Superdiffusion in high viscosity liquids

* 非技术性摘要 * 自爱因斯坦？100年前，他对布朗运动的最初研究，随机行走和扩散已经成为科学家理解微观粒子运动的典范。最近，人们发现，在高粘度流体中，普通扩散被一种以前未被认识到的、仍然没有完全表征的过程所取代，在这种过程中，颗粒在扩散的基础上移动得比预期的要远。 因此，这种运动被描述为超扩散的。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个粒子水平上的超扩散粒子运动。拟议的实验将创造新的知识，并激发新的理论描述的颗粒和颗粒悬浮液在高粘度流体中的动力学。这将改变我们对高粘性流体的理解，高粘性流体的性质以目前尚不清楚的方式引起超扩散。该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，并将支持教育博士生，他们将学习如何在这些设施中尽可能地进行科学研究，满足国家对此类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理解凝聚态系统动力学的范例。最近出现的情况是，在高粘性流体中，普通扩散被以前未被认识到的、仍然不完全表征的过程所取代，对于该过程，颗粒的均方位移不像扩散那样随时间线性变化，而是比随时间线性变化更快。 因此，这种运动被描述为超扩散的。该项目将系统地阐明超扩散粒子动力学在合奏水平上使用X射线光子相关光谱学，并在单粒子水平上使用后焦平面干涉。拟议的实验将创造新的知识，并激发新的理论描述的颗粒和颗粒悬浮液在高粘度流体中的动力学。这将改变我们对高粘性流体的理解，高粘性流体的性质以目前尚不了解的方式引起超扩散。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，并将支持教育博士生，他们将学习如何在这些设施中尽可能地进行科学研究，满足国家对此类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 Recently it has emerged that in highly viscous fluids, ordinary diffusion is superceded by a previously unrecognized and still incompletely characterized process, in which the particles move further than expected on the basis of diffusion.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 Recently it has emerged that in highly viscous fluids, ordinary diffusion is superceded by a previously unrecognized and still incompletely characterized process, for which the particle's mean-square displacement varies, not linearly in time, as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.