  How to introduce thermodynamics to quantum mechanics ? Among from numerous
possibilities of solving this task, the simple choice is here: The conventional
von Neumann equation deals with a density operator whose probability weights
are time independent. Because there is no reason apart from the reversible
quantum mechanics that these weights have to be time independent, this
constraint is waived, thus making possible to introduce thermodynamical
concepts to quantum mechanics. %\textcolor{green}{ This procedure is similar to
that of Lindblad's equation, but different on principle. %\textcolor{red}{ But
beyond this simple starting-point, the applied thermodynamical concepts of
discrete systems may perform a "source theory" for other versions of
phenomenological quantum thermodynamics.
