emitting transition
41Field electron emission — It is requested that a diagram or diagrams be included in this article to improve its quality. For more information, refer to discussion on this page and/or the listing at Wikipedia:Requested images. Field emission (FE) (also known as field… …
42Atom — The atom is the smallest unit of an element that retains the chemical properties of that element. An atom has an electron cloud consisting of negatively charged electrons surrounding a dense nucleus. The nucleus contains positively charged… …
43Iridium — (pronEng|ɪˈrɪdiəm) is a chemical element that has the symbol Ir and atomic number 77. A very hard, brittle, silvery white transition metal of the platinum family, iridium is the second densest element and is the most corrosion resistant metal,… …
44New Hampshire Public Television — WLED redirects here. For white light emitting diode, see Light emitting diode. New Hampshire Public Television statewide New Hampshire Branding NHPTV Slogan Engaging minds. Connecting Communities. Celebrating New Hampshire …
45Megamaser — A megamaser is a type of astrophysical maser, which is a naturally occurring source of stimulated spectral line emission. Megamasers are distinguished from astrophysical masers by their large isotropic luminosity. Megamasers produce roughly 103… …
46Earth Sciences — ▪ 2009 Introduction Geology and Geochemistry The theme of the 33rd International Geological Congress, which was held in Norway in August 2008, was “Earth System Science: Foundation for Sustainable Development.” It was attended by nearly… …
47Direct and indirect band gaps — In semiconductor physics, the band gap of a semiconductor is always one of two types, a direct band gap or an indirect band gap. The band gap is called direct if the momentum of electrons and holes is the same in both the conduction band and the… …
48Ultraviolet — UV redirects here. For other uses, see UV (disambiguation). UVB redirects here. For the mysterious shortwave radio station in Russia, see UVB 76. For other uses, see Ultraviolet (disambiguation). False color image of the Sun s corona as seen in… …
49Radioactive waste — 2007 ISO radioactivity danger logo, designed in part for long term radioactive waste depositories which might survive into a far future time in which all knowledge of the meaning of present common radiation danger symbols and signs has been lost… …
50Doppler effect — Change of wavelength caused by motion of the source. An animation illustrating how the Doppler effect causes a car engine or siren to soun …
