论文标题
部分可观测时空混沌系统的无模型预测
Relaxation to steady states of a binary liquid mixture around an optically heated colloid
论文作者
论文摘要
我们使用实验和理论模型在打开和关闭照明后，研究了二进制液体混合物的松弛动力学。动力学由加热粒子周围形成的温度梯度控制。我们的结果表明，松弛是不对称的：非平衡稳态的方法比返回热平衡的速度要慢得多。接近非平衡稳态是一个两步过程，导致浓度场的空间差异的行为，类似于初始过冲，响应于各种软材料中发现的外部场。打开照明后浓度波动的初始生长遵循与流体动力和纯粹扩散模型一致的功率定律。关闭照明后系统的能量流量通过时间的拉伸指数函数很好地描述，其特征时间与稳态状态中存储的能量与该状态的总能量通量的比率成正比。
We study the relaxation dynamics of a binary liquid mixture near a light-absorbing Janus particle after switching on and off illumination using experiments and theoretical models. The dynamics is controlled by the temperature gradient formed around the heated particle. Our results show that the relaxation is asymmetric: the approach to a nonequilibrium steady state is much slower than the return to thermal equilibrium. Approaching a nonequilibrium steady state is a two-step process leading to the behavior of the spatial variance of concentration field similar to the initial overshoot in response to an external field found in diverse soft materials. The initial growth of concentration fluctuations after switching on illumination follows a power law in agreement with the hydrodynamic and purely diffusive model. The energy out-flow from the system after switching off illumination is well described by a stretched exponential function of time with characteristic time proportional to the ratio of the energy stored in the steady state to the total energy flux in this state.
