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研究了一类具有收获率的扩散Leslie系统的周期解存在性.利用重合度理论中的延拓定理和一些分析技巧,获得了其至少存在八个正周期解的充分条件. 相似文献
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秦发金 《数学物理学报(A辑)》2009,29(6):1613-1622
该文研究了一类具有收获率和扩散的时滞阶段结构捕食系统周期解存在性问题,利用重合度理论中的延拓定理,通过一些分析技巧, 获得了该系统至少存在四个正周期解的充分条件. 相似文献
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本文讨论一类具有交叉扩散效应的捕食者-食饵系统的反应扩散方程组的时间周期解的存在性与稳定性.运用分歧理论、隐函数定理以及渐近展开的方法,获得了共存周期解的存在性与稳定性的结果. 相似文献
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本文利用重合度理论中的延拓定理讨论了具有连续时滞和比率型功能反应的非自治扩散竞争系统的正周期解的存在性,得到了正周期解存在的充分条件。 相似文献
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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 总被引:1,自引:0,他引:1
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. 相似文献
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时间测度上具有Holling-N类功能反应和扩散的捕食系统的周期解 总被引:1,自引:0,他引:1
在时间测度上研究了一类具有Holling-N类功能反应和扩散的捕食系统,利用Mawhin重合度理论建立了这类系统周期解存在的一些新的充分性判据,从而使这一类系统的连续与离散情形,即相应的微分方程和差分方程的周期解存在性问题得到了统一. 相似文献
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本文讨论了一类周期竞争扩散系统,给出了诺依曼边界条件下周期竞争扩散系统的周期解唯一的充分条件,并讨论了对应周期竞争扩散系统初边值问题解的渐近性态. 相似文献
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研究了一类含有五次非线性反应项和常数扩散项的反应扩散方程的小振幅孤立周期波解,以及它的行波方程局部临界周期分支问题.运用行波变换将反应扩散方程转换为对应的行波系统,应用奇点量方法和计算机代数软件MATHEMATICA计算出该系统的前8个奇点量,得到该系统奇点的两个中心条件,并证明行波系统原点处可分支出8个极限环,对应的非线性反应扩散方程存在8个小振幅孤立周期波解;通过周期常数的计算,得到了行波系统原点的细中心阶数,并证明该系统最多有3个局部临界周期分支,且能达到3个局部临界周期分支;通过分析行波系统的临界周期分支,得到该反应扩散方程有3个临界周期波长. 相似文献
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By treating the periodic Riccati equation ${\rm\dot{z}=a(t)z^2+b(t)z+c(t)}$ as a dynamical system on the sphere S, the number and stability of its periodic solutions are determined. Using properties of Moebius transformations, an exact algebraic relation is obtained between any periodic solution and any complex-valued periodic solution. This leads to a new method for constructing the periodic solutions. 相似文献
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An infinitely differentiable periodic two-dimensional system of differential equations is considered. It is assumed that there is a hyperbolic periodic solution and there exists a homoclinic solution to the periodic solution. It is shown that, for a certain type of tangency of the stable manifold and unstable manifold, any neighborhood of the nontransversal homoclinic solution contains a countable set of stable periodic solutions such that their characteristic exponents are separated from zero. 相似文献
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We call a one-way infinite word w over a finite alphabet (ρ,l)-repetitive if all long enough prefixes of w contain as a suffix a ρth power (or more generally a repetition of order ρ) of a word of length at most l. We show that each (2,4)-repetitive word is ultimately periodic, as well as that there exist continuum many, and hence also nonultimately periodic, (2,5)-repetitive words. Further, we characterize nonultimately periodic (2,5)-repetitive words both structurally and algebraically. 相似文献
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Lin Faxing 《数学年刊B辑(英文版)》1990,11(4):525-535
In this paper, it is obtained that a periodic system has an almost periodic solution if it has a solution x=\phi(t) uniformly stable with respect to \Omega_\phi ,and has a periodic solution if x=\phi(t) is weakly uniformly asymptotically stable with respect to \Omega_\phi. Meanwhile, it is also obtained that a uniformly almost periodic system has an almost periodic solution if it has a solution x=\phi(t) uniformly asymptotically stable with respect to A_\phi^j. 相似文献
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