当系统同时通过传热和作功与外界交换能量,改变 状态(内能变化)时,遵守能量守恒与转化定律一热 力学第一定律。 △E W
当系统同时通过传热和作功与外界交换能量，改变 状态（内能变化）时，遵守能量守恒与转化定律—热 力学第一定律。 Q W E
87-2 The First Law of Thermodynamics 热力学第一定律 1. The first Law of Thermodynamics The system: changes from an initial state E to a final state E2. In this process, heat Q is transferred into the system and work w is done on the surrounding by the system. 吸热Q E E 作功
1. The First Law of Thermodynamics The system: changes from an initial state E1 to a final state E2 . In this process, heat Q is transferred into the system and work W is done on the surrounding by the system. E1 E2 吸热Q 作功 §7-2 The First Law of Thermodynamics 热力学第一定律
吃吃吃!! 玩玩玩学学 工作!!!
吃吃吃！！ 玩玩玩学学 工作！！！
The experiments have shown Q that △E Q=(E2-E1)+W It is the first law of thermodynamics(热力学第一定理) The first law of thermodynamics is the law of conservation of energy, generalized to include energy transfer through heat as well as mechanical energy (能量守恒推广到热学领域)
Q W E The experiments have shown that Q = (E2 − E1 )+W It is the first law of thermodynamics(热力学第一定理）. The first law of thermodynamics is the law of conservation of energy, generalized to include energy transfer through heat as well as mechanical energy. （能量守恒推广到热学领域）
The following conventions (2kE) have been adopted: (1)Q>0, which is added to system(吸热); Q<0, which is removed from system(放热) (2)W>0, done on the surrounding by the system W<0, done on the system by its surroundings; Q 3)IfE2-E1>0, the internal energy of system Increases; △E If E-E<o the internal energy of system decreases;
The following conventions（约定） have been adopted: （1）Q>0, which is added to system(吸热）; Q<0, which is removed from system（放热）; （2）W>0, done on the surrounding by the system; W<0, done on the system by its surroundings; (3) If E2 -E1>0, the internal energy of system increases; If E2 -E1<0, the internal energy of system decreases; Q W E