The general boundary value problem for nonlinear elliptic equations of second order 二阶非线性椭圆型方程的一般边值问题
They stated the existence of weak solution in if space and some hilbert spaces for the general boundary value problem of linear degenerate elliptic equations , and made a certain further contribution to the regularity theory . during the past three decades , several progresses have been made in the research of second order degenerate elliptic equations 第二章在周期区域上考虑一类二阶半线性退化椭圆型方程边值问题的适定性及解的正则性,使用椭圆正则化方法和压缩映象原理来研究问题。