acid free,acidless,free from acid
相关英语词汇推荐
- push out
- optical deformation
- chronophotography
- optical head controllers,control ics/modules
- frequency summing
- Varotal lens
- filters
- mode pattern
- diatomic roto
- astrospectrograph camera
- geometrical focus
- time-averaged shadow-moire method
- holographic gratings
- intensifying screen
- infra-red beam folower
- metacrystalline
- multilongitudianl-mode laser
- optical harmonic generation
- visible emissivity
- upper state relaxation