Chercher aussi sur: Web Actualités Encyclopédie Images
Collins

polar

  

      adj  
1    situated at or near, coming from, or relating to either of the earth's poles or the area inside the Arctic or Antarctic Circles  
polar regions     
2    having or relating to a pole or poles  
3    pivotal or guiding in the manner of the Pole Star  
4    directly opposite, as in tendency or character  
5      (Chem)  
a    (of a molecule or compound) being or having a molecule in which there is an uneven distribution of electrons and thus a permanent dipole moment  
water has polar molecules     
b    (of a crystal or substance) being or having a crystal that is bound by ionic bonds  
sodium chloride forms polar crystals     


polar axis  
      n   the fixed line in a system of polar coordinates from which the polar angle, θ, is measured anticlockwise  
polar bear  
      n   a white carnivorous bear, Thalarctos maritimus, of coastal regions of the North Pole  
polar body  
      n     (Physiol)   a tiny cell containing little cytoplasm that is produced with the ovum during oogenesis when the oocyte undergoes meiosis  
polar circle  
      n      a term for either the       Arctic Circle       Antarctic Circle  
polar coordinates  
      pl n   a pair of coordinates for locating a point in a plane by means of the length of a radius vector, r, which pivots about the origin to establish the angle, θ, that the position of the point makes with a fixed line. Usually written (r, θ)  
   See also       Cartesian coordinates       spherical coordinates  
polar distance  
      n   the angular distance of a star, planet, etc., from the celestial pole; the complement of the declination,   (Also called)    codeclination  
polar equation  
      n   an equation in polar coordinates  
polar front  
      n     (Meteorol)   a front dividing cold polar air from warmer temperate or tropical air  
polar lights  
      pl n   the aurora borealis in the N hemisphere or the aurora australis in the S hemisphere  
polar sequence  
      n     (Astronomy)   a series of stars in the vicinity of the N celestial pole whose accurately determined magnitudes serve as the standard for visual and photographic magnitudes of stars  
polar wandering  
      n     (Geology)   the movement of the earth's magnetic poles with respect to the geographic poles  
Dictionnaire anglais Collins English definition-Thesaurus  
Ajouter votre entrée dans le Dictionnaire Collaboratif .

Publicité