До того, как процесс избранного портала прекратился в 2017 году, он был обозначен как избранный портал.
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Научный портал

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Научные знания, используемые в практических приложениях

Наука (от латинского слова scientia , что означает «знание») - это систематическое предприятие, которое создает и систематизирует знания в форме проверяемых объяснений и предсказаний о Вселенной .

Самые ранние корни науки можно проследить в Древнем Египте и Месопотамии примерно в 3500–3000 годах до нашей эры. Их вклад в математику , астрономию и медицины вошли и в форме греческой натурфилософии в классической древности , в результате чего было сделаны формальные попытки дать объяснение событий в физическом мире на основе естественных причин. После падения Западной Римской империи в первые века (400–1000 гг. Н.э.) средневековья в Западной Европе ухудшились знания о представлениях греков о мире., но сохранился в мусульманском мире во время Золотого века ислама . Восстановление и ассимиляция греческих работ и исламских исследований в Западной Европе с 10 по 13 век возродили « натуральную философию », которая позже была преобразована научной революцией , начавшейся в 16 веке, когда новые идеи и открытия отклонились от предыдущих греческих концепций и традиции. Научный метод вскоре сыграл большую роль в создании знаний и он не был до 19 - го века , что многие институциональные и профессиональныеначали складываться особенности науки; наряду с заменой «натурфилософии» на «естествознание».

Современная наука обычно делится на три основные отрасли, которые состоят из естественных наук (например, биологии , химии и физики ), изучающих природу в самом широком смысле; в социальных науках (например, экономика , психология и социология ), что изучение отдельных лиц и общества; и формальные науки (например, логика , математика и теоретическая информатика), которые изучают абстрактные понятия. Однако существуют разногласия относительно того, действительно ли формальные науки представляют собой науку, поскольку они не полагаются на эмпирические данные . Дисциплины, использующие существующие научные знания для практических целей, такие как инженерия и медицина, называются прикладными науками .

Наука основана на исследованиях , которые обычно проводятся учеными, работающими в академических и исследовательских учреждениях , государственных учреждениях и компаниях . Практическое влияние научных исследований привело к появлению научных политик, которые стремятся повлиять на научное предприятие, отдавая приоритет развитию коммерческой продукции , вооружений , здравоохранения , общественной инфраструктуры и защиты окружающей среды . ( Полная статья ... )

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  • Hygrophoropsis aurantiaca , широко известный какложная лисичка, является разновидностьюгрибовсемействаHygrophoropsidaceae.
    Он встречается на нескольких континентах, растет в лесах ивересках, а иногда и нащепе,используемой в садоводстве и озеленении.Плодовые тела(грибы) желто-оранжевый цвет, с воронкообразнойкрышкойдо 8 см (3 1 / 8   в) через который имеет войлок глади. Тонкие, часто раздвоенныежабрына нижней стороне шляпки частично проходят по длине гладкойножки.. Сообщения о съедобности гриба разнятся - он может служить пищей, хотя и не особенно ароматным, или может быть немного ядовитым .

    Австрийский естествоиспытатель Франц Ксавер фон Вульфен описал фальшивую лисичку в 1781 году, отметив как ее сходство с настоящими лисичками, так и склонность людей путать их. Затем ложные лисички были отнесены к роду Clitocybe , но позже было обнаружено, что их раздвоенные жабры и споры декстриноидов указывают на родство с Paxillus . Генетический анализ подтвердил, что он относится к отряду Boletales и более тесно связан с подберезовиками.. ( Полная статья ... )
  • Lightning Bar (1951–1960) was an American Quarter Horse who raced and subsequently became a breeding stallion. He was bred by his lifelong owner Art Pollard of Sonoita, Arizona, and was the offspring of Three Bars, a Thoroughbred, and Della P, a Quarter Horse mare from Louisiana, then noted for the breeding of sprint horses. Lightning Bar raced ten times, achieving four victories and four other top three finishes. His racing career was cut short by illness after only one year, following which he spent two years as a show horse. As a breeding stallion he sired seven crops, or years, of foals, among whom Doc Bar was the best known. In 1960 Lightning Bar died of an intestinal infection at the age of nine. He was inducted into the American Quarter Horse Association's (AQHA) Hall of Fame in 2008. (Full article...)
  • Taare Zameen Par (titled Like Stars on Earth internationally) is a 2007 Indian Hindi-language drama film produced and directed by Aamir Khan. The film explores the life and imagination of Ishaan, an 8-year-old dyslexic child. Although he excels in art, his poor academic performance leads his parents to send him to a boarding school. Ishaan's new art teacher suspects that he is dyslexic and helps him to overcome his disability. Darsheel Safary stars as 8-year-old Ishaan, and Aamir Khan plays his art teacher.

    Creative director and writer Amole Gupte initially developed the idea with his wife Deepa Bhatia, who served as the film's editor. Shankar–Ehsaan–Loy composed the film's score, and Prasoon Joshi wrote the lyrics for many of the songs. Principal photography took place in Mumbai and in Panchgani's New Era High School, and some of the school's students make appearances. (Full article...)
  • Sites where Plesiorycteropus has been found. Blue: P. madagascariensis and P. germainepetterae; green: P. madagascariensis; red: Plesiorycteropus, species uncertain.

    Plesiorycteropus, also known as the bibymalagasy or Malagasy aardvark, is a recently extinct eutherian mammalian genus from Madagascar. Upon its description in 1895, it was classified with the aardvark, but more recent molecular evidence instead suggests that it is most closely related to the tenrecs (a group extant on the island). Two species are currently recognized, the larger P. madagascariensis and the smaller P. germainepetterae. They probably overlapped in distribution, as subfossil remains of both species have been found in the same site.

    Knowledge of the skeletal anatomy is limited, as only limb, partial pelvis, and skull bones have been recovered to date. Plesiorycteropus was probably a digging animal that fed on insects such as termites and ants. It also shows adaptations for climbing and sitting. Estimates of its mass range from 6 to 18 kilograms (13 to 40 lb). When and why it became extinct remains unknown. One bone has been radiocarbon dated to 200 BCE; forest destruction by humans may have contributed to its extinction. (Full article...)
  • Cape petrel (Daption capense)

    The family Procellariidae is a group of seabirds that comprises the fulmarine petrels, the gadfly petrels, the prions, and the shearwaters. This family is part of the bird order Procellariiformes (or tubenoses), which also includes the albatrosses and the storm petrels.

    The procellariids are the most numerous family of tubenoses, and the most diverse. They range in size from the giant petrels, which are almost as large as the albatrosses, to the prions, which are as small as the larger storm petrels. They feed on fish, squid and crustacea, with many also taking fisheries discards and carrion. All species are accomplished long-distance foragers, and many undertake long trans-equatorial migrations. They are colonial breeders, exhibiting long-term mate fidelity and site philopatry. In all species, each pair lays a single egg per breeding season. Their incubation times and chick-rearing periods are exceptionally long compared to other birds. (Full article...)
  • Banksia ericifolia, cultivated at Colac, Victoria

    Banksia ericifolia, the heath-leaved banksia, or lantern banksia, is a species of woody shrub of the family Proteaceae native to Australia. It grows in two separate regions of Central and Northern New South Wales east of the Great Dividing Range. Well known for its orange or red autumn inflorescences, which contrast with its green fine-leaved heath-like foliage, it is a medium to large shrub that can reach 6 m (20 ft) high and wide, though is usually half that size. In exposed heathlands and coastal areas it is more often 1–2 m (3.3–6.6 ft).

    Banksia ericifolia was one of the original Banksia species collected by Joseph Banks around Botany Bay in 1770 and was named by Carl Linnaeus the Younger, son of Carl Linnaeus, in 1782. A distinctive plant, it has split into two subspecies: Banksia ericifolia subspecies ericifolia of the Sydney region and Banksia ericifolia subspecies macrantha of the New South Wales Far North Coast which was recognized in 1996. (Full article...)

  • Hurricane Lenny was the fourth strongest November Atlantic hurricane on record, behind the 1932 Cuba hurricane and 2020's Hurricanes Iota and Eta. It was the twelfth tropical storm, eighth hurricane, and record-breaking fifth Category 4 hurricane in the 1999 Atlantic hurricane season. Lenny formed on November 13 in the western Caribbean Sea and maintained an unprecedented west-to-east track for its entire duration, which gave it the common nickname, "Wrong Way Lenny". It attained hurricane status south of Jamaica on November 15 and passed south of Hispaniola and Puerto Rico over the next few days. Lenny rapidly intensified over the northeastern Caribbean on November 17, attaining peak winds of 155 mph (249 km/h) about 21 mi (34 km) south of Saint Croix in the United States Virgin Islands. It gradually weakened while moving through the Leeward Islands, eventually dissipating on November 23 over the open Atlantic Ocean.

    Before moving through the Lesser Antilles, Lenny produced rough surf that killed two people in northern Colombia. Strong winds and rainfall resulted in heavy crop damage in southeastern Puerto Rico. Despite the hurricane's passage near Saint Croix at peak intensity, damage on the small island was only described as "moderate", although there was widespread flooding and erosion. Damage in the United States territories totaled about $330 million. The highest precipitation total was 34.12 in (867 mm) at the police station on the French side of Saint Martin. On the island, the hurricane killed three people and destroyed more than 200 properties. In nearby Antigua and Barbuda, the hurricane killed one person; torrential rainfall there contaminated the local water supply. Significant storm damage occurred as far south as Grenada, where high surf isolated towns from the capital city. (Full article...)

  • Xixiasaurus (/ˌʃiːʃiəˈsɔːrəs/) is a genus of troodontid dinosaur that lived during the Late Cretaceous Period in what is now China. The only known specimen was discovered in Xixia County, Henan Province, in central China, and became the holotype of the new genus and species Xixiasaurus henanensis in 2010. The names refer to the areas of discovery, and can be translated as "Henan Xixia lizard". The specimen consists of an almost complete skull (except for the hindmost portion), part of the lower jaw, and teeth, as well as a partial right forelimb.

    Xixiasaurus is estimated to have been 1.5 metres (5 ft) long and to have weighed 8 kilograms (18 lb). As a troodontid, it would have been bird-like and lightly built, with grasping hands and an enlarged sickle-shaped claw on the second toe. Its skull was long, with a long, low snout that formed a tapering U-shape when seen from below. The frontal bone of the forehead was dome-like in side view, which indicates it had an enlarged braincase. It differed from other troodontids in that the front of the dentary bone of the lower jaw was down-turned. Unlike in most troodontids, the teeth of Xixiasaurus did not have serrations; instead, their carinae (front and back edges) were smooth and sharp. It was distinct among troodontids in having 22 teeth in each maxilla (in other genera the maxillary tooth count was either higher or lower). (Full article...)
  • Meninges of the central nervous system: dura mater, arachnoid mater, and pia mater.

    Meningitis is an acute inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The most common symptoms are fever, headache, and neck stiffness. Other symptoms include confusion or altered consciousness, vomiting, and an inability to tolerate light or loud noises. Young children often exhibit only nonspecific symptoms, such as irritability, drowsiness, or poor feeding. If a rash is present, it may indicate a particular cause of meningitis; for instance, meningitis caused by meningococcal bacteria may be accompanied by a characteristic rash.


    The inflammation may be caused by infection with bacteria, other microorganisms, or viruses, and less commonly by certain drugs. Meningitis can be life-threatening because of the inflammation's proximity to the brain and spinal cord; therefore, the condition is classified as a medical emergency. A lumbar puncture, in which a needle is inserted into the spinal canal to collect a sample of cerebrospinal fluid (CSF), can diagnose or exclude meningitis. (Full article...)
  • Title page from the second volume of Lives of the Most Eminent Literary and Scientific Men of France (1838)


    The Lives of the Most Eminent Literary and Scientific Men comprised ten volumes of Dionysius Lardner's 133-volume Cabinet Cyclopaedia (1829–46). Aimed at the self-educating middle class, this encyclopedia was written during the 19th-century literary revolution in Britain that encouraged more people to read.

    The Lives formed part of the Cabinet of Biography in the Cabinet Cyclopaedia. Within the set of ten, the three-volume Lives of the Most Eminent Literary and Scientific Men of Italy, Spain and Portugal (1835–37) and the two-volume Lives of the Most Eminent Literary and Scientific Men of France (1838–39) consist of biographies of important writers and thinkers of the 14th to 18th centuries. Most of them were written by the Romantic writer Mary Shelley. Shelley's biographies reveal her as a professional woman of letters, contracted to produce several volumes of works and paid well to do so. Her extensive knowledge of history and languages, her ability to tell a gripping biographical narrative, and her interest in the burgeoning field of feminist historiography are reflected in these works. (Full article...)
  • Great kiva of Chetro Ketl

    Chaco Culture National Historical Park is a United States National Historical Park in the American Southwest hosting a concentration of pueblos. The park is located in northwestern New Mexico, between Albuquerque and Farmington, in a remote canyon cut by the Chaco Wash. Containing the most sweeping collection of ancient ruins north of Mexico, the park preserves one of the most important pre-Columbian cultural and historical areas in the United States.

    Between AD 900 and 1150, Chaco Canyon was a major center of culture for the Ancestral Puebloans. Chacoans quarried sandstone blocks and hauled timber from great distances, assembling fifteen major complexes that remained the largest buildings ever built in North America until the 19th century. Evidence of archaeoastronomy at Chaco has been proposed, with the "Sun Dagger" petroglyph at Fajada Butte a popular example. Many Chacoan buildings may have been aligned to capture the solar and lunar cycles, requiring generations of astronomical observations and centuries of skillfully coordinated construction. Climate change is thought to have led to the emigration of Chacoans and the eventual abandonment of the canyon, beginning with a fifty-year drought commencing in 1130. (Full article...)

  • Marasmius rotula is a common species of agaric fungus in the family Marasmiaceae. Widespread in the Northern Hemisphere, it is commonly known variously as the pinwheel mushroom, the pinwheel marasmius, the little wheel, the collared parachute, or the horse hair fungus. The type species of the genus Marasmius, M. rotula was first described scientifically in 1772 by mycologist Giovanni Antonio Scopoli and assigned its current name in 1838 by Elias Fries.

    The fruit bodies, or mushrooms, of M. rotula are characterized by their whitish, thin, and membranous caps up to 2 cm (0.8 in) wide that are sunken in the center, and pleated with scalloped margins. The slender and wiry black hollow stems measure up to 8.0 cm (3.1 in) long by 1.5 mm (0.06 in) thick. On the underside of the caps are widely spaced white gills that are attached to a collar encircling the stem. The mushrooms grow in groups or clusters on decaying wood such as fallen twigs and sticks, moss-covered logs, and stumps. (Full article...)
  • Figure 1. A mechanical filter made by the Kokusai Electric Company intended for selecting the narrow 2 kHz bandwidth signals in SSB radio receivers. It operates at 455 kHz, a common IF for these receivers, and is dimensioned 45×15×15 mm (1 34×​712×​712 in).


    A mechanical filter is a signal processing filter usually used in place of an electronic filter at radio frequencies. Its purpose is the same as that of a normal electronic filter: to pass a range of signal frequencies, but to block others. The filter acts on mechanical vibrations which are the analogue of the electrical signal. At the input and output of the filter, transducers convert the electrical signal into, and then back from, these mechanical vibrations.

    The components of a mechanical filter are all directly analogous to the various elements found in electrical circuits. The mechanical elements obey mathematical functions which are identical to their corresponding electrical elements. This makes it possible to apply electrical network analysis and filter design methods to mechanical filters. Electrical theory has developed a large library of mathematical forms that produce useful filter frequency responses and the mechanical filter designer is able to make direct use of these. It is only necessary to set the mechanical components to appropriate values to produce a filter with an identical response to the electrical counterpart. (Full article...)
  • A male on a Jacaranda

    The black honeyeater (Sugomel niger) is a species of bird in the honeyeater family Meliphagidae and the sole species in the genus Sugomel. The black honeyeater exhibits sexual dimorphism, with the male being black and white while the female is a speckled grey-brown; immature birds look like the female. The species is endemic to Australia, and ranges widely across the arid areas of the continent, through open woodland and shrubland, particularly in areas where the emu bush and related species occur.

    A nectar feeder, the black honeyeater has a long curved bill to reach the base of tubular flowers such as those of the emu bush. It also takes insects in the air, and regularly eats ash left behind at campfires. Cup-shaped nests are built in the forks of small trees or shrubs. The male engages in a soaring song flight in the mating season, but contributes little to nest-building or incubating the clutch of two to three eggs. Both sexes feed and care for the young. While the population appears to be decreasing, the black honeyeater is sufficiently numerous and widespread and hence is considered to be of least concern on the International Union for Conservation of Nature (IUCN)'s Red List of Endangered species. (Full article...)
  • Teresa Cristina at age 66, 1888

    Dona Teresa Cristina delle Due Sicilie (14 March 1822 – 28 December 1889), nicknamed "the Mother of the Brazilians", was the Empress consort of Emperor Dom Pedro II of Brazil, who reigned from 1831 to 1889. Born a Princess of the Kingdom of the Two Sicilies in present-day southern Italy, she was the daughter of King Don Francesco I (Francis I) of the Italian branch of the House of Bourbon and his wife Maria Isabel (Maria Isabella). It was long believed by historians that the Princess was raised in an ultra-conservative, intolerant atmosphere which resulted in a timid and unassertive character in public and an ability to be contented with very little materially or emotionally. Recent studies revealed a more complex character, who despite having respected the social norms of the era, was able to assert a limited independence due to her strongly opinionated personality as well as her interest in learning, sciences and culture.

    The Princess was married by proxy to Pedro II in 1843. Her spouse's expectations had been raised when a portrait was presented that depicted Teresa Cristina as an idealized beauty, but he was displeased by his bride's plain looks upon their first meeting later that year. Despite a cold beginning, the couple's relationship improved as time passed, due primarily to Teresa Cristina's patience, kindness, generosity and simplicity. These traits also helped her win the hearts of the Brazilian people, and her distance from political controversies shielded her from criticism. She also sponsored archaeological studies in Italy and Italian immigration to Brazil. (Full article...)

Выбранное изображение

Рэйлган представляет собой форму пистолета , который преобразует электрическую энергию -rather , чем более обычной химической энергии от взрывчатого метательного -в снаряда кинетической энергии . Его не следует путать с койлганом (пистолетом Гаусса). Термин « рельсотрон» также используется для обозначения обычного огнестрельного оружия, используемого в классе бенчрестной стрельбы без ограничений .

Рейлган - это тип пистолета с магнитным ускорителем (MAG), который использует электромагнитную силу для приведения в движение электропроводящего снаряда, который изначально является частью пути тока. Иногда также используют подвижную арматуру, соединяющую рельсы. Ток , протекающий через рельсы устанавливают магнитное поле между ними и через снаряд перпендикулярно к току в нем. Это приводит к тому, что рельсы и снаряд толкают друг друга и ускоряют снаряд по рельсам.

Избранная биография

Вольфганг Эрнст Паули (25 апреля 1900 - 15 декабря 1958) был австрийским физиком, известным своими работами по теории спина , и в частности открытием принципа исключения , который лежит в основе всей химии и квантовой механики .

Он редко публиковал статьи, предпочитая длительную переписку с коллегами (такими, как Бор и Гейзенберг , с которыми у него были близкие дружеские отношения). Многие из его идей и результатов никогда не публиковались и появлялись только в его письмах, которые часто копировались и распространялись получателями. . Паули, очевидно, не волновало, что большая часть его работ осталась незарегистрированной.

Вы знали...

  • ... эта окраска - это свойство громкоговорителей , из-за которого громкоговоритель продолжает издавать звук при прекращении электрического сигнала?
  • ... что свет в плазменном дисплее создается люминофором, возбуждаемым ультрафиолетовым излучением, испускаемым плазменным разрядом между двумя плоскими стеклянными панелями ?
  • ... Великий шторм в Аппалачах в ноябре 1950 года привел к порывам ветра со скоростью более 100 миль в час / 87 узлов в Нью-Йорке , Нью-Джерси и Новой Англии ?
  • ... что два предсердия человека не имеют клапанов на входе?

Новости науки

5 февраля 2021 г. -
Ученые , принадлежащие к немецким - малагасийским экспедициям объявляют об открытии брукезии Наны , ящерицу нашли на Мадагаскаре. Размер тела самца составляет всего 13,5 миллиметра (0,5 дюйма), это потенциально самая маленькая рептилия на Земле. (BBC)
22 января 2021 г. - пандемия COVID-19
Группа ученых, консультирующая правительство Великобритании, объявляет, что вариант, впервые обнаруженный в Соединенном Королевстве, на 30% более смертоносен, чем исходный вирус SARS-CoV-2 . (Форбс)
19 января 2021 - Открытие экзопланет
Ученые обнаружили, что WASP-107b - это супер-пуховик . WASP-107b - это экзопланета того же размера, что и Юпитер, но с одной десятой массы, расположенная на расстоянии 212 световых лет от Земли . (Новости CBS) (Новости науки)
30 декабря 2020-2020 по палеонтологии
Ученые Российской академии наук объявляют об обнаружении "хорошо сохранившейся" туши шерстистого носорога в Абыйском районе , Саха , Россия , которая была обнаружена в результате таяния вечной мерзлоты в августе. Российская академия наук утверждает, что шерстистому носорогу, вероятно, было 3 или 4 года, когда он умер, утонув в реке, и может быть от 20 000 до 50 000 лет. (Новости ABC)
18 декабря 2020 -
Обзор некоторых недавних медицинских исследований показывает, что Т-клетки памяти могут играть роль в явлении, известном как перекрестная реактивность , которая, как выяснили исследователи, может в некоторых случаях дать определенным людям определенный уровень иммунитета к вирусу, вызывающему COVID-19 даже если они не подвергались воздействию вируса, не были инфицированы им или не получили вакцину. Между вирусом, вызывающим COVID-19, и другими связанными с ним коронавирусами, вызывающими SARS и MERS, есть определенное структурное и клиническое сходство . (MSN)
16 декабря 2020 - Китайская космическая программа
Китайское национальное космическое управление (CNSA) космический аппарат Чанъэ 5 возвращается на Землю проведения образцов лунных пород и почвы с поверхности на Луне . По сообщению CNSA, капсула будет доставлена по воздуху в Пекин для официального открытия, а образцы будут предоставлены ученым из других стран. ( Хранитель )

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