摘要
State functions play important roles in thermodynamics.Different from the process function,such as the exchanged heatδQ and the applied workδW,the change of the state function can be expressed as an exact differential.We prove here that,for a generic thermodynamic system,only the inverse of the temperature,namely 1/T,can serve as the integration factor for the exchanged heatδQ.The uniqueness of the integration factor invalidates any attempt to define other state functions associated with the exchanged heat,and in turn,reveals the incorrectness of defining the entransy E_(vh)=CVT^(2)/2 as a state function by treating T as an integration factor.We further show the errors in the derivation of entransy by treating the heat capacity C_(V)as a temperature-independent constant.
基金
This work was supported by the National Natural Science Foundation of China(NSFC)(Grants No.11534002,No.12088101,No.U1530402,No.U1930403,No.11775001,No.11534002,and No.11825001)
the National Basic Research Program of China(Grants No.2016YFA0301201).
