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论文类型：期刊论文

发表时间：2010-03-01

发表刊物：ADVANCES IN DIFFERENTIAL EQUATIONS

收录刊物：SCIE、Scopus

卷号：15

期号：3-4

页面范围：381-400

ISSN号：1079-9389

摘要：In 1966, Fujita started the close investigation of the blow-up phenomena arising in some semilinear parabolic problems and found the so-called Fujita exponent. Later, Galaktionov and Levine researched nonlinear parabolic equations involving p-Laplace operators with nonlinear boundary conditions. In the present paper we extend their results to a non-Newtonian filtration system coupled via nonlinear boundary conditions. In terms of a characteristic algebraic system introduced for the problem, we obtain a clear and simple representation of both the critical Fujita exponent and the blow-up rate for this complicated coupled system containing six nonlinear exponent parameters. The proof for establishing the critical exponents is based on careful constructions of the comparison functions, especially for the blow-up case, by using the Barlenbratt-type solutions. The analysis of the blow-up rate relies on the appropriate scale transformation of the independent and the dependent variables with some differential inequalities satisfied by the L(infinity)-norm of blowing up solutions. This paper provides a complete result for such a coupled degenerate parabolic system.