Magnetic coils focus the electron beams into fine spots.

磁线圈将电子束聚焦成细小的点。

《柯林斯英汉双解大词典》

The focus of the light on the solar cell can also be fine-tuned by changing the air pressure within the balloon, and thus the curvature of the mirror.

借由改变气球内的气压，就可以调整气球反射给太阳能电池的光线焦距，还有气球内的凹面镜弧度。

youdao

The focus of the light on the solar cell can also be fine-tuned by changing the air pressure within the balloon, and thus the curvature of the mirror.

藉由改变气球内的气压，就可以调整气球反射给太阳能电池的光线焦距，还有气球内的凹面镜弧度。

youdao

The most important thing you can do is to get more focus and fine-tune the streams of content that you see.

FORBES: If You Do Nothing Else... A Minimalist's Guide to Business Planning for 2012, Part 2

Such a fine focus would make them better able to buy modern technologies and to build the most innovative power plants.

FORBES: Utilities Aren't Just Blowing Smoke -- They are Generating Goodwill

Other refinements include a MF Assist function that magnifies a portion of the image while framing to simplify fine focus adjustments, as well as a Peaking function that highlights sharply-focused areas of the image on screen.

ENGADGET: Sony's Cyber-shot RX1 compact camera packs a full-frame sensor, 'fits in your palm' (hands-on)