Multiple quantum NMR dynamics of spin-1/2 carrying molecules of a gas in nanopores

We consider the multiple quantum (MQ) NMR dynamics of a gas of spin carrying molecules in nanocavities. MQ NMR dynamics is determined by the residual dipole-dipole interactions which are not averaged completely due to the molecular diffusion in nanopores. Since the averaged non-secular Hamiltonian describing MQ NMR dynamics depends on only one coupling constant, this Hamiltonian commutes with the square of the total spin angular momentum $\hat I^2$. We use the basis of common eigenstates of $\hat I^2$ and the projection of $I$ on the external magnetic field for investigation of MQ NMR dynamics. This approach allows us to study MQ NMR dynamics in systems consisting of several hundreds of spins. The analytical approximation of the stationary profile of MQ coherences is obtained. The analytical expressions for MQ NMR coherence intensities of the five-spin system in a nanopore are found. Numerical investigations allow us to find the dependencies of intensities of MQ coherences on their orders (the profiles of MQ coherences) in systems consisting of 600 spins and even more. It is shown that the stationary MQ coherence profile in the considered system is an exponential one.Comment: 8 pages, 5 figure

Organization of the Public Procurement System in Japan and the Possibility of Applying Experience in Russia

Purpose: is to identify the features of the organization of the Japanese public procurement system and the applicability of the positive experience for Russia. For this, it is necessary to study the organization of the public procurement system in Japan, highlighting the most effective elements and tools; to show the features of the functioning of the system and possible ways of future development; to give a comparative description of the procurement systems of Japan and Russia; to suggest ways to improve the Russian procurement system, using the experience of Japan.Methods: during the work, general scientific and special research methods were used, including statistical analysis, processing of analytical data, analogies, scientific generalizations, etc.Results: as a result of the analysis of changes in the legislative framework, on the basis of which public procurement in Japan is regulated, the authors examined the qualitative characteristics of the interconnections of the procurement system participants and assessed the development prospects, incl. Special attention is paid to the content and hierarchy of regulatory legal acts regulating the scope of procurement.The important link of the author's research was the procedure for organizing procurement in the course of applying various types of procurement procedures, including open, selective and limited procurement methods. A comparative analysis of the procurement systems of Japan and the Russian Federation allowed us to determine the similarities and differences in the organization of the procurement process.Conclusions and Relevance: as a result of the analysis the validity of the execution of the state order through the competitive procurement system used in world practice has been substantiated. This formed the basis of the targeted approach and the identification of promising directions in the development of the public procurement system in Japan until 2030. The authors highlight the areas that are successfully implemented in the field of public procurement in the Russian Federation. This indicates the positive development of the Russian system, which was created taking into account the best international experience, including Japanese practice. To improve the mechanism of interaction between participants and exchange of experience in the public procurement system, directions have been identified and the most effective tools have been identified

Upper limit on the ultra-high-energy photon flux from AGASA and Yakutsk data

We present the interpretation of the muon and scintillation signals of ultra-high-energy air showers observed by AGASA and Yakutsk extensive air shower array experiments. We consider case-by-case ten highest energy events with known muon content and conclude that at the 95% confidence level (C.L.) none of them was induced by a primary photon. Taking into account statistical fluctuations and differences in the energy estimation of proton and photon primaries, we derive an upper limit of 36% at 95% C.L. on the fraction of primary photons in the cosmic-ray flux above 10^20 eV. This result disfavors the Z-burst and superheavy dark-matter solutions to the GZK-cutoff problem.Comment: revtex, 8 pages, 4 figure

Modification of the transmission spectrum of the ”semiconductor-dielectric” photonic crystal in an external magnetic field

In this paper, some features of electromagnetic transmission of the waves of ”semiconductor dielectric” periodic Bragg structure with a finite number of periods have been investigated. In the absence of absorption, for a structure with p-type semiconductor layers, we have analyzed the dependences on the external magnetic field of photon spectrum and transmission coefficient spectrum. It has been shown that with an increasing magnetic field, there is a significant narrowing of bandwidth and broadening of band gaps, as well as formation of new band gaps in the resonance region. The boundaries of all forbidden and allowed bands are shifted to higher frequencies with the increase of the angle of radiation incidence

Overcoming of intercultural barriers in the educational environment

The article is devoted to topical issues related to the emergence and overcoming of intercultural barriers in the educational environment. The goal of the article lies in the analysis of the theoretical foundations of intercultural barriers, clarification of their types, examination of coping methods, as well as the investigation of experience of intercultural barriers' solution in educational environment of post-Soviet republics, identifying of problem areas and making recommendations for their elimination. The most significant scientific and practical results, obtained in the study, are: author's interpretation of the content and the conceptual nature of the intercultural barriers in the learning environment; specified types of intercultural barriers in education; model of multicultural education, developed on the example of the middle school, that will allow effectively to overcome intercultural barriers and to minimize their negative impact on the upbringing and education in educational institutions of the CIS countries thanks to the integration of multicultural component in the educational process and extracurricular work

The role of non-commercial cyprinids in maintenance and spread of the opisthorchiasis focus in the middle Ob River basin (Tomsk region, Russia)

The study assessed the role of non-commercial cyprinid species in maintaining the opisthorchiasis focus in the middle Ob River basin, Tomsk region, Russia. The source of O. felineus infection for humans and carnivores is fish of the family Cyprinidae. This is the most numerous family, 14 species live in the middle Ob River basin, which includes 6 commercial species and 8 non-commercial species. This study aimed to investigate the current situation on infestation of non-commercial cyprinids with O. felineus metacercariae and their role in maintaining and spreading the natural focus of opisthorchiasis in the middle Ob River basin. We investigated 4 non-commercial species (tench, sunbleak, common bleak, gudgeon), which are highly abundant in water bodies. Tench, common bleak and gudgeon are objects of amateur fishing. These species are traditionally included in the diet of the local population. Opisthorchis felineus metacercariae were recorded in muscles of all the examined fish species. The identification of metacercariae was confirmed by morphological methods and PCR diagnostics. Tench and sunbleak are the main sources of opisthorchiasis infection in the floodplain lakes of the Ob River basin (the prevalence of tench infection is 89.3% and mean intensity of infection is 11.2 metacercariae per fish, the prevalence of sunbleak infection is 50.9% and the intensity of infection is 4.25 metacercariae per fish). The prevalence of infection in the introduced common bleak from the rivers of the middle Ob River basin is rapidly increasing from 2.4 (2016-2018) to 37.5% (2020-2021), and mean intensity of infection increased from 1 to 4.15. The epizootic state of water bodies in the middle Ob River basin remains unfavorable in relation to opisthorchiasis. Tench, common bleak and sunbleak, along with ide and dace, are the main source of infection for humans and animals, which is evidenced by high infection with Opisthorchis felineus metacercariae in these numerous fish species. They pose the greatest danger of infection of people and animals with opisthorchiasis. These species should be included in the campaign to avoid raw and poorly cooked fish in the diet. In addition, such species as roach, bream and sunbleak also pose the danger of infection with opisthorchiasis, but to a lesser extent