Funding for this research was provided by:
the work of Chinese Geological Survey (12120114002101)
the work of Chinese Geological Survey (DD20160268)
the Science and Technique Foundation of Henan Province (182102310001)
the Doctoral Fund of the Henan University of Engineering (2016004)
Article History
Received: 19 July 2018
Accepted: 20 February 2019
First Online: 25 February 2019
Compliance with ethical standards
:
: On behalf of all authors, the corresponding author states that there is no conflict of interest.