Research of polytropic process in thermodynamics

To solve the problem of the polytropic process which hasn’t been studied in a deepgoing way in the thermodynamics,the formula of the merit in course,the increment of internal energy and the calculation that turns the heat in the polytropic process have been given according to the basically theoretical calculation of thermodynamics,the oblique straight line in P-V picture is discussed as the requirements of the polytropic process,a kind of simple judging method and the basic judging method of inhaling and releasing the heat in different interval are offered,which remedied the deficiency in the research of the polytropic process in the thermodynamic.