国产无码

Difference methods are widely used for the numerical solution of problems in mechanics and physics. When constructing discrete analogs, it is important to preserve the basic properties of the original differential problem. The main goal of this work is to discretize a system of equations of the form C(x,t,u) u_t+E(x,t,u_α )=0 based on its functional --- the Hamiltonian action. Necessary and sufficient conditions for potentiality with respect to a given bilinear form are obtained. The Hamiltonian action for this system is constructed and its representation in the form of Birkhoff equations for infinite-dimensional systems is obtained. By approximating the constructed functional with its discrete analog, a discrete-time analog of Birkhoff equations is obtained based on the variational principle. Theoretical results are illustrated by the example of a wave equation with axial symmetry.