limit of visible spetru
可见光谱范围

• flying spot store
• flying spot television microscope
• flying spot tube
• flying spot tube character generator
• fly-over junction
• fly-past
• fly's eye
• fly's -eye lens
• fly spot scanning
• flywheel
• FM-CW laser ranging
• fm demodulation
• FM laser
• FM reticle
• FM signal
• FM signal generator
• f-number
• foam
• foamed
• foamed material
• foamed plastics
• foamed polyethylene insulation
• foam glass
• foaming agent
• foam metal