w,q trend on p-v diagram w=∫pdn q=∫7ds W>0 9>0 n=0 n=0 n=1 n=1 n=k n=k n=0o→ n=o0 ≥V V 上游充通大 Mar/15,Wed,2017 12 SHANGHAI JLAO TONG UNIVERSITYMar/15, Wed, 2017 12 w, q trend on p-v diagram p v n=0 n=1 n=k n=∞ w>0 p v n=0 n=1 n=k n=∞ q>0 w p v  d  q T s  d 