讲座报告主题：Mapping Atomic Motions with Ultrabright Electrons: Fundamental Space-Time Limits to Imaging Chemistry and Biological Processes
主讲概况：R.J.Dwayne Miller教授，是德国马普所原子分辨动力学研究组主任，加拿大皇家科学院院士，研究的主要方向是发展一种新的激光和光谱技术，用于在原子层面下，探究和生命运动有关的结构变化的过程。创新点在于发展新的电子源，使其拥有足够的时间和空间分辨率去研究原子层面上的动力学过程。目前已发表334篇研究论文（含多篇Nature、Science论文）和11项专利。研究成果获得波兰尼奖、卢瑟福化学奖、E.B. Wilson光谱学奖、Dr. Karl-Robert Brauns眼科贡献奖、欧洲激光科学物理学奖等。
主讲内容：One of the dream experiments in science has been to watch atomic motions on the primary timescales of chemistry. This prospect would provide a direct observation of the reaction forces, the very essence of chemistry, and the central unifying concept of transition states that links chemistry to biology. This experiment has been referred to as "making the molecular movie" with respect to observing net rms atomic motions during structural changes. There are not only extraordinary requirements for simultaneous spatial-temporal resolution but equally important, due to sample limitations, also one on source brightness. Taking the problem to be an imaging problem, as one makes the shutter speed shorter and shorter, a brighter and brighter source is needed to maintain image contrast. With the development of ultrabright electron capable of literally lighting up atomic motions, this experiment was first realized (Siwick et al Science 2003) and efforts accelerated with the onset of XFELs (Miller, Science 2014). How far can this reductionist view be extended with respect to complexity? The ultimate goal in scaling system complexity is to obtain atomically resolved protein functions to understand how nature tamed chemistry over all conceivable length scales. New approaches based on the prinicples used for femtosecond electron diffraction, both in terms of source technology and image reconstruction, hold promise for real space studies of single biomolecules. This prospect is within reach and will provide a definitive test of the collective mode coupling model (Miller Acc. Chem. Research 1994) to bridge chemistry to biology, which will be discussed as the driving force for this work.