基金supported by the Humanities and Social Sciences Foundation for the Youth Scholars of Ministry of Education of China(No.15YJCZH066)the Science and Technology Plan Project of Hunan Province(No.2016TP1020)+4 种基金the Science and Technology Plan Project of Hengyang City(No.2017KJ183)the Construct Program of the Key Discipline in Hunan Province and University Students Research and Innovation Experiment Project of Hunan Province(No.C1718)the Scientific Research Fund of Hunan Provincial Education Department(No.17A030)Hunan Provincial Natural Science Foundation of China(No.2018JJ4024)the 2018 National Statistical Science Research Project of China(No.2018LY05)