难切断 meaning in Chinese

hard-to-break

The curves showed that the moisture contents of straw and the shear bar are the main factors impacting the cutting ratio besides cutting speed . the speed of 40mm / s is necessary to cut off wet straw . ( 4 ) the testing results indicate that the rotary speed of the blade axle need to be more then 1230 rpm ( rotary radius of the blade is 25cm ) to cut off straw ( with moisture content less then 20 % )
试验结果表明，对于干的长秸秆，刀片切割速度达到15m / s时，切断率达100 ；对于干的短秸秆，刀片切割速度需达到20m / m / s以上；要切断湿秸秆需要有40m / s以上的切割线速度；加定刀与不加定刀对于切断麦秸这类软质秸秆是非常重要的，其切断速度差别很大；另外，麦秸不同部位所需要的切断速度也是不一样的，根部较之顶部和中部更难切断。