Molecular Turbulence : rearrangement dynamics of network

将氢键网络视为晶格上的随机图，用0-1位模式表示。采用耦合映射-格技术对随机图进行动态重排。该模型的能量涨落具有先前分子动力学研究中发现的类似1/f的长时间涨落。由于该模型的统计抽样相对容易，因此可以获得比MD模拟更清晰的视图。详细分析了该模型的径向分布函数。更多的努力集中在获得时空网络波动的定量规律和研究对溶质和溶质反应的影响。将随机图模型的计算结果与MD计算结果进行了比较。我们发现，在MD计算中，存在着较强的结构有序和无序的局部波动。每个水分子都会经历结构有序和无序的周期，持续时间长达几皮秒。定义了一种新的结构有序测度——局部结构指数，并分析了局部结构指数的时空格局。

Hydrogen bond network was regarded as a random graph on the lattice and represented by a 0-1 bit pattern. Dynamical rearrangement of this random graph was followed with the coupled-map-lattice technique. Energy fluctuation of this model was shown to have the 1/f-like long time fluctuation as was previously found in the molecular dynamics study. Due to the relative easiness of statistical sampling in this model, it is possible to obtain clearer view than in MD simulations. Radial distribution function in this model was analyzed in detail. More efforts are being concentrated to get the quantitative law of spatiotemporal network fluctuations and to examine the effects on solutes and solute reactions.Results of the random graph model was compared with the MD calculation. We found that in the MD calculation, there are strong local fluctuations of structural ordering and disordering. Each water molecule goes through the strucuturally ordered and disorderd periods which last as long as a few picoseconds. A new measure of the structural order, local strutural index (LSI) was defined and the spatio-temporal pattern of LSI was analyzed.