297 research outputs found
Nonmatrix varieties of nonassociative algebras
A variety of associative algebras is called nonmatrix if it does not contain
the algebra of 2 x 2 matrices over the given field. Nonmatrix varieties were
introduced and studied by V.N.Latyshev in relation with the Specht problem.
Some characterizations of nonmatrix varieties were obtained in the paper [10].
In the given paper the notion of nonmatrix variety is extended for
nonassociative algebras, and the characterization from [10] is generalized for
alternative, Jordan, and some other varieties of algebras
Control of the magnitude and spatial distribution of interference energy flows in near fields of systems of identical radiators
The problem of active control for both the magnitude and spatial distribution of individual components of the interference component of the Poynting vector within the near zone of a system of radiators is studied. The characteristic size of this zone is on the order of the wavelength and is characterized by the presence of evanescent (nonpropagating) fields, which are formed due to the interference interaction of radiators. Using multipole expansions for fields and special summation formulas for such expansions allows one to obtain concise expressions convenient in carrying out numerical calculations. The results of calculations confirm the feasibility of the above-mentioned control in principle in solving problems of medium and object sensing
The role played by evanescent fields in the process of formation of radiation of combined radiating systems
The problem of active controlling of the structure of fields of combined radiating systems within their near zone is studied. The characteristic size of this zone is on the order of the wavelength and is characterized by the presence of evanescent (nonpropagating) fields, which are formed, among other things, due to the interference interaction of radiators of the system. Using multipole expansions for fields and special summation formulas for such expansions allows one to obtain concise expressions convenient in carrying out numerical calculations. The results of calculations confirm that the evanescent fields’ structure plays a significant part in the process of the formation of the radiation field
One-year periodization of training loads of Russian and Norwegian elite cross-country skiers
The study intended to compare the training load volume (TrV) distribution of elite Russian (RuXC) and Norwegian (NorXC) cross-country skiers in a one-year macrocycle. Daily TrV of 11 RuXC skiers averaged for the period 2014/15–2017/18. The NorXC skiers’ TrV obtained from the study by Sandbakk (2017). RuXC skiers had a lower volume of low-intensity (LIT, below aerobic threshold) and high-intensity (HIT, above anaerobic threshold) endurance training. They used a “pyramidal” model of intensity ratio during the entire macrocycle and did not decrease the volume of moderate-intensity (MIT) endurance training in competition periods (CPs). Conversely, NorXC skiers followed the “pyramidal” model of intensity in the preparation period (PP) but the “polarized” model in CP, significantly reducing the volume of MIT and increasing that of HIT. RuXC skiers increased TrVs more rapidly at the beginning of PPs, achieving TrV peak in June, and then gradually decreased them by March. NorXC skiers increased TrVs gradually by July and then maintained this approximate volume until November. RuXC skiers had peak volumes of LIT and strength training simultaneously in June; NorXC skiers engaged in large amounts of strength training in May and June until reaching maximum endurance loads. RuXC skiers had two “blocks” of strength training; NorXC skiers had three. A comparative analysis of the TrV distributions among the RuXC and NorXC skiers revealed significant similarity. Therefore, they can consider as models of the modern annual periodization of training loads for this kind of sport
National Report for the IAG of the IUGG 2019-2022
Major results of researches conducted by Russian geodesists in 2019-2022 on
the topics of the International Association of Geodesy (IAG) of the
International Union of Geodesy and Geophysics (IUGG) are presented in this
issue. This report is prepared by the Section of Geodesy of the National
Geophysical Committee of Russia. In the report prepared for the XXVII General
Assembly of IUGG (Germany, Berlin, 11-20 July 2023), the results of principal
researches in geodesy, geodynamics, gravimetry, in the studies of geodetic
reference frame creation and development, Earth's shape and gravity field,
Earth's rotation, geodetic theory, its application and some other directions
are briefly described. For some objective reasons not all results obtained by
Russian scientists on the field of geodesy are included in the report.Comment: Misprint in the title of the arXiv record has been corrected. The
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Hydrogen Release from Irradiated Vanadium Alloy V-4Cr-4Ti
The present work is an attempt to obtain data concerning the influence of neutron and ? irradiation upon hydrogen retention in V-4Cr-4Ti vanadium alloy. The experiments on in-pile loading of vanadium alloy specimens at the neutron flux density 1014 n/cm2s, hydrogen pressure of 80 Pa, and temperatures of 563, 613, and 773 K were carried out using the IVG.1M reactor of the Kazakhstan National Nuclear Center. A preliminary set of loading/degassing experiments with non-irradiated material has been carried out to obtain data on hydrogen interaction with vanadium alloy. The, data presented in this work are related both to non-irradiated and irradiated samples
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