[1] Chinese Acad Sci, Lanzhou Inst Chem Phys, State Key Lab Solid Lubricat, Lanzhou 730000, Peoples R China
[2] Lanzhou Univ, Sch Phys Sci & Technol, Lanzhou 73000, Peoples R China
[3] Univ Southampton, Sch Engn Sci, nCATS, Southampton SO17 1BJ, Hants, England