On the basis of the nontopological soliton bag model, it is proposed that the quark decon-finement may be indicated by the unstability and disappearance of solition solutions at finite-temperature and finite-density. The thermal effects on the vacuum structure of strongly interacting matter are investigated, and the soliton field equation of the model is solved directly in the whole range of temperature via a numerical method. The phase structure of the system and the features of deconfining phase transition are analysed in detail. In addition, the collective excitations in the vacuum caused b...
