An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



<< < -cl con for lin lin lin neb qua str > >>

Number of Results: 174 Search : line
nebular line
  خط ِ میغی   
xatt-e miqi

Fr.: raie nébulaire   

A → forbidden line that is found in the spectra of → interstellar  → ionized gas. The nebular lines are emitted by several atomic species (e.g. O, O+, O++, N+, S++) and correspond to the → transition from the electronic → metastable state 1D to the → ground state  3P. Examples are the doubly ionized oxygen lines [O III] at 4959 and 5007 Å (→ [O III] doublet) and the ionized nitrogen doublet [N II] at 6548 and 6583 Å. See also → auroral line; → transauroral line.

nebular; → line.

Neumann line
  خط ِ نویمان   
xatt-e Neumann

Fr.: raie de Neumann   

In → iron meteorites, any of very fine parallel lines that cross each other at various angles. They can be seen after cutting diagonally across the sample.

Named after Johann G. Neumann, who discovered them in 1848 in the iron meteorite Braunau, which fell in 1847; → line.

nodal line
  خط ِ گره‌ها   
xatt-e gerehhâ

Fr.: ligne des noeuds   

The line connecting the ascending and descending nodes of an orbit.

nodal; → line.

nonhomogeneous linear differential equation
  هموگش ِ دگرسانه‌ای ِ خطی ناهمگن   
hamugeš-e degarsâne-yi-ye xatti nâhamgen

Fr.: équation différentielle linéaire non homogène   

A → linear differential equation if Q(x)≠ 0 on interval I.

nonhomogeneous; → linear; → differential; → equation.

nâxatti (#)

Fr.: non-linéaire   

Not a linear function of the relevant variables.
Containing a variable with an exponent other than one; opposite of → linear.

non-; → linear.

nonlinear device
  دستگاه ِ ناخطی   
dastgâh-e nâxatti

Fr.: dispositif non-linéaire   

An electronic device whose output is not directly proportional to its input. For example, in a → diode the current is a nonlinear function of the voltage; its voltage-current characteristics do not obey → Ohm's law.

nonlinear; → device.

nonlinear dynamics
  توانیک ِ ناخطی   
tavânik-e nâxatti

Fr.: dynamique non-linéaire   

Same as → chaos.

nonlinear; → dynamics.

nonlinear instability
  ناپایداری ِ ناخطی   
nâpâydâri-ye nâxatti

Fr.: instabilité non-linéaire   

The instability of a physical or mathematical system that arises from the nonlinear nature of relevant variables and their interactions within the system.

nonlinear; → instability.

nonlinear system
  راژمان ِ ناخطی   
râžmân-e nâxatti

Fr.: système non-linéaire   

A system in which small changes can result in large effects, and large changes in small effects.

nonlinear; → system.


Fr.: non-linéarité   

The property, condition, or state of being → nonlinear.

non-; → linearity.

  اپ-تان، اپ-خط   
ap-tân, ap-xatt


Of computers, operating independently of, or disconnected from, an associated computer.

off; → line.

OH line
  خطِ OH   
xatt-e OH

Fr.: raie de OH   

Emission or absorption lines on an electromagnetic spectrum generated by hydroxyl, → OH molecules. At present, four principal lines are known in the radio domain at frequencies of 1612, 1665, 1667, and 1720 MHz, or wavelengths of approximately 18 centimeters.

OH; → line.


Fr.: en ligne   

The state when two or more devices are directly connected and are communicating efficiently.
Of computers, operating under the direct control of, or connected to, a main computer.

on; → line.

on-line reduction
  باز‌هازشِ بر-خط   
bâzhâzeš-e bar-xatt

Fr.: réduction enligne   

Preliminary reduction of observational data at a telescope simultaneously with their acquisition.

on-line; → reduction.

open magnetic field line
  خط ِ باز ِ میدان ِ مغناتیسی   
xatt-e bâz-e meydân-e meqnâtisi-ye

Fr.: ligne ouverte de champ magnétique   

In the context of solar physics, a → magnetic field line when it crosses the solar surface only once, i.e., when it goes from surface to infinity. This is the case at a sufficiently large scale in → coronal holes. This is mostly not the case in → active regions.

open; → magnetic; → field; → line.

orthogonal lines
  خط‌هایِ ارداکنج   
xatthâ-ye ardâkonj

Fr.: droites orthogonales   

Perpendicular lines.

orthogonal; → line.

path line
  خط ِ په   
xatt-e pah

Fr.: trajectoire particulaire   

The path followed by an individual particle of fluid over an interval of time. It contrasts with the → streamline that represents an instantaneous picture of the motion of particles.

path; → line.

permitted line
  خط ِ پرزامیده   
xatt-e parzâmidé

Fr.: raie permise   

An ordinary spectral line emitted by atoms undergoing energy transitions that are allowed by the selection rules of quantum mechanics. → forbidden lines.

permitted; → line.

  خط ِ لوله   
xatt-e lulé (#)

Fr.: pipeline, conduite, gazoduc, oléoduc, canalisation   

1) A long tubular conduit or series of pipes used to transport crude oil, natural gas, water, etc., often underground and over great distances.
2) A channel or process along which something passes or is provided at a steady rate.

pipe; → line.

plumb line
šâqul (#)

Fr.: fil à plomb   

A cord with a weight attached to one end, used to verify a true vertical alignment or to find the depth of water.

plumb; → line.

Šâqul, variants šâhul, sâhul, probably from sahi + suffix -ul, variant -âl. The first element sahi "upright, right," variants (Tabari, Torbat-Heydariyeyi: šax) "right, upright, straight, level," colloquial Pers. šaq (o raq = râst) "upright, erect." For the second element → -âl.

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