1. 大学物理（热学）
Review
Carnot’s cycle
Entropy
2019/4/29

4. 用热做功——存在限制否？

5. Carnot’s ideas Q W

6. Carnot’s ideas
“The necessary condition of the maximum is, then, that in the bodies employed by realize the motive power of heat there should not occur any change of temperature which may not due to a change of volume.”

7. Carnot’s Cycle

9. Carnot’s theorem
“All reversible engines operating between the same two constant temperatures TH and TL have the same efficiency.
Any irreversible engine operating between the same two fixed temperatures will have an efficiency less than this.”

10. Clausuis statement
Not possible

12. Clapeyron’s Graph (1834)

14. 绝热 绝热

22. (Q/T)=0 e= W/ QH = 1-QL/QH =1-TL/TH QL/ TL=QH /TH, QH/ TH-QL /TL =0
Clausius’ deduction (1865)
e= W/ QH
= 1-QL/QH
=1-TL/TH
QL/ TL=QH /TH, QH/ TH-QL /TL =0
(Q/T)=0

24. (Q1/ T1+Q2 /T2)+(-Q2 /T2 +Q3 /T3 )+…+ (-Q6 /T6 +Q7 /T7 )=0

25. 克劳修斯 R. Clausius
熵的引入

27. (Q/T)<0 Irreversible: e= W/ QH = 1-QL/QH < 1-TL/TH
QL/ TL>QH /TH
(Q/T)<0

28. For isolated system: S  0
R&IR
For isolated system: S  0

29. Clausius’ Statement
“The energy of the universe is a constant. The entropy of the universe approaches a maximum.”