（一）

报告人：周圣高 副教授（苏州大学数学科学学院交叉科学研究中心）

报告题目：Variational implicit-solvent predictions of the dry–wet transition pathways for ligand–receptor binding and unbinding kinetics.
报告摘要: Solvent fluctuations play a fundamental role in many water-mediated biological processes of importance. Capillary evaporation and condensation, induced by solvent fluctuations, take place in hydrophobic confinements. Based on a variational implicit solvent model, we combine the level-set method and the string method to study such dry-wet transitions, e.g., transition pathways and energy barriers. The resulting transition rates are then used in a spatially dependent multistate Brownian dynamics simulation and the related Fokker–Planck equation calculations of a ligand–receptor system. We find the hydration transitions to significantly slow down the binding process, in semiquantitative agreement with existing explicit-water simulations, but significantly accelerate the unbinding process. Moreover, our approach  allows the characterization of nonequilibrium hydration states of pocket and ligand during the ligand movement, for which we find substantial memory and hysteresis effects for binding vs. unbinding. Our study thus provides a significant step forward toward efficient, physics-based interpretation and predictions of the complex kinetics in realistic ligand–receptor systems.This is a joint work with Dr. R. G. Weiß, L. Cheng, J. Dzubiella, J. A. McCammon, and B. Li.
报告人简介：周圣高，2015年于美国加州大学圣地亚哥分校完成博士后研究工作后入职苏州大学数学科学学院交叉科学研究中心。近年来主要从事生物物理建模、模型数学理论分析及高性能科学计算等方面的研究，取得了一系列重要创新研究成果。

报告时间：2019年7月24日（星期三）上午9:00

报告地点：科技楼(南楼)702

（二）

报告人：王忠明 副教授（佛罗里达国际大学）

报告题目：Finite difference methods for the multi-dimensional Poisson--Nernst--Planck equations
报告摘要：We design and analyze some finite difference methods for solving the Poisson-Nernst-Planck (PNP) equations. Central-differencing discretization based finite difference methods are proposed for the Nernst--Planck (NP) with geometric-mean/harmonic-mean types of approximations. The numerical schemes, with proper time discretization, respect three desired properties that are possessed by analytical solutions: I) conservation, II) positivity of solution, and III) free-energy dissipation. The semi-implicit scheme based on the harmonic-mean approximation is further shown to preserve positivity unconditionally and have bounded condition numbers of the associated matrix.  Numerical experiments validate the numerical analysis. An application to an electrochemical charging system is also studied to demonstrate the effectiveness of our schemes in solving realistic problems. This is a joint work with, J. Ding, H. Liu and S. Zhou.

报告人简介：王忠明，2008年毕业于爱荷华州立大学，获博士学位。2008-2011年，加州大学圣地亚哥分校博士后。现为佛罗里达国际大学副教授，主要研究方向为数值计算，偏微分方程数值解。在SIAM，JCP，JSC等期刊上发表重要论文数十篇。

报告时间：2019年7月24日（星期三）上午10:00

报告地点：科技楼(南楼)702