mean profile farâpâl-e miyângin Fr.: profil moyen The shape of a pulsar's pulse as determined by averaging several pulses. |
mean sidereal day ruz-e axtari-ye miyângin Fr.: jour sidéral moyen The average time interval between two successive → upper transits of the → mean equinox. |
mean sidereal time zamân-e axtari-ye miyângin (#) Fr.: temps sidéral moyen The hour angle of the mean equinox for a given observer. |
mean solar day ruz-e xoršidi-ye miyângin (#) Fr.: jour solaire moyen The average length of the apparent solar day. In other words, the interval between successive transits of the mean Sun for a given observer. |
mean solar time zamân-e xoršidi-ye miyângin (#) Fr.: temps solaire moyen The time since the mean Sun crossed the meridian with 12 hours added to make the day begin at midnight. |
mean spectrum binâb-e miyângin Fr.: spectre moyen A plot of the mass-to-charge ratio of elementary particles, sorted by their isotopic mass. |
mean Sun xoršid-e miyângin (#) Fr.: Soleil moyen A hypothetical Sun that moves along the ecliptic at a uniform rate equal to the average motion of the real Sun. |
mean term tarm-e miyâni Fr.: terme moyen In → syllogism, the term which is common to both → premises and is excluded from the → conclusion. |
mean value theorem farbin-e arzeš-e miyângin Fr.: théorème des accroissements finis 1) If f(x) is a continuous function on the interval from a to b, then: |
meaning cemâr (#) Fr.: sens, signification The sense or significance of a word, sentence, symbol, etc. The study dealing with meanings is called → semantics. See also → semiotics. M.E., from mean; O.E. mænan "to mean, intend, signify" (cf. O.Fris. mena "to signify," O.S. menian "to intend, signify," M.Du. menen, Du. meenen, Ger. meinen "think, suppose"), related to Pers. maneš "disposition, temperament," mênidan "to think, consider," → idea; + → -ing. Cemâr, from cem or cim "meaning, signification;" Mid.Pers. cim "meaning, reason, cause;" ultimately from Proto-Ir. *cahmāt "wherefore?" cf. Skt. kasmāt "why, where from? whence?," kim "what? how? why?" + âr short form of âvar present stem of âvardan "to cause or produce; to bring," → production, as in bonâr, → cause, used also as a nuance suffix; see also the verb → mean. |
period-mean density relation bâzâneš-e dowré-cagâli-ye miyângin Fr.: relation période-densité moyenne A relation that gives a rough estimate of the oscillation period of a → pulsating star as a function of its mean density. This relation is obtained by considering how long it would take a sound wave to travel across the diameter of a model star: Π ≅ (3π/2γGρ)^{1/2}, where ρ is the mean density, γ the ratio of → specific heats (C_{p}/C_{v}), and G the → gravitational constant. This relation shows that the pulsation period of a star is inversely proportional to the square root of its mean density. And this is the reason why the pulsation periods decrease along the → instability strip from the luminous, very tenuous → supergiants to the faint, very dense → white dwarfs. |
root mean square (rms) riše-ye câruši-ye miyângin, ~ dovom-e ~ Fr.: valeur quadratique moyenne The square root of the arithmetic mean of the squares of the numbers in a given set. |
root-mean-square error irang-e riše-ye câruši-ye miyângin, ~ ~ dovom-e ~ Fr.: The square root of the second moment corresponding to the frequency function of a random variable. |
root-mean-square value arzeš-e riše-ye câruši-ye miyângin Fr.: écart quadratique moyen, écart type Statistics: The square root of the arithmetic mean of the squares of the deviation of observed values from their arithmetic mean. |
Rosseland mean opacity kederi-ye miyângin-e Rosseland Fr.: opacité moyenne de Rosseland The → opacity of a gas of given composition, temperature, and density averaged over the various wavelengths of the radiation being absorbed and scattered. The radiation is assumed to be in → thermal equilibrium with the gas, and hence have a → blackbody spectrum. Since → monochromatic opacity in stellar plasma has a complex frequency dependence, the Rosseland mean opacity facilitates the analysis. Denoted κ_{R}, it is defined by: 1/κ_{R} = (π/4σT^{3}) ∫(1/k_{ν}) (∂B/∂T)_{ν}dν, summed from 0 to ∞, where σ is the → Stefan-Boltzmann constant, T temperature, B(T,ν) the → Planck function, and k_{ν} monochromatic opacity (See Rogers, F.J., Iglesias, C. A. Radiative atomic Rosseland mean opacity tables, 1992, ApJS 79, 507). Named after Svein Rosseland (1894-1985), a Norwegian astrophysicist, who obtained the expression in 1924; → mean; → opacity. |
weighted mean miyângin-e vazni (#) Fr.: moyenne pondérée An mean which is obtained by combining different numbers according to the relative importance of each. |