U and in the throttling process adiabatic 2 =0, then U7,-U1=△=W Left, Surroundings compresses gaseous system work, system got W=-P△=n(△=0-1=-71) Right gaseous system expansion k surr. got 2=-2△=-P2V2(△=12-0=12) 4上一内容下一内容令回主目录 返回 2021/223上一内容 下一内容 回主目录 返回 2021/2/23 U and H in the throttling process W p V 1 1 = −  Left, Surroundings compresses gaseous system: work, system got： Adiabatic Q=0 ，then： U U U W 2 1 − =  = Right, gaseous system expansion： work , surr. got: W p V 2 2 = −  1 1 1 1 =  − = − pV V V V ( =0 ) 2 2 2 2 = −  − = p V V V V ( = 0 )