报告题目：Effects of (small) permanent charge and channel geometry on ionic flows via classical Poisson-Nernst-Planck models
报告时间：2018年6月21日下午2:00——4:00
地点：3N-113 A
报告人：张明吉
摘要： In this work, we examine effects of permanent charges on ionic flows through ion channels via a quasi-one-dimensional classical Poisson-Nernst-Planck(PNP) model. The geometry of the three-dimensional channel is presented in this model to a certain extent, which is crucial for the study in this paper. Two ion species, one positively charged and one negatively charged, are considered with a simple profile of permanent charges: zeros at the two end regions and a constant Q0 over the middle region. The classical PNP model can be viewed as a boundary value problem(BVP) of a singularly perturbed system. The singular orbit of the BVP depends on Q0 in a regular way. Assuming |Q0| is small, a regular perturbation analysis is carried out for the singular orbits. Our analysis indicates that effects of permanent charges depend on a rich interplay between boundary conditions and the channel geometry. Furthermore, interesting common features are revealed: for Q0=0, only an average quantity of the channel geometry plays a role; however, for Q00, details of the channel geometry matter; in particular, to optimize effects of a permanent charge, the channel should have a short and narrow neck within which the permanent charge is confined. The latter is consistent with structures of typical ion channels.
报告人简介：
张明吉,副教授，博士生导师， 2013年获得美国堪萨斯大学数学系博士学位，随后在美国密歇根州立大学跟随著名数学家Peter W. Bates 做博士后研究。2015年起，在美国新墨西哥矿业理工学院任职。其主要研究领域包括几何奇异摄动理论及其在Poisson-Nernst-Planck模型上的应用，发展生物学上的多尺度分析及非线性微分方程的动力学行为。在《SIAM J. on Applied Mathematics》, 《SIAM J. on Applied Dynamical System》，《J. Differential Equations》,《J. Dynamics and Differential Equations》，《Advances in Computational Mathematics》，《Communication in Mathematical Sciences》，《Discrete and Continuous Dynamical Systems》等国际顶级期刊发表论文二十余篇。
