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Vojtěch Šafařík
Vojtěch Šafařík (26 October 1829 in Újvidék, Bács-Bodrog County, Vojvodina, Kingdom of Hungary (1526–1867), Hungary (today Serbia) – 2 July 1902 in Prague, Bohemia) was a Czech chemist, specialising in inorganic chemistry. Šafařík was the son of Pavel Jozef Šafárik, a Slovaks, Slovak Philology, philologist and historian. The crater Šafařík (crater), Šafařík on the Moon is named after him, and so is the minor planet 8336 Šafařík (in conjunction with his wife). Work In Göttingen, he was involved in the investigation of the reaction of metals with Organoiodine compound, alkyl iodides and produced diethylmagnesium. He also worked on the chemical composition of platinum and vanadium catalysts, and on Organometallic chemistry, organometallic compounds (Grignard reaction, Grignard compounds). At the Imperial Academy of Sciences in Vienna, Vienna Academy he published a work on physical chemistry. He also studied mineralogy. In 1859, together with fellow chemist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organoiodine Compound
Organoiodine compounds are organic compounds that contain one or more carbon–iodine bonds. They occur widely in organic chemistry, but are relatively rare in nature. The thyroxine hormones are organoiodine compounds that are required for health and the reason for government-mandated iodization of salt. Structure, bonding, general properties Almost all organoiodine compounds feature iodide connected to one carbon center. These are usually classified as derivatives of I−. Some organoiodine compounds feature iodine in higher oxidation states. The C–I bond is the weakest of the carbon–halogen bonds. These bond strengths correlate with the electronegativity of the halogen, decreasing in the order F > Cl > Br > I. This periodic order also follows the atomic radius of halogens and the length of the carbon-halogen bond. For example, in the molecules represented by CH3X, where X is a halide, the carbon-X bonds have strengths, or bond dissociation energies, of 115 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adalbert Of Prague
Adalbert of Prague ( la, Sanctus Adalbertus, cs, svatý Vojtěch, sk, svätý Vojtech, pl, święty Wojciech, hu, Szent Adalbert (Béla); 95623 April 997), known in the Czech Republic, Poland and Slovakia by his birth name Vojtěch ( la, Voitecus), was a White Croatian missionary and Christian saint. He was the Bishop of Prague and a missionary to the Hungarians, Poles, and Prussians, who was martyred in his efforts to convert the Baltic Prussians to Christianity. He is said to be the composer of the oldest Czech hymn ''Hospodine, pomiluj ny'' and '' Bogurodzica'', the oldest known Polish hymn, but his authorship of them has not been confirmed. Adalbert was later declared the patron saint of the Czech Republic, Poland, and the Duchy of Prussia. He is also the patron saint of the Archdiocese of Esztergom in Hungary. Life Early years Born as ''Vojtěch'' in 952 or ca. 956 in gord Libice, he belonged to the Slavnik clan, one of the two most powerful families in Bohemia. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variable Star
A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are classified as either: * Intrinsic variables, whose luminosity actually changes; for example, because the star periodically swells and shrinks. * Extrinsic variables, whose apparent changes in brightness are due to changes in the amount of their light that can reach Earth; for example, because the star has an orbiting companion that sometimes eclipses it. Many, possibly most, stars have at least some variation in luminosity: the energy output of the Sun, for example, varies by about 0.1% over an 11-year solar cycle. Discovery An ancient Egyptian calendar of lucky and unlucky days composed some 3,200 years ago may be the oldest preserved historical document of the discovery of a variable star, the eclipsing binary Algol. Of the modern astronomers, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles University
) , image_name = Carolinum_Logo.svg , image_size = 200px , established = , type = Public, Ancient , budget = 8.9 billion CZK , rector = Milena Králíčková , faculty = 4,057 , administrative_staff = 4,026 , students = 51,438 , undergrad = 32,520 , postgrad = 9,288 , doctoral = 7,428 , city = Prague , country = Czech Republic , campus = Urban , colors = , affiliations = Coimbra Group EUA Europaeum , website = Charles University ( cs, Univerzita Karlova, UK; la, Universitas Carolina; german: Karls-Universität), also known as Charles University in Prague or historically as the University of Prague ( la, Universitas Pragensis, links=no), is the oldest and largest university in the Czech Republic. It is one of the oldest universities in Europe in continuous operation. Today, the university consists of 17 faculties located in Prague, Hradec Králové, and Plzeň. Charles University belongs among the top three universities in Central and Eastern Europe. It is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josef Jungmann
Josef Jungmann (16 July 1773 in Hudlice, near Beroun – 14 November 1847 in Prague) was a Czech poet and linguist, and a leading figure of the Czech National Revival. Together with Josef Dobrovský, he is considered to be a creator of the modern Czech language. Life Jungmann was the sixth child (out of ten) of a cobbler. His father was of Bohemian German descent and his mother was of Czech descent. The children grew up speaking both languages at home, which contributed heavily to Jungmann's later role as a revivalist of the Czech language. In his youth, he wanted to become a priest. After he completed grammar school in 1788-1792 however, he went on to study Philosophy and Law. Beginning in 1799, he started teaching at the local high school ("Gymnasium") in Litoměřice (''Leitmeritz''), which had a German majority at that time. In 1815, he moved to Prague, where he worked until 1845 in the Old Town Academic Grammar School as a Czech professor. He earned a doctorate in Philoso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Svatopluk Presl
Jan Svatopluk Presl (4 September 1791 – 6 April 1849) was a Czech natural scientist. He was the brother of botanist Carl Borivoj Presl (1794–1852). The Czech Botanical Society commemorated the two brothers by naming its principal publication ''Preslia'' (founded in 1914). He is the author of Czech scientific terminology of various branches of science, including the Czech chemical nomenclature Foundations of the Czech chemical nomenclature (official term in Czech: ''české chemické názvosloví'') and terminology were laid during the 1820s and 1830s. These early naming conventions fit the Czech language and, being mostly work of a singl .... He was the co-author of an important Czech taxonomic work, '' O Přirozenosti Rostlin''. Selected publications * * See also * Carl Borivoj Presl (C.Presl, 1794–1852) — Czech botanist, and younger brother of Jan Presl. * :Taxa named by Jan Svatopluk Presl References External links * Quido.cz: "Biography of Jan Svatoplu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prussian Blue
Prussian blue (also known as Berlin blue, Brandenburg blue or, in painting, Parisian or Paris blue) is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula Fe CN)">Cyanide.html" ;"title="e(Cyanide">CN) Turnbull's blue is chemically identical, but is made from different reagents, and its slightly different color stems from different impurities and particle sizes. Prussian blue was the first modern synthetic pigment. It is prepared as a very fine colloidal dispersion, because the compound is not soluble in water. It contains variable amounts of other ions and its appearance depends sensitively on the size of the colloidal particles. The pigment is used in paints, and it is the traditional "blue" in blueprints, and became prominent in 19th-century () Japanese woodblock prints. In medicine, orally administered Prussian blue is used as an antidote for certain kinds of heavy metal poisoning, e.g., by thallium(I) and radioactive is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manuscripts Of Dvůr Králové And Of Zelená Hora
A manuscript (abbreviated MS for singular and MSS for plural) was, traditionally, any document written by hand – or, once practical typewriters became available, typewritten – as opposed to mechanically printed or reproduced in some indirect or automated way. More recently, the term has come to be understood to further include ''any'' written, typed, or word-processed copy of an author's work, as distinguished from the rendition as a printed version of the same. Before the arrival of printing, all documents and books were manuscripts. Manuscripts are not defined by their contents, which may combine writing with mathematical calculations, maps, music notation, explanatory figures, or illustrations. Terminology The study of the writing in surviving manuscripts, the "hand", is termed palaeography (or paleography). The traditional abbreviations are MS for manuscript and MSS for manuscripts, while the forms MS., ms or ms. for singular, and MSS., mss or mss. for plu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antonín Bělohoubek
Antonin, Antonín, and Antoñín are masculine given names. Antonín, a Czech name in use in the Czech Republic, and Antonin, a French name in use in France, and French-speaking countries, are both considered alternate forms of Antonino. Antoñín, a Spanish name in use in Spain and Spanish-speaking countries, is a diminutive form of Antonio. As a surname it is derived from the Antonius root name. Notable people with these names include: Given name: Antonin * Antonin Artaud (1896–1948), French theatre director, writer, actor, and artist * Antonin Bajewski (1915–1941), Polish Franciscan friar * Antonin Baudry (born 1975), French diplomat * Antonin Berruyer (born 1998), French rugby union player *Antonin Berval (1891–1966), French film actor * Antonin Besse (1877–1951), French businessman * Antonin Bobichon (born 1995), French footballer * Antonin Brémond (died 1755), French Master of the Order of Preachers *Antonin Carlès (1851–1919), French sculptor *Antonin Cloche ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grignard Reaction
The Grignard reaction () is an organometallic chemical reaction in which alkyl, allyl, vinyl, or aryl-magnesium halides ( Grignard reagent) is added to a carbonyl group in an aldehyde or ketone. This reaction is important for the formation of carbon–carbon bonds. The reaction of an organic halide with magnesium is ''not'' a Grignard reaction, but provides a Grignard reagent. : Grignard reactions and reagents were discovered by and are named after the French chemist François Auguste Victor Grignard (University of Nancy, France), who published it in 1900 and was awarded the 1912 Nobel Prize in Chemistry for this work. Reaction mechanism Because carbon is more electronegative than magnesium, the carbon attached to magnesium functions as a nucleophile and attacks the electrophilic carbon atom that is present within the polar bond of a carbonyl group. The addition of the Grignard reagent to the carbonyl typically proceeds through a six-membered ring transition state. Based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
