讨论在方形区域[0,π]×[0,π]内,当f满足一定条件时,Neumann边值问题{△u+λu+f(x,u)=0 au/an=0在平凡解(2λ,0)处产生分歧解,并且精确给出解的个数及解曲线的参数表达式。
Study bifurcation from the branch of trivial solutions for a class of semilinear elliptic equations, {△u+λu+f(x,u)=0 au/an=0 at the second eigenvalue of the Laplacian in, [0,π ) ×[0,π] and we give the exact bifurcation solutions formular.