perfect gas
5.Viewed goaf gas as no-glutinosity compressible gas, and the goaf gas flow as adiabatic flow at the perfect gas state, based on the continuous equation, movement differential equation, energy equation, finally got the velocity of shock gas which was produced by the instantaneous fall large area roof in goaf, and the frictional resistance that shock gas bearing when it flowing in the entry.
7.The results of analysis show that the shock detached distance computed by two temperature model or three temperature compare well with the experiment data, and the heat transfer rate is highest for one temperature model with non-catalytic wall, and lowest for equilibrium gas model, and the heat transfer rate for perfect gas model is between the non-catalytic wall and fully catalytic wall .
8.Up to 1995, this idea were demonstrated in experiment of near-perfect gas of alkali atom 87 Rb ,23 Ma and 7 Li by loading laser-cooled atoms into a magnetic trap and successive cooling by evaporating, the BEC of atomic hydrogen was observed in 1998. A million or so atoms in the macroscopic quantum system are all evolving in a coherent way.
