hemispherical integration
半球面积分

• useful work
• utiliscope
• utilization factor
• Utrecht solar eclipse expedition
• UV dye laser
• UV filter
• uvicon
• uviol
• uviol glass
• uvioresistant
• UV irradiation
• UV lamp
• UV laser
• UV light
• UV-nitrogen laser
• UV photostat
• UV scanner
• UV-transmitting
• UV (ultra-violet) detector
• UV-visible photoemitter
• UV-visible spectral response
• uxmeter
• vacancy
• vacant electron site
• vacant lattice site