heliumn.氦
helium-strong star强氦星
helium spectrum lamp氦谱灯
helium leak detecter氧气探漏器
helium leak detector氦探漏仪,氦探漏器,氦检漏器
helium mass spectrum氦质谱
helium cadmium laser氦镉激光器
helium cooled reactor氦冷反应堆
helium family element氦族元素
helium oxygen mixture氦氧混合气
helium pressurization压缩氦挤压