front operationaperture
前作业孔径

• meridianal reflexion
• meridian angular aberration
• meridian circle
• meridian direction
• meridian image point
• meridian of lens
• meridian plane
• meridional plane
• meridional ray
• merit function
• meropia
• Merte surfacer
• mesa transistor
• mesh
• mesh-dielectric mirror
• mesh electrode
• mesh of grid
• mesh spacing
• mesh storage tube
• symmetrical wave
• symmetrical wide-angle objective
• symmetroid
• symmetry
• sync
• synchro