本学位论文主要研究一类加权Lane-Emden方程组稳定正解的不存在性,其中Ω（?）RN,0...

The deviation control of directional drilling is essentially the controlling of two angles of the wellbore actually dril......

A novel ellipsoidal acoustic infinite element is proposed. It is based a new pressure representation, which can describe......

A new and simple method is developed to establish the pseudo orthogonal properties(POP) of the eigenfunction expansion f......