  This paper has been withdrawn by the authors.
  Quantum radiative characteristics of 4D semi-classical nonstationary black
holes in the general case are investigated by using the method of generalized
tortoise coordinate transformation. It is generally shown that the temperature
and the shape of the event horizon of this kind of black holes depend on both
the time and different angles. Further, we discover that there is a certain
relationship that is ignored before between thermal radiation and non-thermal
radiation of black holes, which is that the chemical potential in thermal
radiation spectrum is equal to the highest energy of the negative energy state
of particles in non-thermal radiation for 4D semi-classical nonstationary black
holes. Also, we show that the deduced general results can be applied to
different concrete conditions.
