527 research outputs found

    Poisson-Lie T-duality and N=2 superconformal WZNW models on compact groups

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    The supersymmetric generalization of Pisson-Lie T-duality in N=2 superconformal WZNW models on the compact groups is considered. It is shown that the role of Drinfeld's doubles play the complexifications of the corresponding compact groups. These complex doubles are used to define the natural actions of the isotropic subgroups forming the doubles on the group manifolds of the N=2 superconformal WZNW models. The Poisson- Lie T-duality in N=2 superconformal U(2)-WZNW model considered in details. It is shown that this model admits Poisson-Lie symmetries with respect to the isotropic subgroups forming Drinfeld's double Gl(2,C). Poisson-Lie T-duality transformation maps this model into itself but acts nontrivialy on the space of classical solutions. Supersymmetric generalization of Poisson-Lie T-duality in N=2 superconformal WZNW models on the compact groups of higher dimensions is proposed.Comment: 12 pages, latex, misprints correcte

    Mass Shift of Axion in Magnetic Field

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    A mass-shift of the axion propagating in an external constant homogenious magnetic field is calculated. The contributions via an electron loop and a virtual photon are examined. It is shown that the virtual photon contribution dominates substantially over the electron-loop one. Under the conditions of the early Universe the electron-loop contribution to the massless axion mass-shift is equal to zero while the virtual photon contribution is finite and can be of order of the recent restrictions on the axion mass.Comment: 4 pages, latex2e, 2 PS figures, uses ws-p8-50x6-00.sty (included) and amssymb.sty. Talk at the International Workshop on Particle Physics and the Early Universe (COSMO-99), Trieste, Italy, 27 September - 3 October 199

    Field-induced axion emission via process e+eβˆ’β†’ae^+ e^- \to a in plasma

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    The annihilation into axion e+eβˆ’β†’ae^+ e^- \to a is investigated in a plasma and an external magnetic field. This process via a plasmon intermediate state has a resonant character at a particular energy of the emitted axion. The emissivity by e+eβˆ’β†’ae^+ e^- \to a is compared with the axion cyclotron emissivity.Comment: 8 pages, latex, 4 PS figure

    Structural Peculiarities of A3B5 Nanocrystals Created in Si by Ion-Beam Synthesis

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    We reported the structure peculiarities of nanocrystals formed in Si by means of high-fluence implantation at 25 and 500 Β°Π‘ followed by rapid thermal annealing (RTA). The structure of implanted samples has been investigated by means of transmission electron microscopy (TEM). The crystalline nature of the precipitates is proved by the MoirΓ© fringe patterns presence in the TEM images. The MoirΓ© fringe distance (MoirΓ© period) is equal of 1.8 nm for small precipitates. This experimental value coincides with the calculated one for crystalline InAs. It is noted a MoirΓ© period increasing in the case of large precipitates. We suppose that this feature is a result of surplus As or In atoms embedded in precipitates. One can see an interesting effect – β€œglowng” of nanocrystal/Si interfaces at the dark-field images of implanted and annealed samples. We ascribe this effect to a presence of misfit dislocation networks at the InAs/Si interfaces generated as a result of strain relaxation in highly mismatched InAs/Si system. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3543

    Damage accumulation in multilayer thin films on gamma titanium aluminides

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    The present paper involves comprehensive investigations towards an understanding on how aggressive environments, high service temperatures and long dwell times affect damage growth and lifetime reduction of different components of automotive combustion engines and aero-engines made out of gamma titanium aluminides with protective coatings. The outcome of this paper is related to the practical recommendations on how damage growth at high temperatures in multilayer thin films on gamma titanium aluminides under thermal cyclic conditions and multiaxial stress state may be controlled in order to reduce environmental degradation, optimize the protective coating and extend lifetime of a component for automotive, energy and aerospace applications.Настоящая ΡΡ‚Π°Ρ‚ΡŒΡ Π²ΠΊΠ»ΡŽΡ‡Π°Π΅Ρ‚ Π² сСбя Π²ΡΠ΅ΠΎΠ±ΡŠΠ΅ΠΌΠ»ΡŽΡ‰ΠΈΠ΅ исслСдования, Π½Π°ΠΏΡ€Π°Π²Π»Π΅Π½Π½Ρ‹Π΅ Π½Π° ΠΏΠΎΠ½ΠΈΠΌΠ°Π½ΠΈΠ΅ Ρ‚ΠΎΠ³ΠΎ, ΠΊΠ°ΠΊ агрСссивныС срСды, высокиС Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Ρ‹ ΠΈ врСмя Ρ†ΠΈΠΊΠ»Π° нагруТСния Π²Π»ΠΈΡΡŽΡ‚ Π½Π° рост поврСТдаСмости ΠΈ сокращСниС долговСчности Ρ€Π°Π·Π»ΠΈΡ‡Π½Ρ‹Ρ… ΠΊΠΎΠΌΠΏΠΎΠ½Π΅Π½Ρ‚ΠΎΠ² Π°Π²Ρ‚ΠΎΠΌΠΎΠ±ΠΈΠ»ΡŒΠ½Ρ‹Ρ… Π΄Π²ΠΈΠ³Π°Ρ‚Π΅Π»Π΅ΠΉ Π²Π½ΡƒΡ‚Ρ€Π΅Π½Π½Π΅Π³ΠΎ сгорания ΠΈ Π°Π²ΠΈΠ°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… Π΄Π²ΠΈΠ³Π°Ρ‚Π΅Π»Π΅ΠΉ, ΠΈΠ·Π³ΠΎΡ‚ΠΎΠ²Π»Π΅Π½Π½Ρ‹Ρ… ΠΈΠ· Π³Π°ΠΌΠΌΠ° алюминидов Ρ‚ΠΈΡ‚Π°Π½Π° с Π·Π°Ρ‰ΠΈΡ‚Π½Ρ‹ΠΌΠΈ покрытиями. Π’ Ρ€Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Π΅ этих исслСдований установлСно, ΠΊΠ°ΠΊ рост поврСТдСнности ΠΏΡ€ΠΈ высоких Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π°Ρ… Π² многослойных Ρ‚ΠΎΠ½ΠΊΠΈΡ… ΠΏΠ»Π΅Π½ΠΊΠ°Ρ… Π½Π° основС Π³Π°ΠΌΠΌΠ° алюминидов Ρ‚ΠΈΡ‚Π°Π½Π° Π² условиях Ρ‚Π΅ΠΏΠ»ΠΎΠ²ΠΎΠ³ΠΎ цикличСского нагруТСния ΠΈ многоосного напряТСнного состояния ΠΌΠΎΠΆΠ½ΠΎ ΠΊΠΎΠ½Ρ‚Ρ€ΠΎΠ»ΠΈΡ€ΠΎΠ²Π°Ρ‚ΡŒ с Ρ†Π΅Π»ΡŒΡŽ сниТСния Π΄Π΅Π³Ρ€Π°Π΄Π°Ρ†ΠΈΠΈ ΠΏΠΎΠ΄ влияниСм ΠΎΠΊΡ€ΡƒΠΆΠ°ΡŽΡ‰Π΅ΠΉ срСды, ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ Π·Π°Ρ‰ΠΈΡ‚Π½ΠΎΠ³ΠΎ покрытия ΠΈ увСличСния срока слуТбы элСмСнтов конструкций для Π°Π²Ρ‚ΠΎΠΌΠΎΠ±ΠΈΠ»ΡŒΠ½ΠΎΠΉ, энСргСтичСской ΠΈ аэрокосмичСской ΠΏΡ€ΠΎΠΌΡ‹ΡˆΠ»Π΅Π½Π½ΠΎΡΡ‚ΠΈ

    Π’Π½Π΅Π΄Ρ€Π΅Π½ΠΈΠ΅ элСмСнтов систСмы управлСния качСством Π½Π° ΠΌΠ°Π»ΠΎΠΌ полиграфичСском производствС ΠΊΠ°ΠΊ ΠΌΠ΅Ρ…Π°Π½ΠΈΠ·ΠΌΠ° Π±ΠΎΡ€ΡŒΠ±Ρ‹ с ΠΎΡ‚Ρ…ΠΎΠ΄Π°ΠΌΠΈ

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    Π’ΠΈΠ·Π½Π°Ρ‡Π΅Π½ΠΎ ΡΡƒΡ‚Π½Ρ–ΡΡ‚ΡŒ, Ρ€ΠΎΠ»ΡŒ Ρ‚Π° ΠΏΡ–Π΄Ρ…ΠΎΠ΄ΠΈ впровадТСння Π΅Π»Π΅ΠΌΠ΅Π½Ρ‚Ρ–Π² систСми управління ΡΠΊΡ–ΡΡ‚ΡŽ Π½Π° ΠΌΠ°Π»ΠΎΠΌΡƒ ΠΏΠΎΠ»Ρ–Π³Ρ€Π°Ρ„Ρ–Ρ‡Π½ΠΎΠΌΡƒ підприємстві Π· ΠΌΠ΅Ρ‚ΠΎΡŽ управління Π±Ρ€Π°ΠΊΠΎΠ²Π°Π½ΠΎΡŽ ΠΏΡ€ΠΎΠ΄ΡƒΠΊΡ†Ρ–Ρ”ΡŽ Ρ‚Π° ΡƒΡ‚ΠΈΠ»Ρ–Π·Π°Ρ†Ρ–Ρ”ΡŽ Π²Ρ–Π΄Ρ…ΠΎΠ΄Ρ–Π².The nature, role and approaches to implementing the elements of quality management system for small printing enterprise to manage defective products and recycling. Methodological aspects of improving the quality of printed products on the basis of principles that are basic to the quality management system. The key aspects of quality control functions on a small printing company and features the use of certain methods of measurement, evaluation and analysis of the production process of printed products. The causes of defective products and the algorithm quality management that will reduce shortages and waste, and thus make the process of production and management of defective products managed.ΠžΠΏΡ€Π΅Π΄Π΅Π»Π΅Π½Π° ΡΡƒΡ‰Π½ΠΎΡΡ‚ΡŒ, Ρ€ΠΎΠ»ΡŒ ΠΈ ΠΏΠΎΠ΄Ρ…ΠΎΠ΄Ρ‹ внСдрСния элСмСнтов систСмы управлСния качСством Π½Π° ΠΌΠ°Π»ΠΎΠΌ полиграфичСском прСдприятии с Ρ†Π΅Π»ΡŒΡŽ управлСния Π±Ρ€Π°ΠΊΠΎΠ²Π°Π½Π½ΠΎΠΉ ΠΏΡ€ΠΎΠ΄ΡƒΠΊΡ†ΠΈΠ΅ΠΉ ΠΈ ΡƒΡ‚ΠΈΠ»ΠΈΠ·Π°Ρ†ΠΈΠ΅ΠΉ ΠΎΡ‚Ρ…ΠΎΠ΄ΠΎΠ²

    A Note on the Cosmic Evolution of the Axion in a Strong Magnetic Field

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    It has been pointed out in the literature that in the presence of an external magnetic field the axion mass receives an electromagnetic contribution. We show that if a magnetic field with energy density larger than ~10^{-8} times the energy density of the Universe existed at temperatures of a few GeV, that contribution would be dominant and consequently the cosmic evolution of the axion field would change substantially. In particular, the expected axion relic abundance would be lowered, allowing a small relaxation of the present cosmological bound on the Peccei-Quinn constant.Comment: 2 pages, no figures. Minor changes. References added. Accepted for publication in JCA
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