Funding for this research was provided by:
National Key Research and Development Project (2019YFC1520604)
Major Special Projects of Science and Technology in Gansu Province (18ZD2FA001)
Science and Technology Research Project of Cultural Relics Protection in Gansu Province (201604)
Received: 24 January 2021
Accepted: 13 May 2021
First Online: 27 May 2021
: The authors declare that they have no competing interests.