[1]Pao C V.Nonlinear Parabolic and Elliptic Equations.New York: Plenum Press,1992

[2]Sheng Q,Khaliq A Q A compound adaptive approach to degenerate nonlinear quenching problems.Numer Methods for Partial Differential Equations,1999,15:29-47

[3]Kawarada,H.On solutions of initial boundary problem for u_t=u_{xx}+1/(1-u).Publ RIMS Kyoto Univ,1975,10: 729-736

[4]Acker A,Walter W.The quenching problem for nonlinear partial differential equations.Berlin: Springer,1976

[5]Levine H A.Quenching, nonquenching,and beyond quenching for solutions of some paraolic equa tions.Annali di Mat pura et Appl,1989,155: 243-260

[6]Dai Qiuyi,Gu Yonggeng. A short note on quenching phenomena for  semilinear par abolic equations.J Differential Equations, 1997,137: 240-250

[7]Chan C Y,Kong P C.Quenching for degenerate semilinear parabolic equations.Applicable Analysis,1994, 54: 17-25

[8]Ke L,Ning S.Quenching for degenerate parabolic equations.Nonlinear Analysis, 1998,34:1123-1135

[9]Pao C  V. Quenching problem of a reactiondiffusion equation with time delay.Nonlinear Analysis, 2000,  41: 133-142

[10]Friedman A.  Partial Differential Equations of Parabolic Type.Englewood Cliffs: Prentice Hall Inc,1964

[11]Floater M S.Blow up at the boundary for degenerate semilinear parabolic equations.Arch Rat Mech Anal,1991, 114:  57-77

[12]Chen Y P.Quenching problem of a kind of degenerate reaction diffusion equations.Journal of Nanjing University Mathematical Biquarterly,1999,16(1):133-143

[13]Friedman A,Mcleod B.Blow up of positive solutions of semilinear heat equations.Indiana Univ Math J, 1985,34:  425-447