.  相似文献   

2.
研究了生态学中含控制策略项的一类Filippov捕食-被捕食系统,由于害虫的环境容纳量受外界环境因素的影响而变化,故将害虫的环境容纳量视为周期慢变量,当慢变量的频率与系统的固有频率存在量级差异时,使得该Filippov捕食-被捕食系统体现出两时间尺度效应.通过将周期演变的环境容纳量视为控制参数,针对相应的广义自治系统,进行了平衡点的稳定性与分岔分析.借助于快慢分析法、微分包含理论,得到了在典型参数条件下,系统展现的一些特殊分岔模式,并对相关的机理予以了解释,由此丰富了对该类Filippov捕食-被捕食系统的研究.  相似文献   

3.
本文以经典的带有时滞的捕食-被捕食系统为基础,构造了一类泛函微分方程作为描述分布在由n个岛屿构成的环状区域上的捕食-被捕食种群生长过程的模型.我们假设种群在最相邻的岛屿间相互迁移,以迁移率为分支参数,研究了该系统的锁相振动,给出了离散波分支的存在条件.  相似文献   

4.
魏俊杰  吴建宏 《数学学报》1996,39(4):566-573
本文以经典的带有时滞的捕食-被捕食系统为基础,构造了一类泛函微分方程作为描述分布在由n个岛屿构成的环状区域上的捕食-被捕食种群生长过程的模型.我们假设种群在最相邻的岛屿间相互迁移,以迁移率为分支参数,研究了该系统的锁相振动,给出了离散波分支的存在条件.  相似文献   

5.
建立了发生食饵避难的Leslie-Gower捕食与被捕食系统模型,考虑对捕食种群进行有选择捕获.通过控制税收量加以管理来保护渔业资源不被过渡开发,且讨论了系统平衡点的存在性和稳定性,运用Pontryagin最大值原理得到了达到最优税收量的最优平衡解.  相似文献   

6.
本文获得了一类捕食和被捕食系统持久性的充分条件 ,推广了文 [1]的部分结果  相似文献   

7.
本文利用单调逼近方法,研究带大小结构的捕食-被捕食系统的初边值问题,得到了系统解的存在唯一性,并且证明了序列是线性收敛的.  相似文献   

8.
周期捕食与被捕食系统正周期解的稳定性   总被引:5,自引:0,他引:5  
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。  相似文献   

9.
捕食者和被捕食者都具有密度制约的捕食-被捕食模型更符合实际的生物环境,也更有一定的现实意义,所以该文考虑了密度制约且具有Beddington-DeAngelis功能反应函数的时滞捕食-被捕食系统.首先,给出系统的稳定性变换为后面讨论分支周期解做好准备.其次,由中心流形定理和规范型理论,得到Hopf分支关于分支方向、稳定性以及周期情况的特性指标.最后,在数值模拟这部分对系统稳定性变换和系统的Hopf分支进行了验证.  相似文献   

10.
离散Leslie捕食与被捕食系统周期解的稳定性   总被引:4,自引:0,他引:4       下载免费PDF全文
该文讨论了一类离散Leslie捕食与被捕食系统,获得了该系统的持久性,当系统为周期系统时,得到了它的周期解的存在性,并且在某些条件下,该周期解是全局稳定的.  相似文献   

11.
GLOBALANALYSISOFACLASSOFCUBICSYSTEMSWangXian(王现)(NanjingUniversity,南京大学,邮编:210093)Abstract:Thepapergivesacompletegolbalphasep...  相似文献   

12.
BIFURCATION OF PERIODIC ORBITS OF A THREE-DIMENSIONAL SYSTEM   总被引:1,自引:0,他引:1  
§ 1 . IntroductionThere has been a general theory on bifurcation of periodic orbits for two or higher-dimensional systems, and the theory for two-dimensional systems is much richer than thatfor higher-dimensional systems (see [1–11]). We have a relative…  相似文献   

13.
1引言 抛物型方程是一类十分重要的方程,它出现在很多数学物理问题中,对这类方程的研究已有大量工作,如[10-12]等.随着无穷维动力系统研究的深入,人们越来越关心系统的长时间性态,而追踪系统长时间性态很大程度上依赖数值计算.  相似文献   

14.
In this note it is shown that the Vlasov-Poisson-Fokker-Planck system in the three-dimensional whole space driven by a time-periodic background profile near a positive constant state admits a time-periodic small-amplitude solution with the same period. The proof follows by the Serrin's method on the basis of the exponential time-decay property of the linearized system in the case of the constant background profile.  相似文献   

15.
讨论一类三维系统在周期扰动下的分支问题.假设此三维系统有一族闭轨,利用 Poincar\'e映射及积分流形定理,得到了在周期扰动下由这族闭轨产生次调和解和不变环面的条件,并讨论了次调和解的鞍结点分支.  相似文献   

16.
The SEIR epidemic model studied here includes constant inflows of new susceptibles, exposeds, infectives, and recovereds. This model also incorporates a population size dependent contact rate and a disease-related death. As the infected fraction cannot be eliminated from the population, this kind of model has only the unique endemic equilibrium that is globally asymptotically stable. Under the special case where the new members of immigration are all susceptible, the model considered here shows a threshold phenomenon and a sharp threshold has been obtained. In order to prove the global asymptotical stability of the endemic equilibrium, the authors introduce the change of variable, which can reduce our four-dimensional system to a three-dimensional asymptotical autonomous system with limit equation.  相似文献   

17.
研究具有反应一扩散现象的三维种群生态动力系统的参数识别问题,依该系统正问题解的性质,建立了参数识别的数学模型;论证了系统正问题解关于待识别参数的连续依赖性与参数识别问题最优解的存在性。  相似文献   

18.
Coupled system of multilayer dynamics of fluids in porous media is to describe the history of oil-gas transport and accumulation in basin evolution.It is of great value in rational evaluation of prospecting and exploiting oil-gas resources.The mathematical model can be described as a coupled system of nonlinear partial differential equations with moving boundary values.The upwind finite difference schemes applicable to parallel arithmetic are put forward and two-dimensional and three-dimensional schemes are used to form a complete set.Some techniques,such as change of variables,calculus of variations, multiplicative commutation rule of difference operators,decomposition of high order difference operators and prior estimates,are adopted.The estimates in l~2 norm are derived to determine the error in the approximate solution.This method was already applied to the numerical simulation of migration-accumulation of oil resources.  相似文献   

19.
Transonic shocks play a pivotal role in designation of supersonic inlets and ramjets. For the three-dimensional steady non-isentropic compressible Euler system with frictions, we constructe a family of transonic shock solutions in rectilinear ducts with square cross-sections. In this article, we are devoted to proving rigorously that a large class of these transonic shock solutions are stable, under multidimensional small perturbations of the upcoming supersonic flows and back pressures at the exits of ducts in suitable function spaces.This manifests that frictions have a stabilization effect on transonic shocks in ducts, in consideration of previous works which shown that transonic shocks in purely steady Euler flows are not stable in such ducts. Except its implications to applications, because frictions lead to a stronger coupling between the elliptic and hyperbolic parts of the three-dimensional steady subsonic Euler system, we develop the framework established in previous works to study more complex and interesting Venttsel problems of nonlocal elliptic equations.  相似文献   

20.
In this paper,we study a nematic liquid crystals system in three-dimensional whole space R~3 and obtain the time decay rates of the higher-order spatial derivatives of the solution by the method of spectral analysis and energy estimates if the initial data belongs to L~1(R~3) additionally.  相似文献   

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