X-ray Diffraction Study of the NaF – LiF – LnF3 (Ln=La,Nd) Eutectic Composition in the Liquid and Solid States

The ternary eutectic alloy with the composition 33 mol % NaF+53 mol % LiF+14 mol % NdF3 has been studied in the liquid and solid states using differential thermal analysis and X-ray diffraction at room and high temperatures. The obtained results demonstrate that the eutectic alloy undergoes no phase transformations at temperatures from 298 K to melting point. Analysis of RMC models of the melt indicates that there is no dense non-crystalline packing of the fluorine anions in contrast to the eutectic NaF—LiF—LaF3 melt

Thermal fluctuations and longitudinal relaxation of single-domain magnetic particles at elevated temperatures

We present numerical and analytical results for the swiching times of magnetic nanoparticles with uniaxial anisotropy at elevated temperatures, including the vicinity of T_c. The consideration is based in the Landau-Lifshitz-Bloch equation that includes the relaxation of the magnetization magnitude M. The resulting switching times are shorter than those following from the naive Landau-Lifshitz equation due to (i) additional barrier lowering because of the reduction of M at the barrier and (ii) critical divergence of the damping parameters.Comment: 4 PR pages, 1 figur

Fagopyrum esculentum Moench plants’ photosynthetic activity correlation with efficient grading factors

About 95% of dry matter of agricultural crops is known to be provided by photosynthesis of plants. At the same time, its potential is realized by less than half: the efficiency of use of PAR by crops is usually in the range of 0.9 -1.5%, at best it reaches 2%. Obviously, activation of photosynthetic activity of plants by means of breeding can be considered as one of the promising ways to increase crop yields. This task is also relevant for buckwheat, which is a demanded food crop in the world market. In this regard, the purpose of the research was to study the possibility of using in buckwheat breeding the indicators of photosynthetic activity of plants based on their relationship with useful - economic characteristics of the variety. The results of the correlation analysis showed that the indicators of photosynthetic activity of buckwheat plants have a significant impact on the formation of the variety yield. Significant relationship of cultivar yield was revealed with leaf area (r=0.71), water use efficiency (r=0.68), photosynthetic potential (r=0.66) and photosynthetic intensity (r=0.35). Similar character of interrelation of these indicators in crop varieties was traced with harvesting index. It was found that the relationship between the structural and functional indicators of the leaf system of plants and the yield of buckwheat varieties does not remain constant, and significantly changes during the growing season of plants. The high polymorphism of the crop gene pool in terms of photosynthetic activity of plants and their significant relationship with the yield of the variety indicate the possibility of targeted breeding work in this direction

The use of microarrays for the identification of the origin of genes of avian influenza viruses in wild birds

Forty-two strains of avian influenza viruses were isolated from the wild waterfowls’ feces in the city of Moscow. These viruses, as well as reference strains and some experimental reassortants, were analyzed by microarrays. The microarrays contained 176 probes to the different segments of influenza virus genome. The microarray helps to determine 1) the hemagglutinin and neuraminidase proteins subtype; 2) the primary structure of the C-terminal sequence of the viral NS1 protein, which serves as a ligand for the PDZ domain; 3) the presence of stop codons in the reading frame of PB1-F2 as well as the N66S substitution in the PB1-F2 viral protein; 4) the presence of the polybasic site for hemagglutinin cleavage. The viruses of the H3N1, H3N6, H3N8, H4N6, H1N1, H5N3, and H11N9 subtypes were identified from the group of wild birds’ isolates. All isolates contained the ESEV sequence at the C-terminus of the NS1 protein and the full-length reading frame for the PB1-F2 protein. The replacement of N66S in PB1-F2 was found in six strains. However, the presence of the ESEV sequence (ligand of PDZ domain) in the NS1 virus protein and the N66S substitution in PB1-F2 did not lead to the pathogenicity of these viruses for mice. All isolates demonstrated high yield growth in chicken embryos and were infectious and immunogenic for mice, but did not induce any clinical symptoms.Forty-two strains of avian influenza viruses were isolated from the wild waterfowls’ feces in the city of Moscow. These viruses, as well as reference strains and some experimental reassortants, were analyzed by microarrays. The microarrays contained 176 probes to the different segments of influenza virus genome. The microarray helps to determine 1) the hemagglutinin and neuraminidase proteins subtype; 2) the primary structure of the C-terminal sequence of the viral NS1 protein, which serves as a ligand for the PDZ domain; 3) the presence of stop codons in the reading frame of PB1-F2 as well as the N66S substitution in the PB1-F2 viral protein; 4) the presence of the polybasic site for hemagglutinin cleavage. The viruses of the H3N1, H3N6, H3N8, H4N6, H1N1, H5N3, and H11N9 subtypes were identified from the group of wild birds’ isolates. All isolates contained the ESEV sequence at the C-terminus of the NS1 protein and the full-length reading frame for the PB1-F2 protein. The replacement of N66S in PB1-F2 was found in six strains. However, the presence of the ESEV sequence (ligand of PDZ domain) in the NS1 virus protein and the N66S substitution in PB1-F2 did not lead to the pathogenicity of these viruses for mice. All isolates demonstrated high yield growth in chicken embryos and were infectious and immunogenic for mice, but did not induce any clinical symptoms

Optically Isotropic and Monoclinic Ferroelectric Phases in PZT Single Crystals near Morphotropic Phase Boundary

We report the finding of unusual scale-dependent symmetry below the ferroelectric Curie temperature in the perovskite Pb(Zr1-xTix)O3 single crystals of morphotropic phase boundary compositions. The crystals of tetragonal symmetry (from x-ray diffraction experiments) on sub-micrometer scale exhibit a macroscopic (optically determined) cubic symmetry. This peculiar optical isotropy is explained by the anomalously small size of tetragonal ferroelectric domains. Upon further cooling the crystals transform to the phase consisting of micrometer-sized domains of monoclinic Cm symmetry.Comment: 7 pages, 3 figure

TECHNOLOGY FOR PRODUCING IRON CASTINGS WITH A HARD WEAR-RESISTANT AND IMPACT-RESISTANT VISCOUS PART OF A MELT

В работе предложена и исследована технология получения чугунных отливок с дифференцированной структурой и свойствами обеспечивающая формирование рабочего слоя изделия из твердого износостойкого белого чугуна, а монтажной части – из вязкого ударостойкого высокопрочного чугуна с шаровидным графитом. Многочисленными лабораторными исследованиями с использованием методов физического и компьютерного моделирования, а также на натурных отливках подтверждена возможность реализации предлагаемой технологии, которая предназначается для изготовления деталей, работающих в условиях ударно-абразивного износа.The work proposed and studied technology for producing iron castings with differentiated structure and properties ensuring the formation of the working layer of wear-resistant products made of hard white iron, and mounting parts – impact-resistant high-strength ductile cast iron with nodular graphite. Numerous laboratory research using the methods of physical and computer simulation as well as natural castings confirmed the feasibility of the proposed technology, which is intended for parts operating under impact-abrasive wear

The influence of Pb vacancies on the properties of PZT-type ceramics transducers

This article is dedicated to prof. J. Ranachowski The result of investigations of the influence of lead vacancies on the crystalline structure of PZT-type ceramic piezoelectric materials is presented. The solid solution of PbTiO3 - PbZrO3 - sigma n=13 Pb(B'1-alpha B''alpha)O3, characterized by the perovskite-type structure (ABO3), is the basis of those materials. The lead vacancies (VPb) was originated by a thermal treatment. Investigations of the influence of the lead deficiency on the crystalline structure of PZT-type ceramics have been performed for solid solutions characterized by compositions corresponding to the tetragonal or rhombohedral boundary of the morphotropic region (PCR-1, PCR-8: Piezoelectric Ceramics of Rostov) and to tetragonal phase region compositions (ceramics of Pb1-x(Zr0.39Ti0.59W0.01Cd0.01) O3). It has been found that the deficiency in lead causes a reconstruction of the perovskite phase crystalline structure or a change of the elementary cell parameters of that phase. The solid solutions on the basis of Pb(Zr,Ti)O3 resolve themselves into PbTiO3, ZrO2 and PbO when the lead deficiency caused by thermal treatment increases

The 2020 magnetism roadmap

Following the success and relevance of the 2014 and 2017 Magnetism Roadmap articles, this 2020 Magnetism Roadmap edition takes yet another timely look at newly relevant and highly active areas in magnetism research. The overall layout of this article is unchanged, given that it has proved the most appropriate way to convey the most relevant aspects of today's magnetism research in a wide variety of sub-fields to a broad readership. A different group of experts has again been selected for this article, representing both the breadth of new research areas, and the desire to incorporate different voices and viewpoints. The latter is especially relevant for thistype of article, in which one's field of expertise has to be accommodated on two printed pages only, so that personal selection preferences are naturally rather more visible than in other types of articles. Most importantly, the very relevant advances in the field of magnetism research in recent years make the publication of yet another Magnetism Roadmap a very sensible and timely endeavour, allowing its authors and readers to take another broad-based, but concise look at the most significant developments in magnetism, their precise status, their challenges, and their anticipated future developments. While many of the contributions in this 2020 Magnetism Roadmap edition have significant associations with different aspects of magnetism, the general layout can nonetheless be classified in terms of three main themes: (i) phenomena, (ii) materials and characterization, and (iii) applications and devices. While these categories are unsurprisingly rather similar to the 2017 Roadmap, the order is different, in that the 2020 Roadmap considers phenomena first, even if their occurrences are naturally very difficult to separate from the materials exhibiting such phenomena. Nonetheless, the specifically selected topics seemed to be best displayed in the order presented here, in particular, because many of the phenomena or geometries discussed in (i) can be found or designed into a large variety of materials, so that the progression of the article embarks from more general concepts to more specific classes of materials in the selected order. Given that applications and devices are based on both phenomena and materials, it seemed most appropriate to close the article with the application and devices section (iii) once again. The 2020 Magnetism Roadmap article contains 14 sections, all of which were written by individual authors and experts, specifically addressing a subject in terms of its status, advances, challenges and perspectives in just two pages. Evidently, this two-page format limits the depth to which each subject can be described. Nonetheless, the most relevant and key aspects of each field are touched upon, which enables the Roadmap as whole to give its readership an initial overview of and outlook into a wide variety of topics and fields in a fairly condensed format. Correspondingly, the Roadmap pursues the goal of giving each reader a brief reference frame of relevant and current topics in modern applied magnetism research, even if not all sub-fields can be represented here. The first block of this 2020 Magnetism Roadmap, which is focussed on (i) phenomena, contains five contributions, which address the areas of interfacial Dzyaloshinskii-Moriya interactions, and two-dimensional and curvilinear magnetism, as well as spin-orbit torque phenomena and all optical magnetization reversal. All of these contributions describe cutting edge aspects of rather fundamental physical processes and properties, associated with new and improved magnetic materials' properties, together with potential developments in terms of future devices and technology. As such, they form part of a widening magnetism 'phenomena reservoir' for utilization in applied magnetism and related device technology. The final block (iii) of this article focuses on such applications and device-related fields in four contributions relating to currently active areas of research, which are of course utilizing magnetic phenomena to enable specific functions. These contributions highlight the role of magnetism or spintronics in the field of neuromorphic and reservoir computing, terahertz technology, and domain wall-based logic. One aspect common to all of these application-related contributions is that they are not yet being utilized in commercially available technology; it is currently still an open question, whether or not such technological applications will be magnetism-based at all in the future, or if other types of materials and phenomena will yet outperform magnetism. This last point is actually a very good indication of the vibrancy of applied magnetism research today, given that it demonstrates that magnetism research is able to venture into novel application fields, based upon its portfolio of phenomena, effects and materials. This materials portfolio in particular defines the central block (ii) of this article, with its five contributions interconnecting phenomena with devices, for which materials and the characterization of their properties is the decisive discriminator between purely academically interesting aspects and the true viability of real-life devices, because only available materials and their associated fabrication and characterization methods permit reliable technological implementation. These five contributions specifically address magnetic films and multiferroic heterostructures for the purpose of spin electronic utilization, multi-scale materials modelling, and magnetic materials design based upon machine-learning, as well as materials characterization via polarized neutron measurements. As such, these contributions illustrate the balanced relevance of research into experimental and modelling magnetic materials, as well the importance of sophisticated characterization methods that allow for an ever-more refined understanding of materials. As a combined and integrated article, this 2020 Magnetism Roadmap is intended to be a reference point for current, novel and emerging research directions in modern magnetism, just as its 2014 and 2017 predecessors have been in previous years

DEVELOPMENT OF RECIPE AND TECHNOLOGY OF COMBINEDSEMI-FINISHED PRODUCTS

The authors set the goal - to develop a formulation of semi-finished meat and vegetable horse meat, poultry, minced eggplant. Compiled by experienced formulation of model samples of meat and vegetable raw materials. In model samples of minced meat the pH was studied, organoleptic characteristics and output were determined in the finished experimental products. As a result of experimental studies, the recipe of meat and cereal cutlets with the optimal ratio of raw materials has been established

Generalised Kawada-Satake method for Mackey functors in class field theory

We propose and study a generalised Kawada--Satake method for Mackey functors in the class field theory of positive characteristic. The root of this method is in the use of explicit pairings, such as the Artin--Schreier--Witt pairing, for groups describing abelian extensions. We separate and simplify the algebraic component of the method and discuss a relation between the existence theorem in class field theory and topological reflexivity with respect to the explicit pairing. We apply this method to derive higher local class field theory of positive characteristic, using advanced properties of topological Milnor K-groups of such fields