大家都搜：
氦气保护
1、helium───n.[化学]氦 (He)
2、oxidizing atmosphere───[冶]氧化气氛；权化气氛
3、superabundant atmosphere───大气过剩
4、enliven atmosphere───活跃气氛
5、helium balloon───氦气球
6、chorded helium───弦氦
7、atmosphere───n.气氛；大气；空气
8、helium space───氦空间
9、atmosphere pressure───大气压力，大气压强
1、The particles are generally protons , electrons and helium nuclei and when they collide with nuclei in the Earth's upper atmosphere they can produce shower s of daughter particles.───这些粒子主要是质子、电子和氦原子核，并且当他们与地球高层大气中的原子核碰撞，就能产生次级粒子簇射。
2、Measurements can be performed in a vacuum or helium atmosphere.───测量可在真空或氦气氛中进行。
3、In general, the heavier atoms in the atmosphere sink and the light ones remain at the surface, which is why some white dwarfs, for example, have mostly pure hydrogen or helium atmospheres.───总体来说，较重的原子在大气圈中沉积，而较轻的原子则存在于大气圈表面，这也是一些白矮星具有较纯净的氢和氦大气圈的原因。