1. State Key Laboratory of Deep Oil and Gas, China University of Petroleum (East China), Qingdao, Shandong 266580, PR China
2. State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China
3. Key Laboratory of Nuclear Resources and Environment (Ministry of Education), College of Earth Sciences, East China Institute of Technology, Nanchang 330013, China