论文标题
预言波动
Premelting fluctuations
论文作者
论文摘要
基于应用于一阶相变的Landau平均场理论，提出了预言波动的模型。使用热力学势，制定了阶参数的非线性langevin方程，该方程描述了考虑显微镜热波动的相变的动力学。显示了低频波动的起源，与在热噪声的影响下与双态系统中的开关相关。开发了预言波动的分析两尺度模型，并且由于固体液体过渡而引起的潜在最小值和较大的大波动的特征频繁的小振幅波动在附近混乱运动。基于对随机微分方程的溶液的数值模拟，获得了阶参数波动及其频谱的动力学。该模型定性地再现了等热波动的实验光谱。
A model of the premelting fluctuations is proposed, based on the Landau mean field theory applied to a first-order phase transition. Using the thermodynamic potential, the nonlinear Langevin equation for the order parameter is formulated, which describes the dynamics of the phase transition considering microscopic thermal fluctuations. The origin of the low-frequency fluctuations, associated with a switching in a bistable system under the influence of a thermal noise, is shown. Analytical two-scale model of the premelting fluctuations is developed, with characteristic frequent small-amplitude fluctuations of chaotic motion in the vicinity of potential minima and rarer large fluctuations due to solid-liquid transitions. Based on the numerical simulation of the solutions to the stochastic differential equation, both the dynamics of the order parameter fluctuations and their spectrum are obtained. The model qualitatively reproduces experimental spectrum of isothermal fluctuations.
