---skin is the largest organ of the body, it constitutes about 16% of body weight ---its total surface area is about 1.2-2.2 m2 ---function: protection, sensory reception, excretion and thermoregulation
上海交通大学：《热力系统设计与实践 Design and Practice of Thermodynamic System》课程教学资源（课件讲稿）第11讲 实际气体性质及热力学一般关系式 Behavior of real gases and generalized thermodynamic relationships（麦克斯韦关系和热系数）
