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Per Teodor Cleve
Per Teodor Cleve (10 February 1840 – 18 June 1905) was a Swedish chemist, biologist, mineralogist and oceanographer. He is best known for his discovery of the chemical elements holmium and thulium. Born in Stockholm in 1840, Cleve earned his BSc and PhD from Uppsala University in 1863 and 1868, respectively. After receiving his PhD, he became an assistant professor of chemistry at the university. He later became professor of general and agricultural chemistry. In 1874 he theorised that didymium was in fact two elements; this theory was confirmed in 1885 when Carl Auer von Welsbach discovered neodymium and praseodymium. In 1879 Cleve discovered holmium and thulium. His other contributions to chemistry include the discovery of aminonaphthalenesulfonic acids, also known as Cleve's acids. From 1890 on he focused on biological studies. He developed a method of determining the age and order of late glacial and postglacial deposits from the types of diatom fossils in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stockholm
Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately 1 million people live in the Stockholm Municipality, municipality, with 1.6 million in the Stockholm urban area, urban area, and 2.5 million in the Metropolitan Stockholm, metropolitan area. The city stretches across fourteen islands where Mälaren, Lake Mälaren flows into the Baltic Sea. Outside the city to the east, and along the coast, is the island chain of the Stockholm archipelago. The area has been settled since the Stone Age, in the 6th millennium BC, and was founded as a city in 1252 by Swedish statesman Birger Jarl. The city serves as the county seat of Stockholm County. Stockholm is the cultural, media, political, and economic centre of Sweden. The Stockholm region alone accounts for over a third of the country's Gros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Didymium
Didymium () is a mixture of the elements praseodymium and neodymium. It is used in safety glasses for glassblowing and blacksmithing and filter lenses for flame testing, especially with a gas (propane)-powered forge, where it provides a filter that selectively blocks the yellowish light at 589 nm emitted by the hot sodium in the glass without having a detrimental effect on general vision, unlike dark welder's glasses and cobalt glasses. The usefulness of didymium glass for eye protection of this sort was discovered by Sir William Crookes. Didymium photographic filters are often used to enhance autumn scenery by making leaves appear more vibrant. It does this by removing part of the orange region of the color spectrum, acting as an optical band-stop filter. Unfiltered, this group of colors tends to make certain elements of a picture appear "muddy". These photographic filters are also used by nightscape photographers, as they absorb part of the light pollution caused b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Uppsala
Uppsala University (UU) () is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. Initially founded in the 15th century, the university rose to significance during the rise of Sweden as a great power at the end of the 16th century and was then given relative financial stability with a large donation from King Gustavus Adolphus in the early 17th century. Uppsala also has an important historical place in Swedish national culture, and identity for the Swedish establishment: in historiography, religion, literature, politics, and music. Many aspects of Swedish academic culture in general, such as the white student cap, originated in Uppsala. It shares some peculiarities, such as the student nation system, with Lund University and the University of Helsinki. Uppsala belongs to the Coimbra Group of European universities and to the Guild of European Research-Intensive Universities. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineralogy
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization. History Early writing on mineralogy, especially on gemstones, comes from ancient Babylonia, the ancient Greco-Roman world, ancient and medieval History of China, China, and Sanskrit texts from History of India, ancient India and the ancient Islamic world. Books on the subject included the ''Naturalis Historia, Natural History'' of Pliny the Elder, which not only described many different minerals but also explained many of their properties, and Kitab al Jawahir (Book of Precious Stones) by Persian scientist Al-Biruni. The German Renaissance specialist Georgius Agricola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assistant Professor
Assistant professor is an academic rank just below the rank of an associate professor used in universities or colleges, mainly in the United States, Canada, Japan, and South Korea. Overview This position is generally taken after earning a doctoral degree and sometimes after several years of holding one or more postdoctoral research A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). Postdocs most commonly, but not always, have a temporary acade ...er positions. It is below the position of associate professor at most universities and is equivalent to the rank of lecturer at most Commonwealth universities. In the United States, assistant professor is often the first position held in a tenure track, although it can also be a non-tenure track position. A typical professorship sequence is assistant professor, associate professor, and full professo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bachelor Of Science
A Bachelor of Science (BS, BSc, B.S., B.Sc., SB, or ScB; from the Latin ') is a bachelor's degree that is awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University of London in 1860. In the United States, the Lawrence Scientific School first conferred the degree in 1851, followed by the University of Michigan in 1855. Nathaniel Shaler, who was Harvard's Dean of Sciences, wrote in a private letter that "the degree of Bachelor of Science came to be introduced into our system through the influence of Louis Agassiz, who had much to do in shaping the plans of this School." Whether Bachelor of Science or Bachelor of Arts degrees are awarded in particular subjects varies between universities. For example, an economics student may graduate as a Bachelor of Arts in one university but as a Bachelor of Science in another, and occasionally, both options are offered. Some universities follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural History
Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is called a naturalist or natural historian. Natural history encompasses scientific research but is not limited to it. It involves the systematic study of any category of natural objects or organisms, so while it dates from studies in the ancient Greco-Roman world and the mediaeval Arabic world, through to European Renaissance naturalists working in near isolation, today's natural history is a cross-discipline umbrella of many specialty sciences; e.g., geobiology has a strong multidisciplinary nature. Definitions Before 1900 The meaning of the English term "natural history" (a calque of the Latin ''historia naturalis'') has narrowed progressively with time, while, by contrast, the meaning of the related term "nature" has widened (see also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Science
Natural science or empirical science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and reproducibility of findings are used to try to ensure the validity of scientific advances. Natural science can be divided into two main branches: list of life sciences, life science and Outline of physical science, physical science. Life science is alternatively known as biology. Physical science is subdivided into branches: physics, astronomy, Earth science and chemistry. These branches of natural science may be further divided into more specialized branches (also known as fields). As empirical sciences, natural sciences use tools from the formal sciences, such as mathematics and logic, converting information about nature into measurements that can be explained as clear statements of the "laws of science, laws of nature". Mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Teodor Cleve 1863
Per or PER may refer to: Places * Peru (IOC country code) * Pér, a village in Hungary * Perthshire (Chapman code), historic county in Scotland Science and technology * Physics education research * Packed Encoding Rules, in computing, an ASN.1 wire format * Per (storm), a January 2007 storm in Sweden Mathematics * Rate (mathematics), ratio between quantities in different units * Price–earnings ratio, in finance, a measure of growth in earnings * Player efficiency rating, a measure of basketball player performance * Partial equivalence relation, class of relations that are symmetric and transitive Science * Perseus (constellation) (standard astronomical abbreviation) * Period (gene) or ''per'', that regulates the biological clock and its corresponding protein PER * Protein efficiency ratio, of food * PER or peregrinibacteria, a candidate bacterial phylum Media and entertainment * PeR (band), a Latvian pop band * ''Per'' (film), a 1975 Danish film Transport * Perth Airport ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatom
A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's Biomass (ecology), biomass. They generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion tonnes of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The Protist shell, shells of dead diatoms are a significant component of marine sediment, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes. Diatoms are unicellular organisms: they occur either as solitary cells or in Colony (biology), colonies, which can take the shape of ribb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Till
image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is diagnostic of till. image:Glacial till exposed in roadcut-750px.jpg, Glacial till with tufts of grass Till or glacial till is unsorted glacier, glacial sediment. Till is derived from the erosion and entrainment of material by the moving ice of a glacier. It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines. Till is classified into primary deposits, laid down directly by glaciers, and secondary deposits, reworked by fluvial transport and other processes. Description Till is a form of '' glacial drift'', which is rock material transported by a glacier and deposited directly from the ice or from running water emerging from the ice. It is distinguished from other forms of drift in that it is de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aminonaphthalenesulfonic Acids
Aminonaphthalenesulfonic acids are compounds with the composition C10H6(NH2)(SO3H), being derived from naphthalene (C10H8) substituted by an amino and sulfonic acid groups. These compounds are colorless solids. They are useful precursors to dyes.Gerald Booth "Naphthalene Derivatives" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. . Notes: Peri-acid dehydrates to the sultam. Via the Bucherer reaction, heating periacid with anilinium salts gives the N-phenyl derivative, precursor to Acid Blue 113. {, class="wikitable" style="margin-left: auto; margin-right: auto; border: none;" , + 2-Aminonaphthalenesulfonic acids , - ! scope="col" , Isomer ! scope="col" , CAS Registry Number ! scope="col" , Alternative names ! scope="col" , Preparative route and notes , - , 2-Aminonaphthalene-1-sulfonic acid, , 81-16-3, , Tobias acid, , Bucherer reaction The Bucherer reaction in organic chemistry is the reversible conversion of a naphthol to a naphthyla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
