半封

半封离型500瓦CO2激光器的设计和工艺

Design and technology of a partly sealed-off CO_2 laser of 500W output power Two Letters

用于全过程欠平衡钻井施工的井下封井器BQFZ18&35半封-全封一体化封井器的研制

Development and application of downhole hole-closure device in the overall process of underbalanced drilling operation

有活塞、涡旋、螺杆、全封、半封等不同机型可供选择；

There piston , scroll , screw , full closure , half-seal different models to choose from ;

阐述三种常见全封或半封螺杆压缩机电机冷却方式的优劣，以及不同的电机冷却方式造成的在系统配置和性能方面的差异。

Illustrates the superiority and inferiority of different motor cooling modes for full-or semi-hermetic screw compressor , and corresponding disposition and performance differences .

植被盖度和生物量以半封育区为最高，对照区次之，完全封育区最低。

The vegetation coverage and biomass is the highest in semi enclosed region , second in the contest area , lowest in complete enclosure .

亲爱的丽萃，写了上半封信之后，发生了一件极其出人意料、极其严重的事；可是我又怕吓坏了你。

Since writing the above , dearest Lizzy , something has occurred of a most unexpected and serious nature ; but I am afraid of alarming you & be assured that we are all well .

研究了水封水表和半液封水表在冰冻前后其误差的变化。

Variations of the errors before and after freezing on water hermetic meter and semi-liquid hermetic meter were investigated .

半干旱区封禁草地凋落物的积累与分解

Accumulation and decomposition of litter in the semiarid enclosed grassland

半干旱沙地封育草场的植被变化及其与土壤因子间的关系

Vegetation variations under different exclusion measures and their correlation to soil factors

封育措施对半干旱沙地草场植被群落特征及地上生物量的影响半干旱沙地封育草场的植被变化及其与土壤因子间的关系

Impacts of exclusion on vegetative features and aboveground biomass in semi-arid degraded rangeland Vegetation variations under different exclusion measures and their correlation to soil factors

给我一整个夏夜的空闲，我该先回一年半前的那封信呢，还是七个月前的这封信？

Even if I spared myself a whole summer night , I would be wavering on which letter to reply first , the18-month-old one or the7-month-old ?