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arXiv 2107.00499cond-mat.softcond-mat.stat-mech
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气液界面压力参考系的重要性

The Importance of Reference Frame for Pressure at the Liquid-Vapour Interface

Edward R. Smith

摘要:

局部压力张量是非唯一的,这一事实在欧文·柯克伍德的开创性工作之后的70年里产生了混乱和争论。这种非唯一性通常归因于分子之间的相互作用路径,特别是在界面科学界。在这项工作中,我们重新架构的位置,或参考系,用于测量压力方面的非唯一性的讨论。通过使用一个通用的数学描述的液体-蒸汽界面,我们得到一个参考系,通过时间移动的接口,提供了一个新的洞察力的压力。我们比较了这个瞬时运动的参考系与固定的欧拉参考系。通过这个过程中,我们显示的要求,正常的压力平衡在移动的表面满足表面通量,但需要一个额外的校正项的基础上表面曲率的平均压力的体积。我们的情况下,一个重点的整合路径是在文献中的混乱的原因。使用一个明确的参考系与一个更一般的压力推导澄清了一些问题的唯一性的压力张量,并提供了一个压力张量,这是定义在任何时刻的时间和有效的远离热力学平衡。

英文摘要:

The local pressure tensor is non-unique, a fact which has generated confusion and debate in the seventy years since the seminal work by Irving Kirkwood. This non-uniqueness is normally attributed to the interaction path between molecules, especially in the interfacial-science community. In this work we reframe this discussion of non-uniqueness in terms of the location, or reference frame, used to measure the pressure. By using a general mathematical description of the liquid-vapour interface, we obtain a reference frame that moves with the interface through time, providing a new insight into the pressure. We compare this instantaneous moving reference frame with the fixed Eulerian one. Through this process, we show the requirement that normal pressure balance at the moving surface is satisfied by surface fluxes, however an additional corrective term based on surface curvature is required for the average pressure in a volume. We make the case that a focus on the path of integration is the cause of much of the confusion in the literature. Using an explicit reference frame with a more general derivation of pressure clarifies some of the issues of uniqueness in the pressure tensor and provides a pressure tensor which is defined at any instant in time and valid away from thermodynamic equilibrium.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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