helium detection
41CRYOLOGIE - Cryogénie — La production de froid, ou extraction de chaleur, a pour but soit d’abaisser la température d’un milieu, et éventuellement, dans le cas de l’air, sa teneur en vapeur d’eau, soit de refroidir une substance au cours d’un processus de conservation… …
42Atmosphere of Uranus — The atmosphere of Uranus, like that of Neptune, is markedly different from those of the larger gas giants, Jupiter and Saturn. While still composed primarily of hydrogen and helium, it possesses a higher proportion of volatiles (dubbed ices )… …
43LASERS — Les lasers (le mot «laser» est formé des initiales des mots anglais light amplification by stimulated emission of radiations , signifiant: amplification de lumière par émission stimulée de rayonnement) sont des sources nouvelles de rayonnement,… …
44Neutron — This article is about the subatomic particle. For other uses, see Neutron (disambiguation). Neutron The quark structure of the neutron. (The color assignment of individual quarks is not important, only that all three colors are present.)… …
45Magnetometer — A magnetometer is a measuring instrument used to measure the strength or direction of a magnetic field either produced in the laboratory or existing in nature. Some countries such as the USA, Canada and Australia classify the more sensitive… …
46Ammonia — For other uses, see Ammonia (disambiguation). Ammonia …
47Stellar classification — In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are… …
48Brown dwarf — Brown dwarfs are sub stellar objects which are too low in mass to sustain hydrogen 1 fusion reactions in their cores, which is characteristic of stars on the main sequence. Brown dwarfs have fully convective surfaces and interiors, with no… …
49Binary star — For the hip hop group, see Binary Star (band). Hubble image of the …
50Earth and Space Sciences — ▪ 1996 Introduction GEOLOGY AND GEOCHEMISTRY In 1995 significant developments took place in the realm of geologic mapping, which provides the foundation for the presentation and comparison of data in the Earth sciences. The most important… …
