An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



Number of Results: 9 Search : dipole
  دیپل، دی‌قطبه   
dipol, diqotbé

Fr.: dipole   

1) A combination of two electrically or magnetically charged particles of opposite signs, which are separated by a very small distance.
2) Chemistry: A molecule containing both positively and negatively charged groups.

di- "two, twice, double," + → pole.

dipole anisotropy
  ناهمسانگردی ِ دی‌پل، ~ دی‌قطبه   
nâhamsângardi-ye dipol, ~ diqotbé

Fr.: anisotropie dipolaire   

A form of anistropy in the temperature of the → cosmic microwave background radiation, appearing as one hot pole and one cold pole, caused by our motion with respect to the cosmic background radiation. The temperature variations, amounting to 1 part in 1000, yield a velocity of about 600 km/sec for our Galaxy with respect to the background. → cosmic microwave background anisotropy.

dipole; → anisotropy.

dipole antenna
  آنتن ِ دیپل، ~ دی‌قطبه   
ânten-e dipol, ~ diqotbé

Fr.: antenne dipôle   

One of the simplest kinds of antenna which is connected at the center to a radio-frequency feed line for transmitting or receiving radio frequency energy. It differs from the dish antenna in that it consists of many separate antennas that collect energy by feeding all their weak individual signals into one common receiving set.

dipole; → antenna.

dipole moment
  گشتاور ِ دوقطبه   
gaštâvar-e doqotbé (#)

Fr.: moment dipolaire   

1) The product of the strength of either of the charges in an → electric dipole and the distance separating the two charges. It is expressed in → coulomb meters. Dipole moment is a → vector quantity. Its direction is defined as toward the positive charge. In chemistry dipole moment is a quantitative measure of polarity in a molecule; the unit is the → debye.
2) The product of the strength of either of the poles in a → magnetic dipole and the distance separating the two poles. Dipole moment is a vector quantity. Its direction is defined as toward the magnetic north pole.

dipole; → moment.

dipole radiation
  تابش ِ دوقطبه   
tâbeš-e doqotbé

Fr.: rayonnement dipolaire   

The electromagnetic radiation produced by an oscillating → electric dipole or → magnetic dipole.

dipole; → radiation.

electric dipole
  دیپل ِ برقی، دی‌قطبه ِ ~   
dipol-e barqi, diqotbe-ye ~

Fr.: dipôle électrique   

1) A type of → charge distribution consisting of two charges, a positive and a negative charge of the same magnitude separated by a distance s, which is small compared to the distance r to the point P at which the → electric potential is V and the → electric field intensity is E.The potential falls as the square of the distance (1/r2) and the electric field intensity decreases as the cube of the distance (1/r3).
2) A simple → antenna consisting of a pair of oppositely charged → conductors capable of radiating an → electromagnetic wave in response to the movement of an electric charge from one conductor to the other.

electric; → dipole.

magnetic dipole
  دوقطبه‌ی ِ مغناتیسی   
doqotbe-ye maqnâtisi

Fr.: dipole magnétique   

A system that generates a → magnetic field in which the field is considered to result from two opposite poles, as in the north and south poles of a magnet, much as an → electric field originates from a positive and a negative charge in an → electric dipole. A loop carrying an electric current also acts as a magnetic dipole. Magnetic dipoles experience a torque in the presence of magnetic fields. → dipole moment; → magnetic moment.

magnetic; → dipole.

magnetic dipole moment
  گشتاور ِ دوقطبه‌ی ِ مغناتیسی   
gaštâvar-e doqotbe-ye meqnâtisi

Fr.: moment dipolaire magnétique   

Same as → magnetic moment.

magnetic; → dipole; → moment.

magnetic-dipole radiation
  تابش ِ دوقطبه‌ی ِ مغناتیسی   
tâbeš-e doqotbe-ye meqnâtisi (#)

Fr.: rayonnement du dipôle magnétique   

Radiation emitted by a rotating magnet.

magnetic; → dipole; → radiation.