【判断题】确定加工路线时的工作重点是确定粗加工及空行程的加工路线。( )
【简答题】What are the two ductility indexes?
【判断题】Ductility and malleability are not always coextensive – for instance, while gold has high ductility and malleability, lead has low ductility but high malleability.
【简答题】Among the following properties, temperatures have the greatest effect on ______. A) ductility B) impactstrength C) hardness D) strength
【单选题】Which is the ductility?
A.
stress at where strain deviates from being proportional to stress
C.
deformation at necking
D.
deformation at fracture
【简答题】在高速运转或载荷较小的摩擦部位及温度不高的工况下,宜选用粘度较 (高、低)的润滑油。
【判断题】轮作是在同一块土地上,按照一定年限轮换种植仅两种不同性质的蔬菜。