Unified Expressions of all Integral Variational Principles

In terms of the quantitative causal principle, this paper obtains a general variational principle, gives unified expressions of the general, Hamilton, Voss, Holder, Maupertuis–Lagrange variational principles of integral style, the invariant quantities of the general, Voss, Holder, Maupertuis–Lagrange variational principles are given, finally the Noether conservation charges of the general, Voss, Holder, Maupertuis–Lagrange variational principles are deduced, and the intrinsic relations among the invariant quantities and the Noether conservation charges of all the integral variational principles are achieved.