Before revision:  Based on a lemma about a special Cholesky decomposition, it can be proved that the discrete fractional derivative of energy is nonpositive, i.e., the discrete time-fractional energy dissipation law , and that a discrete weighted energy can be constructed to be dissipative, i. e., the discrete weighted energy dissipation law. In addition, some numerical tests are provided } to verify our theoretical analysis.
After revision:  Based on a lemma about a special Cholesky decomposition, it can be proved that the discrete fractional derivative of energy is nonpositive, i.e., the discrete time-fractional energy dissipation law , and that a discrete weighted energy law. The extension for a (2- } to verify our theoretical analysis.