choppers

n.

斧子，斧头( chopper的名词复数 )；直升机；

1. We broke open the crate with a blow from the chopper.
   我们用斧头一敲就打开了板条箱。
2. Jack said nothing and found a chopper in the corner of the house.
   杰克什么都不说，在屋子的一角找了把斧头。
3. He hacked open a path with a chopper on the way through the forest.
   在穿过森林的路上，他用砍刀开出一条小径。
4. The chopper was carrying victims of a traffic accident.
   这架直升机上载有一起车祸的受害人。
5. They all board the chopper en route to safety.
   他们一家人登上了直升机，飞向安全地点。

Novel topologies of AC choppers
Multi-Level Choppers for High Voltage Applications
High-current DC choppers in the metals industry
An improved PWM technique for AC choppers
Characteristics and design of multilevel choppers
Multi-level conversion: high voltage choppers and voltage-source inverters
Multi-level conversion : high voltage choppers and voltage-source inverters
Modulation of the Chopping Frequency in DC Choppers and PWM Inverters Having Current-Hysteresis Controllers
Formation of Microdroplets in Liquids Utilizing Active Pneumatic Choppers on a Microfluidic Chip
New family of matrix-reactance frequency converters based on unipolar PWM AC matrix-reactance choppers