956 research outputs found
On increasing of the competitiveness of the garment industry in Siberian Federal District on the basis of the industrial cluster establishment
The issue of the development prospects of the Russian economy and the economy of its individual branches in the regions is highly relevant in terms of the increasing crises and economic development challenges. The scope of the study is a garment industry of the Siberian Federal District, which includes 12 subjects, and only six of them develop the garment industry actively. There are the regions of Kemerovo, Novosibirsk, Omsk, Tomsk, Krasnoyarsk Krai and the Republic of Khakassia. The subject matter of the research is the state and prospects of the garment industry of the Siberian Federal District. It also includes the assessment of the garment industry as one of the sub-sectors of the light industry in terms of its competitiveness in the domestic market. The purpose of the comprehensive study is to determine the conditions and factors affecting the development of the industry, as well as to identify its development reserves and competitiveness on the basis of industrial cluster’s generation. The hypothesis of this study is that in the Siberian Federal District, there are a need and reserves to create a cluster of the garment industry. The main methods of the study are the comparative analysis, the expert assessment of the sector in certain regions of the Siberian Federal District, as well as the assessment of possible formation of the industrial cluster in the region. The results of the study are the evaluation of the competitiveness and prospects of the garment industry in Russia and the Siberian Federal District (a low level of development and competitiveness); the evaluation of the development level of the garment industry in the Federal District, which have showed the demand for apparel products from the population and enterprises, as well as the conditions for the provision of clothing manufacture with natural fabrics and synthetic materials, labor resources and research and development achievements; also the justification of the existing potential for development of a sectoral cluster by means of pooling together the productions and economic communications of the Novosibirsk and Omsk regions at the initial stage. The obtained results should be used to strengthen works for the development of regional industrial cluster (with a creation of a working group at the regional governments, the garment industry development programs, and practical measures for its realization), as well as a creation of conditions for stimulation of investment activity of entrepreneurs. The research has confirmed the hypothesis, that in the Siberian Federal District, there are a need and reserves to create a cluster of the garment industry
Theory of resonant Raman scattering due to spin-flips of resident charge carries and excitons in perovskite semiconductors
We have developed a theory of Raman scattering with single and double spin
flips of localized resident electrons and holes as well as nonequilibrium
localized excitons in semiconductor perovskite crystals under optical
excitation in the resonant exciton region. Scattering mechanisms involving
localized excitons, biexcitons and exciton polaritons as intermediate states
has been examined, the spin-flip Raman scattering by polaritons being a novel
mechanism. The derived equations are presented in the invariant form allowing
one for the analysis of the dependence of scattering efficiency on the
polarization of the initial and scattered light and on the orientation of the
external magnetic field.Comment: 15 pages, 2 figures, 2 table
Kinematic Hopf algebra for amplitudes from higher-derivative operators
Recently it has been shown that Bern-Carrasco-Johansson (BCJ) numerators of colour-kinematic duality for tree-level scattering amplitudes in Yang-Mills theory (coupled with scalars) can be determined using a quasi-shuffle Hopf algebra. In this paper we consider the same theory, but with higher-derivative corrections of the forms α′F3 and α′2F4, where F is the field strength. In the heavy mass limit of the scalars, we show that the BCJ numerators of these higher-derivative theories are governed by the same Hopf algebra. In particular, the kinematic algebraic structure is unaltered and the derivative corrections only arise when mapping the abstract algebraic generators to physical BCJ numerators. The underlying kinematic Hopf algebra enables us to obtain a compact expression for the BCJ numerators of any number of gluons and two heavy scalars for amplitudes with higher-derivative operators. The pure gluon BCJ numerators can also be obtained from our results by a simple factorisation limit where the massive particles decouple
Exciton spin dynamics and photoluminescence polarization of CdSe/CdS dot-in-rod nanocrystals in high magnetic fields
The exciton spin dynamics and polarization properties of the related emission
are investigated in colloidal CdSe/CdS dot-in-rod (DiR) and spherical
core/shell nanocrystal (NC) ensembles by magneto-optical photoluminescence (PL)
spectroscopy in magnetic fields up to 15 T. It is shown that the degree of
circular polarization (DCP) of the exciton emission induced by the magnetic
field is affected by the NC geometry as well as the exciton fine structure and
can provide information on nanorod orientation. A theory to describe the
circular and linear polarization properties of the NC emission in magnetic
field is developed. It takes into account phonon mediated coupling between the
exciton fine structure states as well as the dielectric enhancement effect
resulting from the anisotropic shell of DiR NCs. This theoretical approach is
used to model the experimental results and allows us to explain most of the
measured features. The spin dynamics of the dark excitons is investigated in
magnetic fields by time-resolved photoluminescence. The results highlight the
importance of confined acoustic phonons in the spin relaxation of dark
excitons. The bare core surface as well as the core/shell interface give rise
to an efficient spin relaxation channel, while the surface of core/shell NCs
seems to play only a minor role.Comment: 18 pages, 15 figure
HIV Epidemic situation among Small Indigenous Populations of Northeast Russia
The aim of the study was to analyze and assess the real situation of HIV infection among indigenous peoples established , to investigate the prevalence of risky behavior in relation to HIV also determine the level of awareness of the indigenous population about HIV / AIDS.Materials and Methods 1. Analysis of the data cards of the epidemical investigation hearth HIV data form number 283 «About measures on prevention of HIV , hepatitis B and C , detection and treatment of HIV» , form number 61 «Information on the groups of HIV», outpatients patient. 2. The analysis of the statistical prevalence of HIV infection among men and women , including among indigenous representatives , the structure of HIV transmission , coverage of clinical examination. 3. Data analysis of the sociological study among indigenous representatives. The proposed questionnaire contained both closed and open-ended questions to assess the risk factors of respondents’ behavior and their level of awareness of HIV infection. Evaluation of the reliability of the data performed using Student t-test. Results. In 2000, HIV infection in region penetrated into the population of indigenous peoples and continues to spread. Particular way of life and living conditions, such as seasonal migration within the county, early sexual activity, lack of skills in safe sexual behavior , bad habits contributed to the spread of HIV among this ethnic group. Link transition of HIV infection in a group of indigenous peoples is a high incidence of working shifts and workers, among them 30% are already infected with HIV. In connection with this, the spread of HIV infection among women occurs rapidly. Special role in the spread of HIV infection among women of indigenous peoples plays lifestyle and delated psychosocial problems.Conclusion 1. The most vulnerable to HIV infection and sexually transmitted infections by representatives of indigenous peoples living in the national villages , due to a number of social and psychological factors. 2. In turn, representatives of indigenous peoples living in major cities and towns YaNAO more socially adapted and susceptible to preventive action. 3. In connection with developed family ties can not be ruled skid HIV in tundra communities of nomadic population. 4. Since the nomadic population inaccessible to preventive measures and insufficiently receptive to health information to control the spread of HIV epidemic process on tundra areas will be virtually impossible
Discovery of a flux-related change of the cyclotron line energy in Her X-1
We present the results of ten years of repeated measurements of the Cyclotron
Resonance Scattering Feature (CRSF) in the spectrum of the binary X-ray pulsar
Her X-1 and report the discovery of a positive correlation of the centroid
energy of this absorption feature in pulse phase averaged spectra with source
luminosity.Our results are based on a uniform analysis of observations bythe
RXTE satellite from 1996 to 2005, using sufficiently long observations of 12
individual 35-day Main-On states of the source. The mean centroid energy E_c of
the CRSF in pulse phase averaged spectra of Her X-1 during this time is around
40 keV, with significant variations from one Main-On state to the next. We find
that the centroid energy of the CRSF in Her X-1 changes by ~5% in energy for a
factor of 2 in luminosity. The correlation is positive, contrary to what is
observed in some high luminosity transient pulsars. Our finding is the first
significant measurement of a positive correlation between E_c and luminosity in
any X-ray pulsar. We suggest that this behaviour is expected in the case of
sub-Eddington accretion and present a calculation of a quantitative estimate,
which is very consistent with the effect observed in Her X-1.We urge that Her
X-1 is regularly monitored further and that other X-ray pulsars are
investigated for a similar behaviour.Comment: 4 pages, 2 figures, accepted by A&A Letter
Effect of the Surface on the Electron Quantum Size Levels and Electron g-Factor in Spherical Semiconductor Nanocrystals
The structure of the electron quantum size levels in spherical nanocrystals
is studied in the framework of an eight--band effective mass model at zero and
weak magnetic fields. The effect of the nanocrystal surface is modeled through
the boundary condition imposed on the envelope wave function at the surface. We
show that the spin--orbit splitting of the valence band leads to the
surface--induced spin--orbit splitting of the excited conduction band states
and to the additional surface--induced magnetic moment for electrons in bare
nanocrystals. This additional magnetic moment manifests itself in a nonzero
surface contribution to the linear Zeeman splitting of all quantum size energy
levels including the ground 1S electron state. The fitting of the size
dependence of the ground state electron g factor in CdSe nanocrystals has
allowed us to determine the appropriate surface parameter of the boundary
conditions. The structure of the excited electron states is considered in the
limits of weak and strong magnetic fields.Comment: 11 pages, 4 figures, submitted to Phys. Rev.
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