# 克劳修斯定理

$\oint \frac{\delta Q}{T} \leq 0,$

## 歷史

$\oint \frac{\delta Q}{T} = 0$

δQ為由系統轉移到熱庫的熱（注意其正負號定義恰與上式相反）。
T為系統的絕對溫度。

## 參考資料

1. ^ Clausius theorem at Wolfram Research
2. ^ The algebraic sum of all the transformations occurring in a cyclical process can only be positive, or, as an extreme case, equal to nothing.”