1) downlink multi-antenna multi-user system
下行多天线多用户系统
2) downlink
下行
3) downward ventilation
下行通风
1.
Research on application of downward ventilation to coal mining face in horizontal seam with coal outburst in potential;
近水平突出煤层回采工作面下行通风应用研究
2.
Field experiments using downward ventilation were studied and the gas emission and distribution laws at the goaf working face were discussed.
结果表明,在采用下行通风后,采空区绝对瓦斯涌出量为上行风时的80%,工作面φ(CH4)下降了75%,瓦斯不再超限。
4) downer
下行管
1.
In order to investigate the solid concentrations in the fully developed region of the circulating fluidized bed(CFB)downers,the actual solid concentration was measured by an optical solid concentration probe in a 9.
在较宽的操作条件范围内采用光纤颗粒浓度探头测定了下行管(φ100mm×9。
5) downriver ventilation
下行风
1.
This paper discussed methane emission,the reasons for methane reduction in up corner,problems should be considered in the condition of change from normal ventilation into downriver ventilation.
对下行通风时瓦斯涌出及下隅角瓦斯减少的原因进行论证,对上行风改为下行风应注意的问题进行了论证。
6) down dismantling
下行拆除
1.
After finishing the face mining,the down dismantling method is applied for face move.
工作面回采结束后,采用下行拆除的方法进行搬面。
参考词条
补充资料：多苯基多亚甲基多异氰酸酯
多苯基多亚甲基多异氰酸酯，简称PAPI，或称粗MDI，浅黄色至褐色粘稠液体．有刺激性气味。相对密度(20℃／20 ℃)1．2，燃点218℃。PAPI实际上是由50％MDI与50％官能度大于2以上的多异氰酸酯组成的混合物。升温时能发生自聚作用。溶于氯苯、邻二氯苯、甲苯等。PAPI的活性低，蒸气压低，只是TDI的百分之一，故毒性很低。
用于制造聚氨脂胶粘剂。也可直接加入橡胶胶粘剂中，改善橡胶与尼龙或聚酯线的粘接性能。贮存于阴凉、通风、干燥的库房内，远离火种、热源。严格防水、防潮，避免光照。
用于制造聚氨脂胶粘剂。也可直接加入橡胶胶粘剂中，改善橡胶与尼龙或聚酯线的粘接性能。贮存于阴凉、通风、干燥的库房内，远离火种、热源。严格防水、防潮，避免光照。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。