diffuse-reflective cavity
漫反射腔

• upper hemispherical flux
• upper-hybrid-resonace absorption
• upper laser level
• upper limb
• upper limit
• upper margin
• upper right
• upper side band wave
• upper side frequency
• upper state
• upper state relaxation
• upright
• upright image
• upright post
• upright projection
• upscattering
• upside
• upside down
• upstage
• upstream
• upstream ionization
• upwash
• upwelling
• uranin
• uraninite