Yonghong Hao, Tianjin Normal University, Tianjin, China, Zaibin Liu, Xi’an Research Institute Company of China Coal Technology and Engineering Group, Xi'an, China, Tian-Chyi J Yeh, Univ Arizona, Tucson, AZ, United States, Wenke Wang, Chang'an University, School of Environmental Science and Engineering, Xi'an, China and Ming Zhang, Geol. Survy of Japan, AIST, Tsukuba, Japan