The inhomogeneous nonlinear diffusion equation is studied by invariant subspace and condi- tional Lie=Bgcklund symmetry methods. It is shown that the equations admit a class of invariant subspaces governed by the nonlinear ordinary differential equations, which is equivalent to a kind of higher=order conditional Lie-B^icklund symmetries of the equations. As a consequence, a number of new solutions to the inhomogeneous nonlinear diffusion equations are constructed explicitly or reduced to solving finite-dimensional dynamical sys- tems.
研究了一类带有非线性耗散项的双曲型方程 u tt - ∑ n i=1 ( ? u ? x i p-2 ? u ? x i )+a|u t| q-2 u t=b|u| r-2 u 在有界闭区域内的初边值问题,通过在Sobolev空间W 1,p 0(Ω) 上构造稳定集,证明了这类问题的整体解的存在性,并利用Komornik的一个重要引理给出了整体解的渐近性态.
