报告题目：Mechanical and Mathematical Properties of Quasicrystals
报告人： Prof. Włodzimierz Domański（Military University of Technology）
报告时间：2018年4月14日（周六）下午15:30-16：30
报告地点：18号楼526会议室
主办单位: 国际合作处、科协、机械结构力学及控制国家重点实验室、航空宇航学院
报告摘要：
The discovery of quasicrystals in 1984 by D. Shechtman , destroyed the fundamental concepts of crystallography which relied on a traditional definition of a crystal as a periodic arrangement of identical unit cells. In his experiments with a rapidly cooled Al-Mn alloy, Shechtman obtained a sharp diffraction pattern with a rotational symmetry incompatible with periodicity. His findings forced the International Union of Crystallography to redefine the notion of a crystal as any solid having discrete diffraction diagram.
Quasicrystals are new class of materials which thanks to their unique properties such as electrical, optical, hardness and nonstick features are finding new and promising applications e.g. in nonstick coatings, thermal barriers. infra red sensor etc. Two decades after the first publication on quasicrystals, a soft quasicrystal was found in nature and a number of materials including liquid crystals, polymers, nanoparticles and colloids enriched the family of soft quasicrystals , enhancing the potential applications of these quasi-periodic structures.
The talk will present a brief history of the discovery of quasicrystals and will discuss some of the fascinating mechanical and mathematical properties of quasicrystals. In particular the talk will focus on elastic constitutive relations in which besides the phonon space there is also a contribution from the phason space. The talk will present the form of the energy density function in some of these quasi-periodic structures. Recent findings of natural quasicrystals will also be mentioned.
报告人简介：
Włodzimierz Domański, is currently a Professor of the Institute of Mathematics and Cryptology, a faculty of Cybernetics at the Military University of Technology. He was a Fulbright Postdoctoral Fellow Department of Mathematics and Program in Applied and Computational Mathematics, Princeton University, USA.
