“…Fractional differential equations are generalized differential operations from integer orders to fractional derivative operations. The problem of fractional calculus has wide applications in fractal theory, signal processing, system control, quantum mechanics, environmental science, and finance (Jiang and Qi, 2010;Mainardi, 1996). The time-fractional differential equation is obtained by replacing the integer order in the classical model to fractional derivative, the fractional derivative at a certain time depends on all the values of the function before this time point, so the fractional partial differential equation is applicable for problems with memory process, genetic property and heterogeneous material (Rossikhin and Shitikova, 1997;Ichise et al, 1971).…”