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Mikhail Aleksandrovich Bonch-Bruevich
Mikhail Aleksandrovich Bonch-Bruevich ( rus, Михаил Александрович Бонч-Бруевич, p=mʲɪxɐˈil ɐlʲɪkˈsandrəvʲɪdʑ ˈbondʑ brʊˈjevʲɪtɕ , a=Ru-Mikhail_Aleksandrovich_Bonch-Bruevich.ogg; 22 February 1888 – 7 March 1940), sometimes spelled Bonch-Bruyevich, was an engineer, scientist, and professor. Generally considered the leading authority on radio in Russian Empire and Soviet Union in the first decades of the 20th century, he greatly influenced the pre-radar development of radio-location in that nation. Career and accomplishments M. A. Bonch-Bruevich was born in Oryol, a town in Oryol Oblast in Central Russia. The family, which was of royal Polish origin, the original surname being Boncz-Brujewicz, moved to Kiev in 1896. Bonch-Bruevich attended the Nikolaevsky Engineering School in St. Petersburg, completing undergraduate studies in 1909. He then entered the Imperial Russian Army and did graduate study and performed research at the Imper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Soviet Union 1988 CPA 5921 Stamp (Birth Centenary Of Mikhail Aleksandrovich Bonch-Bruevich, Radio-frequency Engineer)
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun ''thee'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionosphere
The ionosphere () is the ionized part of the upper atmosphere of Earth, from about to above sea level, a region that includes the thermosphere and parts of the mesosphere and exosphere. The ionosphere is ionized by solar radiation. It plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on Earth. Travel through this layer also impacts GPS signals, resulting in effects such as deflection in their path and delay in the arrival of the signal. History of discovery As early as 1839, the German mathematician and physicist Carl Friedrich Gauss postulated that an electrically conducting region of the atmosphere could account for observed variations of Earth's magnetic field. Sixty years later, Guglielmo Marconi received the first trans-Atlantic radio signal on December 12, 1901, in St. John's, Newfoundland (now in Canada) usin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Footnotes
In publishing, a note is a brief text in which the author comments on the subject and themes of the book and names supporting citations. In the editorial production of books and documents, typographically, a note is usually several lines of text at the bottom of the page, at the end of a chapter, at the end of a volume, or a house-style typographic usage throughout the text. Notes are usually identified with superscript numbers or a symbol.''The Oxford Companion to the English Language'' (1992) p. 709. Footnotes are informational notes located at the foot of the thematically relevant page, whilst endnotes are informational notes published at the end of a chapter, the end of a volume, or the conclusion of a multi-volume book. Unlike footnotes, which require manipulating the page design (text-block and page layouts) to accommodate the additional text, endnotes are advantageous to editorial production because the textual inclusion does not alter the design of the publication. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflex Klystron
Sutton tube was the name given to the first reflex klystron, developed in 1940 by Robert W. Sutton of Signal School group at the Bristol University. The Sutton tube was developed as a local oscillator for the receiver of 10cm microwave radar sets. Due to its geometry and long drift space, it suffered from mode jumping through the tuning range. For this reason, from late 1941 onward, it was replaced in many sets by the Western Electric 707A (also known as McNally tube, named by its developer). The reflex klystron is a type of vacuum tube used to generate microwaves. It is a low-power device used primarily for two purposes: one is to provide a tuneable low-power frequency source for the local oscillators in receiver circuits, and the other, with minor modifications, as a switch that could turn on and off another microwave source. The second use, sometimes known as a soft Sutton tube or rhumbatron switch, was a key component in the development of microwave radar by Britain during Wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Klystron
A klystron is a specialized linear-beam vacuum tube, invented in 1937 by American electrical engineers Russell and Sigurd Varian,Pond, Norman H. "The Tube Guys". Russ Cochran, 2008 p.31-40 which is used as an amplifier for high radio frequencies, from ultra high frequency, UHF up into the microwave range. Low-power klystrons are used as oscillators in terrestrial microwave relay communications links, while high-power klystrons are used as output tubes in UHF television transmitters, satellite communication, radar transmitters, and to generate the drive power for modern particle accelerators. In a klystron, an electron beam interacts with radio waves as it passes through cavity resonator, resonant cavities, metal boxes along the length of a tube. The electron beam first passes through a cavity to which the input signal is applied. The energy of the electron beam amplifies the signal, and the amplified signal is taken from a cavity at the other end of the tube. The output signal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triangulation
In trigonometry and geometry, triangulation is the process of determining the location of a point by forming triangles to the point from known points. Applications In surveying Specifically in surveying, triangulation involves only angle measurements at known points, rather than measuring distances to the point directly as in trilateration; the use of both angles and distance measurements is referred to as triangulateration. In computer vision Computer stereo vision and optical 3D measuring systems use this principle to determine the spatial dimensions and the geometry of an item. Basically, the configuration consists of two sensors observing the item. One of the sensors is typically a digital camera device, and the other one can also be a camera or a light projector. The projection centers of the sensors and the considered point on the object's surface define a (spatial) triangle. Within this triangle, the distance between the sensors is the base ''b'' and must be kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Stalin
Joseph Vissarionovich Stalin (born Dzhugashvili; 5 March 1953) was a Soviet politician and revolutionary who led the Soviet Union from 1924 until Death and state funeral of Joseph Stalin, his death in 1953. He held power as General Secretary of the Communist Party of the Soviet Union, General Secretary of the Communist Party from 1922 to 1952 and as the fourth Premier of the Soviet Union, premier from 1941 until his death. He initially governed as part of a Collective leadership in the Soviet Union, collective leadership, but Joseph Stalin's rise to power, consolidated power to become an absolute dictator by the 1930s. Stalin codified the party's official interpretation of Marxism as Marxism–Leninism, while the totalitarian political system he created is known as Stalinism. Born into a poor Georgian family in Gori, Georgia, Gori, Russian Empire, Stalin attended the Tiflis Theological Seminary before joining the Marxist Russian Social Democratic Labour Party. He raised f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Purge
The Great Purge, or the Great Terror (), also known as the Year of '37 () and the Yezhovshchina ( , ), was a political purge in the Soviet Union that took place from 1936 to 1938. After the Assassination of Sergei Kirov, assassination of Sergei Kirov by Leonid Nikolaev in 1934, Joseph Stalin launched a series of show trials known as the Moscow trials to remove suspected party dissenters from the Communist Party of the Soviet Union, especially those aligned with the Bolsheviks, Bolshevik party. The term "great purge" was popularized by the historian Robert Conquest in his 1968 book ''The Great Terror (book), The Great Terror'', whose title was an allusion to the French Revolution's Reign of Terror. The purges were largely conducted by the NKVD (People's Commissariat for Internal Affairs), which functioned as the Ministry of home affairs, interior ministry and secret police of the USSR. Starting in 1936, the NKVD under chief Genrikh Yagoda began the removal of the central pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ukraine
Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the north; Poland and Slovakia to the west; Hungary, Romania and Moldova to the southwest; and the Black Sea and the Sea of Azov to the south and southeast. Kyiv is the nation's capital and List of cities in Ukraine, largest city, followed by Kharkiv, Odesa, and Dnipro. Ukraine's official language is Ukrainian language, Ukrainian. Humans have inhabited Ukraine since 32,000 BC. During the Middle Ages, it was the site of early Slavs, early Slavic expansion and later became a key centre of East Slavs, East Slavic culture under the state of Kievan Rus', which emerged in the 9th century. Kievan Rus' became the largest and most powerful realm in Europe in the 10th and 11th centuries, but gradually disintegrated into rival regional powers before being d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kharkov
Kharkiv, also known as Kharkov, is the second-largest List of cities in Ukraine, city in Ukraine.Kharkiv "never had eastern-western conflicts" , ''Euronews'' (23 October 2014) Located in the northeast of the country, it is the largest city of the historic region of Sloboda Ukraine. Kharkiv is the administrative centre of Kharkiv Oblast and Kharkiv Raion. Prior to the Russian invasion of Ukraine in early 2022, it had an estimated population of 1,421,125. Founded in 1654 as a Cossacks, Cossack fortress, by late 19th century Kharkiv had developed within the Russian Empire as a major commercial and industrial centre. From December 1919 to January 1934, Kharkiv was the capital of the Ukrainian Soviet Socialist Rep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavity Magnetron
The cavity magnetron is a high-power vacuum tube used in early radar systems and subsequently in microwave ovens and in linear particle accelerators. A cavity magnetron generates microwaves using the interaction of a stream of electrons with a magnetic field, while moving past a series of cavity resonators, which are small, open cavities in a metal block. Electrons pass by the cavities and cause microwaves to oscillate within, similar to the functioning of a whistle producing a tone when excited by an air stream blown past its opening. The resonant frequency of the arrangement is determined by the cavities' physical dimensions. Unlike other vacuum tubes, such as a klystron or a traveling-wave tube (TWT), the magnetron cannot function as an amplifier for increasing the intensity of an applied microwave signal; the magnetron serves solely as an electronic oscillator generating a microwave signal from direct-current electricity supplied to the vacuum tube. The use of magne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russian Academy Of Sciences
The Russian Academy of Sciences (RAS; ''Rossíyskaya akadémiya naúk'') consists of the national academy of Russia; a network of scientific research institutes from across the Russian Federation; and additional scientific and social units such as libraries, publishing units, and hospitals. Peter the Great established the academy (then the St. Petersburg Academy of Sciences) in 1724 with guidance from Gottfried Wilhelm Leibniz, Gottfried Leibniz. From its establishment, the academy benefitted from a slate of foreign scholars as professors; the academy then gained its first clear set of goals from the 1747 Charter. The academy functioned as a university and research center throughout the mid-18th century until the university was dissolved, leaving research as the main pillar of the institution. The rest of the 18th century continuing on through the 19th century consisted of many published academic works from Academy scholars and a few Academy name changes, ending as The Imperial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
