Derenyi I., Tegzes P., Vicsek T.
Department of Surgery, MC 6035, University of Chicago, 5841 South Maryland Avenue, Chicago, Illinois 60637.
Chaos. 1998 Sep;8(3):657-664. doi: 10.1063/1.166348.
In this paper we give an overview of the cooperative effects in fluctuation driven transport arising from the interaction of a large number of particles. (i) First, we study a model with finite-sized, overdamped Brownian particles interacting via hard-core repulsion. Computer simulations and theoretical calculations reveal a number of novel cooperative transport phenomena in this system, including the reversal of direction of the net current as the particle density is increased, and a very strong and complex dependence of the average velocity on both the size and the average distance of the particles. (ii) Next, we consider the cooperation of a collection of motors rigidly attached to a backbone. This system possesses dynamical phase transition allowing spontaneous directed motion even if the system is spatially symmetric. (iii) Finally, we report on an experimental investigation exploring the horizontal transport of granular particles in a vertically vibrated system whose base has a sawtooth-shaped profile. The resulting material flow exhibits complex collective behavior, both as a function of the number of layers of particles and the driving frequency; in particular, under certain conditions, increasing the layer thickness leads to a reversal of the current, while the onset of transport as a function of frequency occurs gradually in a manner reminiscent of a phase transition. (c) 1998 American Institute of Physics.
在本文中，我们概述了由大量粒子相互作用所产生的涨落驱动输运中的协同效应。(i) 首先，我们研究一个模型，其中有限尺寸的过阻尼布朗粒子通过硬核排斥相互作用。计算机模拟和理论计算揭示了该系统中一些新颖的协同输运现象，包括随着粒子密度增加净电流方向的反转，以及平均速度对粒子尺寸和平均距离的非常强烈且复杂的依赖性。(ii) 接下来，我们考虑一组刚性附着在主干上的马达的协同作用。即使系统在空间上是对称的，该系统也具有动态相变，允许自发的定向运动。(iii) 最后，我们报告了一项实验研究，该研究探索了在底部具有锯齿形轮廓的垂直振动系统中颗粒的水平输运。所产生的物质流表现出复杂的集体行为，这是粒子层数和驱动频率的函数；特别是在某些条件下，增加层厚度会导致电流反转，而作为频率函数的输运起始以一种让人联想到相变的方式逐渐发生。(c) 1998美国物理研究所。
