User:Harkalelibre/Sandbox2
維基百科,自由的 encyclopedia
热力学(英語:Thermodynamics)是物理学中研究热量和温度以及它们与能量及功的分支。在热力学中,一个物质系统或辐射系统的状态由一系列宏观量,如内能、熵以及压强,来描述。而这些量之间的约束关系需符合适用于任何物质系统的热力学定律。热力学研究对象是系统的宏观状态,而不研究其微观状态,如构成它的分子的运动状态。热力学定律可以由研究物质微观状态对宏观状态影响的统计力学进行理论解释。
从历史的角度来说,热力学起源于人们在提高早期蒸汽机的效率方面所做的研究。其中,在这方面做出基础性工作的是法国物理学家尼古拉·卡诺。他认为提高热机的效率是法国取得拿破仑战争胜利的关键。[1] 1854年,英国科学家开尔文勋爵首次提出较为精炼的定义:[2]
“ | 热力学是有关热量与作用在物体邻接部分之间的作用力的关系及其与电介质之间关系的一门科学。 | ” |
起初,热力学研究热机的“工作物质”的性质Initially, thermodynamics, as applied to heat engines, was concerned with the thermal properties of their 'working materials' such as steam, in an effort to increase the efficiency and power output of engines. Thermodynamics later expanded to the study of energy transfers in chemical processes, for example to the investigation, published in 1840, of the heats of chemical reactions[3] by Germain Hess, which was not originally explicitly concerned with the relation between energy exchanges by heat and work. From this evolved the study of Chemical thermodynamics and the role of entropy in chemical reactions.[4][5][6][7][8][9][10][11][12]