1. Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 Gansu, China, State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou, 730050 Gansu, China, and School of Material Science and Engineering, Lanzhou University of Technology, Lanzhou, 730050 Gansu, China