物理学 13-2内能热力学第一定律 第五版 作机械功改变系统 作电功改变系统 状态的焦耳实验 状态的实验 Joule experiment of the Experiment of the system state changed by system state changed mechanical work by electric work 第十三章热力学基础 /12
13-2 内能 热力学第一定律 第十三章 热力学基础 物理学 第五版 1/12 作机械功改变系统 状态的焦耳实验 Joule experiment of the system state changed by mechanical work A V 作电功改变系统 状态的实验 Experiment of the system state changed by electric work
物理学 13-2内能热力学第一定律 第五版 实验证明系统从状态4变化到状态B,可以 采用做功和传热的方法,不管经过什么过程,只 要始末状态确定,做功和传热之和保持不变 Experiments prove: The system changes from state A state B, can be used to working heat transporting, regardless of the the path or processes that the system goes throgh between the given initial state the final state, the total of working heat transporting remain unchanged 2 B B 2 AlB +O41B-Wa2B +22B WAIB24+0AB24 =0 n 第十三章热力学基础 2/12
13-2 内能 热力学第一定律 第十三章 热力学基础 物理学 第五版 2/12 2 A B * 1 * p o V 0 WA1B2A + QA1B2A = W Q W Q A B A B A B A B 1 1 2 2 + = + 2 A B * 1 * p o V 实验证明系统从状态A 变化到状态B，可以 采用做功和传热的方法，不管经过什么过程，只 要始末状态确定，做功和传热之和保持不变. Experiments prove: The system changes from state A to state B, can be used to working & heat transporting, regardless of the the path or processes that the system goes throgh between the given initial state & the final state,the total of working & heat transporting remain unchanged
物理学 13-2内能热力学第一定律 第五版 内能( nternal energy) 热力学系统在一定的状态下,具有一定的能量, 称为热力学系统的内能。 The definite energy described by the thermodynamic system in the certain state is called the internal energy 内能是状态量,内能的变化只决定于出末两个状态, 与所经历的过程无关,即内能是系统状态的单值函数 The internal energy is state quantity the increment of the internal energy only depends on the initial state the final state, regardless of the paths or the processes that system goes trough, that is the internal energy is single-valued function of the system state 第十三章热力学基础 3/12
13-2 内能 热力学第一定律 第十三章 热力学基础 物理学 第五版 3/12 一 内能(Internal energy) 热力学系统在一定的状态下，具有一定的能量， 称为热力学系统的内能。 The definite energy described by the thermodynamic system in the certain state is called the internal energy 内能是状态量,内能的变化只决定于出末两个状态, 与所经历的过程无关,即内能是系统状态的单值函数。 The internal energy is state quantity, the increment of the internal energy only depends on the initial state & the final state, regardless of the paths or the processes that system goes trough, that is the internal energy is single-valued function of the system state
物理学 13-2内能热力学第一定律 第五版 E=E(7) 理想气体的内能仅是温度的单值函数 The internal energy of the ideal gas is only single-valued function of the system temperature 若不考虑分子内部结构,系统的内能就是系统中所 有分子的热运动能量和分子间相互作用的势能的总和。 If does not consider the internal structure of molecules, the internal energy of the system is the total sum of the kinetic energies of the molecules the potential energies between interactive molecules 17t E RT M 2 第十三章热力学基础 4/12
13-2 内能 热力学第一定律 第十三章 热力学基础 物理学 第五版 4/12 若不考虑分子内部结构，系统的内能就是系统中所 有分子的热运动能量和分子间相互作用的势能的总和。 2 m i E RT M = 理想气体的内能仅是温度的单值函数 E = E(T) The internal energy of the ideal gas is only single-valued function of the system temperature If does not consider the internal structure of molecules, the internal energy of the system is the total sum of the kinetic energies of the molecules & the potential energies between interactive molecules
物理学 13-2内能热力学第一定律 第五版 系统内能的增量只与系统的初态和末态有关, 与系统所经历的过程无关 The increment of the internal energy of the system only depends on the initial state the final state, it is naepenaen at of the processes that system goes trough B B 2 △E AB △E A1B24 第十三章热力学基础 5/12
13-2 内能 热力学第一定律 第十三章 热力学基础 物理学 第五版 5/12 系统内能的增量只与系统的初态和末态有关， 与系统所经历的过程无关 . EAB =C EA1B2A = 0 2 A B * 1 * p o V 2 A B * 1 * p o V The increment of the internal energy of the system only depends on the initial state & the final state, it is independent of the processes that system goes trough