经典麦克斯韦妖系统中熵随时间的变化关系  

THE RELATIONSHIP BETWEEN ENTROPY AND TIME IN THE CLASSICAL MAXWELL DEMON SYSTEM

作　　者：赵欣林 薛郁[1] 蒋绍周 ZHAO Xinlin;XUE Yu;JIANG Shaozhou(School of Physical Science and Technology, Guangxi University, Nanning, Jiangsu 530004)

机构地区：[1]广西大学物理科学与工程技术学院,广西南宁530004

出　　处：《物理与工程》2022年第1期18-24,共7页Physics and Engineering

基　　金：广西自然科学基金(2018GXNSFAA281180)。

摘　　要：麦克斯韦妖的提出是为了表明热力学第二定律可能有问题,但这可以通过引入信息熵解决。本文从统计的角度研究了两种简单的麦克斯韦妖系统的最小熵变随时间的变化关系。第一种模型的冷热分子的速度分别相等;第二种模型包含两种分子量的分子,每种分子都满足麦克斯韦速度分布律。通过概率论的方法,研究了系统的热力学熵、信息熵以及总熵的变化情况。系统熵变的理论结果能够得到定量的解释,无需引入任何待定参量或者模拟数据。同时,我们也讨论了不同条件下的系统熵变的情况。所得到的理论结果和模拟数据完全相符。Maxwell's demon system seems to violate the second law of thermodynamics.The problem is solved by introducing the information entropy.This paper introduces two simple models for the Maxwell's demon system to study the least entropy change in the sense of statistic.In the first model,the velocities of hot and cold molecules are equal respectively.The second model contains two molecules with different molecular weights,each of which satisfies Maxwell's velocity distribution law.The changes of thermodynamic entropy,the information entropy and the total entropy are studied in probability theory.The theoretical results are quantitative,without any undetermined parameters and also confirm the simulation data.The entropy changes in different conditions are also discussed.The theoretical results are in good agreement with the simulated data.

关 键 词：麦克斯韦妖 信息熵 麦克斯韦速率分布 热力学熵 

分 类 号：O41[理学—理论物理]