Fr.: contrepartie optique
1) A portion or division of a whole that is separate or distinct; piece, fragment, fraction,
or section; constituent.
M.E., from O.Fr. part "share, portion; character; dominion; side, path," from L. partem (nominative pars) "a part, piece, a share, a division; a party or faction," related to portio "share, portion," from PIE root *per- "to assign, allot;" cf. Pers. pâr, pâré "piece, part, portion, fragment;" as below.
Pâr, variant pâré "piece, part, portion," parré "portion, segment (of an orange)," pargâlé, "piece, portion; patch;" (dialects Kermâni pariké "portion, half;" Tabari perik "minute quantity, particle;" Lârestâni pakva "patch;" Borujerdi parru "patch"); 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 assign;" Gk. peprotai "it has been granted;" L. pars, as above; Skt. purti- "reward;" Hitt. pars-, parsiya- "to break, crumble."
pâri (#), pârâl
Being such in part only; not total or general; incomplete.
Fr.: dérivée partielle
The derivative of a function of two or more variables, e.g., z = f(x,y), with respect to one of the variables, the others being considered constants (denoted ∂z / ∂x).
partial differential equation
hamugeš-e degarsâne-yi bâ vâxane-ye pâri
Fr.: équation différentielle aux dérivées partielles
A type of differential equation involving an unknown function (or functions) of several independent variables and its (or their) partial derivatives with respect to those variables.
Fr.: éclipse partielle
partial ionization zone
zonâr-e yoneš-e pâri
Fr.: zone d'ionisation partielle
One of several zones of the stellar interior where increased → opacity can provide the → kappa mechanism to drive → pulsations. See also → Kramers' law. In these zones where the gases are partially ionized, part of the energy released during a layer's compression can be used for further ionization, rather than raising the temperature of the gas. Partial ionization zones modulate the flow of energy through the layers of the star and are the direct cause of → stellar pulsation. The partial ionization zones were first identified by the Russian astronomer Sergei A. Zhevakin (1916-2001) in the 1950s. In most stars there are two main ionization zones. The hydrogen partial ionization zone where both the ionization of neutral hydrogen (H ↔ H+ + e-) and the first ionization of helium (He ↔ He+ + e-) occurs in layers with a characteristic temperature of 1.5 x 104 K. The second, deeper zone is called the He+ partial ionization zone, and involves the second ionization of helium (He+↔ He++ + e-), which occurs deeper at a characteristic temperature of 4 x 104 K. The location of these ionization zones within the star determines its pulsational properties. In fact if the → effective temperature of the star is ≥ 7500 K, the pulsation is not active, because the ionization zones will be located very near to the surface. In this region the density is quite low and there is not enough mass available to drive the oscillations. This explains the blue (hot) edge of the instability strip on the → H-R diagram. Otherwise if a star's surface temperature is too low, ≤ 5500 K, the onset of efficient convection in its outer layers may dampen the oscillations. The red (cool) edge of the instability strip is believed to be the result of the damping effect of convection. He+ ionization is the driving agent in → Cepheids. See also → gamma mechanism.
partial lunar eclipse
Fr.: éclipse partielle de lune
partial solar eclipse
Fr.: éclipse partielle de soleil
râstini-ye pâri, ~ pârâl
Fr.: vérité partielle
To take part, be or become actively involved.
An act or instance of participating. The fact of taking part.
Verbal noun of → participate.
A lexical form derived from a verb, that has some of the characteristics and functions of both verbs and adjectives. In most Indo-European languages participles are used to express participation in an action (present participle) or relate to a completed action (past participle). They can also appear in attributive form as adjectives.
M.E., from O.Fr. participle, variant of participe, from L. participium, literally "a sharing, partaking," from particeps "sharing, partaking," → participate.
Pârgerté, from pârgert present stem of pârgertidan, → participate, + nuance suffix -é.
1) , 2) zarré (#), 1), 2), 3) pârul
1) A unit of → matter smaller than the
→ atom or its main components.
The term particle also includes any (currently hypothetical) new particles
that might be discovered, such as the supersymmetric partners of the
→ quarks and → leptons
and → bosons.
From L. particula "little bit or part," diminutive of pars (genitive partis), from PIE base *per- "to assign, allot;" cf. Mid.Pers. pârag "gift, offering, bribe;" Mod.Pers. pâreh "gift" (→ partial); Gk. porein "to provide, give, grant," peprotai "it has been granted;" Skt. purtá- "gift, pay, reward."
Fr.: horizon des particules
For an observer at a given epoch t0, the boundary between the observable and the unobservable regions of the → Universe. Therefore, the distance to the particle horizon at t0 defines the size of the → observable Universe. Same as → cosmic horizon.
Fr.: nature de particule
fizik-e zarreyi (#)
Fr.: physique des particules
The branch of physics that deals with the smallest known structures of matter and energy in order to understand the fundamental particles and forces of nature.
1) pâruli; 2) pârulé
1) (adj.) Of or pertaining to a single or specific person, thing, group, class, occasion, etc.,
rather than to others or all; special rather than → general.
Pâruli, adj. from pârul, → particle; pârulé, from pârul + nuance adj. -é.
Fr.: astrolabe particulier
Fr.: solution particulière