Cover: Scanning electron micrographs of the wear debris of the Mg–6Gd–3Y–0.5Zr alloy for 400 m sliding distance and v=0.06 ms-1, F=15 N, T=25 °C.[H.R. Jafari Nodooshan, W.C. Liu, G.H. Wu, W.J. Ding, R. Mahmudi: Effect of Gd addition on the wear behavior of Mg–xGd–3Y–0.5Zr alloys. p. 1135].