ducted

1.a ventilation system that must be ducted through the wall.

必须穿过墙壁的管道通风系统。

2.A test of arrosion performance of anticorrocive built-up weld layer in different meeiums was con-ducted by using a self-made arrosion testing machine.

用自制的腐磨损试验机堆焊层在不同介中的腐磨损性能进行了试验，结果表明：腐介不同，堆焊层的磨损速率也不同。

3.In addition, the USAF continues to fund development work of the Aerojet (formerly Atlantic Research) Variable Flow Ducted Rocket ramjet system as a future propulsion option for an extended range AAM.

此外，美国空军继续投资于航空喷气所（原来的大西洋所）的可变喷流管火箭发动机系统，将其作为增程空空导弹的未来推进选项。