中国科学院国际人才计划（PIFI）国际杰出学者学术报告

报告时间：2019年3月22日（星期五） 上午10:00至12:00

报告地点：能源基础楼一楼会议室

报告人：Daniel M. Neumark，美国加州大学伯克利分校

　　报告摘要

　　The unimolecular isomerization of vinylidene (H2CC) to acetylene and the photodissociation dynamics of IBr are investigated using two complementary techniques:  high resolution photoelectron spectroscopy of cryogenically-cooled anions and attosecond transient absorption.  In the anion experiments, H2CCˉ anions are photodetached to access various vibrational levels of weakly bound H2CC; variations in the peak widths and underlying structure point to highly state-specific isomerization dynamics, thus resolving a long-standing controversy into the isomerization “lifetime” of vinylidene.  In the attosecond experiments, IBr is photodissociated with one or two visible photons. The dissociation dynamics are monitored using an attosecond XUV pulse with sufficient bandwidth to probe core-to-valence transitions in both the I and Br atoms.  The resulting transient absorption spectra map out the adiabatic and non-adiabatic pathways associated with curve-crossings en route to dissociation.

　　报告人简介

　　Prof. Daniel M. Neumark is one of the leading scientist in physical chemistry on the world. He is the member of the American National Academy of Sciences; fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the American Physical Society (APS), the American Chemical Society (ACS), and the Royal Society of Chemistry (RSC). He has received the Peter Debye Award in Physical Chemistry and the Irving Langmuir Award in Chemical Physics from the ACS, the Herbert P. Broida Prize from the APS, the Bourke Award and the Chemical Dynamics Award from the RSC. Now he is the member of the board of reviewing editors for Science Magazine, and the panel member of the European research Council.

　　Prof. Neumark and his research group carry out state-of-the-art experiments to probe fundamental problems in chemical physics. The projects in his laboratories encompass (i) reaction dynamics of bimolecular and unimolecular reactions, in which one maps out in detail the potential energy surfaces on which chemistry occurs, (ii) cluster spectroscopy and dynamics, which explore how the properties of matter evolve with size, and (iii) ultrafast x-ray science, where novel femtosecond and attosecond light source initiate and/or probe dynamics in the soft x-ray regime. Much of his work uses photoelectron spectroscopy of negative ions in either the frequency and time-domain to probe the spectroscopy and dynamics of transient and reactive species. His research has yielded new insights into transition state spectroscopy, the electronic and vibrational spectroscopy of clusters, the photodissociation of reactive free radicals, hydrated electron dynamics in clusters and liquid jets, and the ultrafast dynamics of helium nanodroplets excited by femtosecond soft x-ray pulses.

　　联系人：十一室 程丽娜

　　联系电话：84379702）