1. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical PhysicsChinese Academy of Sciences Lanzhou 730000 China
2. Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of Sciences Beijing 100049 China
3. Jiangxi Key Laboratory of Mining Engineering, School of Resources and Environmental EngineeringJiangxi University of Science and Technology Ganzhou 341000 China