The interval is two mass units because these isotopes of the elements differ by two neutrons. 因为这些元素的同位素相差两个中子,所以其间隔为两个质量单位(MU)。
This is12.011 grams per mole or12.011 atomic mass units, AMU. 这是12。011克每摩尔,或者12。011原子质量单位(MU)。
The units painted on the dial of a scale are often mass units, not force units. 秤的刻度盘上所标单位是质量的单位,而不是力的单位。
Different methods can be used to make comprehensive evaluations of the structure of rock bodies and to make divisions of rock mass units so as to give out the load-belt bearing capacity of every rock mass unit. 采用多种方法综合评价岩体的结构,划分岩质单元,以便给出各岩质单元地基承载力值。
This is why people are encouraged to have X-rays taken in the mass radiography units which go to schools and factories and such places. 这也是为什么人们被鼓励在学校、工厂这类的大规模的放射线照相术中使用X光技术。