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1848 In Science
The year 1848 in science and technology involved some significant events, listed below. Events * September 20 – The American Association for the Advancement of Science is set up in Pennsylvania by re-formation of the Association of American Geologists and Naturalists, with William Charles Redfield as its first president. Astronomy * September 16 – William Cranch Bond and William Lassell discover Hyperion, Saturn's moon. * Lord Rosse studies M1 and names it the Crab Nebula. * Édouard Roche calculates the Roche limit. * Rudolf Wolf (in Zurich) devises a way of quantifying sunspot activity, the Wolf number. Botany * April 16 – Joseph Dalton Hooker arrives at Darjeeling to begin the first European plant collecting expedition in the Himalayas. Chemistry * Edward Frankland, working in Germany, discovers the organometallic compound diethylzinc. Exploration * Admiral Nevelskoi demonstrates that the Strait of Tartary is a strait. Medicine * September 13 – Vermo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science
Science is a systematic endeavor that Scientific method, builds and organizes knowledge in the form of Testability, testable explanations and predictions about the universe. Science may be as old as the human species, and some of the earliest archeological evidence for scientific reasoning is tens of thousands of years old. The earliest written records in the history of science come from Ancient Egypt and Mesopotamia in around 3000 to 1200 Common Era, BCE. Their contributions to mathematics, astronomy, and medicine entered and shaped Greek natural philosophy of classical antiquity, whereby formal attempts were made to provide explanations of events in the Universe, physical world based on natural causes. After the fall of the Western Roman Empire, knowledge of History of science in classical antiquity, Greek conceptions of the world deteriorated in Western Europe during the early centuries (400 to 1000 CE) of the Middle Ages, but was preserved in the Muslim world during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Admiral
Admiral is one of the highest ranks in some navies. In the Commonwealth nations and the United States, a "full" admiral is equivalent to a "full" general in the army or the air force, and is above vice admiral and below admiral of the fleet, or fleet admiral. Etymology The word in Middle English comes from Anglo-French , "commander", from Medieval Latin , . These evolved from the Arabic () – (), “king, prince, chief, leader, nobleman, lord, a governor, commander, or person who rules over a number of people,” and (), the Arabic article answering to “the.” In Arabic, admiral is also represented as (), where () means the sea. The 1818 edition of Samuel Johnson's ''A Dictionary of the English Language'', edited and revised by the Rev. Henry John Todd, states that the term “has been traced to the Arab. emir or amir, lord or commander, and the Gr. , the sea, q. d. ''prince of the sea''. The word is written both with and without the d, in other languages, as w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diethylzinc
Diethylzinc (C2H5)2Zn, or DEZ, is a highly pyrophoric and reactive organozinc compound consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is available commercially as a solution in hexanes, heptane, or toluene, or as a pure liquid. Synthesis Edward Frankland first reported the compound in 1848 from zinc and ethyl iodide, the first organozinc compound discovered. He improved the synthesis by using diethyl mercury as starting material. The contemporary synthesis consists of the reaction of a 1:1 mixture of ethyl iodide and ethyl bromide with a zinc-copper couple, a source of reactive zinc. Structure The compound crystallizes in a tetragonal body-centered unit cell of space group symmetry I41md. In the solid-state diethylzinc shows nearly linear Zn centres. The Zn-C bonds measure 194.8(5) pm, while the C-Zn-C angle is slightly bent with 176.2(4)°. The structure of the gas-phase shows a very similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organometallic Chemistry
Organometallic chemistry is the study of organometallic compounds, chemical compounds containing at least one chemical bond between a carbon atom of an organic molecule and a metal, including alkali, alkaline earth, and transition metals, and sometimes broadened to include metalloids like boron, silicon, and selenium, as well. Aside from bonds to organyl fragments or molecules, bonds to 'inorganic' carbon, like carbon monoxide (metal carbonyls), cyanide, or carbide, are generally considered to be organometallic as well. Some related compounds such as transition metal hydrides and metal phosphine complexes are often included in discussions of organometallic compounds, though strictly speaking, they are not necessarily organometallic. The related but distinct term " metalorganic compound" refers to metal-containing compounds lacking direct metal-carbon bonds but which contain organic ligands. Metal β-diketonates, alkoxides, dialkylamides, and metal phosphine complexes are r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Frankland
Sir Edward Frankland, (18 January 18259 August 1899) was an English chemist. He was one of the originators of organometallic chemistry and introduced the concept of combining power or valence. An expert in water quality and analysis, he was a member of the second royal commission on the pollution of rivers, and studied London's water quality for decades. He also studied luminous flames and the effects of atmospheric pressure on dense ignited gas, and was one of the discoverers of helium. Biography Edward Frankland was born in Catterall, Lancashire and baptised at Churchtown, Lancashire on 20 February 1825. As his baptismal record shows, his birth was illegitimate. His mother, Margaret "Peggy" Frankland, later married William Helm, a Lancaster cabinet-maker. "His illegitimacy cast a shadow over all his life since he was pledged to silence as to the identity of his natural father, though a handsome annuity was paid to his mother". From age 3 to 8 Edward lived and was ed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Himalayas
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 peaks exceeding in elevation lie in the Himalayas. By contrast, the highest peak outside Asia (Aconcagua, in the Andes) is tall. The Himalayas abut or cross five countries: Bhutan, India, Nepal, China, and Pakistan. The sovereignty of the range in the Kashmir region is disputed among India, Pakistan, and China. The Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges, on the north by the Tibetan Plateau, and on the south by the Indo-Gangetic Plain. Some of the world's major rivers, the Indus, the Ganges, and the Tsangpo– Brahmaputra, rise in the vicinity of the Himalayas, and their combined drainage basin is home to some 600 million people; 53 million people live in the Himalayas. The Himalayas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Collecting
Plant collecting is the acquisition of plant specimens for the purposes of research, cultivation, or as a hobby. Plant specimens may be kept alive, but are more commonly dried and pressed to preserve the quality of the specimen. Plant collecting is an ancient practice with records of a Chinese botanist collecting roses over 5000 years ago. Herbaria are collections of preserved plants samples and their associated data for scientific purposes. The largest herbarium in the world exist at the Muséum National d'Histoire Naturelle, in Paris, France. Plant samples in herbaria typically include a reference sheet with information about the plant and details of collection. This detailed and organized system of filing provides horticulturist and other researchers alike with a way to find information about a certain plant, and a way to add new information to an existing plant sample file. The collection of live plant specimens from the wild, sometimes referred to as plant hunting, is an ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. Comprising the westernmost peninsulas of Eurasia, it shares the continental landmass of Afro-Eurasia with both Africa and Asia. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south and Asia to the east. Europe is commonly considered to be separated from Asia by the watershed of the Ural Mountains, the Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea and the waterways of the Turkish Straits. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and Europe ... is formed by the Ural Mountains, Ural River, Caspian Sea, Caucasus Mountains, and the Black Sea wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Darjeeling
Darjeeling (, , ) is a town and municipality in the northernmost region of the Indian state of West Bengal. Located in the Eastern Himalayas, it has an average elevation of . To the west of Darjeeling lies the easternmost province of Nepal, to the east the Kingdom of Bhutan, to the north the Indian state of Sikkim, and farther north the Tibet Autonomous Region region of China. Bangladesh lies to the south and southeast, and most of the state of West Bengal lies to the south and southwest, connected to the Darjeeling region by a narrow tract. Kangchenjunga, the world's third-highest mountain, rises to the north and is prominently visible on clear days. In the early 19th century, during East India Company rule in India, Darjeeling was identified as a potential summer retreat for British officials, soldiers and their families. The narrow mountain ridge was leased from the Kingdom of Sikkim, and eventually annexed to British India. Experimentation with growing tea on the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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