Stable multiple-charged localized optical vortices in cubic-quintic nonlinear media

The stability of two-dimensional bright vortex solitons in a media with focusing cubic and defocusing quintic nonlinearities is investigated analytically and numerically. It is proved that above some critical beam powers not only one- and two-charged but also multiple-charged stable vortex solitons do exist. A vortex soliton occurs robust with respect to symmetry-breaking modulational instability in the self-defocusing regime provided that its radial profile becomes flattened, so that a self-trapped wave beam gets a pronounced surface. It is demonstrated that the dynamics of a slightly perturbed stable vortex soliton resembles an oscillation of a liquid stream having a surface tension. Using the idea of sustaining effective surface tension for spatial vortex soliton in a media with competing nonlinearities the explanation of a suppression of the modulational instability is proposed.Comment: 4 pages, 3 figures. Submitted to Journal of Optics A. The proceedings of the workshop NATO ARW, Kiev 2003 Singular Optics 200

Russian retail ESG transformations development

The article analyse the formation of the sustainable development paradigm and the ESG agenda in Russia. The activities of the largest Russian retailers: leaders in sustainable development and companies with a weaker position in this area is revealed. The relationship between the form of the company and its position in the ESG ratings has been noted. Thus, companies that are required to provide information publicly are higher in level than non-public ones. A characteristic feature of passing the ESG rating assessment is getting high scores in terms of the G-aspect and the E-aspect associated with the demands of the modern market. The authors recommended deepening activities in the field of sustainable development in terms of training employees in digital and environmental competencies, and to strengthen communication strategies regarding the ESG agenda of the largest retailers

Forecast of the dynamics of world import by commodity groups

Objective to forecast the structure and volume of world imports by commodity groups. Methods statistical processing of global trade data with Big Data methods regression and correlation analysis. Results the Russian economy needs to restructure exports. To solve this problem it is important to assess and forecast the global demand for certain goods. The article presents the results of the analysis of the main trends and forecasts of the development of individual industries as well as their place in the global trade. It is shown that in accordance with the forecasts of analysts there are significant prospects in the coming years in the fields of pharmaceutics automotive industry aircraft production telecommunications etc. UNCTAD data with a sample of product groups for each country were used to model the forecast demand for product groups. As a result of the trends modeling the article identifies the main product categories that will have the greatest growth in the global trade. It is established that the constructed forecasts correspond to the data of economic research and forecasts of analytical companies. The article also determines the relationship between imports of goods by country and various indicators. The indicators that are characterized by the highest level of correlation with the studied product categories are revealed. On the basis of the obtained results the conclusions are formulated about the most promising sectors for Russian exports in order to transit to a nonresource economy. Scientific novelty the technique is developed which enables to make longterm forecasts of trade dynamics of large volumes of data. Practical significance the results of the forecast should be used to determine the priorities of Russiarsquos industrial policy aimed at accelerated transition to a nonresource economy

Lymphocyte apoptosis and immune response in patients with drug-resistant fibro-cavernous tuberculosis with different prevalence of destructive changes in the lungs

Disturbances of programmed cell death are at the heart of many immunopathological processes in tuberculosis. The relationship between activity of apoptosis and severity of immune response is of particular interest in the patients with fibrous-cavernous drug-resistant pulmonary tuberculosis at different extent of the process. The paper concerns features of apoptosis, proliferative activity of lymphocytes, cytokine’s production and subpopulation composition of peripheral blood lymphocytes in the patients with uni- and bilateral fibrous-cavernous drug-resistant pulmonary tuberculosis. It was shown that apoptotic rates in the examined patients is closely related to extent of pathological process. Extent of early and late apoptosis and, accordingly, the number of living cells reflected the progression degree of destructive process in the lungs affected by fibrous-cavernous tuberculosis. The possibility of predicting the extent of destructive changes in affected lungs based on expression of apoptosis markers is presumed. Index of activity for early apoptosis of T lymphocytes, exceeding normal values by 25% and higher were clinically significant. A clear relationship between the immune response and apoptosis level was revealed. Ambiguous changes of immunological parameters were shown with increasing apoptosis associated with the severity of destructive changes. Increased apoptotic cell death in all patients with fibrous-cavernous tuberculosis, regardless of extent of the process, was associated with inhibition of antigen-specific proliferative response, decrease in CD25+ lymphocytes, increased numbers of B cells, along with decreased production of IFNγ, IL-8, and increased IL-2 response to PPD. In cases of unilateral destruction, increased apoptotic rates were accompanied by a decrease in the CD95+ cell numbers, and a decrease in TNFα production. On the contrary, in patients with bilateral destruction it was characterized by a high content of CD95+ lymphocytes, increased production of TNFα and IL-10. An index of extremely unfavorable course of the process is a combination of high apoptosis levels and low antigen-specific response with low expression of CD25+ cells, increased number of CD19+ and CD95+ lymphocytes, decreased production of IFNγ, IL-8 and increased production of IL-2, TNFα, IL-10. The relationships found in the work indicate that the combined assessment of apoptosis indexes, together with immunological parameters, has a higher informative value when assessing the state of immunocompetent cells, the origin of the process and trends for its development. Detecting the features of programmed lymphocyte death, in conjunction with immune parameters, allows to evaluate the role of apoptosis in each single case and to predict the course of the process, with subsequent justification of immunotherapy administration

Structural and thermodynamic properties of molecular complexes of aluminum and gallium trihalides with bifunctional donor pyrazine: decisive role of Lewis acidity in 1D polymer formation

Solid state structures of group 13 metal halide complexes with pyrazine (pyz) of 2 : 1 and 1 : 1 composition have been established by X-ray structural analysis. Complexes of 2 : 1 composition adopt molecular structures MX3·pyz·MX3 with tetrahedral geometry of group 13 metals. Complexes of AlBr3 and GaCl3 of 1 : 1 composition are 1D polymers (MX3·pyz)∞ with trigonal bipyramidal geometry of the group 13 metal, while the weaker Lewis acid GaI3 forms the monomeric molecular complex GaI3·pyz, which is isostructural to its pyridine analog GaI3·py. Tensimetry studies of vaporization and thermal dissociation of AlBr3·pyz and AlBr3·pyz·AlBr3 complexes have been carried out using the static method with a glass membrane null-manometer. Thermodynamic characteristics of vaporization and equilibrium gas phase dissociation of the AlBr3·pyz complex have been determined. Comprehensive theoretical studies of (MX3)n·(pyz)m complexes (M = Al, Ga; X = Cl, Br, I; n = 1, 2; m = 1–3) have been carried out at the B3LYP/TZVP level of theory. Donor–acceptor bond energies were obtained taking into account reorganization energies of the fragments. Computational data indicate that the formation of (MX3·pyz)∞ polymers with coordination number 5 is only slightly more energetically favorable than the formation of molecular complexes of type MX3·pyz for X = Cl, Br. It is expected that on melting (MX3·pyz)∞ polymers dissociate into individual MX3·pyz molecules. This dovetails with low melting enthalpies of the (MX3·pyz)∞ complexes. Polymer stability decreases in the order AlCl3 > AlBr3 > GaCl3 > AlI3 > GaBr3 > GaI3. For MI3·pyz complexes computations predict that the monomeric structure motif is more energetically favorable compared to the catena polymer. These theoretical predictions agree well with the experimentally observed monomeric complex GaI3·pyz in the solid state. Thus, the Lewis acidity of the group 13 halides may play a decisive role in the formation of 1D polymeric networks

The influence of a combined strain-heat treatment on the features of electromagnetic testing of fatigue degradation of quenched constructional steel

The possibilities of the magnetic and eddy-current methods for testing fatigue degradation during low-cycle loading of quenched steel 50 (0.51% C) that was subjected to a combined strain-heat treatment according to an optimal regime that included friction treatment with subsequent tempering at T = 350 C, were investigated. It is shown that for steel that was subjected to a combined nanostructuring treatment, the accumulation of a plastic strain under "hard" cyclic loading can be tested using the coercimetric method and values of the residual magnetic induction on the major and minor magnetic-hysteresis loops, values of the maximum and initial magnetic permeabilities, and readings of an eddy-current instrument at a low excitation frequency of the eddy-current transducer. The appearance of surface fatigue cracks can be tested via eddy-current measurements at high frequencies, when the contribution of the crack formation in the hardened layer to the eddy-current characteristics is considerable. © 2013 Pleiades Publishing, Ltd

New materials based on polylactide modified with silver and carbon ions

An integrated study of poly-L-lactide (PL) synthesis and the physicochemical properties of film surfaces, both modified by silver and carbon ion implantation and also unmodified PL surfaces, has been carried out. Surface modification was done using aMevva-5.Ru metal ion source with ion implantation doses of 1·1014, 1·1015 and 1·1016 ion/cm2. Material characterization was done using NMR, IRS, XPS and AFM. The molecular weight (MW), micro-hardness, surface resistivity, and limiting wetting angle of both un-implanted and implanted samples were measured. The results reveal that degradation of PL macromolecules occurs during ion implantation, followed by CO or CO2 removal and MW decrease. With increasing implantation dose, the glycerol wettability of the PL surface increases but the water affinity decreases (hydrophobic behavior). After silver and carbon ion implantation into the PL samples, the surface resistivity is reduced by several orders of magnitude and a tendency to micro-hardness reductionis induced

Eddy-current testing of fatigue degradation upon contact fatigue loading of gas powder laser clad NiCrBSi-Cr 3 C 2 composite coating

The possibilities of the eddy-current method for testing the fatigue degradation under contact loading of gas powder laser clad NiCrBSi-Cr 3 C 2 composite coating with 15 wt.% of Cr 3 C 2 additive have been investigated. It is shown that the eddy-current testing of the fatigue degradation under contact loading of the NiCrBSi-15%Cr 3 C 2 composite coating can be performed at high excitation frequencies 72-120 kHz of the eddy-current transducer. At that, the dependences of the eddy-current instrument readings on the number of loading cycles have both downward and upward branches, with the boundary between the branches being 3×10 5 cycles in the given loading conditions. This is caused, on the one hand, by cracking, and, on the other hand, by cohesive spalling and compaction of the composite coating, which affect oppositely the material resistivity and, correspondingly, the eddy-current instrument readings. The downward branch can be used to monitor the processes of crack formation and growth, the upward branch - to monitor the degree of cohesive spalling, while taking into account in the testing methodology an ambiguous character of the dependences of the eddy-current instrument readings on the number of loading cycles. © 2017 Author(s)