Fr.: transformée de Fourier
A powerful mathematical tool which is the generalization of the → Fourier series for the analysis of non-periodic functions. The Fourier transform transforms a function defined on physical space into a function defined on the space of frequencies, whose values quantify the "amount" of each periodic frequency contained in the original function. The inverse Fourier transform then reconstructs the original function from its transformed frequency components. The integral F(α) = ∫ f(u)e-iαudu is called the Fourier transform of F(x) = (1/2π)∫ f(α)eiαxdx, both integrals from -∞ to + ∞.
Fr.: quatrième contact
The end of a solar eclipse marked by the disk of the Moon completely passing away from the disk of the Sun.
From M.E. fourthe, O.E. féowertha, from four, from O.E. feower, from P.Gmc. *petwor- (cf. Du. and Ger. vier, O.N. fjorir, Dan. fire, Sw. fyra), from PIE *qwetwor (cf. Mod.Pers. cahâr, Av. caθwar-, catur-, Skt. catvarah, Gk. tessares, L. quattuor) + -th a suffix used in the formation of ordinal numbers, from M.E. -the, -te, O.E. -tha, -the; cf. O.N. -thi, -di; L. -tus; Gk -tos; → contact.
Parmâs, → contact; cahârom cardinal form from cahâr "four," cognate with E. four, as above.
lake-ye zard (#)
A small depression, approximately 1.5 millimeters in diameter, at the back of the → retina. It forms the area of the most acute vision.
Contraction of fovea centralis, from L. fovea "small pit," of unknown origin.
A geometrical or physical structure that repeats itself or nearly repeats itself on many different scales of magnification.
Fr.: cosmologie fractale
The postulate that the concentrations of matter in the Universe follow a → fractal structure over a wide range of scales.
Fr.: structure fractale
A → hierarchial structure that can be likened to fractals.
A rational number of the form a/b where a is called the numerator and b is called the denominator.
From L.L. fractionem (nom. fractio) "a breaking in pieces," from frangere "to break," from PIE base *bhreg- "to break" (cf. Goth. brikan, O.E. brecan "to break;" Lith. brasketi "crash, crack").
Barxé, from barx "lot, portion," variant bahr, from Mid.Pers. bahr "lot, share, portion," Av. baxəδra- "portion."
Fr.: fractionnaire, fractionné, partiel
1) Math.: Pertaining to fractions; constituting a fraction.
fractional sky coverage
pušeš-e barxe-yi-ye âsmân
Fr.: couverture partielle du ciel
The portion of the 4π → steradians of the sky that a radiotelescope can observe from a given location on Earth over a 24-hour time interval.
1) To break something up into smaller parts.
From → fraction + -ate a suffix forming verbs or nouns, from L. -atus, -ata, -atum.
Barxândan, from barx, barxé, → fraction, + -ândan suffix of transitive verbs.
1) Any of various methods of separating the components of a mixture into
fractions of different properties.
Verbal noun from → fractionate.
1) latté (#), latt (#), pâré (#); 2) latpâr šodan (#); 3) latpâridan
Fr.: 1) fragment; 2) se fragmenter; 3) fragmenter
1) (n.) A part broken off or detached.
From L. fragmentum, from frangere "to break."
1) Latté, lat, variant laxt, laxté "piece, part;"
pâré "piece, part, portion, fragment;" Mid.Pers. pârag
"piece, part, portion; gift, offering, bribe;" Av. pāra- "debt," from
par- "to remunerate, equalize; to condemn;"
PIE *per- "to sell, hand over, distribute; to assigne;" cf. L. pars
"part, piece, side, share,"
portio "share, portion;" Gk. peprotai "it has been granted;"
Skt. purti- "reward;"
Hitt. pars-, parsiya- "to break, crumble."
Generally, the process of breaking up into smaller parts. In particular, the splitting of a large molecular cloud into smaller, denser clumps. → cloud fragmentation.
From → fragmenta + -ation, a combination of -ate and -ion, used to form nouns from stems in -ate.
Latpâreš, verbal noun from latpâridan, → fragment.
Fr.: processus de fragmentation
1) cârcub (#); 2), 3) tasvirak
Fr.: 1) cadre; 2), 3) image
1) A border or case for enclosing a picture, mirror, etc.; a structure for admitting or
Frame, from M.E. verb framen "to prepare (timber)," from O.E. framian "to avail, profit."; cf. O.H.G. (gi)framon "to do."
1) Cârcub "frame," from câr, contraction of cahâr "four" (→ four) + cub "stick, satff, beam," Mid.Pers. côp "wood, stick." 2) Tasvirak from Ar. tasvir "image" + -ak suffix of relation and similarity (as in poštak, dastak, nâxonak), → fibril.
kerre-ye cârcub, cârcub-kerré
Fr.: entraînement des repères, effet Lense-Thirring
The alteration in the → free fall motion of a test → mass in the presence of a massive → rotating object, as compared to the identical case of a non-rotating object. This dragging of → inertial frames is predicted by → general relativity. Also called → Lense-Thirring effect.
Fr.: fréquence image
The number of times per second that the frame is scanned in television. Also known as picture frequency.
frame of reference
Fr.: système de référence
A set of axes to which positions and motions in a system can be referred.
The process of adjusting a television picture to a desired position in the direction of progression.
Cârcubeš, verbal noun of cârcubidan, from cârcub→ frame.
An extremely rare radioactive chemical element; symbol Fr. Atomic number 87; atomic weight of most stable isotope 223; melting point about 27°C; boiling point about 677°C. Its most stable isotope (half-life about 22 minutes) occurs naturally, to a very limited extent, in uranium minerals. More than 30 other isotopes of francium are known; some are prepared by bombarding thorium with protons, deuterons, or alpha particles.
From France, where the French physicist Marguerite Perey (1919-1975) discovered it in 1939 in the alpha particle decay of actinium.