-
1 mesh of cells
Большой англо-русский и русско-английский словарь > mesh of cells
-
2 mesh of cells
Вычислительная техника: сетка ячеек -
3 mesh of cells
English-Russian dictionary of computer science and programming > mesh of cells
-
4 mesh
English-Russian dictionary of computer science and programming > mesh
-
5 сетка ячеек
Большой англо-русский и русско-английский словарь > сетка ячеек
-
6 сетка ячеек
Русско-английский словарь по вычислительной технике и программированию > сетка ячеек
-
7 сетка ячеек
Information technology: mesh of cells -
8 De Forest, Lee
SUBJECT AREA: Broadcasting, Electronics and information technology, Photography, film and optics, Recording, Telecommunications[br]b. 26 August 1873 Council Bluffs, Iowa, USAd. 30 June 1961 Hollywood, California, USA[br]American electrical engineer and inventor principally known for his invention of the Audion, or triode, vacuum tube; also a pioneer of sound in the cinema.[br]De Forest was born into the family of a Congregational minister that moved to Alabama in 1879 when the father became President of a college for African-Americans; this was a position that led to the family's social ostracism by the white community. By the time he was 13 years old, De Forest was already a keen mechanical inventor, and in 1893, rejecting his father's plan for him to become a clergyman, he entered the Sheffield Scientific School of Yale University. Following his first degree, he went on to study the propagation of electromagnetic waves, gaining a PhD in physics in 1899 for his thesis on the "Reflection of Hertzian Waves from the Ends of Parallel Wires", probably the first US thesis in the field of radio.He then joined the Western Electric Company in Chicago where he helped develop the infant technology of wireless, working his way up from a modest post in the production area to a position in the experimental laboratory. There, working alone after normal working hours, he developed a detector of electromagnetic waves based on an electrolytic device similar to that already invented by Fleming in England. Recognizing his talents, a number of financial backers enabled him to set up his own business in 1902 under the name of De Forest Wireless Telegraphy Company; he was soon demonstrating wireless telegraphy to interested parties and entering into competition with the American Marconi Company.Despite the failure of this company because of fraud by his partners, he continued his experiments; in 1907, by adding a third electrode, a wire mesh, between the anode and cathode of the thermionic diode invented by Fleming in 1904, he was able to produce the amplifying device now known as the triode valve and achieve a sensitivity of radio-signal reception much greater than possible with the passive carborundum and electrolytic detectors hitherto available. Patented under the name Audion, this new vacuum device was soon successfully used for experimental broadcasts of music and speech in New York and Paris. The invention of the Audion has been described as the beginning of the electronic era. Although much development work was required before its full potential was realized, the Audion opened the way to progress in all areas of sound transmission, recording and reproduction. The patent was challenged by Fleming and it was not until 1943 that De Forest's claim was finally recognized.Overcoming the near failure of his new company, the De Forest Radio Telephone Company, as well as unsuccessful charges of fraudulent promotion of the Audion, he continued to exploit the potential of his invention. By 1912 he had used transformer-coupling of several Audion stages to achieve high gain at radio frequencies, making long-distance communication a practical proposition, and had applied positive feedback from the Audion output anode to its input grid to realize a stable transmitter oscillator and modulator. These successes led to prolonged patent litigation with Edwin Armstrong and others, and he eventually sold the manufacturing rights, in retrospect often for a pittance.During the early 1920s De Forest began a fruitful association with T.W.Case, who for around ten years had been working to perfect a moving-picture sound system. De Forest claimed to have had an interest in sound films as early as 1900, and Case now began to supply him with photoelectric cells and primitive sound cameras. He eventually devised a variable-density sound-on-film system utilizing a glow-discharge modulator, the Photion. By 1926 De Forest's Phonofilm had been successfully demonstrated in over fifty theatres and this system became the basis of Movietone. Though his ideas were on the right lines, the technology was insufficiently developed and it was left to others to produce a system acceptable to the film industry. However, De Forest had played a key role in transforming the nature of the film industry; within a space of five years the production of silent films had all but ceased.In the following decade De Forest applied the Audion to the development of medical diathermy. Finally, after spending most of his working life as an independent inventor and entrepreneur, he worked for a time during the Second World War at the Bell Telephone Laboratories on military applications of electronics.[br]Principal Honours and DistinctionsInstitute of Electronic and Radio Engineers Medal of Honour 1922. President, Institute of Electronic and Radio Engineers 1930. Institute of Electrical and Electronics Engineers Edison Medal 1946.Bibliography1904, "Electrolytic detectors", Electrician 54:94 (describes the electrolytic detector). 1907, US patent no. 841,387 (the Audion).1950, Father of Radio, Chicago: WIlcox \& Follett (autobiography).De Forest gave his own account of the development of his sound-on-film system in a series of articles: 1923. "The Phonofilm", Transactions of the Society of Motion Picture Engineers 16 (May): 61–75; 1924. "Phonofilm progress", Transactions of the Society of Motion Picture Engineers 20:17–19; 1927, "Recent developments in the Phonofilm", Transactions of the Society of Motion Picture Engineers 27:64–76; 1941, "Pioneering in talking pictures", Journal of the Society of Motion Picture Engineers 36 (January): 41–9.Further ReadingG.Carneal, 1930, A Conqueror of Space (biography).I.Levine, 1964, Electronics Pioneer, Lee De Forest (biography).E.I.Sponable, 1947, "Historical development of sound films", Journal of the Society of Motion Picture Engineers 48 (April): 275–303 (an authoritative account of De Forest's sound-film work, by Case's assistant).W.R.McLaurin, 1949, Invention and Innovation in the Radio Industry.C.F.Booth, 1955, "Fleming and De Forest. An appreciation", in Thermionic Valves 1904– 1954, IEE.V.J.Phillips, 1980, Early Radio Detectors, London: Peter Peregrinus.KF / JW
См. также в других словарях:
Adaptive mesh refinement — This article is about the use of adaptive meshing in numerical analysis. See Subdivision surface for the use of adaptive techniques in Computer Graphics modelling. In numerical analysis, adaptive mesh refinement is a method of adaptive meshing.… … Wikipedia
Particle Mesh — (PM) is a computational method for determining the gravity forces in a system of particles. These particles could refer to atoms, stars, or fluid components and so the method is applicable to many fields, including molecular dynamics and… … Wikipedia
Follicular dendritic cells — (FDC) are cells of the immune system found in lymph follicles. [cite journal |author=Liu Y, Grouard G, de Bouteiller O, Banchereau J |title=Follicular dendritic cells and germinal centers |journal=Int Rev Cytol |volume=166 |issue= |pages=139–79… … Wikipedia
Dendritic cell — A dendritic cell Dendritic cells in skin Dendritic cells … Wikipedia
Mast cell — Mast cells Latin mastocytus Code TH … Wikipedia
Neuroepithelial cell — Neuroepithelial Cells are progenitor cells in the nervous system, deriving from stem cells in several different stages of development. They appear during embryonic development of the neural tube as well as in adult neurogenesis in specific areas… … Wikipedia
Delta cell — Not to be confused with D battery. Delta cell Control of stomach acid Latin endocrinocytus D … Wikipedia
Giant cell — Multinucleated giant cells due to an infection. H E stain. A giant cell is a mass formed by the union of several distinct cells (usually macrophages).[1] It can arise in response to an infection or foreign body. Types include: foreign body giant… … Wikipedia
Null cell — A null cell is a large granular lymphocyte without surface markers or membrane associated proteins from B lymphocytes or T lymphocytes. Natural killer cells are usually null cells with surface marker CD 16 which bind to the Fc portion of the IgG … Wikipedia
Oxyphil cell (parathyroid) — Micrograph of a parathyroid gland. H E stain. MeSH … Wikipedia
Merkel nerve ending — Merkel nerve endings are mechanoreceptors found in the skin and mucosa of vertebrates that provide touch information to the brain. The information they provide are those regarding pressure and texture. Each ending consists of a Merkel cell in… … Wikipedia
