Success in school learning has attracted considerable attention in educational research.To facilitate success in school learn-ing,researchers have conducted muc
This paper first describes the phenomenon of channel widening during degradation of alluvial rivers,explains the mechanisms of channel widening, and analyzes th
A new composited biomaterial (TGH)was prepared with titanium powder,glasspowder and hydroxylapatite powder,which were mixed well at certain preparationand were