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Karl Ernst Claus
Karl Ernst Claus (also Karl Klaus or Carl Claus, russian: Карл Ка́рлович Кла́ус, 22 January 1796 – 24 March 1864) was a German-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 i ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tartu
Tartu is the second largest city in Estonia after the Northern European country's political and financial capital, Tallinn. Tartu has a population of 91,407 (as of 2021). 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, the Estonian National Museum, and the oldest Estonian-language theatre, Vanemuine. It is also the birthplace of the Estonian Song Festivals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kazan
Kazan ( ; rus, Казань, p=kɐˈzanʲ; tt-Cyrl, Казан, ''Qazan'', IPA: Help:IPA/Tatar, [qɑzan]) is the capital city, capital and largest city of the Republic of Tatarstan in 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 1.2 million residents, up to roughly 1.6 million residents in the urban agglomeration. Kazan is the List of cities and towns in Russia by population, fifth-largest city in Russia, and the Volga#Biggest cities on the shores of the Volga, most populous city on the Volga, as well as the Volga Federal District. Kazan became the capital of the Khanate of Kazan and was Siege of Kazan, conquered by Ivan the Terrible in the 16th century, becoming a part of Russia. The city was seized and largely destroyed during Pugachev's Rebellion of 1773–1775, but was later rebuilt during the reign of Catherine the Great. In the following centuries, Kazan grew to become a majo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osmium
Osmium (from Greek grc, ὀσμή, osme, smell, label=none) is a chemical element with the symbol Os and atomic number 76. It is a hard, brittle, bluish-white transition metal in the platinum group that is found as a 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 tipping, electrical contacts, and in other applications that require extreme durability and hardness. Osmium is among the rarest elements in the Earth's crust, making up only 50 parts per trillion ( ppt). It is estimated to be about 0.6 parts per billion in the universe and is therefore the rarest precious metal. Characteristics Physical properties Osmium has a blue-gray tint and is the densest stable element; it is approximately twice as dense as lead and narrowly denser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iridium
Iridium is a chemical element with the symbol Ir and atomic number 77. A very hard, brittle, silvery-white transition metal of the platinum group, it is considered the second-densest naturally occurring metal (after osmium) with a density of as defined by experimental X-ray crystallography. It is one of the most corrosion-resistant metals, even at temperatures as high as . However, corrosion-resistance is not quantifiable in absolute terms; although only certain molten salts and halogens are corrosive to solid iridium, finely divided iridium dust is much more reactive and can be flammable, whereas gold dust is not flammable but can be attacked by substances that iridium resists, such as aqua regia. Iridium was discovered in 1803 among insoluble impurities in natural platinum. Smithson Tennant, the primary discoverer, named it after the Greek goddess Iris, personification of the rainbow, because of the striking and diverse colors of its salts. Iridium is one of the ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodium
Rhodium is a chemical element with the 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: 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 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 most aggressive chemicals, and because of its rarity, r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noble Metal
A noble metal is ordinarily regarded as a metallic chemical element that is generally resistant to corrosion and is usually found in nature in its raw form. Gold, platinum, and the other platinum group metals ( ruthenium, rhodium, palladium, osmium, iridium) are most often so classified. Silver, copper and mercury are sometimes included as noble metals, however less often as 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. In physics, there are only three noble metals: copper, silver and gold. In dentistry, silver is not always counted as a noble metal since it is subject to corrosion when present in the mouth. In chemistry, the term noble metal 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. This broader set includes copper, mercury, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
St Petersburg Mint
Saint Petersburg Mint (russian: Санкт-Петербу́ргский моне́тный двор) 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 ''Государственный знак'', or State Insignia) is a Russian joint-stock company responsible for research and development as well as manufacturing security products including banknotes, coi ... 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 si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural Mountains
The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western Russia, from the coast of the Arctic Ocean to the river Ural and northwestern Kazakhstan.Ural Mountains Encyclopædia Britannica on-line The mountain range forms part of the conventional boundary between the regions of and |
Habilitation
Habilitation is the highest university degree, or the procedure by which it is achieved, in many European countries. The candidate fulfills a university's set criteria of excellence in research, teaching and further education, usually including a dissertation. The degree, abbreviated "Dr. habil." (Doctor habilitatus) or "PD" (for "Privatdozent"), is a qualification for professorship in those countries. The conferral is usually accompanied by a lecture to a colloquium as well as a public inaugural lecture. History and etymology The term ''habilitation'' is derived from the Medieval Latin , meaning "to make suitable, to fit", from Classical Latin "fit, proper, skillful". The degree developed in Germany in the seventeenth century (). Initially, habilitation was synonymous with "doctoral qualification". The term became synonymous with "post-doctoral qualification" in Germany in the 19th century "when holding a doctorate seemed no longer sufficient to guarantee a proficient transfer ... [...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 unde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volga River
The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the longest river in Europe. 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 which is more than twice the size of . It is also Europe's largest river in terms of average at delta – between and – and of drainage basin. It is widely regarded as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural River
The Ural (russian: Урал, ), known before 1775 as Yaik (russian: Яик, ba, Яйыҡ, translit=Yayıq, ; kk, Жайық, translit=Jaiyq, ), 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 18th-longest river in Asia. The Ural is conventionally considered part of the boundary between the continents of Europe and Asia. The Ural arises 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 joins. From Orenburg it continues west, passing into Kazakhstan, then turning south again at Oral, and meandering through a broad flat plain until it reaches the Caspian a few mile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
