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The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature limit in tilted magnetic fields. At low electron densities, the effective mass is found to be strongly enhanced and independent of the degree of spin polarization, which indicates that the mass enhancement is not related to the electrons’ spins. The observed effect turns out to be universal for silicon-based 2D electron systems, regardless of random potential, and cannot be explained by existing theories.

The coherent elastic scattering of neutrinos off nuclei has eluded detection for four decades, even though its predicted cross section is by far the largest of all low-energy neutrino couplings. This mode of interaction offers new opportunities to study neutrino properties and leads to a miniaturization of detector size, with potential technological applications. We observed this process at a 6.7σ̃ confidence level, using a low-background, 14.6-kilogram CsI[Na] scintillator exposed to the neutrino emissions from the Spallation Neutron Source at Oak Ridge National Laboratory. Characteristic signatures in energy and time, predicted by the standard model for this process, were observed in high signal-to-background conditions. Improved constraints on nonstandard neutrino interactions with quarks are derived from this initial data set.

The work demonstrates the results of noise-like (spread-spectrum) signal application in oil industry. A functional practical scheme of information support in bottom-to-head communication channel is presented. Some of spread-spectrum signal noise resistance issues are described.

The temperatures of the phase transitions for polyethyleneterephthalate samples containing recycled PET (the product Vivilen) and the waste materials from its production were analyzed by differential scanning calorimetry and x-ray structural analysis, and the ratio of the crystalline and amorphous phases was determined. The polyethyleneterephthalate samples were arranged according to their glass transition and melting points, which made it possible to correlate the samples according to the degree of crystallinity. In order to obtain a filament based on the dust waste from the solid-phase polycondensation process an extrusion temperature regime was established, and samples of filaments for 3D printing that meet the requirements of GOST R 59100-2020 were obtained.

Features of obtaining fullerene-containing soot during combustion of gaseous and liquid hydrocarbons with the influence of an electric field on the flame are discussed. The characteristic voltage - current characteristics of the discharge created in the flame region and electron microscopic photographs of fullerene-containing soot were obtained.

— A laboratory experimental setup based on scintillation detectors is described, which is used in the educational process at MEPhI. The setup is designed to study methods for investigating the characteristics of scintillators as well as the operation of a silicon photoelectron multiplier. The results of measuring the spectra from standard gamma-radiation sources using various scintillators are shown, calibration is carried out, and an estimation of the energy resolution of the detectors is given.

An experimental facility has been developed by MEPhI to study the spectrometric characteristics of gas mixtures for cascade gas electron multipliers (GEMs), which are widely used in modern tracking, Cherenkov, and synchrotron-radiation detectors designed for high-energy physics experiments. The characteristics of the gas mixture for the GEMs used in the BM@N international experiment (Joint Institute for Nuclear Research, Dubna) have been investigated. The applicability of this facility for laboratory works accompanying the Nuclear Physics and Technology master’s courses is noted.

A method is proposed for the rapid determination of the phase composition of polyethylene terephthalate materials using a portable Raman spectrometer. A crystallinity index is defined as the ratio of the intensity of a characteristic peak for crystalline samples to the sum of the intensities of the characteristic peaks of crystalline and amorphous samples. The correspondence between the crystallinity of the samples determined by this rapid determination procedure and from the corresponding differential scanning calorimetry data is characterized by a coefficient of determination R2 = 0.9684.

The use of mathematical modelling at the early stages of product design makes it possible to substantiate fundamental technical solutions, taking into account all possible (large number) requirements for the product by consumers and operation. At this (early) stage, it is important to use well-tested and convenient tools for designers to create virtual stands and digital twins (DC), confirming compliance, as well as forming the structure of systems and products as a whole. The article discusses a comprehensive methodology for the process of constructing a numerical model of a locomotive for analysing dynamics under various operating conditions. It is based on the top-level structural model (LBM), which is presented in the form of a block diagram and is used at all stages of product design. The required detailing of such a model depends on the actual tasks. The detailed models of the systems that have been developed within the framework of the work are presented.

We presented the results of a spectroscopic study of LiCaAlF 6 (LiCAF) samples doped with Ce 3+ and Yb 3+ ions. Change in the valence of the Yb 3+ → Yb 2+ ions were detected upon excitation resonant to Ce 3+ absorption. Luminescence of Ce 3+ and Yb 2+ ions was observed at the wavelengths of 280–320 nm and 380 nm, respectively. We associate the appearance of divalent ytterbium with photoionization of Ce 3+ ions and subsequent capture of a free charge carriers by Yb 3+ ions. Based on the temperature dependence of the lifetimes of excited Yb 2+ , we conclude that energy transfer to the Yb 3+ ion occurs due to the charge exchange processes of Yb 2+ ions. However, we also see additional quenching of Yb 2+ luminescence when the temperature is raised to room temperature.