National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [81100212, 81170277, 81100106]; PhD Programs Foundation of the Ministry of Education of the People's Republic of China [20114324120004, 20124324110003]; China Postdoctoral Science FoundationChina Postdoctoral Science Foundation [2012 M511383]; Scientific Research Fund of Hunan Provincial Education DepartmentHunan Provincial Education Department [11C1094, 11C1095]; Science and Technology Project of Hunan Province [2014FJ3014]; Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province [2008-244]; Construct Program of the Key Discipline in Human Hunan Province [2011-76]