1. School of Engineering and Technology, China University of Geosciences (Beijing), Beijing, P.R. China;
2. Aviation Key Laboratory of Science and Technology on Precision Manufacturing, Beijing Precision Engineering Institute for Aircraft Industry, Beijing, P.R. China;
3. SINOPEC Lubricant Company(Beijing), Beijing, P.R. China;
4. Mechanical Engineering Department, Tsinghua University, Beijing, P.R. China