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1.
周期捕食被捕食系统正周期解存在的充要条件 总被引:8,自引:2,他引:6
研究周期环境下的Lotka-Volterra捕食被捕食系统。采用分歧理论和微分不等式方法,建立了关于正周期解存在的一个充分必要判别准则,总结和推广了文[1—4]中的主要结果。 相似文献
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该文运用周期抛物型算子理论,Schauder估计和分歧理论讨论了一类周期反应扩散方程,即带扩散项捕食-食饵系统的周期解的存在性,得出了系统正周期解存在的充要条件. 相似文献
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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。 相似文献
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雷岩松 《高校应用数学学报(A辑)》1991,6(1):110-117
本文研究人口动力学中一类含时滞周期反应-扩散方程的正周期解问题;利用紧算子的全局分歧结果给出了这个方程正周期解存在的充分必要条件。 相似文献
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研究一类具有多时滞Holling II型功能性反应非自治捕食-被捕食系统, 利用重合度理论得到系统全局正周期解存在的充分条件.推广了相关的已有结果. 相似文献
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本文讨论了一类时滞微分方程正概周期解的存在性问题,利用锥中u_0-凹算子与增算子的性质,不仅得到了上述系统的正概周期解的存在性与非存在性的结论,还改进了现有的结果,并且我们的方法也适用于更一般的系统. 相似文献
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In the present paper,we consider the existence of positive periodic solu-tions for a kind of delay Logistic equations.By using a fixed point theorem in cones,we give some new existence results of single and multiple positive periodic solutionsfor a kind of delay Logistic equations.Some biomathematical models are presentedto illustrate our results. 相似文献
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考虑非线性脉冲微分方程{x'(t)=x(t)[a(t)-b(t)x^p(t)],t≠tk, △x|t=tk=ckx(tk),k∈N.得到了该方程存在正周期解的充要条件为m∏k=1(1+ck)^pexp(p∫^w 0)a(σ)dσ)>1. 相似文献
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具有常数输入的非自治SIR流行病模型周期解的存在性 总被引:1,自引:0,他引:1
胡新利 《纯粹数学与应用数学》2007,23(3):372-376,380
利用MAWHIN重合度理论中的延拓定理研究了一类具有常数输入的非自治SIR流行病模型的非平凡周期解的存在性.并用MatLab对其进行了数值模拟,作出了模型的相图和解曲线图形. 相似文献
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The existence, uniqueness and stability of positive periodic solution for periodic reaction-diffusion system 总被引:1,自引:0,他引:1
1. IntroductionLet fi e RN be a bounded open domain with smooth boundary afl, and for eachi E {1, 2,', m}, let Li be a second order differelltial operator defined byand Bi be a boundary operator given bywhere % denotes the outward normal derivative of m on an.We consider the following boundary value problem of the reaction-diffusion system withtime delaywhere i = 1, 2,'. I m) mr = "i(x, t -- r), r 2 0 is a constant. If r ~ 0, it means that system(I) does not include the terms of time lag… 相似文献
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The dynamics of a physiological control systems described by a first-order nonlinear delay differential equations are investigated. we proved that a sequence of Hopf bifurcations occur at the positive equilibrium as the delay increases. Explicit algorithm for determining the direction of the Hopf bifurcations and the stability of the bifurcating periodic solutions are derived, using the theory of normal form and center manifold. Global existence of periodic solutions are established using a global Hopf bifurcation result due to Wu [Symmetric functional differential equations and neural networks with memory, Trans. Amer. Math. Soc. 350 (1998) 4799–4838]. 相似文献
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Zheng-qiu ZHANG & Zhi-cheng WANG College of Mathematics Econometrics Hunan University Changsha China 《中国科学A辑(英文版)》2007,50(1):27-34
In this paper, the existence of two positive periodic solutions for a generalized delayed population model with an exploited term is established by using the continuation theorem of the coincidence degree theory. 相似文献
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In this paper, a HTLV-I infection model with CTL immune response is considered. Taking the immune delay as a bifurcation parameter we investigate the global existence of periodic solutions of this model which shows existence of multiple periodic solutions theoretically. 相似文献
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Philip Korman 《Applicable analysis》2013,92(1):124-136
Using continuation methods, we study the global solution structure of periodic solutions for a class of periodically forced equations, generalizing the case of relativistic pendulum. We obtain results on the existence and multiplicity of periodic solutions. Our approach is suitable for numerical computations, and in fact we present some numerically computed bifurcation diagrams illustrating our results. 相似文献
17.
Zhengqiu Zhang Hengsheng Tang 《Journal of Mathematical Analysis and Applications》2007,332(1):123-136
In this paper, we establish the existence of four positive periodic solutions for the first order differential system by using the continuation theorem of coincidence degree theory. When our result is applied to a competition Lotka-Volterra population model, we obtain the existence of four positive periodic solutions for this model. 相似文献
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讨论了一类无穷时滞非线性生态竞争系统的正周期解,利用变量变换和不动点定理,得到了该系统的正周期解的存在性和存在唯一性的充分性条件,获得了一些新的结果. 相似文献
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运用Krasnosel’skii不动点理论研究了一类含参泛函微分方程半正问题正周期解的存在性.获得了当参数充分小时正周期解的存在性结果以及半正问题正周期解存在的充分条件.丰富了一阶泛函微分方程解的存在性理论. 相似文献