A Year after the Outbreak of COVID-19: Applicants’ Perception of Higher Education Quality in the Context of Digitalization and Blended Learning

Introduction. The forced transition of Russian universities to distance learning in 2020 and accelerated digital transformation of educational processes in higher education are the first effects of the COVID-19 pandemic. A key aspect of measuring higher education quality is the perception of its formats by students as university change agents. The aim of the study is to identify the factors that determine the applicants’ positive attitude to learning that includes online elements in the context of the Russian universities’ transition to the blended learning model. Materials and Methods. The empirical base of the research includes the results of an online sociological survey conducted among the applicants for Ural Federal University undergraduate and graduate programmes in 2021. The methods of classification, factor analysis, and coefficients of pair correlations were applied. Additionally, for comparison, data from 2015 for a similar sample (1st year bachelor’s degree students) were used. Results. Positive attitudes towards online and blended learning are gradually increasing. The factor analysis of data from 2021 showed that applicants who support the online and blended learning include: those aspiring for master’s degree upon completing their bachelor’s degree course; those who choose their degree field rationally – men who apply for a state-funded education in any Russian university (including participants of federal contests – ‘Academic Olympics’). The above groups are formed mainly under the influence of external factors. Another group includes those oriented towards self-realization – women who choose their degree field relying on their personal inclinations for a future profession (the influence of internal factors). Discussion and Conclusion. The research results contribute to the development of scientific ideas about the blended learning model and emphasize the value of institutional research based on feedback from university students for making informed management decisions on change. The materials of the paper will be useful when designing the educational process in the Russian universities’ transition to the blended learning model.

rmc-discord: reverse Monte Carlo refinement of diffuse scattering and correlated disorder from single crystals

A user-friendly program has been developed to analyze diffuse scattering from single crystals with the reverse Monte Carlo method. The approach allows for refinement of correlated disorder from atomistic supercells with magnetic or structural (occupational and/or displacive) disorder. The program is written in Python and optimized for performance and efficiency. Refinements of two user cases obtained with legacy neutron-scattering data demonstrate the effectiveness of the approach and the developed program. It is shown with bixbyite, a naturally occurring magnetic mineral, that the calculated three-dimensional spin-pair correlations are resolved with finer real-space resolution compared with the pair distribution function calculated directly from the reciprocal-space pattern. With the triangular lattice Ba3Co2O6(CO3)0.7, refinements of occupational and displacive disorder are combined to extract the one-dimensional intra-chain correlations of carbonate molecules that move toward neighboring vacant sites to accommodate strain induced by electrostatic interactions. The program is packaged with a graphical user interface and extensible to serve the needs of single-crystal diffractometer instruments that collect diffuse-scattering data.

The Nuclear Cooper Pair

This monograph presents a unified theory of nuclear structure and nuclear reactions in the language of quantum electrodynamics, Feynman diagrams. It describes how two-nucleon transfer reaction processes can be used as a quantitative tool to interpret experimental findings with the help of computer codes and nuclear field theory. Making use of Cooper pair transfer processes, the theory is applied to the study of pair correlations in both stable and unstable exotic nuclei. Special attention is given to unstable, exotic halo systems, which lie at the forefront of the nuclear physics research being carried out at major laboratories around the world. This volume is distinctive in dealing in both nuclear structure and reactions and benefits from comparing the nuclear field theory with experimental observables, making it a valuable resource for incoming and experienced researchers who are working in nuclear pairing and using transfer reactions to probe them.

Frequency and polarization emission properties of a photon-pair source based on a photonic crystal fiber

In this work, we experimentally demonstrate a photon-pair source with correlations in the frequency and polarization degrees of freedom. We base our source on the spontaneous four-wave mixing (SFWM) process in a photonic crystal fiber. We show theoretically that the two-photon state is the coherent superposition of up to six distinct SFWM processes, each corresponding to a distinct combination of polarizations for the four waves involved and giving rise to an energy-conserving pair of peaks. Our experimental measurements, both in terms of single and coincidence counts, confirm the presence of these pairs of peaks, while we also present related numerical simulations with excellent experiment-theory agreement. We explicitly show how the pump frequency and polarization may be used to effectively control the signal-idler photon-pair properties, defining which of the six processes can participate in the overall two-photon state and at which optical frequencies. We analyze the signal-idler correlations in frequency and polarization, and in terms of fiber characterization, we input the SFWM-peak experimental data into a genetic algorithm which successfully predicts the values of the parameters that characterize the fiber cross section, as well as predict the particular SFWM process associated with a given pair of peaks. We believe our work will help advance the exploitation of photon-pair correlations in the frequency and polarization degrees of freedom.

Remarks about inhomogeneous pair correlations

Given an infinite subset $\mathcal{A} \subseteq\mathbb{N}$ , let A denote its smallest N elements. There is a rich and growing literature on the question of whether for typical $\alpha\in[0,1]$ , the pair correlations of the set $\alpha A (\textrm{mod}\ 1)\subset [0,1]$ are asymptotically Poissonian as N increases. We define an inhomogeneous generalisation of the concept of pair correlation, and we consider the corresponding doubly metric question. Many of the results from the usual setting carry over to this new setting. Moreover, the double metricity allows us to establish some new results whose singly metric analogues are missing from the literature.

Formation and Assessment of the Investment and Reputation Capital of the Enterprise

The article assesses the influence of factors that form the reputation of an enterprise in the real sector of the economy, on the ability to attract investments and form investment capital. The study aims to identify the most important components of reputation capital that stimulate the inflow of investments for the implementation of projects that are significant for the development of the region. The author applies methods of multidimensional weighted scoring assessment of business reputation, construction of factor models, and identification of regression relationships between investment capital and factors that form business reputation, methods of pair correlations, and modelling. This study assesses the impact of factors on the level of investment capital and business reputation of 38 regionally significant organizations included in the list of residents of the Territory of Advanced Social and Economic Development (TASED) of the Far East and receiving tax incentives and administrative benefits. The scientific hypothesis that the investment capital of an enterprise as a key element of the territorial economic system is formed under the influence of a complex of factors of business reputation is subject to verification. The types of business reputation are identified for enterprises of regional significance. The author makes a conclusion that the inflow of investments and the accumulation of capital is facilitated by information transparency, participation of the enterprise in socio-cultural, educational events in the region, support of ethical and corporate principles. The research results can be used by the management companies of the territories of advanced development and the management of enterprises implementing national projects for the development of the regional economy.

Superconductivity in the doped quantum spin liquid on the triangular lattice

Broad interest in quantum spin liquid (QSL) phases was triggered by the notion that they can be viewed as insulating phases with preexisting electron pairs, such that upon light doping they might automatically yield high temperature superconductivity. Yet despite intense experimental and numerical efforts, definitive evidence showing that doping QSLs leads to superconductivity has been lacking. We address the problem of a lightly doped QSL through a large-scale density-matrix renormalization group study of the t-J model on finite-circumference triangular cylinders with a small but nonzero concentration of doped holes. We provide direct evidences that doping QSL can naturally give rise to d-wave superconductivity. Specifically, we find power-law superconducting correlations with a Luttinger exponent, Ksc ≈ 1, which is consistent with a strongly diverging superconducting susceptibility, $${\chi }_{sc} \,\sim\, {T}^{-(2\,-\,{K}_{sc})}$$ χ s c ~ T − ( 2 − K s c ) as the temperature T → 0. The spin–spin correlations—as in the undoped QSL state—fall exponentially which suggests that the superconducting pair-pair correlations evolve smoothly from the insulating parent state.

Long-range supercurrents through a chiral non-collinear antiferromagnet in lateral Josephson junctions

The proximity-coupling of a chiral non-collinear antiferromagnet (AFM)1–5 with a singlet superconductor allows spin-unpolarized singlet Cooper pairs to be converted into spin-polarized triplet pairs6–8, thereby enabling non-dissipative, long-range spin correlations9–14. The mechanism of this conversion derives from fictitious magnetic fields that are created by a non-zero Berry phase15 in AFMs with non-collinear atomic-scale spin arrangements1–5. Here we report long-ranged lateral Josephson supercurrents through an epitaxial thin film of the triangular chiral AFM Mn3Ge (refs. 3–5). The Josephson supercurrents in this chiral AFM decay by approximately one to two orders of magnitude slower than would be expected for singlet pair correlations9–14 and their response to an external magnetic field reflects a clear spatial quantum interference. Given the long-range supercurrents present in both single- and mixed-phase Mn3Ge, but absent in a collinear AFM IrMn16, our results pave a way for the topological generation of spin-polarized triplet pairs6–8 via Berry phase engineering15 of the chiral AFMs.