The authors were grateful for the financial support of Hunan Technology Department Foundation , China (No. 2013FJ3028 ), Innovation Foundation for Postgraduate from University of South China (No. 2016XCX08 ), Natural Science Foundation of China [No. 31200140 and 11475079 ], and Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry [No. 2015jyb02 ].