back focus是什么意思

用法例句

It is difficult to deal with saturated asphalt-loaded calcined coke,so resource waste and the second pollution are brought about,and there are many problems existing in common regeneration methods.

吸附了沥青烟的的饱和煅后焦难于处理,造成资源浪费及二次污染,普通的再生法又存在各种问题。

Low density of pitch fume from self-baking anodic trough of aluminum factory was treated by adsorption with activated calcined coke.

采用吸附回收法处理铝厂预焙阳极槽低浓度沥青烟气 ,以煅后焦为吸附剂 ,对其不同质量浓度的沥青烟气 ,进行吸附穿透试验研究 ,得到在常温下对 3种粒径的煅后焦不同质量浓度沥青烟气的吸附特性曲

In order to obtain parallel beam,the retical must be in the rear focus planeof it s objective.

为获得平行光，平行光管的分划权必需严格位于物镜后焦面上。

post-stroke anxiety disorder, (PSAD) is the more commonly encountered complication of stroke.

脑卒中后焦虑障碍(post-stroke anxiety disorder, PSAD)是脑卒中后较常见的并发症,以焦虑、食欲减退、睡眠障碍、兴趣丧失等为特征,本病发病机理复杂,不能用单一机制解释。