Fr.: spectre non thermique
A radio emission with a negative → spectral index. In this type of emission the intensity of the emitted radiation increases with wavelength.
Fr.: spectrum de Planck
Same as → blackbody spectrum.
binâb-e tavâni (#)
Fr.: spectre de puissance
The plot that gives the portion of a signal's power falling within given frequency bins. The most common way of generating a power spectrum is by using a discrete Fourier transform.
Fr.: spectre prismatique
The spectrum formed by a dispersing prism or a dispersing prism system.
Fr.: spectre de rayonnement
The components of radiation arranged in order of their wavelengths, frequencies, or quantum energies. For particle radiation they are arranged in order of their kinetic energies.
Fr.: spectre radio
Fr.: spectre Rayleigh-Jeans
Fr.: spectre rectifié
A spectrum after correction for detector's → baseline.
Fr.: spectre rotation-vibration
The spectrum of a molecule resulting from the simultaneous rotation and vibration of its constituent atoms.
binâb-e xoršid (#), ~ xoršidi (#)
Fr.: spectre solaire
The spectrum of the Sun's electromagnetic radiation, consisting of a continuum spectrum marked with dark absorption lines.
binâb-e axgar, ~ jaraqé
Fr.: spectre d'étincelle
The emission spectrum produced through a gas or vapor as a result of a high-voltage discharge between metallic electrodes.
The → electromagnetic radiation divided into its constituting wavelengths or frequencies.
From L. spectrum "appearance, image, apparition," from specere "to look at, view;" Gk. skopein "to behold, look, consider," skeptesthai "to look at;" PIE base *spek- "to see;" cf. Av. spas-, spaš- "to attend to; to serve; spy," spasiieiti "looks at, perceives" (Mod.Pers. sepâs "kindness, favor, thanksgiving," sepâsidan "to praise for benefits received);" Skt. paś- "to see, watch," spasati "sees;" L. specere "to look at;" O.H.G. spehônn "to spy," Ger. spähen "to spy."
Binâb "a vision;" Mid.Pers. wênâb "vision," from wên-, present stem of didan "to see;" O.Pers. vain- "to see;" Av. vaēn- "to see;" cf. Skt. veda "I know;" Gk. oida "I know," idein "to see;" L. videre "to see;" PIE base *weid- "to know, to see."
binâb-e diyâr, ~ didani
Fr.: spectre visible