Mouvement antinucléairethumb|« Nucléaire ? Non merci ! », Autocollant de 1975 contre l'énergie nucléaire. Le mouvement antinucléaire ou lobby antinucléaire désigne l'ensemble des personnes et organisations (associations, syndicats, partis politiques) qui s'opposent de façon générale (philosophiquement, idéologiquement ou politiquement) à l'utilisation civile ou militaire de l'énergie nucléaire sous quelque forme que ce soit. C'est donc par définition un lobby.
Neutron cross sectionIn nuclear physics, the concept of a neutron cross section is used to express the likelihood of interaction between an incident neutron and a target nucleus. The neutron cross section σ can be defined as the area in cm2 for which the number of neutron-nuclei reactions taking place is equal to the product of the number of incident neutrons that would pass through the area and the number of target nuclei. In conjunction with the neutron flux, it enables the calculation of the reaction rate, for example to derive the thermal power of a nuclear power plant.
Third derivativeIn calculus, a branch of mathematics, the third derivative or third-order derivative is the rate at which the second derivative, or the rate of change of the rate of change, is changing. The third derivative of a function can be denoted by Other notations can be used, but the above are the most common. Let . Then and . Therefore, the third derivative of f is, in this case, or, using Leibniz notation, Now for a more general definition. Let f be any function of x such that f ′′ is differentiable.
Amalgame de sodiumL’amalgame de sodium est un amalgame, ou alliage, de mercure et de sodium découvert par Hans Goldschmidt et Julius Tafel, deux étudiants de Robert Bunsen. C'est un solide blanc argenté ou grisâtre d'apparence spongieuse. Il sert à produire du dihydrogène, de la soude et comme réducteur en chimie organique. Lorsque le sodium métallique (Na) est dissous dans du mercure, il se produit une réaction exothermique qui produit le composé intermétallique NaHg_2. L'échauffement est souvent suffisant pour mettre localement le mercure en ébullition.
Core countriesIn world systems theory, the core countries are the industrialized capitalist or imperialist countries, which depend on appropriation from peripheral countries and semi-peripheral countries. Core countries control and benefit from the global market. They are usually recognized as wealthy states with a wide variety of resources and are in a favorable location compared to other states. They have strong state institutions, a powerful military and powerful global political alliances. Core countries do not always stay core permanently.
