derivative function for pure components
function der_specificEnthalpy_Txi extends TILMedia.BaseClasses.PartialLiquidFunction; input SI.Temperature T "Temperature"; input SI.MassFraction[:] xi "Mass fractions of the first nc-1 components"; input TILMedia.Internals.TILMediaExternalObject liquidPointer; input Real der_T "Derivative of Temperature"; input Real[:] der_xi "Derivative of Mass fractions of the first nc-1 components"; output Real der_h "Derivative of Specific enthalpy"; end der_specificEnthalpy_Txi;