double fan双风扇,二联通风机doubleadj.双重的；成双的；两倍的v.翻一番；使 ... 加倍n.两倍；双份double mould-board ridging plough双壁起垄犁double glow plasma surface alloying双层辉光离子渗金属double integration delta modulation双重积分增量调制Double cut off protection device.双重断电保护装置。double absorption heat transformers双吸收式热变换器double-layer participating medium双层介质double-focusing mass spectrograph双聚焦质谱仪double satellites navigation system“双星”导航系统Double fitting for tabulated curves列表曲线的双圆弧拟合法Double-channel air-water swivel双通道水龙头

1. The process marked with a double ring is an error trapping process.
   使用双环标记的进程为错误捕获进程。