除了氢原子之外，一切原子都含有中子。
All kinds of atoms, with the exception of hydrogen, has neutrons.
氘氢的一种同位素，在其原子核内有一个质子和一个中子，其原子重量为2。014
An isotope of hydrogen with one proton and one neutron in the nucleus having an atomic weight of2.014.
慢化剂一种物质，如水或石墨在核反应堆中用来减缓中子运动速度和提高裂变可能性的物质
A substance, such as water or graphite, that is used in a nuclear reactor to decrease the speed of fast neutrons and increase the likelihood of fission.
