An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Number of Results: 7 Search : half
full-width at half-maximum (FWHM)
  پهنای ِ نیم‌بیشینه   
pahnâ-ye nim-bišiné

Fr.: largeur à mi-hauteur   

The full width of a → profile (spectral line or a cross-cut in an image component) at half-maximum intensity.

full; → width; → half; → maximum.

Pahnâ, → width; nim, → half; bišiné, → maximum.

half
  نیم   
nim (#)

Fr.: moitié, mi-, demi-   

One of two equal or approximately equal parts of a divisible whole.

M.E., from O.E. h(e)alf "side, part," from P.Gmc. *khalbas "something divided" (cf. M.Du. half, Ger. halb, Goth. halbs "half").

Nim, nimé "half," from Mid.Pers. nêm, nêmag "half;" Av. naēma- "half;" cf. Skt.. néma- "half."

half moon
  نیمه‌ماه   
nimé mâh (#)

Fr.: demi-lune   

The moon when, at either quadrature, half its disk is illuminated.

half; → moon.

half-life
  نیم‌زیست   
nim-zist

Fr.: demi-vie   

The length of time required for half of a given quantity of → radioactive material to → decay.

half; → life.

half-power beamwidth (HPBW)
  پهنای ِ تابه در نیم‌توان   
pahnâ-ye tâbé dar nim-tavân

Fr.: largeur à mi-hauteur   

The angle between extreme points of the main lobe of an antenna pattern where the sensitivity of the antenna is half the value at the center of the lobe. This is the nominal resolving power of the antenna system.

half; → power; → beam; → width.

half-value layer (HVL)
  لایه‌ی ِ نیم-تنکش   
lâye-ye nim-tonokeš

Fr.: couche de demi-atténuation   

The thickness of material required to reduce the intensity of an → X-ray beam to one half of its initial value. The HVL is an indirect measure of the photon energies of a beam.

half; → value; → layer; → attenuation.

half-wave plate
  تیغه‌ی ِ نیم‌موج   
tiqe-ye nin-mowj (#)

Fr.: lame demi-onde   

A plate of optical material whose thickness is such that the phase difference between the extraordinary and ordinary rays after passing through the place is exactly one-half cycle. It can serve to rotate the plane of polarization of a light beam.

half; → wave; → plate.