分子串模型中空间弛豫模式的弛豫动力学的蒙特卡罗模拟

Monte Carlo simulations of the relaxation dynamics of the spatial relaxation modes in the molecule-string model

基于玻璃化转变的分子串模型的分子串弛豫方程,提出了更为精确的模拟分子串中所有空间弛豫模式(SRM)的蒙特卡罗模拟方案.模拟得出各个SRM的弛豫时间随温度和分子串长度的变化结果与分子串模型中分子串弛豫方程的预言完全一致,即理论预期和模拟结果相互印证.应当指出,分子串能否作为液态中集体单元的必要条件是在考虑到分子串之间的不均匀随机相互作用后,分子串的所有SRM的定性特征是不能改变的,这就需要对不同分子串的SRM之间的耦合进行研究.但是迄今为止,仍未发现相关的严格解,仅有近似的自洽弛豫平均场方法.由此可知,所提出的模拟方案为研究不同分子串的SRM之间的耦合(包括上述自洽场的可行性)提供了必要的基础.

According to the molecule-string model for glass transition,a more exact Monte Carlo protocol to simulate all the spatial relaxation modes （SRMs） of the string are proposed.The variations of the simulated relaxation times of the SRMs with temperature and string length are consistent with the predictions of the string relaxation equation of the model,i.e.the theretical predictions and the simulation results verify each other.It should be pointed out that the necessary condition of molecule string used as a collective unit in liquid is that the qualitative characteristics of the SRMs cannot be changed when the inter-string interactions are taken into account.This needs to study the coupling between the SRMs,but till now,the corresponding exact solutions have not been achieved,and only the self-consistent relaxation mean-field method is vailable.Therefore,the present simulation protocol will provide a necessary basis to study the coupling between the SRMs of neighboring strings,including the feasibility of the mean-field method.