Funding for this research was provided by:
National Natural Science Foundation of China (51776101, 51206084)
Natural Science Foundation of Shandong Province (ZR2017MB016)
Project of the State Administration of Work Safety (shandong-0039-2017AQ)
Article History
Received: 9 November 2018
Accepted: 27 April 2019
First Online: 16 May 2019