====== 奥托循环 ======
===== 简介 =====
一个奥托循环由下面过程组成：
  - 循环路径的上边和下边：一对准平行的绝热过程
  - 循环路径的左边和右边：一对平行的等容过程

===== 参考文献 =====
  * Halliday, Resnick & Walker. Fundamentals of Physics, 5th edition. John Wiley & Sons, 1997. Chapter 21, Entropy and the Second Law of Thermodynamics.
  * Walter Greiner; Ludwig Neise, Horst Stöcker. Thermodynamics and Statistical Mechanics. Springer. 2008-05-23. ISBN 978-0387942995 （英语）.