4,999 research outputs found
Nuclear reactions in hot stellar matter and nuclear surface deformation
Cross-sections for capture reactions of charged particles in hot stellar
matter turn out be increased by the quadrupole surface oscillations, if the
corresponding phonon energies are of the order of the star temperature. The
increase is studied in a model that combines barrier distribution induced by
surface oscillations and tunneling. The capture of charged particles by nuclei
with well-deformed ground-state is enhanced in stellar matter. It is found that
the influence of quadrupole surface deformation on the nuclear reactions in
stars grows, when mass and proton numbers in colliding nuclei increase.Comment: 12 pages, 10 figure
Nuclear collective motion with a coherent coupling interaction between quadrupole and octupole modes
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 and . The system is
considered to oscillate between positive and negative -values, by
rounding an infinite potential core in the -plane with
. 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 Nd, Sm, Gd and Dy is presented.Comment: 25 pages, 13 figures. Accepted in Phys. Rev.
Large-scale Ferrofluid Simulations on Graphics Processing Units
We present an approach to molecular-dynamics simulations of ferrofluids on
graphics processing units (GPUs). Our numerical scheme is based on a
GPU-oriented modification of the Barnes-Hut (BH) algorithm designed to increase
the parallelism of computations. For an ensemble consisting of one million of
ferromagnetic particles, the performance of the proposed algorithm on a Tesla
M2050 GPU demonstrated a computational-time speed-up of four order of magnitude
compared to the performance of the sequential All-Pairs (AP) algorithm on a
single-core CPU, and two order of magnitude compared to the performance of the
optimized AP algorithm on the GPU. The accuracy of the scheme is corroborated
by comparing the results of numerical simulations with theoretical predictions
Alpha-nucleus potential for alpha-decay and sub-barrier fusion
The set of parameters for alpha-nucleus potential is derived by using the
data for both the alpha-decay half-lives and the fusion cross-sections around
the barrier for reactions alpha+40Ca, alpha+59Co, alpha+208Pb. The alpha-decay
half-lives are obtained in the framework of a cluster model using the WKB
approximation. The evaluated alpha-decay half-lives and the fusion
cross-sections agreed well with the data. Fusion reactions between
alpha-particle and heavy nuclei can be used for both the formation of very
heavy nuclei and spectroscopic studies of the formed compound nuclei.Comment: 10 pages, 5 figure
Two-body Photodisintegration of He with Full Final State Interaction
The cross sections of the processes He()H and
He()He 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
Regional development and banking activities
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
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