The convex surfaces faces toward the left . 凸面朝左方。
A convex surface , body , part , or line 凸面、凸面體、凸面部分或凸線
Closed convex surface 閉凸曲面
Application : grind the surface of wood and metal . lap the hole and surface of work - piece . gind and lap flexible contoured suface , especially concave and convex surface profiles 用途:應(yīng)用于木材和金屬的表面拋光、工件的內(nèi)孔、外壁的精磨、用于彎形物的曲面、尤其是凹凸表面和側(cè)面的研磨、拋光。適用于鑄鐵、木材、鋼材、有色金屬、塑料。
2 . sperm ultrastructure the sperm is nonflagellated and composed of a main body in which including nucleus n apical cap and a little cytoplasm and a single spike extending from the convex surface of the apical cap , which consists of about twenty radial fibrillae on which exhibiting periodic cross - striations . the concave surface of the apical cap surrounds the little cytoplasm which is highly condensed and has n ' t any organella and sperm nucleus , which is uncondensed and composed of filamentous materials and many membrane - bound vesicles 外形呈圖釘樣,由主體部和棘突組成,主體部包括帽狀體、細胞質(zhì)帶和精核。帽狀體由約20根輻射狀排列的纖絲組成,纖絲具橫紋。其凸面延伸成棘突,棘突內(nèi)纖絲是帽狀體內(nèi)纖絲的延續(xù),亦具橫紋。