In this paper, we consider the problem of existence as well as multiplicity results for a bi-harmonic equation under the Navier boundary conditions: △2 u = K(x
This paper summarizes the possible application of lignin extraction from black liquor and the development of lignin extraction technology.Lignin extraction from
Let μ be a nonnegative Radon measure on Rd,which only satisfies the poly-nomial growth condition.Under this assumption,the authors obtain some weighted weak-ty