The cohomology ring of a complex Grassmannian has an additive basis of Schubert cohomology classes. The well-known Littlewood-Richardson rule gives a manifestly positive formula of the structure constants in the cup product of Schubert classes, which count the intersection number of the corresponding Schubert varieties in general position. In this talk, we will discuss how special the general position could be, provided that one given Schubert variety is a divisor. This is my joint work with DongSeon Hwang, Hwayoung Lee and Jae-Hyouk Lee.

In this talk, I present my recent works on some geometric PDEs on manifolds, including Donaldson's equation on Hermitian manifolds for which I give an affirmative answer to an open problem, Ricci-harmonic flow for which I study the long time existence in terms of scalar curvature and Weyl tensor, and heat type flow on vector fields for which a joint work with Kefeng Liu proves the convergence and discusses its applications to the long standing conjectures of Hopf and Yau.

学术报告报告人：Prof J. Peypouquet (Univesidad Tecnica Federico Santa Maria) 题目： Fast Convergence of an Inertial Gradient-like System with Vanishing Viscosity时间：2015年10月23日(星期五)上午10：30—11：30地点：数学系致远楼102欢迎各位参加

学术报告报告人：Prof H. Attouch (Universite Montpellier 2)题目： Convergence of descent methods for semi-algebraic and tame problems时间：2015年10月23日(星期五)上午9：30—10：30地点：数学系致远楼102欢迎各位参加

In this talk, I will present some of our recent work on biological systems with multiple stable states. We show that these models could exhibit multistability phenomena: (i) node-node bistability; (ii) node-cycle bistability; (iii) cycle-cycle bistability; (iv) node-node-cycle tristability and (v) node-node-torus tristability. The talk is based on joint work with Xi Hu, Hongying Shu and James Watmough.

In this talk, we propose a mathematical model for HIV infection with delays in cell infection and virus production. The model examines a viral-therapy for controlling infections through recombining HIV virus with a genetically modified virus. For this model, we derive two biologically insightful quantities (reproduction numbers) R_0 and R_z, and their threshold properties are discussed. When R_0 < 1, the infection-free equilibrium E_0 is globally asymptotically stable. If R_0 > 1 and R_z<1, the

R-M板的若干新的有限元 计算方法石钟慈教授中国科学院院士中科院计算数学研究所研究员1.学术报告时间：2015年10月15日(星期四)下午3：00-3:50地点：数学系（致远楼）107室2.关于学科建设与青年计算数学人才的培养2015年10月15日(星期四)下午4：00-4:50地点：数学系（致远楼）102室欢迎教师、研究生及有兴趣者参

标题： Steiner Systems Over vector Spaces报告人： Tuvi Etzion Department of Computer Science Technion, Israel时间： 9月24日 下午4:00-5:00地点： 致远楼10