Epidemic thresholds in a heterogenous population with competing strains

Among many epidemic models,one epidemic disease may transmit with the existence of other pathogens or other strains from the same pathogen. In this paper,we consider the case where all of the strains obey the susceptible-infected-susceptible mechanism and compete with each other at the expense of common susceptible individuals. By using the heterogenous mean-field approach,we discuss the epidemic threshold for one of two strains. We confirm the existence of epidemic threshold in both finite and infinite populations subject to underlying epidemic transmission. Simulations in the Barabasi-Albert (BA) scale-free networks are in good agreement with the analytical results.     

种间作用的二维非线性时滞动力系统模型的持久性和稳定性

从生物动力学的角度扩展了传统的Lotka-Voltera捕食-被捕食模型,以Holling-II型和修改的Leslie-Gower型功能反应为基础,建立了包括密度制约、功能反应和时滞效应的二维非线性时滞动力系统模型;分析了该动力系统的持久性、稳定性及时滞效应对系统动力学性质的影响;证明了系统在     

关于非线性微分系统的无界性

研究一类非线性微分系统=h(y)-φ(x),=-h(y)f(x)-g(x)k(y)解的无界性问题.给出了判断该系统解的无界性的两个新的充分条件.     

应用计算机实现规范型的自动化简

利用人工智能中的深度优先搜索算法以及Maple数学软件强大的符号运算功能,给出一个Maple程序,用它可以实现规范型的计算机自动计算.应用所得程序简捷地研究了生化反应过程中一类非线性系统{·x1=1-x1x22·x2=αx2(x1x2-1)的Hopf分支.     

以“曲径通幽”的方式讲解傅里叶级数

不同于教材中的讲解方法，在实际教学中先讲正弦级数和余弦级数后过渡到一般的傅里叶级数.这种做法有助于学生掌握傅里叶级数所蕴含的思想方法.     

Synchronization in Complex Networks with Multiple Connections

In this paper a class of networks with multiple connections are discussed. The multiple connections include two different types of links between nodes in complex networks. For this new model, we give a simple generating procedure. Furthermore, we investigate dynamical synchronization behavior in a delayed two-layer network, giving corresponding theoretical analysis and numerical examples.     

不可逆多分子饱和生化反应系统的非线性分析及数值模拟

应用微分方程定性理论研究了一类具有二重饱和反应速度的不可逆多分子生物化学反应系统,得到了其存在唯一极限环的显著不同的参数区域,并进行了计算机数值模拟,其结果可为优化此类反应的实验参数设计提供参考。 更多还原