在化学领域裡,混合物中某种物质的质量分数(mass fraction),是该物质质量 m i {\displaystyle m_{i}} 与混合物总质量 m tot {\displaystyle m_{\text{tot}}} 的比 w i {\displaystyle w_{i}} (或表为 Y i
RC, Hammack H. Phoenix Mars Mission--the thermal evolved gas analyzer. Journal of the American Society for Mass Spectrometry. October 2008, 19 (10): 1377–83
(页面存档备份,存于互联网档案馆) (The Bright Star Catalogue) Unexpectedly large mass loss during the thermal pulse cycle of the red giant R Sculptoris (PDF). Research Paper