Process(过程 Constant-temperature process:a process in which a system changes from an initial state to a final state at a constant temperature.T=T2=T Constant-pressure process:pi=p2=P Constant-volume process:V=12= Path I P=200 kPa P=100 kPa P个，V,T =0.5m3 V=2m3 T=149.075K T=298.15K P2=200 kPa P V2=1m3 Process 2 Process 1 T2=298.15K Path II (Two processes) Process(过程) Constant-temperature process：a process in which a system changes from an initial state to a final state at a constant temperature. T1 =T2 =T Constant-pressure process：p1 =p2 =P Constant-volume process：V1 =V2 =V P1=100 kPa V1=2 m3 T1=298.15Ｋ P2= 200 kPa V2 =１m3 T2=298.15Ｋ P, V, T P=200 kPa V= 0.5 m3 T=149.075Ｋ 始态 Path II (Two processes） Path I Process 1 T Process 2 P