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“创源”大讲堂研究生学术讲座
[发布时间:2016/03/01 作者:办公室]
讲座时间2016年3月3日(星期四)下午2:30—4:30
讲座地点西南交通大学九里校区电气馆物理学院会议室(3223A)
讲座题目一:Wilson Ratio and Quantum Liquid
主讲人简介:
林海清教授,中国工程物理研究院、北京计算科学研究中心主任。1981年获中国科学技术大学学士学位,1983年获美国Iowa州立大学理学硕士学位,1987年获美国加州大学San Diego分校物理学博士学位。19958月至20129月任职于香港中文大学物理系(1995-2002,副教授;2002-,教授)20037月至20106月任香港中文大学物理系主任。20098月任中国工程物理研究院、北京计算科学研究中心主任。担任第28届国际纯物理与应用物理联盟计算物理专业委员会(C20)主席、International Journal of Modern Physics C执行编辑 (亚洲地区)Communication in Computational Physics副编辑、The Frontiers of Physics in China编委《中国物理快报》编委《物理》编委。主要从事凝聚态物理和计算物理的研究。研究兴趣包括强关联系统,量子纠缠和量子相变,以及多体系统的数值方法。
讲座内容简介:
In a wide variety of materials, its low-temperature phases could be characterized by some dimensionless ratios such as the Wilson ratio (WR). In this talk we show that the phases of many-body interacting multi-component quantum liquids in one dimension can be described by WRs based on the compressibility, susceptibility and specific heat associated with each component. These WRs arise due to surprisingly simple additivity rules within subsystems reminiscent of the rules for multi-resistor networks in series and parallel. Using experimentally realized multi-species cold atomic gases as examples, we prove that the Wilson ratios uniquely identify phases of Tomonaga-Luttinger liquids, while providing universal scaling relations at the boundaries between phases. Their values within a phase identify the internal degrees of freedom of said phase such as its spin-degeneracy. This finding reveals deep physical insights into recent experimental measurements of the universal thermodynamics in ultracold atoms and spins.
讲座题目二Carbon and Carbon Nitride Quantum Dots for Photoelectrochemical Applications
主讲人简介:
张瑞勤博士,香港城市大学物理与材料科学系教授。自2013年以来任香港物理学会主席,2011-2014年为吉林大学唐敖庆讲座教授,2011年起为北京计算科学中心客座教授,2013年在德国不来梅大学做访问教授,2014年在法国巴黎第六大学做访问教授。主要研究领域为计算纳米科学,纳米半导体材料量子特性调控及表面钝化和电子转移掺杂理论。
讲座内容简介:
Carbon quantum dots (CQD) and graphitic carbon nitride (g–CN) are promising materials for applications as photocatalysts for fuel conversion, degradation of organic pollutants, bioimaging and sensing, owing to their moderate band gaps, low cost and nontoxicity. In this presentation, I will first describe their electronic and optical properties derived from both computations and experimental studies. I will then introduce our work on synthesising g-CN films using a thermal vapor condensation method and g-CN applications in photoelectrochemical (PEC) H2 generation. The g-CN film shows photocurrent density as high as 0.12 mA cm-2, the highest to date for g–CN based photoanode, at the bias of 1.35 V vs reversible hydrogen electrode with Na2S as the sacrificial reagent. Further, by copolymerizing 2, 6-Diaminopyridine molecules with melamine, C domains are incorporated into g-CN to adjust the electronic properties of g-CN, leading to significantly improved optical, electronic and PEC properties of the modified CN films. The optimal modified CN film exhibits a photocurrent density four times higher than the photocurrent density exhibited by the pristine g-CN film.
 
主办:研究生院          
承办:物理科学与技术学院