4,694 research outputs found
АНТОЛОГИЯ ВЫДАЮЩИХСЯ ДОСТИЖЕНИЙ В НАУКЕ И ТЕХНИКЕ. ЧАСТЬ 53: ЛАУРЕАТЫ НОБЕЛЕВСКОЙ ПРЕМИИ ПО ФИЗИКЕ ЗА 2016−2019 гг.
Purpose. Brief presentation of the distinguished achievements of Nobel Prize Laureates in physics for current time period of 2016-2019. Methodology. Scientific methods of collection, analysis and analytical treatment of scientific and technical information of world level in area of astronomy, astrophysics, physicists of the condensed environments, laser physics, modern theoretical and experimental physics. Results. The brief analytical review of the scientific discovery and distinguished achievements of scientists-physicists in area of modern physical and technical problems which were marked the Nobel Prizes in physics for the period 2016-2019 is presented. In the number of such discovery and achievements of the best representatives of world scientific association entered: theoretical discovery of topology phase transitions and topology phases of matter, experimental discovery of gravity waves, revolutionary inventions in area of laser physics, astronomic discovery and contribution to our understanding of evolution of Universe and place of Earth in space. Originality. Systematization and analytical exposition is executed in short concentrated and accessible to the wide reader to the form of the known scientific and technical materials, awarded with the Nobel Prizes in physics for current time period of 2016-2019 and devoted to: the theoretical openings of topology phase transitions and topology phases of matter, experimental opening of gravity waves, revolutionary inventions in area of laser physics, astronomic discovery and contribution to our understanding of evolution of Universe and place of Earth in space. Practical value. Popularization and deepening of scientific and technical knowledge for students, engineer and technical specialists and research workers in area of astronomy, astrophysics, physicists of the condensed environments, laser physics, modern theoretical and experimental physics, extending their scientific range of interests and further development of scientific and technical progress in human society.Приведен краткий аналитический обзор выдающихся научно-технических достижений ученых, отмеченных Нобелевской премией по физике за период 2016-2019 гг. В число таких достижений представителей мирового научного сообщества вошли: теоретические открытия топологических фазовых переходов и топологических фаз материи, экспериментальное открытие гравитационных волн, революционные изобретения в области лазерной физики, астрономические открытия и вклад в наше понимание эволюции Вселенной и места Земли в космосе.
АНТОЛОГИЯ ВЫДАЮЩИХСЯ ДОСТИЖЕНИЙ В НАУКЕ И ТЕХНИКЕ. ЧАСТЬ 30: ПОРТРЕТ ХАРЬКОВСКОГО МАТЕМАТИКА, МЕХАНИКА И КИБЕРНЕТИКА ВЛАДИМИРА ЛОГВИНОВИЧА РВАЧЕВА
Purpose. Description of basic scientific achievements, features of personality and way of life of the known Kharkov mathematician, mechanical engineer and cyberneticist, academician of NAS of Ukraine Rvachev V.L .in the short form is presented. Methodology. Existent scientific approaches for treatment and systematization of mathematical knowledges, modern achievements in area of methods of direct solution of linear (nonlinear) boundary problems of mechanics and mathematical physics with the scope terms of different types for the physical bodies of difficult geometrical form. Methods of historical method at research of development in society of analytical geometry, applied mathematics, classical mechanics and mathematical physics. Results. Short information is resulted about the basic creative and vital stages, and also fundamental scientific achievements of the indicated scientist-mathematician the scientific legacy of which entered in the treasure-house of world mathematical science. Are some personal qualities of this prominent soviet Ukrainian mathematician of the 20-th century, forming scientific school on the mathematical method of R−functions and leaving about itself kind memory for thankful students and descendants. Originality. First taught in 1970-th at the known mathematician of contemporaneity of Rvachev V.L. to bases of the applied mathematics and theory of R−functions by a scientist-electrophysicist from the Kharkov polytechnic institute presented for the wide circle of readers a short scientifically-historical essay about this large scientist-teacher, being based on his scientific labours, published biobibliographic materials and flashbacks of his devoted students-followers about him. Practical value. Scientific popularization of the special physical and mathematical knowledges and distinguished scientific achievements of the known Kharkov scientist-mathematician Rvachev V.L. in area of the applied mathematics, classical mechanics of continuous media, mathematical physics and technical cybernetics.Приведен краткий научно-исторический очерк об известном ученом-математике Харьковщины − академике АН УССР (НАН Украины) Рвачеве В.Л. и о его выдающемся вкладе в мировую математическую науку.Наведено короткий науково-історичний нарис про відомого вченого-математика Харківщини − академіка АН УРСР (НАН України) Рвачева В.Л. і про його видатний внесок у світову математичну науку
АНТОЛОГИЯ ВЫДАЮЩИХСЯ ДОСТИЖЕНИЙ В НАУКЕ И ТЕХНИКЕ. ЧАСТЬ 44: ТРАДИЦИОННАЯ ЭНЕРГЕТИКА. АТОМНЫЕ ЭЛЕКТРИЧЕСКИЕ СТАНЦИИ: РЕТРОСПЕКТИВА, СОСТОЯНИЕ И ПЕРСПЕКТИВЫ ИХ РАЗВИТИЯ
Purpose. Preparation of brief scientific and technical review about a retrospective view, modern state, achievements, problems, tendencies and prospects of development of world nuclear energy. Methodology. Known scientific methods of collection, analysis and analytical treatment of the opened scientific and technical information, present in scientific monographs, journals and internet-reports, world level in area of nuclear energy. Results. A brief analytical scientific and technical review is resulted about a retrospective view, modern state, basic achievements, existent problems, tendencies and prospects of development of nuclear energy in the industrially developed countries of the world. Considerable progress is marked in development and creation of technical base of modern nuclear energy, including the nuclear power stations (NPP) such their basic devices as nuclear reactors, steam generators, steam turbines and turbogenerators. The basic charts of construction of NPP producing in the world now about 11 % are described annual production electric power. It is indicated that in Ukraine a production of electricity volume at NPP makes more than 50 %, and in France − more than 70 % in annual power balance of country. Nuclear-physical bases of work of nuclear reactor are resulted on thermal-neutron, widely in-use at NPP. The design of most safe water-waters of nuclear power-reactor of type of WWER-1000 is described by thermal power 1000 MW, applied presently at NPP of Ukraine. Basic classification of nuclear reactors is presented. Technical information is resulted about largest NPP of the world. Master data are indicated about a nuclear fuel and radio-active offcuts of nuclear reactors of NPP. Basic measures and facilities are described for the increase of safety of nuclear reactors and NPP. Advantages and lacks of NPP are marked by comparison to the thermal power plants. Nuclear energy of Ukraine is considered and basic technical descriptions of operating domestic NPP are indicated. Basic problems, tendencies and possible prospects of development, are marked in the world and to Ukraine of nuclear energy. Originality. Systematization of the scientific and technical materials touching functioning of such important sector of world economy as nuclear energy known from the sources opened in outer informative space is executed. It is shown on the basis of approach of the systems that in spite of row of existent problems in area of world nuclear energy has the real prospects in the further development and to service society at satisfaction of his increasing requirements in electric and thermal energies. Practical value. Popularization and deepening for students, engineer-technical and scientific workers of scientific and technical knowledge in area of modern nuclear physics and energy, extending their scientific range of interests and further development of scientific and technical progress in society.Приведен краткий научно-технический обзор о ретроспективе, современном состоянии и тенденциях в развитии мировой ядерной энергетики. Приведены ядерно-физические основы функционирования и описаны основные устройства ядерного реактора на уране и тепловых нейтронах, широко используемого на атомных электрических станциях (АЭС). Представлена классификация ядерных реакторов. Приведены данные о применяемом на АЭС ядерном топливе и радиоактивных отходах ядерных реакторов АЭС. Указаны меры для повышения безопасности ядерных реакторов и АЭС. Отмечена важная роль АЭС в годовом объеме выработки электроэнергии в мире и ряде стран. Указаны преимущества и недостатки АЭС. Рассмотрена ядерная энергетика Украины. Обозначены основные проблемы и перспективы развития в мире и Украине ядерной энергетики
АНТОЛОГИЯ ВЫДАЮЩИХСЯ ДОСТИЖЕНИЙ В НАУКЕ И ТЕХНИКЕ. ЧАСТЬ 42: ЭЛЕКТРОНИКА: РЕТРОСПЕКТИВА, УСПЕХИ И ПЕРСПЕКТИВЫ ЕЕ РАЗВИТИЯ
Purpose. Preparation of brief scientific and technical review about sources, retrospective view, basic stages, achievements, problems, trends and prospects of development of world electronics for period of 20th-21st centuries. Methodology. Known scientific methods of collection, analysis and analytical treatment of the opened scientific and technical information of world level in area of a vacuum electronics, semiconductor electronics, vacuum microelectronics and nanoelectronics, and also optical electronics. Results. A brief analytical scientific and technical review is resulted about the primary and present states, achievements, trends and prospects of development of electronics in the developed countries of the world. From positions of approach of the systems advantages and lacks of semiconductor microelectronics are described as compared to a vacuum electronics. Considerable progress is marked in development of semiconductor element base (microtransistors, microprocessors, microcontrollers and other) for creation of different electronic devices and computing engineering. Information, touching the determining deposit of electronic companies of the «Silicon Valley» in the USA in providing of technological breach in area of modern microelectronics, production of computers and their microprocessors, software and creation of devices of mobile communication development, is resulted. The basic problems of space microelectronics are affected. The possible ways of further development are indicated in the world of electronics, including vacuum microelectronics and nanoelectronics, and also optical electronics. The special attention is turned for urgent development of high-efficiency protective facilities specialists against cyber attacks hackers on the computer systems. In a review an accent is done on the sharp necessity of acceptance the proper services of drastic measures for a fight with cyber terrorism. Originality. Systematization of the scientific and technical materials touching world history of development and creation of modern element base of a vacuum electronics and semiconductor microelectronics known from the sources opened in outer informative space is executed. Possible new perspective directions of development in the modern world of microelectronics are formulated. Practical value. Popularization and deepening for students, engineer and technical| specialists and research workers of front-rank scientific and technical knowledge in the topical area of development, creation and application in the modern technique of the different setting of high-computer-integrated electronic devices, extending their scientific range of interests and further development of scientific and technical progress in society.Приведен научно-технический обзор о ретроспективе, успехах, тенденциях и перспективах развития мировой электроники. Рассмотрены основные этапы развития электроники, связанные с изобретением радиолампы, транзистора, интегральной схемы и высокоинтегрированного микропроцессора. Отмечен вклад электронных компаний «Кремниевой долины» США в технологический прорыв в микроэлектронике. Описано состояние работ в области вакуумной микроэлектроники и наноэлектроники
ВЫБОР СЕЧЕНИЙ ЭЛЕКТРИЧЕСКИХ ПРОВОДОВ И КАБЕЛЕЙ В ЦЕПЯХ УСТРОЙСТВ ВЫСОКОВОЛЬТНОЙ СИЛЬНОТОЧНОЙ ИМПУЛЬСНОЙ ТЕХНИКИ
Purpose. Implementation of calculation choice of sections of electric wires and cables in circuits of devices of high-voltage high-current impulse technique (HHIT), characterized flowing of pulsed current ip(t) with different amplitude-temporal parameters (ATP). Methodology. Electrophysics bases of technique of high-voltage and high pulsed currents, theoretical bases of the electrical engineering, bases of electrical power engineering, technique of high electric and magnetic fields, and also measuring technique. Results. The results of the developed generalized electrical engineering investigations are resulted in a calculation choice on the condition of thermal resistibility of cable products of boundary permissible sections SCil of the electric uninsulated wires, and also insulated wires and cables with copper (aluminum) cores (shells) with polyvinyl chloride (PVC), rubber (R) and polyethylene (PET) insulation, on which in the circuits of HHIT the axial-flow of pulsed current ip(t) flows with arbitrary ATP. On the basis of this approach the results of concrete choice of sections SCil are presented for the indicated electric wires (cables) of power circuits of HHIT with pulsed current, ATP of which with amplitudes of Imp=(0.1-1000) кА change on an aperiodic law or law of damped sinusoid in nanо-, micro- and millisecond temporal ranges. The results of calculation estimation present maximum permissible approximations of δCil of pulsed current ip(t) of the examined temporal shapes in the indicated electric wires and cables of power circuits of HHIT. It is shown that the values of current approximations of δCil for the uninsulated copper (aluminum) wires in the nanosecond temporal range of ATP of pulsed currents ip(t) are about 495 (293) kA/mm2, in the microsecond temporal range – 26 (15) kA/mm2 and in a millisecond temporal range – 543 (320) A/mm2. By a calculation it is set that for the insulated wires (cables) with copper (aluminum) cores (shells) and PET with insulation the indicated current approximation of δCil is approximately: for the nanosecond range – 361 (233) kA/mm2; for the microsecond range – 19 (12) kA/mm2 ; for the millisecond range – 396 (256) A/mm2. Originality. Firstly by a calculation for the concrete temporal shapes of pulses of current ip(t) in the discharge circuits of HHIT, changing in the wide range of the amplitudes Imp on a aperiodic law or law of damped sinusoid, the numeral values of cross-sections SCil and current approximations of δCil are obtained for the uninsulated wires, insulated wires and cables with copper (aluminum) cores (shells) with PVC, R and PET insulation. Practical value. Application in practice of model tests of objects of electrical power engineering, aviation and space-rocket technique on resistibility to direct action of pulsed currents ip(t) with different ATP of natural (currents of lightning) and artificial (discharge currents of HHIT) origin to increase electro-thermal resistibility of the electric uninsulated wires, and also the insulated wires and cables with PVC, R and PET insulation of HHIT widely applied in power circuits.Приведены результаты разработанного обобщенного электротехнического подхода к расчетному выбору по условию термической стойкости предельно допустимых сечений SCil электрических неизолированных проводов, а также изолированных проводов и кабелей с поливинилхлоридной (ПВХ), резиновой (Р) и полиэтиленовой (ПЭТ) изоляцией с медными (алюминиевыми) жилами (оболочками), по которым в цепях высоковольтной сильноточной импульсной техники (ВСИТ) протекает аксиальный импульсный ток ip(t) с произвольными амплитудно-временными параметрами (АВП). На основании данного подхода продемонстрированы результаты конкретного выбора сечений SCil для указанных электрических проводов (кабелей) силовых цепей ВСИТ с импульсным током, АВП которого с амплитудами Imp=(0,1-1000) кА изменяются по апериодическому закону или закону затухающей синусоиды в нано-, микро- и миллисекундному временных диапазонах. Представлены результаты расчетной оценки предельно допустимых плотностей δCil импульсного тока ip(t) рассматриваемых временных форм в указанных электрических проводах и кабелях силовых цепей ВСИТ. Полученные результаты будут способствовать повышению электротермической стойкости электрических неизолированных проводов, а также изолированных проводов и кабелей с ПВХ, Р и ПЭТ изоляцией, широко применяемых в силовых цепях ВСИТ.
Critical temperature and Ginzburg-Landau equation for a trapped Fermi gas
We discuss a superfluid phase transition in a trapped neutral-atom Fermi gas.
We consider the case where the critical temperature greatly exceeds the spacing
between the trap levels and derive the corresponding Ginzburg-Landau equation.
The latter turns out to be analogous to the equation for the condensate wave
function in a trapped Bose gas. The analysis of its solution provides us with
the value of the critical temperature and with the spatial and
temperature dependence of the order parameter in the vicinity of the phase
transition point.Comment: 6 pages, 1 figure, REVTeX. The figure improved. Misprints corrected.
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