Funding for this research was provided by:
National Science Foundation of China (51872238, 21806129)
Fundamental Research Funds for the Central Universities (310201911cx019, 3102018zy045, 3102019AX11)
Natural Science Basic Research Plan in Shaanxi Province of China (2020JM-118, 2017JQ5116)
Article History
Received: 21 May 2020
Accepted: 12 June 2020
First Online: 22 June 2020