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Georges Destriau
Georges Destriau (1 August 1903 – 20 January 1960) was a French physicist and early observer of electroluminescence. Education and research In 1926 Destriau became an engineer at the École Centrale des Arts et Manufactures in Paris. Thereafter he worked in the x-ray device industry. From 1932 until 1941 Destriau worked at the Centre National de la Recherche Scientifique. A brief stay at the University of Bordeaux was followed in 1943 by a move to Paris. In 1946 Destriau became professor at the University of Poitiers and in 1954 at the Sorbonne in Paris. Later Destriau worked for Westinghouse Electric. Destriau worked in the field of magnetism and X-ray dosimetry of ionizing radiation. Best-known is his research on electroluminescence, which he carried out in 1935 in the Paris laboratory of Marie Curie, who had died a year earlier. Destriau observed that zinc sulfide crystals fluoresced when doped with traces of copper ions and suspended in castor oil between two mica platel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bordeaux
Bordeaux ( ; ; Gascon language, Gascon ; ) is a city on the river Garonne in the Gironde Departments of France, department, southwestern France. A port city, it is the capital of the Nouvelle-Aquitaine region, as well as the Prefectures in France, prefecture of the Gironde department. Its inhabitants are called "''Bordelais'' (masculine) or "''Bordelaises'' (feminine). The term "Bordelais" may also refer to the city and its surrounding region. The city of Bordeaux proper had a population of 259,809 in 2020 within its small municipal territory of , but together with its suburbs and exurbs the Bordeaux Functional area (France), metropolitan area had a population of 1,376,375 that same year (Jan. 2020 census), the sixth-most populated in France after Paris, Lyon, Marseille, Lille, and Toulouse. Bordeaux and 27 suburban municipalities form the Bordeaux Métropole, Bordeaux Metropolis, an Indirect election, indirectly elected Métropole, metropolitan authority now in charge of wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dosimetry
Radiation dosimetry in the fields of health physics and radiation protection is the measurement, calculation and assessment of the ionizing radiation dose absorbed by an object, usually the human body. This applies both internally, due to ingested or inhaled radioactive substances, or externally due to irradiation by sources of radiation. Internal dosimetry assessment relies on a variety of monitoring, bio-assay or radiation imaging techniques, whilst external dosimetry is based on measurements with a dosimeter, or inferred from measurements made by other radiological protection instruments. Radiation dosimetry is extensively used for radiation protection; routinely applied to monitor occupational radiation workers, where irradiation is expected, or where radiation is unexpected, such as in the contained aftermath of the Three Mile Island, Chernobyl or Fukushima radiological release incidents. The public dose take-up is measured and calculated from a variety of indicators s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1903 Births
Events January * January 1 – Edward VII is proclaimed Emperor of India. * January 10 – The Aceh Sultanate was fully annexed by the Dutch East Indies, Dutch forces, deposing the last sultan, marking the end of the Aceh War that have lasted for almost 30 years. * January 19 – The first west–east transatlantic radio broadcast is made from the United States to England (the first east–west broadcast having been made in 1901#December, 1901). February * February 13 – Venezuelan crisis of 1902–03, Venezuelan crisis: After agreeing to arbitration in Washington, the United Kingdom, Germany and Italy reach a settlement with Venezuela resulting in the Washington Protocols. The naval blockade that began in 1902 ends. * February 23 – Cuba leases Guantánamo Bay to the United States "in perpetuity". March * March 2 – In New York City, the Martha Washington Hotel, the first hotel exclusively for women, opens. * March 3 – The British Admir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon Carbide
Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A wide bandgap semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics that are widely used in applications requiring high endurance, such as car brakes, car clutches and ceramic plates in bulletproof vests. Large single crystals of silicon carbide can be grown by the Lely method and they can be cut into gems known as synthetic moissanite. Electronic applications of silicon carbide such as light-emitting diodes (LEDs) and Cat's whisker detector, detectors in early radios were first demonstrated around 1907. SiC is used in semiconductor electronics devices that operate at high temperatures or high voltages, or both. Natural occurrence Naturally occurring moissanite is found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oleg Vladimirovich Losev
Oleg Vladimirovich Losev (sometimes spelled ''Lossev'' or ''Lossew'' in English; ; 10 May 1903 – 22 January 1942) was a Russian and Soviet scientist and inventor An English translatio M. A. Novikov (January 2004) "Oleg Vladimirovich Losev: Pioneer of Semiconductor Electronics," ''Physics of the Solid State'', vol. 46, no. 1, page 1-4is on the Springer archive who made significant discoveries in the field of p-n junction, semiconductor junctions and the light emitting diode (LED). Although he was never able to complete formal education and never held a research position, Losev conducted some of the earliest research into semiconductors, publishing 43 papers and receiving 16 "Author’s Certificate, author's certificates" (the Soviet version of patents) for his discoveries. He observed light emission from carborundum point-contact junctions, constructing a light-emitting diode (LED), did the first research on them, proposed the first correct theory of how they worked, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compound (chemistry), compounds, produces unique physical property, physical properties including toughness, high rubber elasticity, elasticity, viscoelasticity, and a tendency to form Amorphous solid, amorphous and crystallization of polymers, semicrystalline structures rath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mica
Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as ''perfect basal cleavage''. Mica is common in igneous and metamorphic rock and is occasionally found as small flakes in sedimentary rock. It is particularly prominent in many granites, pegmatites, and schists, and "books" (large individual crystals) of mica several feet across have been found in some pegmatites. Micas are used in products such as drywalls, paints, and fillers, especially in parts for automobiles, roofing, and in electronics. The mineral is used in cosmetics and food to add "shimmer" or "frost". Properties and structure The mica group comprises 37 phyllosilicate minerals. All crystallize in the monoclinic system, with a tendency towards pseudohexagonal crystals, and are similar in structure but vary in chemical composition. Micas are translucent to opa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castor Oil
Castor oil is a vegetable oil pressed from castor beans, the seeds of the plant ''Ricinus communis''. The seeds are 40 to 60 percent oil. It is a colourless or pale yellow liquid with a distinct taste and odor. Its boiling point is and its density is 0.961 g/cm3. It includes a mixture of triglycerides in which about 90 percent of fatty acids are Ricinoleic acid, ricinoleates. Oleic acid and linoleic acid are the other significant components. Some 270,000–360,000 tonnes (600–800 million pounds) of castor oil are produced annually for a variety of uses. Castor oil and its derivatives are used in the manufacturing of soaps, lubricants, hydraulic and brake fluids, paints, dyes, coatings, inks, cold-resistant plastics, waxes and polishes, nylon, and perfumes. Etymology The name probably comes from a confusion between the ''Ricinus'' plant that produces it and another plant, the ''Vitex agnus-castus''. An alternative etymology, though, suggests that it was used as a replace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable, unalloyed metallic form. This means that copper is a native metal. This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopant
A dopant (also called a doping agent) is a small amount of a substance added to a material to alter its physical properties, such as electrical or optics, optical properties. The amount of dopant is typically very low compared to the material being doped. When doped into crystalline substances, the dopant's atoms get incorporated into the crystal lattice of the substance. The crystalline materials are frequently either crystals of a semiconductor such as silicon and germanium for use in solid-state electronics, or transparency and translucency, transparent crystals for use in the production of various laser types; however, in some cases of the latter, noncrystalline substances such as glass can also be doped with impurities. In solid-state electronics using the proper types and amounts of dopants in semiconductors is what produces the p-type semiconductors and n-type semiconductors that are essential for making transistors and diodes. Transparent crystals Lasing media The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluoresce
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colored visible light. The color of the light emitted depends on the chemical composition of the substance. Fluorescent materials generally cease to glow nearly immediately when the radiation source stops. This distinguishes them from the other type of light emission, phosphorescence. Phosphorescent materials continue to emit light for some time after the radiation stops. This difference in duration is a result of quantum spin effects. Fluorescence occurs when a photon from incoming radiation is absorbed by a molecule, exciting it to a higher energy level, followed by the emission of light as the molecule returns to a lower energy state. The emitted light may have a longer wavelength and, therefore, a lower photon energy than the absorbed rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Sulfide
Zinc sulfide (or zinc sulphide) is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparency and translucency, transparent, and it is used as a window for visible light, visible optics and infrared optics. Structure ZnS exists in two main crystalline forms. This dualism is an example of polymorphism (materials science), polymorphism. In each form, the coordination geometry at Zn and S is tetrahedral. The more stable cubic form is known also as zinc blende or sphalerite. The hexagonal form is known as the mineral wurtzite, although it also can be produced synthetically.. The transition from the sphalerite form to the wurtzite form occurs at around 1020 °C. Applications Luminescent mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
