Using the second-order potential theory proposed by the author, this paper gives an investigation to the nonlinear interaction of P and SV waves in isotropic elastic media.

From the framework of the multiple scattering theory, we obtain the antiproton-nucleus optical potential that can best describe the experimental elastic scattering data.

According to Hertz contact theory, this paper discussed the elastic deformation in the ball screw systems and elastic potential energy caused by it.