-
1 Effective Mass Theory
Electronics: EMTУниверсальный русско-английский словарь > Effective Mass Theory
-
2 эффективное время ожидания
Theory of mass service: effective waiting timeУниверсальный русско-английский словарь > эффективное время ожидания
-
3 Davy, Sir Humphry
[br]b. 17 December 1778 Penzance, Cornwall, Englandd. 29 May 1829 Geneva, Switzerland[br]English chemist, discoverer of the alkali and alkaline earth metals and the halogens, inventor of the miner's safety lamp.[br]Educated at the Latin School at Penzance and from 1792 at Truro Grammar School, Davy was apprenticed to a surgeon in Penzance. In 1797 he began to teach himself chemistry by reading, among other works, Lavoisier's elementary treatise on chemistry. In 1798 Dr Thomas Beddoes of Bristol engaged him as assistant in setting up his Pneumatic Institution to pioneer the medical application of the newly discovered gases, especially oxygen.In 1799 he discovered the anaesthetic properties of nitrous oxide, discovered not long before by the chemist Joseph Priestley. He also noted its intoxicating qualities, on account of which it was dubbed "laughing-gas". Two years later Count Rumford, founder of the Royal Institution in 1800, appointed Davy Assistant Lecturer, and the following year Professor. His lecturing ability soon began to attract large audiences, making science both popular and fashionable.Davy was stimulated by Volta's invention of the voltaic pile, or electric battery, to construct one for himself in 1800. That enabled him to embark on the researches into electrochemistry by which is chiefly known. In 1807 he tried decomposing caustic soda and caustic potash, hitherto regarded as elements, by electrolysis and obtained the metals sodium and potassium. He went on to discover the metals barium, strontium, calcium and magnesium by the same means. Next, he turned his attention to chlorine, which was then regarded as an oxide in accordance with Lavoisier's theory that oxygen was the essential component of acids; Davy failed to decompose it, however, even with the aid of electricity and concluded that it was an element, thus disproving Lavoisier's view of the nature of acids. In 1812 Davy published his Elements of Chemical Philosophy, in which he presented his chemical ideas without, however, committing himself to the atomic theory, recently advanced by John Dalton.In 1813 Davy engaged Faraday as Assistant, perhaps his greatest service to science. In April 1815 Davy was asked to assist in the development of a miner's lamp which could be safely used in a firedamp (methane) laden atmosphere. The "Davy lamp", which emerged in January 1816, had its flame completely surrounded by a fine wire mesh; George Stephenson's lamp, based on a similar principle, had been introduced into the Northumberland pits several months earlier, and a bitter controversy as to priority of invention ensued, but it was Davy who was awarded the prize for inventing a successful safety lamp.In 1824 Davy was the first to suggest the possibility of conferring cathodic protection to the copper bottoms of naval vessels by the use of sacrificial electrodes. Zinc and iron were found to be equally effective in inhibiting corrosion, although the scheme was later abandoned when it was found that ships protected in this way were rapidly fouled by weeds and barnacles.[br]Principal Honours and DistinctionsKnighted 1812. FRS 1803; President, Royal Society 1820. Royal Society Copley Medal 1805.Bibliography1812, Elements of Chemical Philosophy.1839–40, The Collected Works of Sir Humphry Davy, 9 vols, ed. John Davy, London.Further ReadingJ.Davy, 1836, Memoirs of the Life of Sir Humphry Davy, London (a classic biography). J.A.Paris, 1831, The Life of Sir Humphry Davy, London (a classic biography). H.Hartley, 1967, Humphry Davy, London (a more recent biography).J.Z.Fullmer, 1969, Cambridge, Mass, (a bibliography of Davy's works).ASD
См. также в других словарях:
Effective field theory — In physics, an effective field theory is an approximate theory (usually a quantum field theory) that includes appropriate degrees of freedom to describe physical phenomena occurring at a chosen length scale, while ignoring substructure and… … Wikipedia
Effective mass — In solid state physics, a particle s effective mass is the mass it seems to carry in the semiclassical model of transport in a crystal. It can be shown that, under most conditions, electrons and holes in a crystal respond to electric and magnetic … Wikipedia
Mass gap — Quantum field theory (Feynman diagram) … Wikipedia
Mass in general relativity — General relativity Introduction Mathematical formulation Resources Fundamental concepts … Wikipedia
Mass line — Part of the Politics series on Maoism … Wikipedia
Mass comparison — is a method developed by Joseph Greenberg to determine the level of genetic relatedness between languages. It is now usually called multilateral comparison. The method is generally rejected by linguists (Campbell 2001, p. 45), though it has… … Wikipedia
Theory of Constraints — (TOC) is an overall management philosophy. Dr. Eliyahu M. Goldratt introduced the Theory of constraints in his 1984 book titled The Goal . It is based on the application of scientific principles and logic reasoning to guide human based… … Wikipedia
Mass psychogenic illness — (MPI), also called mass sociogenic illness,[1] is “the rapid spread of illness signs and symptoms affecting members of a cohesive group, originating from a nervous system disturbance involving excitation, loss or alteration of function, whereby… … Wikipedia
Mass automobility — refers to a period in United States history, beginning in the early 20th century, where individuals had strong desires and aspirations to own an automobile. Autmobility, more simply, refers to the utilization of automobiles as the major means of… … Wikipedia
Mass diffusivity — This article is about coefficient of molecular diffusion of mass. For other uses, see Diffusivity (disambiguation). Diffusivity or diffusion coefficient is a proportionality constant between the molar flux due to molecular diffusion and the… … Wikipedia
Mass society — Sociology … Wikipedia
