357 research outputs found

    Hyperbolic chaos in self-oscillating systems based on mechanical triple linkage: Testing absence of tangencies of stable and unstable manifolds for phase trajectories

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    Dynamical equations are formulated and a numerical study is provided for self-oscillatory model systems based on the triple linkage hinge mechanism of Thurston -- Weeks -- Hunt -- MacKay. We consider systems with holonomic mechanical constraint of three rotators as well as systems, where three rotators interact by potential forces. We present and discuss some quantitative characteristics of the chaotic regimes (Lyapunov exponents, power spectrum). Chaotic dynamics of the models we consider are associated with hyperbolic attractors, at least, at relatively small supercriticality of the self-oscillating modes; that follows from numerical analysis of the distribution for angles of intersection of stable and unstable manifolds of phase trajectories on the attractors. In systems based on rotators with interacting potential the hyperbolicity is violated starting from a certain level of excitation.Comment: 30 pages, 18 figure

    A "saddle-node" bifurcation scenario for birth or destruction of a Smale-Williams solenoid

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    Formation or destruction of hyperbolic chaotic attractor under parameter variation is considered with an example represented by Smale--Williams solenoid in stroboscopic Poincar\'{e} map of two alternately excited non-autonomous van der Pol oscillators. The transition occupies a narrow but finite parameter interval and progresses in such way that periodic orbits constituting a "skeleton" of the attractor undergo saddle-node bifurcation events involving partner orbits from the attractor and from a non-attracting invariant set, which forms together with its stable manifold a basin boundary of the attractor.Comment: 7 pages, 7 figures, 1 tabl

    Plykin-like attractor in non-autonomous coupled oscillators

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    A system of two coupled non-autonomous oscillators is considered. Dynamics of complex amplitudes is governed by differential equations with periodic piecewise continuous dependence of the coefficients on time. The Poincar\'{e} map is derived explicitly. With exclusion of the overall phase, on which the evolution of other variables does not depend, the Poincar\'{e} map is reduced to 3D mapping. It possesses an attractor of Plykin type located on an invariant sphere. Computer verification of the cone criterion confirms the hyperbolic nature of the attractor in the 3D map. Some results of numerical studies of the dynamics for the coupled oscillators are presented, including the attractor portraits, Lyapunov exponents, and the power spectral density.Comment: 11 pages, 9 figure

    Scattering of quasi-optical THz beams on spherical MWCNTs aerogels

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    Results of research of lateral scattering of electromagnetic radiation by aerogel of MWCNTs are presented. Frequency dependences of lateral scattering of THz radiation of spherical MWCNTs aerogels with diameter of 4.5 and 6 mm at frequency range 43-970 GHz are given

    МодСли финансирования СстСствСнных ΠΌΠΎΠ½ΠΎΠΏΠΎΠ»ΠΈΠΉ: Π±ΡŽΠ΄ΠΆΠ΅Ρ‚Π½ΠΎΠ΅, ΠΊΠΎΡ€ΠΏΠΎΡ€Π°Ρ‚ΠΈΠ²Π½ΠΎΠ΅ ΠΈΒ ΠΏΡ€ΠΎΠ΅ΠΊΡ‚Π½ΠΎΠ΅ финансированиС

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    Subject. To ensure sustainable economic development of the country, it is necessary that natural (infrastructure) monopolies develop at a faster pace than other sectors of the economy. The state historically played a major role in financing the infrastructure facilities building, however, in the current tense economic situation a trend is to reduce government spending. In these conditions, for natural monopolies, evaluation and selection of the most effective sources of financing their investment activities become of special importance.Goals. Comparative analysis of typical models of financing of natural monopoliesΒ β€” budgetary, corporative and project financing. Identifying their advantages and disadvantages, and identify areas of the most appropriate and effective application.Methodology. The researching is based on a dialectical approach. The researching used systemic, comparative and institutional approaches.Results. Each of the considered models of financing has its advantages and disadvantages, and also is characterized by its specificity of use. For short-term investment projects, as well as renovation projects for existing infrastructure, it is advisable to implement a corporative financing model. Budgetary financing is applicable for projects with a long payback period and projects with conditionally β€œnegative return on investments” (projects with very long payback period). The model of β€œproject financing” is most effective for the implementation of large-scale projects with medium or long-term payback.Conclusions. It is shown that, in the current economic conditions, the implementation of most of the infrastructure tasks included in the strategy of Russia’s economic development can be achieved mainly through the use of project financing. However, its progress in Russia is hindered by the underdevelopment of the legislative base.ΠŸΡ€Π΅Π΄ΠΌΠ΅Ρ‚. Для обСспСчСния устойчивого экономичСского развития страны Π½Π΅ΠΎΠ±Ρ…ΠΎΠ΄ΠΈΠΌΠΎ, Ρ‡Ρ‚ΠΎΠ±Ρ‹ СстСствСнныС (инфраструктурныС) ΠΌΠΎΠ½ΠΎΠΏΠΎΠ»ΠΈΠΈ Ρ€Π°Π·Π²ΠΈΠ²Π°Π»ΠΈΡΡŒ ΠΎΠΏΠ΅Ρ€Π΅ΠΆΠ°ΡŽΡ‰ΠΈΠΌΠΈ Ρ‚Π΅ΠΌΠΏΠ°ΠΌΠΈ ΠΏΠΎ ΠΎΡ‚Π½ΠΎΡˆΠ΅Π½ΠΈΡŽ ΠΊΒ  ΠΎΡΡ‚Π°Π»ΡŒΠ½Ρ‹ΠΌ отраслям экономики. Государство историчСски ΠΈΠ³Ρ€Π°Π»ΠΎ Π³Π»Π°Π²Π½ΡƒΡŽ Ρ€ΠΎΠ»ΡŒ Π²Β  финансировании ΡΡ‚Ρ€ΠΎΠΈΡ‚Π΅Π»ΡŒΡΡ‚Π²Π° ΠΎΠ±ΡŠΠ΅ΠΊΡ‚ΠΎΠ² инфраструктуры, ΠΎΠ΄Π½Π°ΠΊΠΎ Π²Β  условиях Ρ‚Π΅ΠΊΡƒΡ‰Π΅ΠΉ напряТСнной экономичСской ситуации имССтся тСндСнция ΠΊΒ ΡΠΎΠΊΡ€Π°Ρ‰Π΅Π½ΠΈΡŽ государствСнных ассигнований. Для СстСствСнных ΠΌΠΎΠ½ΠΎΠΏΠΎΠ»ΠΈΠΉ особоС Π·Π½Π°Ρ‡Π΅Π½ΠΈΠ΅ ΠΏΡ€ΠΈΠΎΠ±Ρ€Π΅Ρ‚Π°Π΅Ρ‚ ΠΎΡ†Π΅Π½ΠΊΠ° ΠΈΒ Π²Ρ‹Π±ΠΎΡ€ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ эффСктивных источников финансирования своСй инвСстиционной Π΄Π΅ΡΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ.Π¦Π΅Π»ΠΈ. Π‘Ρ€Π°Π²Π½ΠΈΡ‚Π΅Π»ΡŒΠ½Ρ‹ΠΉ Π°Π½Π°Π»ΠΈΠ· Ρ‚ΠΈΠΏΠΎΠ²Ρ‹Ρ… ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ финансирования СстСствСнных ΠΌΠΎΠ½ΠΎΠΏΠΎΠ»ΠΈΠΉΒ β€” Π±ΡŽΠ΄ΠΆΠ΅Ρ‚Π½ΠΎΠ³ΠΎ, ΠΊΠΎΡ€ΠΏΠΎΡ€Π°Ρ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ ΠΈΒ ΠΏΡ€ΠΎΠ΅ΠΊΡ‚Π½ΠΎΠ³ΠΎ. ВыявлСниС ΠΈΡ… достоинств и нСдостатков, ΠΎΠΏΡ€Π΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ областСй Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ цСлСсообразного и эффСктивного примСнСния.ΠœΠ΅Ρ‚ΠΎΠ΄ΠΎΠ»ΠΎΠ³ΠΈΡ. ИсслСдованиС базируСтся Π½Π° диалСктичСском ΠΏΠΎΠ΄Ρ…ΠΎΠ΄Π΅. Π’Π°ΠΊΠΆΠ΅ ΠΈΡΠΏΠΎΠ»ΡŒΠ·ΠΎΠ²Π°Π½Ρ‹ систСмный, ΡΡ€Π°Π²Π½ΠΈΡ‚Π΅Π»ΡŒΠ½Ρ‹ΠΉ ΠΈΒ ΠΈΠ½ΡΡ‚ΠΈΡ‚ΡƒΡ†ΠΈΠΎΠ½Π°Π»ΡŒΠ½Ρ‹ΠΉ ΠΏΠΎΠ΄Ρ…ΠΎΠ΄Ρ‹.Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹. КаТдая ΠΈΠ· рассмотрСнных ΠΌΠΎΠ΄Π΅Π»Π΅ΠΉ финансирования ΠΈΠΌΠ΅Π΅Ρ‚ свои прСимущСства ΠΈΒ  нСдостатки, Π°Β Ρ‚Π°ΠΊΠΆΠ΅ характСризуСтся спСцификой использования. Для краткосрочных инвСстиционных ΠΏΡ€ΠΎΠ΅ΠΊΡ‚ΠΎΠ², Π°Β Ρ‚Π°ΠΊΠΆΠ΅ ΠΏΡ€ΠΎΠ΅ΠΊΡ‚ΠΎΠ² обновлСния ΡΡƒΡ‰Π΅ΡΡ‚Π²ΡƒΡŽΡ‰ΠΈΡ… ΠΎΠ±ΡŠΠ΅ΠΊΡ‚ΠΎΠ² инфраструктуры цСлСсообразно Ρ€Π΅Π°Π»ΠΈΠ·ΠΎΠ²Ρ‹Π²Π°Ρ‚ΡŒ модСль ΠΊΠΎΡ€ΠΏΠΎΡ€Π°Ρ‚ΠΈΠ²Π½ΠΎΠ³ΠΎ финансирования. Π‘ΡŽΠ΄ΠΆΠ΅Ρ‚Π½ΠΎΠ΅ финансированиС ΠΏΡ€ΠΈΠΌΠ΅Π½ΠΈΠΌΠΎ для ΠΏΡ€ΠΎΠ΅ΠΊΡ‚ΠΎΠ² ΡΒ Π΄Π»ΠΈΡ‚Π΅Π»ΡŒΠ½Ρ‹ΠΌ сроком окупаСмости, Π°Β Ρ‚Π°ΠΊΠΆΠ΅ условно Β«Π½Π΅ΠΎΠΊΡƒΠΏΠ°Π΅ΠΌΡ‹Ρ…Β» ΠΏΡ€ΠΎΠ΅ΠΊΡ‚ΠΎΠ² (ΠΏΡ€ΠΎΠ΅ΠΊΡ‚ΠΎΠ² со ΡΠ²Π΅Ρ€Ρ…Π΄Π»ΠΈΡ‚Π΅Π»ΡŒΠ½Ρ‹ΠΌ сроком окупаСмости). ΠŸΡ€ΠΎΠ΅ΠΊΡ‚Π½ΠΎΠ΅ финансированиС Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ эффСктивно для Ρ€Π΅Π°Π»ΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΌΠ°ΡΡˆΡ‚Π°Π±Π½Ρ‹Ρ… ΠΏΡ€ΠΎΠ΅ΠΊΡ‚ΠΎΠ² со срСднСй ΠΈΠ»ΠΈ Π΄Π»ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠΉ ΠΎΠΊΡƒΠΏΠ°Π΅ΠΌΠΎΡΡ‚ΡŒΡŽ.Π’Ρ‹Π²ΠΎΠ΄Ρ‹. Показано, Ρ‡Ρ‚ΠΎ Π²Β ΡΡƒΡ‰Π΅ΡΡ‚Π²ΡƒΡŽΡ‰ΠΈΡ… экономичСских условиях Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½ΠΈΠ΅ Π±ΠΎΠ»ΡŒΡˆΠΈΠ½ΡΡ‚Π²Π° инфраструктурных Π·Π°Π΄Π°Ρ‡, Π·Π°Π»ΠΎΠΆΠ΅Π½Π½Ρ‹Ρ… Π²Β ΡΡ‚Ρ€Π°Ρ‚Π΅Π³ΠΈΡŽ экономичСского развития России, ΠΌΠΎΠΆΠ΅Ρ‚ Π±Ρ‹Ρ‚ΡŒ обСспСчСно прСимущСствСнно ΠΏΡƒΡ‚Π΅ΠΌ использования ΠΏΡ€ΠΎΠ΅ΠΊΡ‚Π½ΠΎΠ³ΠΎ финансирования. Однако Π΅Π³ΠΎ Ρ€Π°Π·Π²ΠΈΡ‚ΠΈΠ΅ в России тормозится Π½Π΅Ρ€Π°Π·Π²ΠΈΡ‚ΠΎΡΡ‚ΡŒΡŽ Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ Π±Π°Π·

    The number of the intraepithelial T cells correlate with the proliferation index in human bulbourethral gland epithelium

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    Background: Our study has immunohistochemically examined T cells localization and number as well as proliferative activity level for the bulbourethral gland epithelium in men of different ages, using monoclonal antibodies against CD45RO and proliferating cell nuclear antigen (PCNA). Results: We have found that the T cells have been localized mainly in excretory ducts epithelium of the glands in any age group, meanwhile their relative number varies with age. The excretory ducts epithelium has shown a high proliferative activity when in acini the PCNA index has been low. Postnatal dynamics of the epithelium proliferative activity positively correlates with age-related density fluctuations in lymphocytic infiltration of the glands. Conclusions: We consider that intraepithelial T cells may contribute to the regulation of epithelial cells proliferation in the bulbourethral glands
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