double hung,double hook是什么意思

用法例句

Container lifting operations with fixed,telescopic,and 4-guide plate fixed twin-lift spreaders are described respectively,aiming at improving container lifting operation modes and thus increasing container terminal efficiency and benefits.

介绍了集装箱双吊具的使用现状,详细论述了固定式、伸缩式和四导板固定式双吊具的吊运模式。

Stresses of union purchase under the influence of tied-guy positions;

稳索系固位置对双吊杆受力的影响