基于电磁场与电磁波方法的媒质隐藏目标成像探测技术 | 本周物理本周二在中科院物理系“工程师之家”论

1基于电磁场与电磁波方法的媒质隐藏目标成像探测技术

报告人：方广有，中科院电子所

时间：11月14日（周二）14:00

单位：中科院物理所，“工程师之家”论坛

地点：M楼234会议室

基于麦克斯韦理论，电磁场与电磁波对媒质/介质有一定的穿透能力，依照趋肤深度原理，穿透深度与媒质和工作频率有关，频率越低、媒质损耗越小，穿透深度越深；反之，亦反。在频率低端（极低频ELF/甚低频VLF/低频LF），电磁场能量主要依照扩散方式传入到地下，满足扩散方程原理，探测深度可达地下数公里；在频率高端（高频HF/甚高频VHF/微波或毫米波及太赫兹），满足波动方程原理，电磁场能量主要依靠天线辐射方式向媒质空间传播，探测深度浅，一般在数十米以内。报告将较为详细地介绍不同频段的探测原理和成像方法，并以若干实例展示地下深部矿藏、百米以浅地下分层/空洞/管道等目标以及太赫兹人体安检成像结果等内容。

2透射电镜三维成像技术介绍

报告人：李雪明，清华大学生命科学学院

时间：11月14日（周二）14:00

单位：中科院物理所，“工程师之家”论坛

地点：M楼234会议室

冷冻电子显微学三维重构技术，简称冷冻电镜技术或cryoEM，经过近40年的发展，现在已经成为结构生物学中的一个重要结构解析手段。本讲座主要介绍复杂三维分子结构怎样利用透射电子显微技术揭示，并结合自己的研究经历举例说明该技术的独特优势。

3实验证实三重简并半金属和非简单空间群拓扑绝缘体

报告人：钱天，中科院物理所

时间：11月14日（周二）14:00

单位：中科院物理所

地点：M楼236会议室

拓扑物态的发现是近年来凝聚态物理领域的一个重要突破，拓扑量子态具有特征的体态和边界态电子能带结构，角分辨光电子能谱（ARPES）是测量晶体电子结构最直接的实验手段，在验证拓扑量子态的研究中起到了关键的作用。自2014年底上海光源“梦之线”建成以来，我们主要依托“梦之线”ARPES实验站，与同行特别是物理所理论计算和材料制备的同事合作，开展了对拓扑量子材料电子结构的研究。在这个报告中，我将简单介绍上海光源“梦之线”和拓扑绝缘体/半金属的一些基本情况，然后介绍最近一年多在非简单空间群拓扑绝缘体和三重简并半金属的工作。

4High entropy oxides: a new class of functional materials

报告人：Nita DRAGOE，University Paris Sud

时间：11月14日（周二）15:30

单位：北京大学现代光学研究所

地点：物理楼中211

Since the early 2000s, an intense research activity is devoted to the study of high-entropy alloys, which have very interesting properties for many applications. These alloys are obtained by entropy stabilization of single phases from complex mixtures of typically 5 metals. Recently, this concept has been extended to oxides and it has been shown that the entropy stabilization of a solid solution from a mixture of MgO, NiO, CoO, CuO, and ZnO is possible. This structure is stabilized by the large configurational entropy arising from the site distribution of the five cations. Following this study, we have shown that the compounds of this new class of oxides may be substituted or co-substituted, which leads to a considerable number of possible chemical compositions. Furthermore, we studied the physical properties of some specific compounds which are extremely promising for applications such as colossal dielectric constant and super ionic conductivity. During this presentation, we will describe some new compositions belonging to this peculiar family and their outstanding transport properties.

5太赫兹波前获取与调控

报告人：张岩，首都师范大学

时间：11月15日（周三）15:10

单位：北京大学现代光学研究所

地点：物理楼中211

本报告介绍首都师范大学超材料与器件北京市重点实验室在太赫兹波前获取和调控方面取得的进展。利用自主研发的太赫兹脉冲波焦平面成像系统实现太赫兹辐射的频率、振幅、相位以及偏振态的测量，并利用这套系统实现对涡旋光束和太赫兹波段表面等离子体器件的的表征。利用超表面技术实现太赫兹波前的调控，设计了超薄太赫兹平板透镜，长焦深透镜，多焦点透镜、太赫兹全息、分色成像全息以及偏振选择透镜等器件。利用半导体材料在太赫兹波段特殊的光电调控特性，提出了太赫兹波前调制器，实现了太赫兹波前的动态调控。

6Physics and Status of the CEPC Project

报告人：阮曼奇，高能所

时间：11月15日（周三），15:30

单位：北京师范大学物理系

地点：物理楼106

The CEPC, a next generation of electron positron circular collider with total tunnel length of roughly 100 km, was proposed by Chinese HEP community. It will be operated with center of mass energy from Z pole up to ZH threshold, serving as a Higgs factory and a precision EW machine. In this phase, CEPC is expected to deliver 1 Million Higgs boson, 100 Million W boson and 10-100 Billion Z bosons in 10-15 years of operation. In terms of Higgs measurement, CEPC could boost the precision of Higgs signal strength measurement by one order of magnitude w.r.t the HL-LHC result. Meanwhile, the Higgs width measurement and the exotic Higgs decay mode searches could be determined to 2-3 orders of magnitude better than the HL-LHC. In the EW measurement, the CEPC will mainly limited by the systematic control. Preliminary investigations shows that the EW precision could also be boosted by 1 order of magnitude at CEPC, w.r.t nowadays’ result. The CEPC could be upgraded to the super proton proton collider (SPPC), with center of mass energy up to 100 TeV. This talk will briefly introduce the physics potential, the project status and the expected detector performance of the CEPC project.

7Experimental probing of quantum criticality at the Superconductor-Insulator Quantum Phase Transition

报告人：Aviad Frydman，Bar Ilan University

时间：11月16日（周四）10:00

单位：中科院物理所

地点：M楼二层253会议室

The superconductor-insulator transition (SIT) is a prototype of a quantum phase transition which is very versatile experimentally: varying a non-thermal tuning parameter such as disorder, thickness, composition, magnetic field or gate-voltage causes the system to switch from a superconductor to an insulator at zero temperature.

8Early Results of the Subaru Hyper Suprime-Cam Survey for High Redshift Galaxies

报告人：Masami Ouchi

时间：11月16日（周四）14:00

单位：北京大学科维理天文与天体物理研究中心

地点：KIAA-PKU Auditorium

I present progresses of our Subaru Hyper Suprime-Cam (HSC) optical imaging survey for high redshift galaxies including Lyman alpha emitters (LAEs),and overview the early results. The data of the early results allow us to obtain over a half million galaxies at z~4-7 in a total area of >100 deg^2 that are about 1-2 orders of magnitude larger than those of previous high-z galaxy surveys. With the large Subaru/HSC galaxy sample supported by the spectra taken with Keck, Subaru, and Magellan, and the large-area deep Spitzer data, I will present various statistical measurements including luminosity functions and correlation functions,and discuss galaxy formation and cosmic reionization based on our ten papers for refereed journals, seven of which are already accepted for publication.

9Smooth Deposition and Stable Cyclability of Lithium Metal Batteries through Electrolyte Strategy

报告人：Wu Xu，Pacific Northwest National Laboratory

时间：11月16日（周四）14:40

单位：中科院物理所

地点：M楼二层253会议室

Lithium (Li) metal batteries have been regarded as the most promising candidate for next generation energy storage because Li metal as anode has extremely high theoretical specific capacity (3860 mAh g-1), the lowest negative electrochemical potential (-3.040 V vs. the standard hydrogen electrode) and low density (0.534 g cm-3). However, the safety concerns and the short cycle life due to Li dendrite growth and low Coulombic efficiency (CE) hinder the development and practical applications of rechargeable Li metal batteries. During the past four decades, lots of approaches have been reported to suppress the Li dendrite growth and to improve the stability of Li metal anode, including using Li alloys, solid-state electrolytes, polymer electrolytes, ionic liquids, highly concentrated liquid electrolytes, additives, protecting layers, interlayers between Li and separator, nanoscale design, Li-reduced graphene oxide composites, and so on.

10Atomic and Electronic Structures of 2D electronic materials and their Heterostructures

报告人：张晨栋，武汉大学

时间：11月17日（周五）10:00

单位：中科院物理所

地点：A楼二层234会议室

I will first introduce a comprehensive form of scanning tunneling spectroscopy (STS) which allows us to probe not only the quasi-particle band gaps but also the critical point energy locations and their origins in the Brillouin Zone can be revealed using this comprehensive form of STS. By using this new method, we unravel the systematic trend of the critical point energies for TMDs due to atomic orbital couplings, spin-orbital coupling and the interlayer coupling. By using the vertically stacked MoS2/WSe2, I will show how interlayer coupling can be used as a new designing parameter to create a lateral 2D electronic superlattices. I will then turn attention to WSe2-MoS2 lateral heterostructure where I will show a novel method to probe 2D strain tensor and how the strain changes the band profile as well as the band alignment at the interface.

11费米子质量与味混合结构

报告人：邢志忠，中科院高能所

时间：11月17日（周五）13:30

单位：中国科学院大学

地点：雁栖湖校区教1-109

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