报告题目：Sharp Interface Models for Solid-State Dewetting Problems
内容简介：In this talk, I will present sharp interface models with anisotropic surface energy for simulating solid-state dewetting and the morphological evolution of patterned islands on a substrate. We will show how to derive the sharp interface model via thermovariation dynamics, i.e. variation of the interfacial energy via an open curve with two triple points moving along a fixed substrate. The sharp interface model tracks the moving interface explicitly and it is very easy to be handled in two dimensions via arc-length parametrization. An efficient and accurate parameteric finite element method (PFEM) was proposed for the sharp interface models. It is applied to study numerically different setups of solid-state dewetting including short and long island films, pinch-off, hole dynamics, semi-infinite film, tiny particle migration, etc. Our results agree with experimental results very well. In addition, extension to curved substrate and three dimensions will be discussed. Finally, we also present a reduced variatonal model via the Onsager's principle for small particle migration in solid-state dewetting. This is joint works with Wei Jiang, David J. Srolovitz, Carl V. Thompson, Yan Wang and Quan Zhao.
Professor Weizhu Bao is currently a professor at Department of Mathematics, National University of Singapore (NUS). He got his PhD from Tsinghua University in 1995 and afterwards he had postdoc and faculty position at Tsinghua University, Imperial College in UK, Georgia Institute of Technology and University if Wisconsin at Madison in USA. He joined NUS as an Assistant Professor in 2000 and was promoted to Professor in 2009. He had been appointed as the Provost’s Chair Professorship at NUS during 2013-2016. His research interests include numerical methods for partial differential equations, scientific computingHis research interests include numerical methods for partial differential equations, scientific computing/numerical analysis, and computation for problems from physics, chemistry, biology and engineering sciences. He was on the Editorial Board of SIAM Journal on Scientific Computing during 2009-2014. He was awarded the Feng Kang Prize in Scientific Computing by the Chinese Computational Mathematics Society in 2013. He has been invited to give plenary and/or invited talks in many international conferences including the Invited Speaker at the International Congress of Mathematicians (ICM) in 2014