Superdiffusion in high viscosity liquids

****非技术摘要****从爱因斯坦开始？100年前，他首次提出布朗运动，随机游走和扩散一直是科学家们理解微观粒子运动的范例。最近发现，在高粘性流体中，普通的扩散被一种以前未被认识到的、至今仍未完全表征的过程所取代，在这种过程中，颗粒比根据扩散所预期的移动得更远。因此，这种运动被描述为超扩散运动。该项目将使用最先进的x射线和光学技术系统地阐明粒子集合以及单粒子水平的超扩散粒子运动。提出的实验将创造新的知识，并激发高粘性流体中颗粒和颗粒悬浮液动力学的新的理论描述。这将改变我们对高粘性流体的理解，高粘性流体的特性会以一种目前尚不清楚的方式产生超扩散。这项研究还将为下一代国家x射线设施的规划和技术决策提供信息，并将支持博士研究生的教育，他们将学习如何在这些设施中做最好的科学研究，满足国家对这些训练有素的个人的重要需求。****技术摘要****布朗运动，随机游走和扩散是我们如何理解凝聚态系统动力学的范例。最近发现，在高粘性流体中，普通的扩散被一种以前未被认识到的、至今仍未完全表征的过程所取代，在这个过程中，粒子的均方位移不像扩散那样随时间线性变化，而是比时间线性更快。因此，这种运动被描述为超扩散运动。本项目将利用x射线光子相关光谱学系统地阐明系综水平上的超扩散粒子动力学，并利用后焦平面干涉术系统地阐明单粒子水平上的超扩散粒子动力学。提出的实验将创造新的知识，并激发高粘性流体中颗粒和颗粒悬浮液动力学的新的理论描述。这将改变我们对高粘性流体的理解，高粘性流体的特性以一种目前尚不清楚的方式引起超扩散。这项研究还将为下一代国家x射线设施的规划和技术决策提供信息，并将支持博士研究生的教育，他们将学习如何在这些设施中做最好的科学研究，满足国家对这些训练有素的个人的重要需求。

****NON-TECHNICAL ABSTRACT****Since Einstein?s original work on Brownian motion 100 years ago, random walks and diffusion have stood as paradigms for how scientists understand the motions of microscopic particles. Recently it has emerged that in highly viscous fluids, ordinary diffusion is superceded by a previously unrecognized and still incompletely characterized process, in which the particles move further than expected on the basis of diffusion. Such motion is therefore described as superdiffusive. This project will systematically elucidate superdiffusive particle motions of collections of particles as well as at the single particle level using state-of-the-art x-ray and optical techniques. The proposed experiments will create new knowledge and motivate new theoretical descriptions of the dynamics of particles and particle suspensions in highly viscous fluids. This will transform our understanding of highly viscous fluids, whose properties give rise to superdiffusion in a way that is not currently understood. The research will also inform programmatic and technical decisions to be made about the next generation of national x-ray facilities, and it will support the education PhD students, who will learn how to do the best possible science at these facilities, fulfilling a vital national need for such trained individuals.****TECHNICAL ABSTRACT****Brownian motion, random walks and diffusion are paradigms of how we understand the dynamics of condensed matter systems. Recently it has emerged that in highly viscous fluids, ordinary diffusion is superceded by a previously unrecognized and still incompletely characterized process, for which the particle's mean-square displacement varies, not linearly in time, as it does for diffusion, but faster than linearly in time. Such motion is therefore described as superdiffusive. This project will systematically elucidate superdiffusive particle dynamics at the ensemble level using x-ray photon correlation spectroscopy, and at the single particle level by using back-focal-plane interferometry. The proposed experiments will create new knowledge and motivate new theoretical descriptions of the dynamics of particles and particle suspensions in highly viscous fluids. This will be transformative to our understanding of highly viscous fluids, whose properties give rise to superdiffusion in a way that currently is not understood. This research will also inform programmatic and technical decisions to be made about the next generation of national x-ray facilities, and it will support the education PhD students, who will learn how to do the best possible science at these facilities, fulfilling a vital national need for such trained individuals.