食饵具有阶段结构的时滞捕食系统的稳定性

研究了一类食饵具有阶段结构的时滞捕食系统,通过分析相应的特征方程,得到非负平衡点的局部稳定性,利用比较原理和迭代法得到平衡点的全局渐近稳定的充分条件.最后,通过数值模拟阐述了所得结论的正确性.     

一类具有收获率和扩散的时滞阶段结构捕食系统的多重正周期解

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.     

一类具有阶段结构和时滞的非自治捕食系统

本研究一类具有阶段结构和时滞的非自治捕食系统解的渐近性质,在适当条件下,得到系统是持续生存的且全局渐近稳定的。     

一类具有阶段结构和时滞的非自治捕食系统

本文研究一类具有阶段结构和时滞的非自治捕食系统解的渐近性质 ,在适当条件下 ,得到系统是持续生存的且全局渐近稳定的     

一个具有时滞和阶段结构的捕食-被捕食模型

研究一个具有时滞和阶段结构的捕食者-食饵模型.通过构造适当的Lyapunov泛函,讨论了该模型的正平衡点和非负边界平衡点的全局吸引性,从而得到了保证该生态系统永久持续生存与绝灭的充分性条件.     

一类带时滞的阶段结构捕食模型的定性分析

研究了一类具有时滞和阶段结构的捕食模型系统,给出了系统持续生存的充分条件.利用比较定理和构造适当的Lyapunov泛函得到了该系统正平衡态全局渐近稳定的充分条件.     

三种群捕食-被捕食模型中具时滞的抛物系统

本文研究三种群食物链,其中第三种群是第二种群的捕食者,第二种群是第一种群的捕食者。我们用上下解方法研究具时滞的耦合半线性抛物方程组的动力学行为,给出了解的渐近性质。     

一个具有时滞和功能反应的非自治阶段结构的捕食模型

研究一个具有时滞和功能反应的非自治阶段结构的捕食模型,其中食饵种群分两个阶段——幼年和成年,且捕食种群只捕成年食饵.通过利用微分不等式、比较定理和构造适当的Lyapunov泛函,得到该模型的永久持续生存和绝灭的充分条件,同时也得到了周期系统存在唯一全局渐近稳定的周期解的充分条件.     

具有时滞和阶段结构的捕食系统的持久性和全局吸引性

研究一类具有时滞和阶段结构的捕食系统.利用微分方程的比较原理和通过构造适当的Lyaponov泛函,得到保证此系统持久性和全局吸引性的充分条件.最后举例说明结论的可行性并且讨论了所得结果的生态意义.     

一类具有收获率的时滞阶段结构捕食系统的多重正周期解

研究了一类具有收获率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两个正周期解的一组易于验证的充分条件.     

Time delayed parabolic system in a two-species competitive model with stage structure

A two-species competitive model with stage structure is discussed. The dynamics of coupled system of semilinear parabolic equations with time delays are investigated. Results on the local and global stabilities of the axial equilibria and positive equilibrium are given. Our results show that the introduction of diffusion does not affect the permanence and extinction of the species though the introduction of stage structure brings negative effect on it.     

Mathematical models of innovation diffusion with stage structure

Mathematical models with stage structures are proposed to describe the process of awareness, evaluation and decision-making. First, a system of ordinary differential equations is presented that incorporates the awareness stage and the decision-making stage. If the adoption rate is bilinear and imitations are dominant, we find a threshold above which innovation diffusion is successful. Further, if the adoption rate has a higher nonlinearity, it is shown that there exist bistable equilibria and a region such that an innovation diffusion is successful inside and is unsuccessful outside. Secondly, a model with a time delay is proposed that includes an evaluation stage of a product. It is proved that the system exhibits stability switches. The bifurcation direction of equilibria is also discussed.     

具有三个成长阶段的单种群时滞模型的永久持续生存和全局稳定性

该文研究具有分布时滞和三个成长阶段的单种群模型,得到了系统永久持续生存的充分条件;同时通过构造Lyapunov 函数得到了系统全局渐近稳定的充分条件;最后建立具体模型说明所得结果的可行性.     

Stability and travelling waves for a time-delayed population system with stage structure

We study a time-delayed population system with stage structure for the interaction between two species, the adult members of which are in competition. For each of the two species the model incorporates a time delay which represents the time from birth to maturity of that species. The global stability results are established for each equilibrium. The criteria for global convergence to each equilibrium are sharp and involve these delays. By using lower and upper travelling wave solutions, we show that the model has travelling wave solutions that connect the origin and the coexistence equilibrium with speeds greater than the spreading speed of each species in the absence of its rival.     

A Lotka-Volterra type food chain model with stage structure and time delays

A three-species Lotka-Volterra type food chain model with stage structure and time delays is investigated. It is assumed in the model that the individuals in each species may belong to one of two classes: the immatures and the matures, the age to maturity is presented by a time delay, and that the immature predators (immature top predators) do not have the ability to feed on prey (predator). By using some comparison arguments, we first discuss the permanence of the model. By means of an iterative technique, a set of easily verifiable sufficient conditions are established for the global attractivity of the nonnegative equilibria of the model.     

Permanence and periodicity of a delayed ratio-dependent predator-prey model with stage structure

A periodic ratio-dependent predator-prey model with time delays and stage structure for both prey and predator is investigated. It is assumed that immature individuals and mature individuals of each species are divided by a fixed age, and that immature predators do not have the ability to attack prey. Sufficient conditions are derived for the permanence and existence of positive periodic solutions of the model. Numerical simulations are presented to illustrate the feasibility of our main results.     

Permanence and periodicity of a delayed ratio-dependent predator–prey model with Holling type functional response and stage structure

A periodic and delayed ratio-dependent predator–prey system with Holling type III functional response and stage structure for both prey and predator is investigated. It is assumed that immature predator and mature individuals of each species are divided by a fixed age, and immature predator do not have the ability to attack prey. Sufficient conditions are derived for the permanence and existence of positive periodic solution of the model. Numerical simulations are presented to illustrate the feasibility of our main results.     

Stability and Hopf bifurcation in a predator–prey model with stage structure for the predator

A predator–prey system with stage structure for the predator and time delay due to the gestation of the predator is investigated. By analyzing the corresponding characteristic equations, the local stability of a positive equilibrium and two boundary equilibria of the system is discussed, respectively. Further, the existence of a Hopf bifurcation at the positive equilibrium is also studied. By using an iteration technique and comparison argument, respectively, sufficient conditions are derived for the global stability of the positive equilibrium and one of the boundary equilibria of the proposed system. As a result, the threshold is obtained for the permanence and extinction of the system. Numerical simulations are carried out to illustrate the main results.