An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 687
electron-positron pair
  جفت ِ الکترون-پوزیترون   
joft-e elektron-pozitron (#)

Fr.: paire électron-positron   

The simultaneous formation of an → electron and a → positron in the → pair production process.

electron; → positron; → pair.

electron-scattering wing
  بال ِ پراکنش ِ الکترون   
bâl-e parâkaneš-e elektron

Fr.:   

A → line broadening phenomenon involving the scattering effect of → free electrons on the → radiation transfer in → stellar atmospheres. The scattering of radiation by free electrons plays an important role in the atmospheres of → hot stars, such as → O-types, early → B-types, and → Wolf-Rayet stars. The first detailed study of electron scattering in Wolf-Rayet stars was by Castor et al. (1970), who used electron scattering to explain the broad emission wings of N IV λ3483 in HD 192163. In → P Cygni stars the explanation of the very extended (almost symmetric) wings on the → Balmer lines as caused by electron scattering was first made by Bernat & Lambert (1978). Hillier (1991) showed that significant reduction in the strength of an electron-scattering wing can be achieved in a model of → clumped wind for a lower mean → mass loss rate. This resulted in a better agreement between observations and theoretical predictions. Electron-scattering wings provide diagnostics regarding the presence of density inhomogeneities in → stellar winds (Münch, 1948, ApJ 108, 116; Hillier, 1991, A&A 247, 455).

electron; → scattering; → wing.

electron-volt (eV)
  الکترون-ولت   
elektron-volt (#)

Fr.: électron-volt   

The energy acquired by an electron when accelerated through a → potential difference of 1 volt (1 eV = 1.602 × 10-12 → ergs = 11605 → kelvins).

electron; → volt.

electronic
  ۱) الکترونی؛ ۲) الکترونیک   
1) elektroni (#); 2) elektronik (#)

Fr.: électronique   

1) Of or relating to electrons or to an electron.
2) Of or relating to → electronics or to → devices, → circuits, or systems developed through electronics (Dictionary.com).

electron; → -ic.

electronic state
  استات ِ الکترونی   
estât-e elektroni

Fr.: état éléctronique   

In molecular quantum mechanics, any of → quantum states corresponding to a particular → electron configuration (i.e. an arrangement of the electron(s) in certain → orbitals). The electron configuration with the lowest energy is called the → ground state. All higher energy states are called → excited states.

electronic; → state.

electronic transition
  گذرش ِ الکترونی   
gozareš-e elektroni

Fr.: transition électronique   

The → transfer of an → electron from one → energy level to another.

electronic; → transition.

electronics
  الکترونیک   
elektronik (#)

Fr.: électronique   

The science dealing with the development and application of → devices and → systems involving the flow of → electrons in a → vacuum, in → gaseous media, and in → semiconductors (Dictionary.com).

electron; → -ics.

electroscope
  برق‌نما   
barqnemâ (#)

Fr.: électroscope   

An instrument for detecting electric charges or → potential differences.

electro-; → -scope.

electrostatic
  برق‌ایستا   
barqistâ

Fr.: électrostatique   

Referring to electric charges at rest.

electro-; → static.

electrostatic charge
  بار ِ برق‌ایستا   
bâr-e barqistâ

Fr.: charge électrostatique   

A quantity of electricity at rest on the surface of an insulator or an insulated conductor.

electrostatic; → charge.

electrostatic field
  میدان ِ برق‌ایستا   
meydân-e barqistâ (#)

Fr.: champ électrostatique   

A region of space in which a non-moving → electric charge would be subjected to a force of attraction or repulsion as a result of the presence of another stationary electric charge. The electrostatic field is a special case of the → electromagnetic field.

electrostatic; → field.

electrostatic induction
  درهازش ِ برق‌ایستا   
darhâzeš-e barqistâ

Fr.: induction électrostatique   

The production of stationary electric charges on an uncharged object as a result of a charged body being brought near it without touching it. A positive charge will induce a negative charge, and vice versa.

electrostatic; → induction.

electrostatic unit (esu)
  یکای ِ برق‌ایستای ِ بار   
yekâ-ye barqistâ-ye bâr

Fr.: unité électrostatique de charge   

The unit of electric charge in the → cgs system of units. Also called the → statcoulomb. The esu is defined such that if two objects, each carrying a charge of +1 esu, are 1 cm aparat, then they repel each other with a force of 1 → dyne. 1 esu = 3.3356 × 10-10 → coulombs.

electrostatic; → unit; → charge.

electrostatic wave
  موج ِ برق‌ایستا   
mowj-e barqistâ

Fr.: onde électrostatique   

In a → plasma, a disturbance that is devoid of magnetic field, and hence can be expressed by an electrostatic potential. The electric field is always parallel to the propagation vector, so that the electrostatic wave is → longitudinal.

electrostatic; → wave.

electrostatics
  برق‌ایستاییک   
barqistâyik

Fr.: électrostatique   

The branch of → electricity dealing with the phenomena and properties of stationary → electric charges, as opposed to → electrodynamics. It involves the build-up of charge on the → surface of → objects due to → contact with other surfaces.

electro- + → statics.

electroweak
  برقانزار   
barqânezâr

Fr.: électrofaible   

Of, relating to, or being the → unification of → electromagnetism and the → weak interaction.

electro-; → weak.

electroweak epoch
  زیمه‌ی ِ برقانزار   
zime-ye barqânezâr

Fr.: époque électrofaible   

A period in the early history of the Universe lasting from 10-36 to 10-12 seconds after the → Big Bang. The electroweak epoch begins at the same time as cosmic → inflation is triggered. This is also the time when the → strong force breaks from the → grand unified force and ends with another → phase transition will occur in which the → weak interaction breaks from the → electroweak force.

electroweak; → epoch.

electroweak force
  نیروی ِ برقا نزار، ~ برقا کمزور   
niru-ye barqânezâr, ~ barqâkamzur

Fr.: force électrofaible   

The force that takes part in an → electroweak interaction.

electroweak; → force.

electroweak interaction
  اندرژیرش ِ برقانزار   
andaržireš-e barqânezâr

Fr.: interaction électrofaible   

The unified description of two of the four fundamental interactions of nature, → electromagnetism and the → weak interaction which would merge into a single force under conditions of extreme temperature (above 1016 degrees, 102 GeV) prevalent in the early history of the → Universe.

electroweak; → interaction.

electroweak star
  ستاره‌ی ِ برقانزار   
setâre-ye barqânezâr

Fr.: étoile électrofaible   

A postulated type of star that could form toward the end of a → massive star's life, after → nuclear fusion has stopped in its → core, and before the star → collapses into a → black hole. In those → extreme conditions, when → temperature and → density inside the star are very high, → quarks could convert into → leptons. Hence huge amounts of energy can be released, much of which would be in the form of → neutrinos.

electroweak; → star.

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