http://www.elsevier.com/wps/find/journaldescripti on cws home/233/description# description Tetrahedron Letters Tetrahedron Letters TETR△ HEDRON LETT 影响因子:2.484 简讯A Free sample background from www.powerpointbackgrounds.com Slide 10 Tetrahedron Letters TETRAHEDRON LETT 影响因子：2.484 简讯 http://www.elsevier.com/wps/find/journaldescripti on.cws_home/233/description#description