Theoretical Studies Of Dynamical Processes In Chemical P

当液体过冷时，粘度急剧增加。一种可能的解释依赖于爱因斯坦对固体球悬浮液粘度的计算。他的计算的扩展表明，当球体的浓度达到临界值时，粘度应该变得无限大。这不可能是在冷液体中实际发生的情况。更有可能的是，液体区域在类似流体和固体的行为之间随时间波动。这种动力学无序的理论正在研究中。 分子重排有时看起来好像受到了内部摩擦的影响。通过计算机模拟研究了说明这种现象的模型。这个模型是一个分子，有两个最低能量状态耦合到一些内部正常模式。

When liquids are supercooled, viscosity increases dramatically. One possible explanation relies on a calculation by Einstein of the viscosity of a suspension of solid spheres. An extension of his calculation suggests that when the concentration of spheres reaches a critical value, the viscosity should become infinite. This cannot be what actually happens in a cold liquid. What is more likely is that regions of the liquid fluctuate in time between fluid- and solid-like behavior. The theory of this kind of dynamical disorder is under investigation. Molecular rearrangements sometimes look as if they are affected by internal friction. A model illustrating this phenomenon has been studied by computer simulation. This model is a molecule with two minimum energy states coupled to a number of internal normal modes.