Multiple positive solutions for semilinear Dirichlet problems with sign-changing weight function in infinite strip domains

In this paper, existence and multiplicity results to the following Dirichlet problem {−Δu+u=λf(x)|u|q−1+h(x)|u|p−1,in Ωu>0,in Ωu=0,on ∂Ω are established, where Ω=Ω′×R, Ω′⊂RN−1Ω′⊂RN−1 is bounded smooth domain and N≥2N≥2. Here 1