tokens: We are grateful to the anonymous referee for constructive comments leading to significant improvement of this paper. We thank the financial support of the Key Research Program of the CAS (grant No. KJZD-EW-M06), the National Natural Science Foundation of China (NSFC; grant No. 11433004), and the Ministry of Science and Technology of China (2016YFA0400700). We also thank the financial support of the NSFC (grant No. 11273052), and the Youth Innovation Promotion Association, CAS. We also acknowledge the support of the staff of the Lijiang 2.4 m telescope. Funding for this telescope has been provided by the CAS and the People’s Government of Yunnan Province.
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O B-Grant I-Grant I-Grant O O B-Organization B-Grant I-Grant I-Grant O B-Organization I-Organization I-Organization I-Organization I-Organization I-Organization B-Organization B-Grant I-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization I-Organization O B-Location B-Grant O O O O O O O O B-Organization B-Grant I-Grant I-Grant O O B-Organization I-Organization I-Organization I-Organization B-Organization O O O O O O O O O O B-Telescope I-Telescope I-Telescope I-Telescope O O O O O O O O O B-Organization O O B-Organization I-Organization I-Organization I-Organization I-Organization