首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
建立了一个具有时滞和Ivlev功能性反应的食物链模型.同时选择了一个分支参数τ,分析了发生Hopf分支的情况,得出了Hopf分支发生的条件,并用数值模拟验证了分析结果.  相似文献   

2.
该文研究了一个由食饵种群、捕食者种群和杂食者种群所构成的食物链系统, 其捕食功能反应为Monod-Haldane功能反应. 应用定性分析和Hopf分支理论, 得到了该系统边界平衡点的全局稳定性和周期解存在性的判别准则. 为了概括和归类这个系统的全局动力学行为,该文得到了具有不同动力学行为的参数区域. 应用MATLAB软件,该文提供了一个例子来展示这些结论, 并且表明: 这个系统能够产生非常复杂的动力学行为.  相似文献   

3.
In this paper, we study a new model obtained as an extension of athree-species food chain model with ratio-dependent functional response. We provide non-persistence and permanence results and investigate the stability of all possible equilibria in relation tothe ecological parameters. Results are obtained for the trivial andprey-only equilibria where the singularity of the model prevents linearization, and the remaining semi-trivial equilibria are studiedusing linearization. We provide a detailed analysis of conditionsfor existence, uniqueness, and multiplicity of coexistencee quilibria, as well as permanent effect for all species. The complexity of the dynamics in this model is theoretically discussedand graphically demonstrated through various examples and numerical simulations.  相似文献   

4.
研究了一类具有比率型功能反应的食物链时标动力学系统,利用重合度理论中的延拓定理讨论了此系统周期解的存在性问题,得到了保证周期解存在的充分条件,从而使这一类系统的连续与离散情形:微分方程和差分方程的周期解存在性问题得到了统一研究.  相似文献   

5.
一类食物链模型的全局定性分析   总被引:1,自引:1,他引:0       下载免费PDF全文
文系统地研究了由一个食饵种群和两个捕食者种群所构成的食物链系统.结论表明:种群间的相互作用可以导致两个捕食者种群灭绝或一个捕食者种群灭绝,或者所有三个种群能以稳定的正平衡态或振动解的形式共存.利用MATLAB软件,该文提供了两个例子来模拟这些结论.  相似文献   

6.
带有Leslie-Gower功能性反应的三维食物链模型研究   总被引:1,自引:0,他引:1  
研究了离散时间上带有Leslie-Gower功能性反应的三维食物链模型.首先给出保证系统永久持续生成的条件,由于系统系数的周期性,正周期解是存在的,最后通过在正的周期解领域内线性化系统,并通过构造Lyapunov函数,我们得出了保证系统正周期解全局稳定的条件.  相似文献   

7.
许生虎  伏升茂 《应用数学》2008,21(2):345-353
本文首先应用上下解方法讨论一类带Beddington-DeAngelis功能反应项的捕食者-食饵扩散模型解的一致有界性和整体存在性,然后通过线性化方法分别给出该模型的半平凡平衡点和正平衡点局部渐近稳定的充分条件,最后应用Lyapunov泛函方法讨论唯一正平衡点的全局渐近稳定性.  相似文献   

8.
通过非线性控制系统理论研究了一个三种群食物链控制系统正平衡点的稳定性问题.针对不同的输出,分别得到了系统在该点渐近稳定的控制律.对复杂生物系统控制问题的研究具有一定的参考价值.  相似文献   

9.
研究了一类食饵患病且有人为干预和Holling IV功能反应的食饵捕食者模型,讨论了系统平衡点的稳定性,解的有界性及极限环的存在和分岔情况.此外,还分析了文中重要参数对系统的影响,给出了数值模拟结果.  相似文献   

10.
本文利用重合度理论的延拓定理及分析的技巧讨论了具有两个捕获项的比率依赖型食物链系统周期解的存在性问题,得到至少存在四个周期解的充分条件.  相似文献   

11.
A diffusive predator-prey system with Holling functional response is considered. Firstly, existence of positive equilibrium of this reaction diffusion model under Neumann boundary condition is obtained. Meanwhile, the existence conditions for Turing instability and Hopf bifurcations of a system with Holling \uppercase\expandafter{\romannumeral2} functional response are established. Next, the existence of the hydra effect is demonstrated, when the system is undergoing non-homogeneous steady-state solutions. Finally, numerical simulations are illustrated to support our theory results.  相似文献   

12.
In this paper, we prove that a predator-prey model with sigmoid functional response and logistic growth for the prey has a unique stable limit cycle, if the equilibrium point is locally unstable. This extends the results of the literature where it was proved that the equilibrium point is globally asymptotically stable, if it is locally stable. For the proof, we use a combination of three versions of Zhang Zhifen''s uniqueness theorem for limit cycles in Li$\acute{\rm e}$nard systems to cover all possible limit cycle configurations. This technique can be applied to a wide range of differential equations where at most one limit cycle occurs.  相似文献   

13.
一类比率型功能性反应捕食模型的稳定性分析   总被引:1,自引:0,他引:1  
研究了一类具有比率型功能性反应的捕食模型,对模型进行了定性和稳定性分析,讨论了模型唯一正平衡点的存在条件,以及模型各个平衡点的性态.得到了各个平衡点全局渐近稳定的充分条件.通过绘制模型的相轨线,分析轨线的走向得到了原点全局渐近稳定的条件,并证明了模型不存在非平凡正周期解的条件,通过构造Lyapunov函数得到了模型的唯一正平衡点是全局渐近稳定的结论.  相似文献   

14.
A reaction-diffusion system modeling the predation between two species is analyzed in the case in which the predators have to search, share and compete for food. The boundedness and uniqueness of the solutions is proved and conditions guaranteeing the global nonlinear asymptotic stability of the positive equilibrium point have been found. These conditions improve those ones present in the existing literature.  相似文献   

15.
陈滨  王明新 《数学年刊A辑》2007,28(4):495-506
讨论了带有扩散和Beddington-DeAngelis响应函数的捕食模型在齐次Dirichlet边界条件下的正平衡态.给出了正平衡态存在的一个充要条件,当猎物种群相互干扰强的时候,得到正平衡态的稳定性与唯一性.  相似文献   

16.
讨论了带有扩散和Beddington-DeAngelis响应函数的捕食模型在齐次Dirichlet边界条件下的正平衡态,给出了正平衡态存在的一个充要条件,当猎物种群相互干扰强的时候,得到正平衡态的稳定性与唯一性。  相似文献   

17.
本文讨论了有放养的时滞Michaelis Menten型功能性反应的捕食链 .应用微分不等式和V函数法 ,在一定条件下讨论了该系统的一致持久性 ,得到了概周期解的存在唯一性及其全局吸引性 .  相似文献   

18.
A pilot study was conducted on a multimodal educational tool, Peruvian Food Chain Jenga (PFCJ), with 5th‐grade students (N = 54) at a public charter school. The goal was to compare the effectiveness of the multimodal tool to a more traditional presentation of the same materials (food chain) using an experimental/control design. Data collection included a pretest/posttest and a “What I Did/What I Learned” response sheet. Quantitative analysis of pretest/posttest results showed both groups improved from pretest to posttest; however, there was no statistically significant difference between posttest results of experimental and control groups. Qualitative analysis of student open‐ended responses indicated a difference between students who used the PFCJ and students in the control. The most striking difference occurred in how the students perceived the connectedness of species and the awareness of human impact. Our findings suggest that using a model such as PFCJ as a means of teaching and connecting scientific content with practices related to ecosystems is an effective method of engaging students in intelligent discussions about these topics.  相似文献   

19.
谭德君 《应用数学》2007,20(3):491-495
本文研究具有周期脉冲输入营养基和Beddington-DeAnglis功能反应捕食一食饵系统.通过分析营养基和食饵的子系统,获得系统的边界周期解.对边界周期解稳定性的分析,得到了捕食者侵入的阈值.  相似文献   

20.
基于"比例依赖"理论,研究了一类具有时滞和Watt型功能反应函数的恒化器模型.详细讨论了正平衡点的局部渐近稳定性,证明了系统在特定的时滞参量值下将产生Hopf分支.利用Lyapunov-LaSalle不变性原理,得到了正平衡点全局渐近稳定的充分条件.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号