零极限温升下的微米/纳米尺度的热扩散系数的测量
主讲人：王信伟教授
时间：6月11日上午10:00
地点：丽湖校区守信楼518会议室
报告人简介：
王信伟教授，现任爱荷华州立大学Anson Marston杰出讲席教授（个人主页：//web.me.iastate.edu/wang）。他于2001年获得普渡大学机械工程竞彩官网
博士学位，1996年和1994年分别获中国科学技术大学硕士和学士学位。在过去的二十余年中，王教授主要致力于微纳尺度热物性表征新技术的开发及其结构效应研究，取得了一系列开创性成果，包括：首次区分光学声子温度与声学声子温度、揭示共轭声子与热载流子输运机制、探索辐射电子-空穴复合过程，以及提出用于表征结构对能量载流子散射效应的阻温系数理论等。他曾荣获普渡大学首届维斯坎塔研究员奖，以表彰其在热科学领域的原创性与独立研究贡献。王教授是美国航空航天学会（AIAA）Associate Fellow、美国机械工程师协会（ASME） Fellow，以及美国光学学会（OPTICA）Fellow。
讲座摘要：
The transient electro-thermal (TET) technique was developed by our lab for measuring the thermal diffusivity of micro/nanoscale fibers and films through step Joule heating and voltage-based thermal sensing. This talk will cover our recent progress in the TET technique in obtaining thermal diffusivity at the limit of zero temperature rise, which is critical for measurement at cryogenic states where the very low ambient temperature only allows a negligible temperature rise during measurement. Also such capability is of great importance in measuring the thermal diffusivity at phase change point of materials. Our high-fidelity modeling will be presented here to provide the rigorous theoretical base on how to obtain the thermal diffusivity at the zero temperature rise limit. At such limit, the tiny capacitance effect could become non-negligible. Rigorous theoretical and experimental work will also be presented on how to address this effect. Examples will be given on how we measure the thermal diffusivity of fiber and films with thicknesses down to <2 nm, representing unprecedented physics understanding to date.
欢迎有兴趣的师生参加！
