na

(redirected from Numerical aperture)
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NA

The two-character ISO 3166 country code for NAMIBIA.

na

Used in bond transaction tables in newspapers to indicate a bond that trades on a nonaccrual basis (that is, on the basis of no obligation to repay any back interest owed).
References in periodicals archive ?
Because the overcoat used in OCIR allows the lens to be positioned much closer to the recording surface, it is possible to use a higher numerical aperture lens and achieve much higher data densities, significantly increasing capacity and performance.
The optical resolution is enhanced since the immersion fluid, which has a higher refractive index than air, allows using lenses with a higher numerical aperture.
N-STORM is based on the world renowned Nikon Eclipse Ti research inverted microscope incorporating CFI60 objectives featuring high numerical apertures developed using unique optical design, coatings and manufacturing techniques.
It excels at correcting chromatic aberration and curvature of the field of view, plus it offers longer working distances and higher numerical apertures.
With an emission wavelength of 193 nm and a repetition rate of 6,000 Hz, the GT61A is designed for next-generation lithography tools with numerical apertures of 1.
ASPH aspheric lenses are diffraction limited, anti-reflection coated and available with numerical apertures ranging from 0.
Nikon's CFI objectives excel at correcting both chromatic aberration and curvature of the field of view, plus feature longer working distances and higher numerical apertures.
The system uses Nikon's most acclaimed CF160 infinity objectives both oil immersion and dry types, which deliver excellent resolution with high numerical apertures and long working distances.

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