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Karl Ernst Claus
Karl Ernst Claus, also known as Karl Klaus or Carl Claus (; 22 January 1796 – 24 March 1864), was a Russian chemist and naturalist of Baltic German origin. Claus was a professor at Kazan State University and a member of the Russian Academy of Sciences. He was primarily known as a chemist and discoverer of the chemical element ruthenium, which he named after his homeland of Russia, but also as one of the first scientists who applied quantitative methods in botany.Клаус, Карл Карлович in Волков В.А. ''et al'' "Выдающиеся химики мира: Биографический справочник" Moscow, Высш. шк., 1991 (in Russian) Early life and education Karl Claus was born in 1796 in |
Dorpat
Tartu is the second largest city in Estonia after Tallinn. Tartu has a population of 97,759 (as of 2024). It is southeast of Tallinn and 245 kilometres (152 miles) northeast of Riga, Latvia. Tartu lies on the Emajõgi river, which connects the two largest lakes in Estonia, Lake Võrtsjärv and Lake Peipus. From the 13th century until the end of the 19th century, Tartu was known in most of the world by variants of its historical name Dorpat. Tartu, the largest urban centre of southern Estonia, is often considered the "intellectual capital city" of the country, especially as it is home to the nation's oldest and most renowned university, the University of Tartu (founded in 1632). Tartu also houses the Supreme Court of Estonia, the Ministry of Education and Research (Estonia), Ministry of Education and Research, the Estonian National Museum, and the oldest Estonian-language theatre, Vanemuine. It is also the birthplace of the Estonian Song Festivals. Tartu was designated as the E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kazan
Kazan; , IPA: Help:IPA/Tatar, [qɑzan] is the largest city and capital city, capital of Tatarstan, Russia. The city lies at the confluence of the Volga and the Kazanka (river), Kazanka Rivers, covering an area of , with a population of over 1.3 million residents, and up to nearly 2 million residents in the greater Kazan metropolitan area, metropolitan area. Kazan is the List of cities and towns in Russia by population, fifth-largest city in Russia, being the Volga#Biggest cities on the shores of the Volga, most populous city on the Volga, as well as within the Volga Federal District. Historically, Kazan was the capital of the Khanate of Kazan, and was Siege of Kazan, conquered by Ivan the Terrible in the 16th century, at which point the city became a part of the Tsardom of Russia. The city was seized (and largely destroyed) during Pugachev's Rebellion (1773–1775), but was later rebuilt during the reign of Catherine the Great. In the following centuries, Kazan grew to become a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmium
Osmium () is a chemical element; it has Symbol (chemistry), symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a Abundance of elements in Earth's crust, trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element. When experimentally measured using X-ray crystallography, it has a density of . Manufacturers use its alloys with platinum, iridium, and other platinum-group metals to make fountain pen Nib (pen)#Nib tipping, nib tipping, electrical contacts, and in other applications that require extreme durability and hardness. Osmium is among the Abundance of elements in Earth's crust, rarest elements in the Earth's crust, making up only 50 parts per trillion (Parts-per notation#Parts-per expressions, ppt). Characteristics Physical properties Osmium is a hard, brittle, blue-gray metal, and the densest stable element—about twice as dense as lead. The density of os ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium
Iridium is a chemical element; it has the symbol Ir and atomic number 77. This very hard, brittle, silvery-white transition metal of the platinum group, is considered the second-densest naturally occurring metal (after osmium) with a density of as defined by experimental X-ray crystallography. 191Ir and 193Ir are the only two naturally occurring isotopes of iridium, as well as the only stable isotopes; the latter is the more abundant. It is one of the most corrosion-resistant metals, even at temperatures as high as . Iridium was discovered in 1803 in the acid-insoluble residues of platinum ores by the English chemist Smithson Tennant. The name ''iridium'', derived from the Greek word ''iris'' (rainbow), refers to the various colors of its compounds. Iridium is one of the rarest elements in Earth's crust, with an estimated annual production of only in 2023. The dominant uses of iridium are the metal itself and its alloys, as in high-performance spark plugs, crucibles for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodium
Rhodium is a chemical element; it has symbol Rh and atomic number 45. It is a very rare, silvery-white, hard, corrosion-resistant transition metal. It is a noble metal and a member of the platinum group. It has only one naturally occurring isotope, which is 103Rh. Naturally occurring rhodium is usually found as a free metal or as an alloy with similar metals and rarely as a chemical compound in minerals such as bowieite and rhodplumsite. It is one of the rarest and most valuable precious metals. Rhodium is a group 9 element (cobalt group). Rhodium is found in platinum or nickel ores with the other members of the platinum group metals. It was discovered in 1803 by William Hyde Wollaston in one such ore, and named for the rose color of one of its chlorine compounds. The element's major use (consuming about 80% of world rhodium production) is as one of the catalysts in the three-way catalytic converters in automobiles. Because rhodium metal is inert against corrosion and mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noble Metal
A noble metal is ordinarily regarded as a metallic chemical element, element that is generally resistant to corrosion and is usually found in nature in its native element, raw form. Gold, platinum, and the other platinum group metals (ruthenium, rhodium, palladium, osmium, iridium) are most often so classified. Silver, copper, and Mercury (element), mercury are sometimes included as noble metals, but each of these usually occurs in nature combined with sulfur. In more specialized fields of study and applications the number of elements counted as noble metals can be smaller or larger. It is sometimes used for the three metals copper, silver, and gold which have filled D electron count, d-bands, while it is often used mainly for silver and gold when discussing surface-enhanced Raman spectroscopy involving metal nanoparticles. It is sometimes applied more broadly to any metallic or semimetallic element that does not react with a weak acid and give off hydrogen gas in the process. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
St Petersburg Mint
Saint Petersburg Mint () is one of the world's largest mints. It was founded by Peter the Great in 1724 on the territory of Peter and Paul Fortress, so it is one of the oldest industrial enterprises in Saint Petersburg. It is a part of the Goznak Joint Stock Company "Goznak" (; short for , ) is a Russian joint-stock company responsible for research and development as well as manufacturing security products including banknotes, coins, stamps, identity cards, secure documents, state orde ... state-owned corporation. External links Шишанов В. А. К истории создания Банковского монетного двора // Хранитель Эрмитажа: Сборник воспоминаний и научных статей к 100-летию со дня рождения И. Г. Спасского. СПб.: Изд-во Гос. Эрмитажа, 2004. С.221-228 *Official site Buildings and structures in Saint Petersburg Mints (currency) 1724 e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural Mountains
The Ural Mountains ( ),; , ; , or simply the Urals, are a mountain range in Eurasia that runs north–south mostly through Russia, from the coast of the Arctic Ocean to the river Ural (river), Ural and northwestern Kazakhstan.Ural Mountains , Encyclopædia Britannica on-line The mountain range forms part of the Boundaries between the continents of Earth, conventional boundary between the continents of Europe and Asia, marking the separation between European Russia and Siberia. Vaygach Island and the islands of Novaya Zemlya form a further continuation of the chain to the north into the Arctic Ocean. The average altitudes of the Urals are around , the highest point being Mount Narodnaya, which reaches a height of . The mountains lie within the Ural (region), Ural geographical region and significantl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habilitation
Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set criteria of excellence in research, teaching, and further education, which usually includes a dissertation. The degree, sometimes abbreviated ''Dr. habil''. (), ''dr hab.'' (), or ''D.Sc.'' ('' Doctor of Sciences'' in Russia and some CIS countries), is often a qualification for full professorship in those countries. In German-speaking countries it allows the degree holder to bear the title ''PD'' (for ). In a number of countries there exists an academic post of docent, appointment to which often requires such a qualification. The degree conferral is usually accompanied by a public oral defence event (a lecture or a colloquium) with one or more opponents. Habilitation is usually awarded 5–15 years after a PhD degree or its equivalent. Achieving this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytochemistry
Phytochemistry is the study of phytochemicals, which are chemicals derived from plants. Phytochemists strive to describe the structures of the large number of secondary metabolites found in plants, the functions of these compounds in human and plant biology, and the biosynthesis of these compounds. Plants synthesize phytochemicals for many reasons, including to protect themselves against insect attacks and plant diseases. The compounds found in plants are of many kinds, but most can be grouped into four major biosynthetic classes: alkaloids, phenylpropanoids, polyketides, and terpenoids. Phytochemistry can be considered a subfield of botany or chemistry. Activities can be led in botanical gardens or in the wild with the aid of ethnobotany. Phytochemical studies directed toward human (i.e. drug discovery) use may fall under the discipline of pharmacognosy, whereas phytochemical studies focused on the ecological functions and evolution of phytochemicals likely fall under the disci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volga River
The Volga (, ) is the longest river in Europe and the longest endorheic basin river in the world. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchment area of .«Река Волга» , Russian State Water Registry It is also Europe's largest river in terms of average discharge at delta – between and – and of . It is widely regarded as the national river of |
Ural River
The Ural, also known as the Yaik , is a river flowing through Russia and Kazakhstan in the continental border between Europe and Asia. It originates in the southern Ural Mountains and discharges into the Caspian Sea. At , it is the third-longest river in Europe after the Volga and the Danube, and the List of the longest Asian rivers, 18th-longest river in Asia. The Ural is conventionally considered part of the boundary between the continents of Europe and Asia. The Ural rises near Mount Kruglaya in the Ural Mountains, flows south parallel and west of the north-flowing Tobol, through Magnitogorsk, and around the southern end of the Urals, through Orsk where it turns west for about , to Orenburg, where the river Sakmara (river), Sakmara joins. From Orenburg it continues west, passing into Kazakhstan, then turning south again at Oral, Kazakhstan, Oral, and meandering through a broad flat plain until it reaches the Caspian a few kilometers below Atyrau, where it forms a fine 'digita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
