本文主要研究污染环境下具有年龄结构的种群复杂系统的最优控制问题。即建立了小环境容量下具有年龄结构和毒素作用的种群模型， 利用不动点定理讨论了该模型解的存在唯一性；采用法锥技巧得到了控制的最优性条件；同时利用Ekeland's 变分原理得到了最优控制的存在性。

Online social network as a new platform for information diffusion and establishing social relations has gradually become a hot topic of researches. However, due to the less constraint for virtual crowds in online social networks, it has greatly weakened the certainty and the reliability of all kinds of network information. In view of this, through establishing an appropriate mathematical model to analyze, forecast and control rumor propagation is particularly important. This report comprehensively considers the effects of time delay, spatial diffusion, the government, media and network topology on rumor propagation and established several delayed reaction-diffusion network rumor propagation models.

题目:Modular Invariance in Conformal Field Theory报告人:董崇英 (加州大学教授)时间: 2016年5月11日(周三) 10:30-11:30地点：致远楼107室欢迎广大师生参

What is the flow in the center manifold and homoclinc manifold? We consider famous generalized Henon-Heiles(H-H) system. For the three integrable cases, on the basis of the investigation of the dynamical behavior and level curves of the planar dynamical systems, we find all possible explicit exact parametric representations of solutions in the invariant manifolds of the four dimensional phase space. These solutions contain quasi-periodic solutions, homoclinic solutions, periodic solutions as well as blow-up solutions.

The investigations of age structures in population growth via differential systems are presented from three aspects: modeling, model reduction and application. The structured population growth is normally described by a PDE equation equipped with an appropriate boundary condition and initial date. However, various ordinary/functional differential systems can be reduced from the general PDE equation with respective biological assumptions. This talk will present some delay differential equations to describe predator-prey interaction, population growth with inter- and intra- specific competition, and size-structured population growth.

In this talk we propose a prey-predator model in multiple patches through the stage structured maturation time delay with migrations among patches. Focus on the case with two patches, we discuss the existence of equilibrium points and the uniform persistence. In particular, when the maturation times are the same in the patches, we study the local and global attractivity of boundary equilibrium point with general

题目：An Extension of Feller's Strong Law of Large Numbers报告人：Professor Li Deli Department of Mathematical Sciences Lakehead University, Canada (加拿大Lakehead大学数学科学系教授）时间：2016年4月27日（周三）上午10:00开始地点：宁静楼104室欢迎广大师生前来参

题目：Spectral Hypergraph Theory Via Tensors.报告人：祁力群教授 (香港理工大学数学系 )时间: 2016年4月14日(周四)下午16:00.地点: 致远楼107室.欢迎大家前往听讲