[1] Lanzhou Univ Technol, Sch Petrochem Engn, Lanzhou 730050, Gansu, Peoples R China
[2] PetroChina Lanzhou Lubricating Oil R&D Inst, Lanzhou 730060, Gansu, Peoples R China
[3] Lanzhou Univ Technol, State Key Lab Adv Proc & Recycling Nonferrous Met, Lanzhou 730050, Gansu, Peoples R China