全校师生：

我校定于2017年11月23日举办研究生灵犀学术殿堂——Ihor Mryglod教授报告会，现将有关事项通知如下：

1.报告会简介

报告人：Ihor Mryglod教授

时间：2017年11月23日（星期四）上午

地点：理学院学术报告厅

主题：Some old and new puzzles in the dynamics of fluids

内容简介：One of the basic concepts of modern physics with a long prehistory is a fluid in the meaning of a substance that continually flows under an applied shear stress. In this sense fluids form a wide subset are the phases of matter and include liquids, dense gases, plasmas, and to some extent even plastic solids. The fluidity is one of the main dynamical characteristics that depends strongly on material properties or details of local structure and parameters of many-particle interactions in the terms of statistical physics. The last ones determine some relevant time that divide the fluid behavior in two main time regimes, characterizing material like as a viscous liquid over a long time period and as an elastic-like solid over a short time period. Such a property is typical for a viscoelastic substance or in other words for a fluid. Another aspect to be important for understanding of the fluid dynamics is connected with the structural ordering in the arrangement of atoms and molecules. Orderliness over distances comparable to interatomic distances is usually treated as short-range order, whereas orderliness repeated over infinitely large distances is called long-range order. Both long- and short-range order are absent in the ideal gas, but liquids and amorphous solids exhibit short-range order. The physics of phonon in crystalline solids with long-range order is well understood. In liquids, however, the atomic structure is changing with time and the concept of phonon becomes questionable for long time processes. How the phonon-like excitations as well as other collective modes determine the fluid dynamics and are reflected in the response functions? Theoretically the flow of a liquid is commonly described by continuum hydrodynamic theories. Less attention has been paid to the atomic level dynamics because it has been believed that the liquids are so random that details of the atomic motion are irrelevant to the physics of liquid flow. Is it true for fluid systems with short-range order? In this lecture we try to find answers for some old and new questions that make the fluid dynamics still very attractive for the theoretical studies.

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党委研究生工作部

理学院

2017年11月22日

报告人简介

Ihor Mryglod教授现为乌克兰国家科学院副秘书长，乌克兰国家科学院院士，乌克兰国家科学院物理学部主任，乌克兰国家科学院凝固态物理研究所所长。