5Maduako A U, Ofunne G C, Ojinnaka C M. The role of metals in the oxidative degradation of automotive crankcase oils[J]. Tribology International, 1996, 29(2) :153-160.
6Masjuki H H, Maleque M A, Kubo A,et al. Palm oil and mineral oil based lubricants-their tribological and emission performance[J].Tribology International, 1999, 32 (6): 305-314.
7Jawhari T, Roid A, Casado J. Raman spectroscopic characterization of some commercially available carbon black materials[J]. Carbon, 1995, 33 (11): 1 561-1 565.