Fr.: bande G
A conspicuous band of molecular → CH (methylidine) at 4300 Å, which is present in the spectra of late-type G-K stars.
Fr.: bande de Hartley
W. N. Hartley, J. Chem. Soc. 39, 111 (1881).
Fr.: bande de Huggins
W. Huggins and M. Huggins, Proc. R. Soc. London 48, 216 (1890).
Fr.: bande de Lyman
A sequence of → permitted transitions in the → ultraviolet from an → excited state (B) of the → molecular hydrogen (H2) to the electronic → ground state, with ΔE > 11.2 eV, λ < 1108Å (first → band head). When a hydrogen molecule absorbs such a photon, it undergoes a transition from the ground electronic state to the excited state (B). The following rapid → decay creates an → absorption band in that wavelength range. See also → Werner band. → Lyman-Werner photon.
Fr.: ruban de Möbius
A surface with only one side, made by putting a simple twist in a long, rectangular strip of paper, then pasting the ends together.
After the German astronomer and geometer August Ferdinand Möbius (1790-1868); → band.
bând-e molekuli (#)
Fr.: bande moléculaire
bând-e bârik (#), bârik-bând (#)
Fr.: bande étroite
Optics: Of a filter, same as → interference filter.
šidsanji-ye bârik bând
Fr.: photométrie à bande étroite
Photometry using narrow-band filters to isolate a particular spectroscopic line or molecular band.
Fr.: bande passante
The range of wavelengths that are transmitted by a filter. Same as → band-pass.
Pass from O.Fr. passer, from V.L. *passare "to step, walk, pass," from L. passus "step, pace;" cf. Pers. pâ "foot," pey "step;" → band.
Gozar "passage, transit, passing," from gozaštan "to pass, cross, transit," variant gozâštan "to put, to place, let, allow;" Mid.Pers. widardan, widâštan "to pass, to let pass (by);" O.Pers. vitar- "to pass across," viyatarayam "I put across;" Av. vi-tar- "to pass across," from vi- "apart, away from" ( O.Pers. viy- "apart, away;" Av. vi- "apart, away;" cf. Skt. vi- "apart, asunder, away, out;" L. vitare "to avoid, turn aside") + O.Pers./Av. tar- "to cross over"); bând, → band.
bând-e šid-sanjik, ~ nur-sanjik
Fr.: bande photométrique
Fr.: bandes protégées
Certain frequencies, not used for civil or military purposes (radio, television, communication channels, etc.), which are protected for research in radioastronomy, one such being 21 cm.
Bând, → band; negahdâridé p.p. of negahdâridan, variant of negahdâštan "to keep, behold, preserve, take care of," from negah, negâh "watch, care, custody, look" + (Mid.Pers. nikâh "look, glance, observation;" Proto-Iranian *ni-kas- "to look down," from ni- "down" (cf. O.Pers. ni preposition and verbal prefix "down;" Av. nī "down, in ,into;" Skt. ni "down," nitaram "downward;" Gk. neiothen "from below;" E. nether; O.E. niÃ¾era, neoÃ¾era "down, downward, below, beneath," from P.Gmc. *nitheraz (O.S. nithar, O.N. niÃ°r, O.Fris. nither, Du. neder, Ger. nieder); PIE *ni- "down, below") + *kas- "to look, appear;" cf. Av. nikā-, nikāta- (in the name of the 15-th nask) "that which is observed," ākas- "to look;" Mid.Pers. âkâh, Mod.Pers. âgâh "aware, knowing;" Skt. kāś- "to become visible, appear;" Ossetic kast/kaesyn "to look") + dâridan, dâštan "to have, hold, maintain, possess" (Mid.Pers. dâštan; O.Pers./Av. root dar- "to hold, keep back, maintain, keep in mind;" cf. Skt. dhr- "to to hold, keep, preserve," dharma- "law;" Gk. thronos "elevated seat, throne;" L. firmus "firm, stable;" Lith. daryti "to make;" PIE *dher- "to hold, support").
navârhâ-ye sâyé, bândhâ-ye ~
Fr.: ombres volantes
Faint wavy lines of alternating light and dark that sometimes can be seen on flat, light-colored surfaces just before and just after a total solar eclipse. The phenomenon results from sunlight distortion by irregularities in the Earth's atmosphere.
bând-e kenâri, kenâr-bând
Fr.: bande latérale
Either of the two bands of frequencies, one just above (upper side) and one just below (lower side) a carrier frequency, that result from modulation of a carrier wave.
Bând, → band; kenâr "side," variant karân "edge, limit;" Mid.Pers. karân, karânak, kenâr "edge, limit, boundary;" Av. karana- "side, boundary, end."
Fr.: bande de Swan
One of the three prominent bands in the spectra of comets and carbon stars caused by diatomic carbon (C2).
Named after the Scottish physicist William Swan (1818-1894) who first studied the spectral analysis of radical carbon C2 in 1856; → band.
Fr.: bande tellurique
A band seen in the spectra of celestial objects, which is due to absorption by gases such as oxygen, water vapor, and carbon dioxide in the Earth's atmosphere
Fr.: bandes TiO
bând-e tarâgosil (#)
Fr.: bande de transmission
The frequency range above the cutoff frequency in a waveguide or transmission line.
Unidentified Infrared Band (UIB)
bând-e forusorx-e nâ-idânidé
Fr.: bande infrarouge non identifiée
A no longer in general use name for → Aromatic Infrared Band.
Fr.: bande de valence
The range of energy states in the spectrum of a solid crystal which includes the energies of all the electrons binding the crystal together.
Fr.: bande de longueur d'onde
A portion of the electromagnetic spectrum which is defined because of its characteristics or for its use.