In this paper,we consider an autonomous reaction-diffusion Lotka-Volterra systems with nonlocal delays.Using an iterative technique,we prove that n- 1 species are driven to extinction while the remaining species are g...In this paper,we consider an autonomous reaction-diffusion Lotka-Volterra systems with nonlocal delays.Using an iterative technique,we prove that n- 1 species are driven to extinction while the remaining species are globally stable.Finally,we present an example to verify our main result.展开更多
This paper is concerned with the Fisher-KPP equation with diffusion and nonlocal delay.Firstly,we establish the global existence and uniform boundedness of solutions to the Cauchy problem.Then,we establish the spreadi...This paper is concerned with the Fisher-KPP equation with diffusion and nonlocal delay.Firstly,we establish the global existence and uniform boundedness of solutions to the Cauchy problem.Then,we establish the spreading speed for the solutions with compactly supported initial data.Finally,we investigate the long time behavior of solutions by numerical simulations.展开更多
This paper is concerned with the diffusive Nicholson's blowflies equation with nonlocal delay incorporated as an integral convolution over the entire past time up to now and the whole one-dimensional spatial domain R...This paper is concerned with the diffusive Nicholson's blowflies equation with nonlocal delay incorporated as an integral convolution over the entire past time up to now and the whole one-dimensional spatial domain R. Assume that the delay kernel is a strong generic kernel. By the linear chain techniques and the geometric singular perturbation theory, the existence of travelling front solutions is shown for small delay.展开更多
This paper investigates a nonlocal dispersal epidemic model under the multiple nonlocal distributed delays and nonlinear incidence effects.First,the minimal wave speed c*and the basic reproduction number Ro are define...This paper investigates a nonlocal dispersal epidemic model under the multiple nonlocal distributed delays and nonlinear incidence effects.First,the minimal wave speed c*and the basic reproduction number Ro are defined,which determine the existence of traveling wave solutions.Second,with the help of the upper and lower solutions,Schauder's fixed point theorem,and limiting techniques,the traveling waves satisfying some asymptotic boundary conditions are discussed.Specifically,when Ro>1,for every speed c>c^(*) there exists a traveling wave solution satisfying the boundary conditions,and there is no such traveling wave solution for any 0<c<c^(*) when R_(0)>1 or c>0 when R_(0)<1.Finally,we analyze the effects of nonlocal time delay on the minimum wave speed.展开更多
This paper is mainly concerned with the existence and nonexistence of traveling wave solutions of a nonlocal dispersal SIRS model with nonlocal delayed transmissions. We find that the existence and nonexistence of tra...This paper is mainly concerned with the existence and nonexistence of traveling wave solutions of a nonlocal dispersal SIRS model with nonlocal delayed transmissions. We find that the existence and nonexistence of traveling wave solutions are determined by the critical wave speed c^*. More specifically, we establish the existence of traveling wave solutions for every wave speed c〉c^* and R0 〉 1 by means of upper-lower solutions and Schauder's fixed point theorem. Nonexistence of traveling wave solutions is obtained by Laplace transform for any wave speed c ∈ (0, c^*) and R0 〉 1.展开更多
We study the global dynamics of a nonlocal population model with age structure in a bounded domain. We mainly concern with the case where the birth rate decreases as the mature population size become large. The analys...We study the global dynamics of a nonlocal population model with age structure in a bounded domain. We mainly concern with the case where the birth rate decreases as the mature population size become large. The analysis is rather subtle and it is inadequate to apply the powerful theory of monotone dynamical systems. By using the method of super-sub solutions, combined with the careful analysis of the kernel function in the nonlocal term, we prove nonexistence, existence and uniqueness of positive steady states of the model.Moreover, due to the mature individuals do not diffuse, the solution semiflow to the model is not compact. To overcome the difficulty of non-compactness in describing the global asymptotic stability of the unique positive steady state, we first establish an appropriate comparison principle. With the help of the comparison principle,we can employ the theory of dissipative systems to obtain the global asymptotic stability of the unique positive steady state. The main results are illustrated with the nonlocal Nicholson's blowflies equation and the nonlocal Mackey-Glass equation.展开更多
To investigate the impact of the fixed latent periods in the human and vector populations on the disease transmission in heterogenous environment,we formulate a nonlocal and time-delayed reaction-diffusion(NLTD-RD)sys...To investigate the impact of the fixed latent periods in the human and vector populations on the disease transmission in heterogenous environment,we formulate a nonlocal and time-delayed reaction-diffusion(NLTD-RD)system.By appealing to the next generation operator(NGO),we define the basic reproduction number(BRN)Ro,and prove it as a threshold parameter for indicating whether disease persists or not.Specifically,if o<1,the disease-free equilibrium is globally asymptotically stable,while if Ro>1,the disease is shown to be uniformly persistent.In the homogeneous case that all parameters are assumed to be constants,the explicit expression of o is obtained.We further achieved the global attractivity of the constant equilibria by utilizing Lyapunov functionals.Numerical simulations are performed to verify the theoretical results and the effects of the diffusion rate on disease transmission.展开更多
This paper is concerned with travelling front solutions to a vector disease model with a spatio-temporal delay incorporated as an integral convolution over all the past time up to now and the whole one-dimensional spa...This paper is concerned with travelling front solutions to a vector disease model with a spatio-temporal delay incorporated as an integral convolution over all the past time up to now and the whole one-dimensional spatial domain R.When the delay kernel is assumed to be the strong generic kernel,using the linear chain techniques and the geometric singular perturbation theory,the existence of travelling front solutions is shown for small delay.展开更多
文摘In this paper,we consider an autonomous reaction-diffusion Lotka-Volterra systems with nonlocal delays.Using an iterative technique,we prove that n- 1 species are driven to extinction while the remaining species are globally stable.Finally,we present an example to verify our main result.
基金Supported by National Natural Science Foundation of China(12071193,11731005)。
文摘This paper is concerned with the Fisher-KPP equation with diffusion and nonlocal delay.Firstly,we establish the global existence and uniform boundedness of solutions to the Cauchy problem.Then,we establish the spreading speed for the solutions with compactly supported initial data.Finally,we investigate the long time behavior of solutions by numerical simulations.
基金Project supported by the National Natural Science Foundation of China (No. 10961017)the"Qing Lan" Talent Engineering Funds of Lanzhou Jiaotong University (No. QL-05-20A)
文摘This paper is concerned with the diffusive Nicholson's blowflies equation with nonlocal delay incorporated as an integral convolution over the entire past time up to now and the whole one-dimensional spatial domain R. Assume that the delay kernel is a strong generic kernel. By the linear chain techniques and the geometric singular perturbation theory, the existence of travelling front solutions is shown for small delay.
基金supported by a grant from the Young Scientist Funds of Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2022D01C63)Natural Science Foundation of China(No.12271421).
文摘This paper investigates a nonlocal dispersal epidemic model under the multiple nonlocal distributed delays and nonlinear incidence effects.First,the minimal wave speed c*and the basic reproduction number Ro are defined,which determine the existence of traveling wave solutions.Second,with the help of the upper and lower solutions,Schauder's fixed point theorem,and limiting techniques,the traveling waves satisfying some asymptotic boundary conditions are discussed.Specifically,when Ro>1,for every speed c>c^(*) there exists a traveling wave solution satisfying the boundary conditions,and there is no such traveling wave solution for any 0<c<c^(*) when R_(0)>1 or c>0 when R_(0)<1.Finally,we analyze the effects of nonlocal time delay on the minimum wave speed.
基金AcknowledgmentsWe are very grateful to the invaluable suggestions made by anonymous referees. This work is supported by the National Natural Science Foundation of China, RFDP and the Fundamental Research Funds for the Central University.
文摘This paper is mainly concerned with the existence and nonexistence of traveling wave solutions of a nonlocal dispersal SIRS model with nonlocal delayed transmissions. We find that the existence and nonexistence of traveling wave solutions are determined by the critical wave speed c^*. More specifically, we establish the existence of traveling wave solutions for every wave speed c〉c^* and R0 〉 1 by means of upper-lower solutions and Schauder's fixed point theorem. Nonexistence of traveling wave solutions is obtained by Laplace transform for any wave speed c ∈ (0, c^*) and R0 〉 1.
基金supported by National Natural Science Foundation of China(Grant Nos.11031002 and 11371107)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20124410110001)
文摘We study the global dynamics of a nonlocal population model with age structure in a bounded domain. We mainly concern with the case where the birth rate decreases as the mature population size become large. The analysis is rather subtle and it is inadequate to apply the powerful theory of monotone dynamical systems. By using the method of super-sub solutions, combined with the careful analysis of the kernel function in the nonlocal term, we prove nonexistence, existence and uniqueness of positive steady states of the model.Moreover, due to the mature individuals do not diffuse, the solution semiflow to the model is not compact. To overcome the difficulty of non-compactness in describing the global asymptotic stability of the unique positive steady state, we first establish an appropriate comparison principle. With the help of the comparison principle,we can employ the theory of dissipative systems to obtain the global asymptotic stability of the unique positive steady state. The main results are illustrated with the nonlocal Nicholson's blowflies equation and the nonlocal Mackey-Glass equation.
基金supported by National Natural Science Foundation of China(Nos.12071115 and 11871179)Fundamental Research Funds for the Universities in Heilongjiang Province(No.2021-KYYWF-0017)Heilongjiang Provincial Key Laboratory of the Theory and Computation of Complex Systems.
文摘To investigate the impact of the fixed latent periods in the human and vector populations on the disease transmission in heterogenous environment,we formulate a nonlocal and time-delayed reaction-diffusion(NLTD-RD)system.By appealing to the next generation operator(NGO),we define the basic reproduction number(BRN)Ro,and prove it as a threshold parameter for indicating whether disease persists or not.Specifically,if o<1,the disease-free equilibrium is globally asymptotically stable,while if Ro>1,the disease is shown to be uniformly persistent.In the homogeneous case that all parameters are assumed to be constants,the explicit expression of o is obtained.We further achieved the global attractivity of the constant equilibria by utilizing Lyapunov functionals.Numerical simulations are performed to verify the theoretical results and the effects of the diffusion rate on disease transmission.
基金Supported by the National Natural Science Foundation of China (10961017)
文摘This paper is concerned with travelling front solutions to a vector disease model with a spatio-temporal delay incorporated as an integral convolution over all the past time up to now and the whole one-dimensional spatial domain R.When the delay kernel is assumed to be the strong generic kernel,using the linear chain techniques and the geometric singular perturbation theory,the existence of travelling front solutions is shown for small delay.