481 research outputs found

    Position-sensitive detector for the 6-meter optical telescope

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    The Position-Sensitive Detector (PSD) for photometrical and spectral observation on the 6-meter optical telescope of the Special Astrophysical Observatory (Russia) is described. The PSD consists of a position-sensitive tube, amplifiers of output signals, analog-to-digital converters (ADC) and a digital logic plate, which produces a signal for ADC start and an external strob pulse for reading information by registration system. If necessary, the thermoelectric cooler can be used. The position-sensitive tube has the following main elements: a photocathode, electrodes of inverting optics, a block of microchannel plates (MCP) and a position-sensitive collector of quadrant type. The main parameters of the PSD are the diameter of the sensitive surface is 25 mm, the spatial resolution is better than 100 (\mu)m in the centre and a little worse on the periphery; the dead time is near 0.5 (\mu)s; the detection quantum efficiency is defined by the photocathode and it is not less than 0.1, as a rule; dark current is about hundreds of cps, or less, when cooling. PSD spectral sensitivity depends on the type of photocathode and input window material. We use a multialkali photocathode and a fiber or UV-glass, which gives the short- wave cut of 360 nm or 250 nm, respectively.Comment: 4 pages, 7 figures, to be published in Nuclear Instruments & Methods in Physics Researc

    Cooperation in R&D as a leading indicator of innovative activity growth

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    Purpose: The article is focused on new trends in cooperation activity in research and development in the manufacturing industries of Russia. Various types of cooperation are considered, special attention is paid to research organizations and universities. Design/Methodology/Approach: In the context of this issue, it seems necessary to consider the conceptual framework and information basis for the analysis of scientific activity, to study the problems of scientific and technical cooperation, based on the works of foreign and domestic scientists and to develop indicators of cooperative activities. Finding: Authors proposed to rank the regions of Russia by the level of cooperation activity based on a specially developed hidden indicator. Comparison of the results obtained with regional layers of the costs of R&D suggests that joint research and development activities are typical for those regions that pay considerable attention to development of science. Ranking regions of Russia in terms of cooperative activity allowed identifying the leaders and outsiders of this process. Practical implications: The results of the study can be used in the development of measures of regional development of the country in the implementation of R&D. Originality/Value: To study the impact of the resource base on the cooperative activities of the organization, the authors proposed a composite indicator that includes a wide range of indicators that consider various aspects of cooperative activity.This work was supported by a grant of Russian Foundation for Basic Research â„–18-010-00564 Modern Tendencies and Social and Economic Consequences of Digital Technologies Development in Russia.peer-reviewe

    Current status of cosmological MDM model

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    An analysis of cosmological models in spatially flat Friedmann Universe with cosmic gravitational wave background and zero Λ\Lambda-term is presented. The number of free parameters is equal to 5, they are σ8\sigma_8, nn, Ων\Omega_\nu, Ωb\Omega_b, and hh. The normalization of the spectrum of density perturbations on galaxy cluster abundance (σ8=0.52±0.04\sigma_8 = 0.52\pm 0.04) has been used to calculate numerically the value of the large scale CMB anisotropy (ℓ≃10\ell\simeq 10) and the relative contribution of cosmological gravitational waves T/S. Increasing Ων\Omega_\nu weaken the requirements to the value of T/S, however even for Ων≤0.4\Omega_\nu\le 0.4 the models with h+n≥1.5h+n\ge 1.5 suggest considerable abundance of gravitational waves: T/S∼>0.3{}^>_\sim 0.3. In models with Ων≤0.4\Omega_\nu\le 0.4 and scale-invariant spectrum of density perturbations (n=1n=1): T/S∼>10(h−0.47){}^>_\sim 10(h-0.47). Minimization of the value T/S is possible only in the range of the red spectra (n<1n<1) and small hh (<0.6<0.6). It is shown that the models with T/S∈[0,3]\in [0, 3] admit both moderate red and blue spectra of density perturbations, n∈[0.9,1.2]n\in[0.9,1.2], with rather high abundance hot dark matter, Ων∈[0.2,0.4]\Omega_\nu\in [0.2,0.4]. Any condition, n<0.9n<0.9 or Ων<0.2\Omega_\nu<0.2, decreases the relative amplitude of the first acoustic peak for more than 30% in comparison with its hight in the standard CDM normalized by COBE data.Comment: 4 pages, 2 figures included; contribution to the Proceedings of Moriond 2000 "Energy Densities in the Universe", Les Arcs, France, January 22-29 200

    Pulsations and Long-Term Light Variability of Three Candidates to Protoplanetary Nebulae

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    We present new photometric data and analysis of the long-duration UBV photoelectric observations for three candidates to protoplanetary objects - F-supergiants with IR-excesses located at large galactic latitudes, IRAS 18095+2704, IRAS 19386+0155, and IRAS 19500-1709. All three stars have revealed quasiperiodic low-amplitude variabilities caused by pulsations observed against the long-term trends of brightnesses. For IRAS 18095+2704=V887 Her we have found a pulsation period of 109 days and a linear trend of brightness under the constant colours if being averaged over the year timescale. The light curve of IRAS 19386+0155=V1648 Aql over 2000-2008 can be approximated by a wave with a main period of 102 days which is modulated by close frequency, with a period of 98 days, that results in brightness oscillations with a variable amplitude. V1648 Aql has also shown synchronous reddening together with a persistent rise of brightness in the V-band. IRAS 19500-1709=V5112 Sgr experiences irregular pulsations with the periods of 39 and 47 days. The long-term component of the variability of V5112 Sgr may be related to the binary character of this star.Comment: 11 pages, 6 figures, accepted for publication in Pis'ma Astron. Z

    Global regularity of weak solutions to quasilinear elliptic and parabolic equations with controlled growth

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    We establish global regularity for weak solutions to quasilinear divergence form elliptic and parabolic equations over Lipschitz domains with controlled growth conditions on low order terms. The leading coefficients belong to the class of BMO functions with small mean oscillations with respect to xx.Comment: 24 pages, to be submitte
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