Unified expressions of all differential variational principles

A mathematical expression of the quantitative causal principle is given, using the expression this letter shows the unified expressions of D’Alembert–Lagrange, virtual work, Jourdian, Gauss and general D’Alembert–Lagrange principles of differential style, first finds the intrinsic relations among these variational principles, the conservation quantities of the above principles are first found, finally the Noether conservation charges of the all differential variational principles in the systems with the symmetry of Lie group <f>Dm</f> are first obtained. [Copyright &y& Elsevier]