Mr.Obama was in the senator's home state when he died not far from the Kennedy compound in Hyannis Port,Massachusetts.

VOA: standard.2009.08.26

Delta H of formation means the enthalpy of this compound minus the enthalpy of its constituent elements in their most stable state at room temperature and pressure.

生成焓就是这种组分,的焓减去它的所有组成元素,在室温和常压下处于,其最稳定的状态时的焓。

麻省理工公开课 - 热力学与动力学课程节选