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 $\beta_2$ and $\beta_3$. The system is considered to oscillate between positive and negative $\beta_3$-values, by rounding an infinite potential core in the $(\beta_2,\beta_3)$-plane with $\beta_2>0$. 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 $^{150}$Nd, $^{152}$Sm, $^{154}$Gd and $^{156}$Dy is presented.Comment: 25 pages, 13 figures. Accepted in Phys. Rev.

Anomalous biased diffusion in a randomly layered medium

We present analytical results for the biased diffusion of particles moving under a constant force in a randomly layered medium. The influence of this medium on the particle dynamics is modeled by a piecewise constant random force. The long-time behavior of the particle position is studied in the frame of a continuous-time random walk on a semi-infinite one-dimensional lattice. We formulate the conditions for anomalous diffusion, derive the diffusion laws and analyze their dependence on the particle mass and the distribution of the random force.Comment: 19 pages, 1 figur

Magnetic relaxation in finite two-dimensional nanoparticle ensembles

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

Comparison of competitiveness of grid companies and industrial companies' own generating units

In contemporary Russia, the existing electricity supply model is gradually changing, the focus shifting to the priority development of small-scale distributed power generation. It is, however, impossible to significantly reduce grid electricity consumption in the near future. Conditions for grid companies are getting increasingly competitive, which may result in higher tariffs for consumers. At the same time, the development of small-scale power generation in this country is chaotic and its efficiency has never been adequately compared to that of grid electricity consumption. The article looks at factors and conditions that may help boost grid companies' competitiveness. It also provides a new developed methodology for comparative analysis of the efficiency of the construction of a company's own generating unit as opposed to consuming grid electricity. The article contains estimates of the cost of connection technologies to the grid and electricity tariffs for different scenarios of development. The article looks at the potential for tariff reduction and reveals peculiarities and the cost of construction and operation of generating units for industrial companies. The methodology was tested in Chelyabinsk Region which is served by JSC "Interregional Distribution Grid Company of Ural". © 2017 WIT Press

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

The cross sections of the processes $^4$He($\gamma,p$)$^3$H and $^4$He($\gamma,n$)$^3$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

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

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

Financing – The basis of organization and realization of the investment policy of Russian enterprises

The relevance of the research: the relevance of research problem caused the necessity in organization investment policy of Russian enterprises for intensification their strategic investment development and insufficient development of theoretical and methodological aspects in attracting financial resources for the realization of investment decisions. Purpose of the research: the purpose of this article concludes in developing of measures to overcome the negative impact of the factors limiting the financial support of the investment activity of Russian companies in the context of a systematic approach. Methods of research: the main method of research of this problem is dialectical method of cognition of reality, allowing to investigate this issue thoroughly and interpret scientific results. Results of the research: Identify issues that restrict financing and proposed measures to overcome the negative impact of the factors limiting the financial support of the investment activity of Russian companies, including the modernization of the tax policy and the depreciation policy of the enterprise, the solution lowered the carrying amount and the residual value of fixed assets. Developed measures to promote the revitalization of financing strategic investment decisions on the basis of a common mechanism of tax regulation and amortization. Practical significance: realization of these measures could attract significant financial resources for intensification of the investment activity of Russian companies in the long term. © 2016 Charaeva et al