基金This work was supported by the grants fi:om the National Natural Sciences Foundation of China (NSFC-31572276 and NS FC-31601850), the Hunan Provincial Natural Science Foundation (2017JJ3202) and the Singapore Ministry of Education AcRF Tier 1 grant (R-154-000-A52-114)
基金This research was supported by the National Natural Science Foundation of China (31060070),Project on Key Project on Applied Basic Research of Yunnan Provincial Department of Science and Technology (2016FA012)and Applied Basic Research of Yunnan Provincial Department of Science and Technology (2009CD092).