Funding for this research was provided by:
National Key R&D Program of China (2020YFC1522202)
Gansu Science and Technology Department (18YF1WA003)
Program of Dunhuang Academy (2020-KJ-YB-9)
Received: 16 August 2021
Accepted: 19 July 2022
First Online: 31 August 2022
: The author declare that they have no competing interests.