基金This work was jointly supported by the National Natural Science Foundation of China （Grant Nos. 41210004 41661144042 41603018） and National Basic Research Program （973 project） of China （2013CB956401）.
基金This work was jointly supported by the National Key Basic Research and Development Projects of China （Grant Nos. 2016YFA0600601 and 2014CB953901） and the National Natural Science Foundation of China （Grant No. 41375096）.
基金Acknowledgements The study was funded by the National Natural Science Foundation of China （51309134）, the National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China （J1210065）, the Research Starting Funds for Imported Talents, Ningxia University （BQD2012011） and the Natural Science Funds, Ningxia University （ZR1233）. The authors thank CHENG Hongyi, HUANG Yinzhou, ZHAO Liqiang, CHENG Hongbao, LI Mingzhi, LAI Rongsheng, SU Xianbao and YANG Anning for their kind help with the field and laboratory work. We also thank FANG Keyan and two anonymous reviewers for their valuable comments and suggestions.
基金This study was jointly supported by the National Natural Sci- ence Foundation of China [grant number 41475057], [grant number 41221064], [grant number 91437218], [grant number 41505049] the Key Program of Chinese Academy of Meteoro- logical Sciences [grant number 2015Z001].
基金Supported jointly by the US Department of Energy, Pacific Northwest National Laboratory （4331620）, Earth System Science Interdisciplinary Center, University of Maryland, and Department of Atmospheric Sciences, Texas A ＆： M University.