National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [11401184, 11326081]; Hunan Province Natural Science Foundation of ChinaNatural Science Foundation of Hunan Province [2015JJ3025]; Excellent Doctoral Dissertation of Special Foundation of Hunan Province [2050205]; Construct Program of the Key Discipline in Hunan Province [[2011]76]; Vaisala Foundation of The Finnish Academy of Sciences and Letters