This work is supported by National Natural Science Foundation of China (Nos. 41701467 and 41701474), Natural Science Foundation of Hubei Province, China (No. 2016CFB326) and the self-determined research funds of CCNU from the colleges' basic research and operation of MOE (No. CCNU17QN0001). The authors thank Lei Wu, Xiaoli He, Huanhuan Jia, Yong Fan, Yongfeng Dang, Sa Wang and Shu Zhang for participating in the data collection and processing. The authors would like to thank the anonymous reviewers and the editors for their useful ideas for improvement.