核子的质量大约是一个原子质量单位。

The mass of a nucleon is approximately one atomic mass unit.

原子质量的精确值是用一种称为质谱仪的装置来测量的。

Precision values of atomic masses are measured in a device called a mass spectroscope.

原子质量的精确值是用一种称为质谱仪的装置来测量的。

Precision values of atomic masses are measured in a device called a mass spectroscope .

元素, 如果按照他们的原子质量来安排, 则它展示了一个明显的周期特性.

The elements, if arranged according to their atomic mass, exhibit an evident periodicity of properties.

科学家使用原子质量单位来测量原子和分子的质量。

Scientists use amu to measure atomic and molecular masses.

一个原子质量单位被定义为碳-12原子质量的十二分之一。

One amu is defined as one twelfth of the mass of a carbon-12 atom.

一个质子的质量大约是1原子质量单位。

The mass of a proton is approximately 1 amu.

水的分子量大约是18原子质量单位。

The molecular weight of water is approximately 18 amu.

化学家在讨论分子量时经常提到原子质量单位。

Chemists often refer to amu when discussing molecular weights.

微生物溶煤产物的工业分析、元素分析结果表明，煤溶物的灰分明显下降，H/C、N/C原子质量比增大；

Analysis results of solubilizing products indicated that the ash decreased obviously, H/C and N/C atom mass rate increased.