将牙线在齿间来回拉动。Draw the floss backwards and forwards between the teeth.一种棘齿装置把线从线轴转到梭心上。A ratchet mechanism transfers the thread from spool to bobbin.研究人员观察到一只鸟把一只啮齿动物钉在一棵仙人掌上。Researchers observed one bird impale a rodent on...
由金相显微结构的观察,焊合状态可区分为无焊合缝、散洞状 、 细线状及粗条状等四种.The bonding status could be categorized into well bonded scattered holes, thin line and strip.分析了弯曲强度、断裂挠度与焊合率之间的关系及接头的金相组织.The micro structures and the relations between bonding ...