This paper is supported by the National Natural Science Foundation of China (Nos. 61102108), Scientific Research Fund of Hunan Provincial Education Department (Nos. 16B225, YB2013B039), the Natural Science Foundation of Hunan Province (Nos. 2016JJ3106), Young talents program of the University of South China, the construct programof key disciplines in USC (No. NHXK04), and Scientific Research Fund of Hengyang Science and Technology Bureau (Nos. 2015KG51).