8888视频日本_国产一区二区三区精品一级毛片_av在线free_日韩在线欧美在线国产在线_av影片在线一区_国产精品一区精品国产自在

Lian, Y.S., Deng, J.X., Li, SH.P., Yan, G., Lei, SH.T., Friction and wear behavior of WS2/Zr self-lubricating soft coatings in dry sliding against 40Cr-hardened steel balls. Tribology Letters (53, 1), 2014, 237-246.