本论文是一项关于物理熵概念诞生过程的历史研究，旨在结合宏观与微观两个视角，提供关于熵概念诞生的历史叙事，既包括热力学领域的熵的历史，又涵盖统计物理领域的熵。除了叙事的全面、完整之外，也力图就具体问题提出新的观点或新的论证。在具体的研究中，为方便起见，将物理熵的诞生过程分为“热机效率”“热力学第二定律”“数学化的熵”和“熵的概率解释”四个阶段。采用文献研究法和比较研究法，既研读主要的一手文献，也参考不同二手文献对同一问题的不同分析。同时，也借鉴物理科学的研究成果，将物理学史的研究与物理学相结合。本论文研究发现，关于水轮机效率的理论研究对S·卡诺提出热机定理有很重要的启发意义，而卡诺本人的未出版手稿表明，他生前也对热质说的正确性表示过怀疑，甚至也进行过热功当量的研究。因此，卡诺也可以与迈尔、焦耳并列，被看作是能量理论的先驱之一。不仅卡诺关于热功当量的研究被普遍忽视，甚至他在热力学第二定律发现过程中的地位也受到了低估。本研究认为，卡诺对于热力学第二定律发现的历史意义，不亚于迈尔和焦耳对热力学第一定律发现的历史意义。本论文还发现，从热力学第二定律演变到熵的过程，并不只是克劳修斯一个人的成就，事实上热力学第二定律的数学化是一个比较复杂的过程。汤姆森1852年对宇宙热寂的论述，以及1854年提出的热力学第二定律的数学表达，可以说分别先于克劳修斯对宇宙中熵趋于极大的论断以及他的熵概念，而汤姆森提出的第二绝对温度概念更是克劳修斯发明熵的基础。此外，兰金和雷奇也可以被认为在1850年和1853年先于克劳修斯在实质上提出熵的概念。对克劳修斯1862年研究的深入分析则表明，熵的增加可能有两种效应，一个是热的增加，另一个是分子构型的改变（离散度的增加）。后者在现在的物理学教科书中较少被提及，然而很有助于理解熵的概念。而且，分子构型引起熵的变化，已经可以看作是寻找熵的微观基础；尽管克劳修斯并没有发展出熵的概率解释，但这一类似的阐释比玻尔兹曼早了15年。最后，在科学史上的发现之外，本研究认为，对熵的历史的研究还可以产生一些科学意义上的知识。这与张夏硕的补充科学概念有一定的相似之处。因此，本论文也稍微讨论了一下，对物理熵诞生的研究带来的补充科学知识。

This dissertation is a historical research on the birth of the concept of physical entropy, which aims to provide a comprehensive historical narrative of the birth of this important concept from the macro and micro perspectives, including entropy in the sense of thermodynamics and in the sense of statistical physics. In addition to the comprehensive narration, it also tries to put forward new views or new arguments on specific issues.In the specific research, for convenience, the birth of physical entropy is divided into four stages: ‘heat engine efficiency’, ‘the second law of thermodynamics’, ‘mathematization of the second law of thermodynamics’ and ‘the probability interpretation of entropy’. The study uses the methods of literature research on the basis of studying the main primary literature, comparative research referring to different second-hand literature on the same problem; meanwhile, it also learns from the conclusions of physical science and combine the research of the history of physics with physics.This dissertation finds that the theoretical research on the efficiency of hydraulic turbine is of great significance for Sadi Carnot to put forward the heat engine theorem. Carnot’s unpublished manuscripts show that he doubted the correctness of the carolic theory, and even studied the mechanical equivalence of heat. Therefore, Carnot can also be regarded as one of the pioneers of energy theory along with Robert Mayer and James Joule. Not only has Carnot’s research on mechanical equivalence of heat been generally ignored, but also his position in the discovery of the second law of thermodynamics has been underestimated. In my opinion, Carnot’s historical significance to the second law of thermodynamics is no less than that of Mayer and Joule to the first law. This dissertation also finds that the process from the second law of thermodynamics to entropy is not only the achievement of Rudolf Clausius; in fact, the mathematization of the second law of thermodynamics is a complex process. William Thomson’s discussion on the heat death of the universe in 1852 and the mathematical expression of the second law of thermodynamics proposed in 1854 can be said to be prior to Clausius’conclusion that entropy tends to be maximum in the universe and his concept of entropy respectively; and Thomson’s concept of the second absolute temperature is the basis of Clausius’invention of entropy. In addition, William Rankine and Ferdinand Reech can also be considered to have put forward the concept of entropy before Clausius in 1850 and 1853. An in-depth analysis of Clausius’ 1862 study shows that the increase of entropy may have two effects, one is the increase of heat, the other is the change of molecular configuration （the increase of disgregation）; the latter is rarely mentioned in modern physics textbooks, and then it is helpful to understand the concept of entropy. Moreover, the change of entropy caused by molecular configuration can be regarded as the microcosmic basis for searching for entropy; although Clausius did not develop a probabilistic explanation of entropy, this similar explanation was 15 years earlier than Ludwig Boltzmann’s.Finally, in addition to the discoveries in the history of science, the dissertation notices that the study of the history of entropy can also produce some scientific knowledge. This is similar to Hasok Chang’s concept of complementary science. Therefore, this dissertation also discusses the complementary scientific knowledge of the birth of physical entropy.