论文标题
机械系统中的扩展等电位受热流量：局部耗散的情况
Extended equipartition in a mechanical system subject to a heat flow: the case of localised dissipation
论文作者
论文摘要
平衡中的统计物理学授予我们最强大的工具之一：平选原理。它指出，机械系统的自由度充当温度计：温度等于其振荡的平均方差除以其刚度。但是，当考虑非平衡状态时，该原理不再有效。在我们的实验中，我们研究了经受强大热流量的微型局体的波动，从而产生高度不均匀的局部温度。我们独立地测量物体的温度谱和从机械温度计产生的温度，从而测试了平衡的等电原理的有效性。我们证明了最有能力的自由度的波动如何等于悬臂底部的温度，即使平均温度高几百度。然后，我们根据系统中的局部机械耗散提出了一个模型，以解释我们的结果，该模型对应于夹紧位置的机械损耗。
Statistical physics in equilibrium grants us one of its most powerful tools: the equipartition principle. It states that the degrees of freedom of a mechanical system act as a thermometer: temperature is equal to the mean variance of their oscillations divided by their stiffness. However, when a non-equilibrium state is considered, this principle is no longer valid. In our experiment, we study the fluctuations of a micro-cantilever subject to a strong heat flow, which creates a highly non-uniform local temperature. We measure independently the temperature profile of the object and the temperature yielded from the mechanical thermometers, thus testing the validity of the equipartition principle out of equilibrium. We demonstrate how the fluctuations of the most energetic degrees of freedom are equivalent to the temperature at the base of the cantilever, even when the average temperature is several hundreds of degrees higher. We then present a model based on the localised mechanical dissipation in the system to account for our results, which correspond to mechanical losses localised at the clamping position.
