733 research outputs found

    Present and Future Gamma-Ray Probes of the Cygnus OB2 Environment

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    The MAGIC Collaboration has provided new observational data pertaining to the TeV J2032+4130 gamma-ray source (within the Cygnus OB2 region), for energies E_gamma >400 GeV. It is then appropriate to update the impact of these data on gamma-ray production mechanisms in stellar associations. We consider two mechanisms of gamma-ray emission, pion production and decay (PION) and photo-excitation of high-energy nuclei followed by prompt photo-emission from the daughter nuclei (A*). We find that while the data can be accommodated with either scenario, the A* features a spectral bump, corresponding to the threshold for exciting the Giant Dipole Resonance, which can serve to discriminate between them. We comment on neutrino emission and detection from the region if the PION and/or A* processes are operative. We also touch on the implications for this analysis of future Fermi and Cerenkov Telescope Array data.Comment: 6 pp, 2 figs. Matching version publihed in Phys. Rev.

    Josephson tunnel junctions with nonlinear damping for RSFQ-qubit circuit applications

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    We demonstrate that shunting of Superconductor-Insulator-Superconductor Josephson junctions by Superconductor-Insulator-Normal metal (S-I-N) structures having pronounced non-linear I-V characteristics can remarkably modify the Josephson dynamics. In the regime of Josephson generation the phase behaves as an overdamped coordinate, while in the superconducting state the damping and current noise are strikingly small, that is vitally important for application of such junctions for readout and control of Josephson qubits. Superconducting Nb/AlOx{_x}/Nb junction shunted by Nb/AlOx{_x}/AuPd junction of S-I-N type was fabricated and, in agreement with our model, exhibited non-hysteretic I-V characteristics at temperatures down to at least 1.4 K.Comment: 4 pages incl. 3 figure

    Tunnel electron-vibrational spectroscopy of adsorbed complexes on the surface of ultra-small metal nanoparticles

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    This work was supported by the Russian Foundation for Basic Research (the project no. 18-03-00453) and into frameworks of the state task for ICP RAS 0082-2018-0003 (the state registration number АААА-А18-118012390045-2)

    Why to open the closed health care?

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    The article deals with modern aspects of the communication policy in the field of public health. A classic paternalistic and new market (partner) model of interaction in the «doctor-patient» system is described. A hypothesis has been put forward that the crisis of the relationship between the medical and patient communities is the result of a change in the paradigm of behavior caused by economic transformations in the state. To strengthen the regime of citizens’ trust in the national health care system, the necessity of intensifying the communication campaigns of the Ministry of Health of Russia in response to the unfair unilateral information coverage of the media situation in Russian medicine is justified

    Dynamics of Josephson junctions and single-flux-quantum networks with superconductor-insulator-normal metal junction shunts

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    Within the framework of the microscopic model of tunneling, we modelled the behavior of the Josephson junction shunted by the Superconductor-Insulator-Normal metal (SIN) tunnel junction. We found that the electromagnetic impedance of the SIN junction yields both the frequency-dependent damping and dynamic reactance which leads to an increase in the effective capacitance of the circuit. We calculated the dc I-V curves and transient characteristics of these circuits and explained their quantitative differences to the curves obtained within the resistively shunted junction model. The correct operation of the basic single-flux-quanta circuits with such SIN-shunted junctions, i.e. the Josephson transmission line and the toggle flip-flop, have also been modelled.Comment: 8 pages incl. 7 figure

    Microscopic Calculation of Total Ordinary Muon Capture Rates for Medium - Weight and Heavy Nuclei

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    Total Ordinary Muon Capture (OMC) rates are calculated on the basis of the Quasiparticle Random Phase Approximation for several spherical nuclei from 90^Zr to 208^Pb. It is shown that total OMC rates calculated with the free value of the axial-vector coupling constant g_A agree well with the experimental data for medium-size nuclei and exceed considerably the experimental rates for heavy nuclei. The sensitivity of theoretical OMC rates to the nuclear residual interactions is discussed.Comment: 27 pages and 3 figure

    Value-Oriented Model of Tuition in the Context of University 3.0 Paradigm

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    Introduction. This article presents the analysis of transformational changes in the Russian system of higher education. The authors aimed to develop a value-oriented model for the organization of educational activities. The concept of University 3.0 serves as a modern basis for ensuring the global competitiveness of national economies in the digital world. Materials and Methods. The methodological approaches of the study were systematic, comparative and problem-chronological methods. Results. The study expanded the understanding of the main stages of transformation in the higher education system in the Russian Federation. The results show that the destruction of the Soviet academic culture was accompanied by the destruction of the historical institutional balance. As a result, it became necessary to form new norms that define both the rules of interaction within the educational community and the place of this community in the overall social structure. The concept of Education 3.0 is designed to form these normative frameworks and ensure their interiorisation both in the pedagogical community and among students. It is revealed that in the modern Russian educational environment they are formed spontaneously, mainly due to the independent development of new technologies by students, while teachers continue to adhere to the previous educational concepts. Discussion and Conclusion. The practical significance of the study lies in the proposal of specific measures, the implementation of which will form the reputation of the University, attract additional investment, enhance its competitiveness both at the domestic and international level. The timeliness of the study lies in the fact that the analysis of the educational reform was carried out taking into account the needs of value-based management. The results of the study will be useful for the management of higher education institutions to reformulate development concepts, as well as for the executive authorities to further reform the educational system

    Single flux quantum circuits with damping based on dissipative transmission lines

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    We propose and demonstrate the functioning of a special Rapid Single Flux Quantum (RSFQ) circuit with frequency-dependent damping. This damping is achieved by shunting individual Josephson junctions by pieces of open-ended RC transmission lines. Our circuit includes a toggle flip-flop cell, Josephson transmission lines transferring single flux quantum pulses to and from this cell, as well as DC/SFQ and SFQ/DC converters. Due to the desired frequency-dispersion in the RC line shunts which ensures sufficiently low noise at low frequencies, such circuits are well-suited for integrating with the flux/phase Josephson qubit and enable its efficient control.Comment: 6 pages incl. 6 figure

    Relativistic total cross section and angular distribution for Rayleigh scattering by atomic hydrogen

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    We study the total cross section and angular distribution in Rayleigh scattering by hydrogen atom in the ground state, within the framework of Dirac relativistic equation and second-order perturbation theory. The relativistic states used for the calculations are obtained by making use of the finite basis set method and expressed in terms of B-splines and B-polynomials. We pay particular attention to the effects that arise from higher (non-dipole) terms in the expansion of the electron-photon interaction. It is shown that the angular distribution of scattered photons, while it is symmetric with respect to the scattering angle θ\theta=90^\circ within the electric dipole approximation, becomes asymmetric when higher multipoles are taken into account. The analytical expression of the angular distribution is parametrized in terms of Legendre polynomials. Detailed calculations are performed for photons in the energy range 0.5 to 10 keV. When possible, results are compared with previous calculations.Comment: 8 pages, 5 figure
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