threshold mass

• 临界质量

threshold mass的用法和样例：

例句

1. The same ideas of critical size and critical mass apply to bombs.
   同样的临界尺寸概念和临界质量概念适用于原子弹。
2. A chain reaction can be initiated by inserting more and more fuel elements into the reactor core until the critical mass is attained.
   只要在反应堆中加入越来越多的燃料并且一直加到临界质量为止，就可以发生连锁反应。