5,168 research outputs found

    Nuclear collective motion with a coherent coupling interaction between quadrupole and octupole modes

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    A collective Hamiltonian for the rotation-vibration motion of nuclei is considered, in which the axial quadrupole and octupole degrees of freedom are coupled through the centrifugal interaction. The potential of the system depends on the two deformation variables β2\beta_2 and β3\beta_3. The system is considered to oscillate between positive and negative β3\beta_3-values, by rounding an infinite potential core in the (β2,β3)(\beta_2,\beta_3)-plane with β2>0\beta_2>0. By assuming a coherent contribution of the quadrupole and octupole oscillation modes in the collective motion, the energy spectrum is derived in an explicit analytic form, providing specific parity shift effects. On this basis several possible ways in the evolution of quadrupole-octupole collectivity are outlined. A particular application of the model to the energy levels and electric transition probabilities in alternating parity spectra of the nuclei 150^{150}Nd, 152^{152}Sm, 154^{154}Gd and 156^{156}Dy is presented.Comment: 25 pages, 13 figures. Accepted in Phys. Rev.

    Regional development and banking activities

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    This article is a continuation of studies devoted to the interaction of the region and its banking system. The research object in this article is the banking system of the Rostov region, the Southern Federal District, and its impact on the acceleration of socioeconomic development of both the regions. The subject of the study is interaction of banks with the real sector of the economy and the population of the region. The authors analyzed the scientific sources exploring the interaction of the banking and real sectors of the economy and methodological approaches to the analysis of banking activities’s effects on the region and its socio-economic indicators. Based on econometric modeling, quantitative and qualitative regularities of the indicators are revealed. As a result, authors concluded that the growth in the total volume of profits received by existing credit institutions contributes to the growth of such important socio-economic indicators like Gross Regional Product, internal costs of research and development, labor productivity, fixed asset investments, per capita income, growth of deposits attracted by credit institutions, as well as the growth in the amount of debt on loans extended by credit institutions to legal entities and individuals.peer-reviewe

    Two-body Photodisintegration of 4^{4}He with Full Final State Interaction

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    The cross sections of the processes 4^4He(γ,p\gamma,p)3^3H and 4^4He(γ,n\gamma,n)3^3He are calculated taking into account the full final state interaction via the Lorentz integral transform (LIT) method. This is the first consistent microscopic calculation beyond the three--body breakup threshold. The results are obtained with a semirealistic central NN potential including also the Coulomb force. The cross sections show a pronounced dipole peak at 27 MeV which lies within the rather broad experimental band. At higher energies, where experimental uncertainties are considerably smaller, one finds a good agreement between theory and experiment. The calculated sum of three-- and four--body photodisintegration cross sections is also listed and is in fair agreement with the data.Comment: 18 pages, 6 figure

    Magnetic relaxation in finite two-dimensional nanoparticle ensembles

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    We study the slow phase of thermally activated magnetic relaxation in finite two-dimensional ensembles of dipolar interacting ferromagnetic nanoparticles whose easy axes of magnetization are perpendicular to the distribution plane. We develop a method to numerically simulate the magnetic relaxation for the case that the smallest heights of the potential barriers between the equilibrium directions of the nanoparticle magnetic moments are much larger than the thermal energy. Within this framework, we analyze in detail the role that the correlations of the nanoparticle magnetic moments and the finite size of the nanoparticle ensemble play in magnetic relaxation.Comment: 21 pages, 4 figure

    Asymptotic solutions of decoupled continuous-time random walks with superheavy-tailed waiting time and heavy-tailed jump length distributions

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    We study the long-time behavior of decoupled continuous-time random walks characterized by superheavy-tailed distributions of waiting times and symmetric heavy-tailed distributions of jump lengths. Our main quantity of interest is the limiting probability density of the position of the walker multiplied by a scaling function of time. We show that the probability density of the scaled walker position converges in the long-time limit to a non-degenerate one only if the scaling function behaves in a certain way. This function as well as the limiting probability density are determined in explicit form. Also, we express the limiting probability density which has heavy tails in terms of the Fox HH-function and find its behavior for small and large distances.Comment: 16 pages, 1 figur

    Tools and methodologies to improve quality of the education process

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    Для повышения эффективности образовательных технологий анализируются следующие составляющие учебного процесса: профессиональные образовательные программы подготовки, соответствующие требованиям заказчика и образовательных стандартов; удовлетворенность заинтересованных сторон (преподавателей, студентов, работодателей) качеством образовательных услуг. Рассматриваются основные этапы реализации процесса улучшения качества: постановка и обоснованность задачи улучшения; оценка ситуации в области качества; определение причин недостатков и разработка контрмер; осуществление разработанных контрмер и оценка их эффективности.The basic stages of realization of process of improvement of quality are considered: statement and validity of a problem of improvement; an estimation of a situation in the field of quality; definition of the reasons of lacks and development of counter-measures; realization of the developed counter-measures and an estimation of their efficiency

    Big Bang Nucleosynthesis Constraints on Hadronically and Electromagnetically Decaying Relic Neutral Particles

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    Big Bang nucleosynthesis in the presence of decaying relic neutral particles is examined in detail. All non-thermal processes important for the determination of light-element abundance yields of 2H, 3H, 3He, 4He, 6Li, and 7Li are coupled to the thermonuclear fusion reactions to obtain comparatively accurate results. Predicted light-element yields are compared to observationally inferred limits on primordial light-element abundances to infer constraints on the abundances and properties of relic decaying particles with decay times in the interval 0.01 sec < tau < 10^(12) sec. Decaying particles are typically constrained at early times by 4He or 2H, at intermediate times by 6Li, and at large times by the 3He/2H ratio. Constraints are shown for a large number of hadronic branching ratios and decaying particle masses and may be applied to constrain the evolution of the early Universe.Comment: 24 pages (revtex), 11 figures, title changed, matches published versio

    Big-Bang Nucleosynthesis and Hadronic Decay of Long-Lived Massive Particles

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    We study the big-bang nucleosynthesis (BBN) with the long-lived exotic particle, called X. If the lifetime of X is longer than \sim 0.1 sec, its decay may cause non-thermal nuclear reactions during or after the BBN, altering the predictions of the standard BBN scenario. We pay particular attention to its hadronic decay modes and calculate the primordial abundances of the light elements. Using the result, we derive constraints on the primordial abundance of X. Compared to the previous studies, we have improved the following points in our analysis: The JETSET 7.4 Monte Carlo event generator is used to calculate the spectrum of hadrons produced by the decay of X; The evolution of the hadronic shower is studied taking account of the details of the energy-loss processes of the nuclei in the thermal bath; We have used the most recent observational constraints on the primordial abundances of the light elements; In order to estimate the uncertainties, we have performed the Monte Carlo simulation which includes the experimental errors of the cross sections and transfered energies. We will see that the non-thermal productions of D, He3, He4 and Li6 provide stringent upper bounds on the primordial abundance of late-decaying particle, in particular when the hadronic branching ratio of X is sizable. We apply our results to the gravitino problem, and obtain upper bound on the reheating temperature after inflation.Comment: 94 pages, 49 figures, to appear in Phys. Rev. D. This is a full length paper of the preprint astro-ph/040249

    The quality assurance system of the trusted Microelectronic production

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    Trust (in reliable and safe operation) in a microelectronics product is mainly «laid down» at the stage of its development and is managed by guarantees of quality and reliability, the developer's qualifications and experience, a rational choice of key technical solutions that implement specified functional and operational characteristics, as well as parrying the main threats to its safety. Similarly, trust in products during their pilot and mass production is managed by the results of effective interaction and a rational combination of two systems: (1) managing the quality and protection of the manufacturer of products (i.e., using trusted processes) and (2) controlling production batches and samples of finished products (i.e., checking the reliability of a complex of technical means). This interaction implements a mutual «transfer of trust» to production processes and finished products – the possibility of spreading trust in production processes to trust in finished products and vice versa. At the stage of mass production, it is necessary first of all to ensure the stability of functional and operational characteristics, as well as acceptable technical and economic indicators of the product while maintaining the quality and protection levels inherent in its development. The article presents the results of an analysis of the critical stages of the microelectronics products production, typical threats arising at these stages, and methods of their parrying. There results allow us to build trust in such products (trust in their reliability and quality)
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