cross product farâvard-e bordâri Fr.: produit vectoriel Same as → vector product. |
daughter product doxtar (#) Fr.: noyau fils In → nuclear physics, same as → daughter. |
decay product farâvarde-ye tabâhi Fr.: produit de désintégration A → stable nuclide or → radioactive nuclide formed by the → disintegration of a → radioactive isotope, either directly or as a result of a → decay chain. Also called → daughter product. For example, the decay product of ^{238}U is ^{206}Pb, after passing through the following chain: ^{238}U → ^{234}Th (4.5 billion yr) → ^{234}Pa (24 days) → ^{234}U (1 min) → ^{230}Th (245,000 yr) → ^{226}Ra (76,000 yr) → ^{222}Rn (1,600 yr) → ^{218}Po (3.8 d) → ^{214}Pb (3 m) → ^{214}Bi (27 m) → ^{214}Po (160 microseconds) → ^{210}Pb (22 yr) → ^{210}Bi (5 d) → ^{210}Po (138 d) → ^{206}Pb. |
dot product farâvard-e marpeli Fr.: produit scalaire Same as → scalar product. O.E. dott "speck, head of a boil," perhaps related to Norw. dot "lump, knot," Du. dot "knot, wisp;" cognate with O.H.G. tutta "nipple;" → product. |
fission products farâvardehâ-ye šekâft (#) Fr.: produits de fission Nuclides generated by the fission of higher mass elements or by subsequent radioactive decay of nuclides directly generated by fission. |
pair production farâvareš-e joft Fr.: production de paires The creation of an → elementary particle and its → antiparticle from a → boson. For example, the formation of an → electron and a → positron in the interaction of high-energy → gamma ray photons, having at least 1.02 Mev, with an → atomic nucleus (γ → e^{-} + e^{+}). The → rest masses of the electron and positron being 0.51 MeV each, the excess energy will be carried away by these two particles. Pair production is the inverse process to → pair annihilation. → pair; → production |
product 1, 2) farâvardé; 3) farâvard Fr.: produit 1) A thing that is made or created (by a person, machine, or natural process). From M.E., from L. productum "something produced," noun use of neuter p.p. of producere "bring forth," → production. Farâvardé, farâvard, p.p. of farâvardan "to produce;" → production. |
production farâvareš (#) Fr.: production The act of producing; creation; something that is produced; a product. → pair production M.E., from O.Fr. production, from M.L. productionem, from L. productus, p.p. of producere "bring forth," from → pro- "forth" + ducere "to bring, lead." Farâvareš "bringing forth," from far- "forth," → pro-, + âvareš, "bringing," verbal noun âvardan "to bring; to cause, produce" (Mid.Pers. âwurtan, âvaritan; Av. ābar- "to bring; to possess," from prefix ā- + Av./O.Pers. bar- "to bear, carry," bareθre "to bear (infinitive)," bareθri "a female that bears (children), a mother;" Mod.Pers. bordan "to carry;" Skt. bharati "he carries;" Gk. pherein; L. fero "to carry"). |
scalar product farâvard-e marpeli Fr.: produit scalaire A multiplication of two vectors giving a scalar. The scaler product of V_{1} and V_{2} is defined by: V_{1}.V_{2} = V_{1}.V_{2} cos α, where V_{1} and V_{2} are the magnitudes of the vectors and α is the angle between them. Same as dot product. See also → vector product. |
vector product farâvard-e bordâri Fr.: produit vectoriel Of two vectors, a vector whose direction is perpendicular to the plane containing the two initial vectors and whose magnitude is the product of the magnitudes of these vectors and the sine of the angle between them: A x B = C, C = |AB sin α|. The direction of C is given by the → right-hand screw rule. Same as → cross product. See also → scalar product. |