bound 1) bandidé; 2) karân Fr.: lié; lien 1) (adj.) Tied, confined by bonds. → bound cluster,
→ bound charge, → bound system. |
bound charge bâr-e bandidé Fr.: charge liée Any electric charge which is bound to an atom or molecule, in contrast to free charge, such as metallic conduction electrons, which is not. Also known as → polarization charge. |
bound cluster xuše-ye bandidé Fr.: amas lié A cluster of astronomical objects, such as stars or galaxies, held together by their mutual gravitational attraction. → bound system. |
bound occurrence roxdâd-e bandidé Fr.: occurrence liée Any → occurrence of a → variable x in an x-bound part of a → wff. → bound; → occurrence. |
bound orbit madâr-e bandidé Fr.: orbite liée The orbit described by an object around a central gravitational force in a system whose total energy is negative. An elliptical orbit. |
bound system râžmân-e bandidé Fr.: système lié A system composed of several material bodies the total energy of which (the sum of kinetic and potential energies) is negative, e.g. a → bound cluster. |
bound-bound transition gozareš-e bandidé-bandidé Fr.: transition liée-liée A transition between two energy levels of an electron bound to a nucleus. The electron remains tied to the nucleus before and after the transition. → bound-free transition; → free-free emission. Bound, p.p. of → bind; → transition. |
bound-free transition gozareš-e bandidé-âzâd Fr.: transition liée-libre A transition in which a bound electron is liberated. → free-bound emission; → free-free emission. |
boundary karân (#) Fr.: limite, bord 1) General:
Something that indicates a border or limit; the border or limit so indicated. From Fr., from O.Fr. bodne, from M.L. bodina, butina "boundary, boundary marker." Karân, karâné, kenâr from Mid.Pers. karânag, Av. karana- "boundary." |
boundary conditions butârhâ-ye karân, ~ karâni Fr.: conditions à la limite 1) Math: Restriction on the limits of applicability of an equation.
In a differential equation, conditions that allow to fix the constant
of integration and reach a unique solution. The number of boundary conditions
necessary to determine a solution matches the order of the equation. |
boundary effect oskar-e karân Fr.: effet de bords An effect that forbids or invalidate locally the use of an idealized model of a system in which one or several of its dimensions are supposed to be infinite. |
boundary layer lâye-ye karâni Fr.: couche limite A layer of fluid that is formed wherever a fluid flows past a solid surface and the effects of → viscosity are important. The boundary level forms because as the fluid moves past the object, the molecules which are in direct contact with the surface stick to the surface. The molecules just above the surface are slowed down in their collisions with the molecules sticking to the surface. These molecules in turn slow down the flow just above them, but less effectively. This creates a thin layer of fluid near the surface in which the velocity changes from zero at the surface to the free stream value away from the surface. The boundary layer may be either → laminar or → turbulent in character, depending on the value of the → Reynolds number. The concept of boundary level was first put forward by Ludwig Prandlt (1875-1953) in 1904. |
bounded karânmand (#), karândâr (#) Fr.: limité General: Having bounds or limits. Adj. from → bound. |
bounded function karyâ-ye karânmand, ~ karândâr Fr.: fonction bornée The function y = f(x) in a given range of the argument x if there exists a positive number M such that for all values of x in the range under consideration the inequality | f(x) | ≤ M will be fulfilled. → unbounded function. |
density-bounded H II region nâhiye-ye H II-ye cagâli karânmand Fr.: bornée par la densité An → H II region which lacks enough matter to absorb all → Lyman continuum photons of the → exciting star(s). In such an H II region a part of the ionizing photons escape into the → interstellar medium. See also → ionization-bounded H II region. |
free-bound emission gosil-e âzâd-bandidé Fr.: émission libre-liée The radiation emitted when a → free electron is captured by an → ion. See also: → free-free emission; → bound-free transition. |
gravitationally bound gerânešâné bandidé Fr.: gravitationnellement lié Objects held in orbit about each other by their → gravitational attraction. Such objects are part of a → bound system. → gravitational; → bound. |
ionization-bounded H II region nâhiye-ye H II-e yoneš-karânmand Fr.: région H II bornée par ionisation An H II region whose → exciting star(s) do not have enough → Lyman continuum photons to ionize the whole region. → density-bounded H II region. → ionization; → bounded; → H II region. |
laminar boundary layer lâye-ye karâni-ye varaqe-yi Fr.: Couche limite laminaire In a fluid flow, layer next to a fixed boundary. The fluid velocity is zero at the boundary but the molecular viscous stress is large because the velocity gradient normal to the wall is large. → turbulent boundary layer. |
no boundary hypothesis engâre-ye giti bi karân-e âqâzin Fr.: l'hypothèse de l'Univers sans limite initiale The proposal whereby the → Universe would not have begun with a → singularity. Instead, the → Big Bang would be an ordinary point of → space-time. The proposal, advanced by James Hartle and Stephen Hawking (1983) results from an attempt to combine aspects of → general relativity and → quantum mechanics. Based on an imaginary time assumption, it predicts a closed Universe that would start at a single point, that can be compared to the North Pole of the Earth on a two-dimensional space. Before the → Planck era there was space, but the real time began with the Big Bang event. → Hartle-Hawking initial state. → boundary; → hypothesis. |