应数学与统计学院邀请，新墨西哥矿业理工大学Mingji Zhang（张明吉）教授将于2025年6月14-16日访问学院和甘肃省数学与统计学基础学科研究中心，并于14日和15日作专题学术报告。
报告题目1：Effects on ionic flows through membrane channels from permanent charges via Poisson-Nernst-Planck systems: A critical step towards the selectivity of cations
报告摘要：We consider a quasi-one-dimensional Poisson-Nernst Planck system with multiple cations focusing on permanent charge effects on ionic flows through membrane channels, which is critical for one to understand the selectivity of ion channels over distinct cations. Interesting and nonintuitive phenomena are observed including scaling laws on boundary concentrations, inhibited roles played by the flux of the cation and sensitive dependence on channel geometry under different setups of the permanent charge.
报告时间：2025年6月14日10:00
报告地点：致勤楼D07会议室
报告题目2：Qualitative properties of zero-current ionic flows through membrane channels via Poisson-Nernst-Planck models with multiple cations
报告摘要：We focus on the qualitative properties of zero-current ionic flow via a classical Poisson-Nernst-Planck system with two cations and one anion. The existence and uniqueness result is established in the framework of geometric singular perturbation theory, from which explicit approximations of individual fluxes are derived. This is critical for one to further study the internal dynamics of the zero-current ionic flows through membrane channels, which cannot be detected via current technologies. Nonlinear interactions among different system parameters are characterized, which provides deep insights into the mechanism of ionic flows through membrane channels. Meanwhile, it also provides efficient ways to adjust/control boundary conditions to observe distinct dynamics of ionic flows.
报告时间：2025年6月15日14:30
报告地点：致勤楼D07会议室
邀请人：张旭萍 云亭教授
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报告人简介
张明吉，美国新墨西哥矿业理工大学数学系教授，博士生导师。2013年毕业于美国堪萨斯大学，获理学博士学位；2013-2015年跟随著名数学家Peter W. Bates在密歇根州立大学做博士后研究。研究领域是非线性动力系统、微分方程及其应用。目前研究主要侧重于（i）几何奇异摄动理论及其应用, 特别是在离子通道问题和发展生物学中的应用；和（ii）非线性偏微方程的随机动力学研究。研究工具主要是在非线性动力系统不变流形理论上新发展起来的几何奇异摄动理论。在《J. Differential Equations》、《J. Nonlinear Science》、《Nonlinearity》、《J. Dynamics and differential Equations》、《SIAM J. Applied Mathematics》、《SIAM J. Applied Dynamical Systems》等知名刊物发表相关学术论文50余篇. 是SIAM系列， DCDS系列等50余国际SCI杂志的特约审稿人，美国《数学评论》评论员， 德国《数学文摘》评论员。
数学与统计学院
甘肃省数学与统计学基础学科研究中心
2025年6月11日
