报告题目：Selectivity of cations via Poisson-Nernst-Planck systems with local excess chemical potentials: Effects from finite ion sizes
报告时间：2018年6月21日上午10:00——12:00
地点：3N-113 A
报告人：张明吉
摘要： We study a quasi-one-dimensional steady-state Poisson-Nernst-Planck type model for ionic flows through a membrane channel. We consider three ion species, two positively charged with the same valence and one negatively charged, and assume zero permanent charge. Bikerman’s local hard-sphere potential is included in the model to account for finite ion size effect. Treating the ion sizes as small parameters, we derive an approximation of individual fluxes, from which one can further study the qualitative properties of ionic flows and extract concrete information directly related to biological measurements. Of particular interest is the competition between two cations (positively charges ion species) due to finite ion sizes, which is closely related to selectivity phenomena of open ion channels with given protein structures. Furthermore, we are able to characterize the distinct effects of the nonlinear interplays between physical parameters, such as ion sizes, diffusion coefficients, boundary concentrations and boundary potentials. This is the novelty of our work. We believe this work will be useful for future numerical studies and stimulate further analytical studies of ionic flows concerning the selectivity of cations.
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。
