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- ZJ type Roots vacuum pump and the backing pump i.e two stage water ring vacuum pump. 它不仅可以用来抽除一般气体，还可以抽吸含有水分及少量灰尘的气体。
- JZJX type Roots-Vane vacuum system consists of the major pump i.e ZJ type Roots vacumm pump and the backing pump i.e. vane vacuum pump. JZJX系列罗茨-旋片机组是由ZJ型罗茨真空泵（主抽泵）和旋片式真空泵（前级泵）组成的。
- The series H pump can be a backing pump when combined with another high vacuum smelting, vacuum drying, vacuum impregnate and high vacuum simulation testing, ect. 广泛地应用于真空冶炼、真空干燥、真空浸渍、高真空模拟试验以及其他真空作业上。
- Used either solely as Rough Pumps, or in combination with other high vacuum pumps as Backing Pumps. 可单独作低真空泵用,也可与其它高真空泵组合作前级泵用。
- Recommended Model of Backing Pump 前极泵型号
- Rose bushes shoot again after being cut back. 玫瑰丛修剪後还能再长出新枝。
- The intermittent transportation process can be adopted for the low-throughput rate pipeline which the pour depressant is added and the forward and back pumping is also needed. 对于添加降凝剂后还需进行正反输运行的低输量管道,可以采用间歇输油工艺,通过对中洛线间歇输送的试验分析,总结了间歇运行的优点和应该注意的问题。
- Pumping speed of backing pump matched 配用前级泵抽速
- He trudge three hour in the snow to get back home. 他在雪中跋涉三个钟点才回到家。
- The crowd fell back to let the players through. 人群后退让运动员们通过。
- Do exercise every day and you'll be back in condition. 每天锻炼锻炼，你很快会恢复健康的。
- The ship beat back against a monsoon. 船逆着季风艰难地行驶。
- The new leader has a large backing. 那位新领导人有大批的支持者。
- I flap the flies away but soon they fly back. 我把苍蝇赶走，但一会儿又飞回来了。
- I never lend books; you never get them back. 我的书决不外借，因为总是有去无回。
- She leaned her head back and whispered the news. 她向后仰着头，小声说出了这个消息。
- The talks have been put back to Friday morning. 谈判推迟到星期五早上进行。
- He hated to tuck his tail and back down now. 他讨厌此时夹着尾巴退回来。
- After a long coma the sick man slowly came back. 昏睡了好久以后，那个病人慢慢地恢复了活力。
- Back in Nigeria we used to play a lot of tennis. 我们以前在尼日利亚经常打网球。
