National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [11675073, 11575239, 11475083, 11605088]; Hunan Provincial Natural Science Foundation of ChinaNatural Science Foundation of Hunan Province [2015JJ4044]; construct program of fusion and plasma physics innovation team in Hunan province [NHXTD03]; University of South China [2015XDQ43]