ФАКТОРЫ, ВЛИЯЮЩИЕ НА МОТИВАЦИЮ УЧЕНИЯ У СТУДЕНТОВ

The influence of the individual psychological factors on the formation of the motivation in learning was examined in 53 students of the I and II medical faculty. The modern psychological testing were used for definition of the psychological and individual peculiarities. In average the students demonstrated the score of anxiety in the range of middle level, but the 1-course students had the same indices higher a little. The motivation in learning was strongly leveled off in students with high anxiety level.Было изучено влияние индивидуально-психологических факторов на формирование мотивации учения у 53 студентов I и II курсов медицинского вуза. Для изучения индивидуальных, психических особенностей применялись методики, которые используются в современных психологических исследованиях. Показатели тревожности у студентов в среднем находились в пределах среднего уровня, хотя были несколько выше у студентов I курса. У студентов с высоким уровнем тревожности была резко снижена мотивация учения

ВЛИЯНИЕ ПРОЦЕССА СЕЛЕКТИВНОГО ЛАЗЕРНОГО ПЛАВЛЕНИЯ НА СТРУКТУРУ И СВОЙСТВА СПЛАВОВ

On the example of austenitic Fe-17%Cr-12%Ni-0.02%C (316 L) and nickel heat-resistant Ni-11%Cr-5%Co-6%Al-3%Ti-4%Mo-5%W-0.16%C-0.02%B (ZhS6K-VI) alloys, the characteristic features of the structure formed in the process of selective laser melting (SLM) are analyzed. It is shown that alloys after SLM have a hierarchical structure, their dislocation structure is similar to the dislocation structure of a deformed material, atoms of alloying elements form segregations or excess phase particles on dislocation tangles, significant residual stresses are present in the structure, and a crystallographic texture is observed. The peculiarities of the structures formed lead to an increase in the strength characteristics and thermal stability of the alloys in comparison with those observed after standard treatments.На примере аустенитного Fe-17%Cr-12%Ni-0.02%C (316 L) и никелевого жаропрочного Ni-11%Cr-5%Co-6%Al-3%Ti-4%Mo-5%W-0.16%C-0.02%B (ЖС6К-ВИ) сплавов проанализированы характерные особенности структуры, формируемой в процессе селективного лазерного плавления (СЛП). Показано, что сплавы после СЛП имеют иерархичную структуру, их дислокационное строение подобно дислокационному строению деформированного материала, атомы легирующих элементов формируют сегрегации или частицы избыточной фазы на сплетениях дислокаций, в структуре присутствуют значительные остаточные напряжения, наблюдается кристаллографическая текстура. Особенности формируемых структур приводят к повышению прочностных характеристик и термической стабильности сплавов по сравнению с наблюдаемыми после стандартных обработок

Features of nitrided layers in martensitic steel obtained by direct laser melting

Analysis of nitrided layers formed on 25-Cr-13-Ni-2 martensitic class steel obtained by the additive manufacturing process of direct laser melting (DLM) is performed. It is shown that in the process of nitriding in a glow discharge at a temperature of 540 °C for 24 hours, the thickness of the diffusion layer for steel obtained by the DLM method is more than 2 times greater than the layer formed in the same nitriding process for steel obtained by rolling with subsequent improvement. The formed layer on the steel obtained by the DLM method is about 140-160 microns, against approximately 70 microns on the steel obtained by rolling. In the layers obtained on steel produced by the DLM hardness also decreases with depth more slowly than hardness in a layer on steel produced by rolling. X-ray phase analysis revealed the strengthening phases in the nitrided layers, which is the same for all studied cases: y' and CrN nitrides. © 2022 Author(s)

Structural features of alloys manufactured by laser powder bed fusion

Structural features of austenitic steel 316L and nickel alloy Ni-11%, Cr-5%, Co-6%, Al-3%, Ti-4%, Mo-5%, W-0.16%, C-0.02%, B (ZhS6K-VI) manufactured by laser powder bed fusion (L-PBF) were studied in this work. Alloys structures were formed under ultrafast cooling rates from the melt (105-107 K/s) and subsequent thermal cycling during re-melting of materials adjacent regions. It is known that such cooling conditions are nonequilibrium and can result in formation of nonequilibrium structures in alloys. The paper describes the features of such structures and some structural features for different alloys are considered: hierarchical structure, consisting of grains and subgrains; inhomogeneity of the distribution of alloying elements, accumulated at cell boundaries or secondary phases precipitation; high dislocations density with the cellular structure similar to those after plastic deformation; high macro stresses initiated cracking, and crystallographic texture resulted in anisotropy of mechanical properties. © 2022 Author(s)

ФАКТОРЫ, ВЛИЯЮЩИЕ НА МОТИВАЦИЮ УЧЕНИЯ У СТУДЕНТОВ

The influence of the individual psychological factors on the formation of the motivation in learning was examined in 53 students of the I and II medical faculty. The modern psychological testing were used for definition of the psychological and individual peculiarities. In average the students demonstrated the score of anxiety in the range of middle level, but the 1-course students had the same indices higher a little. The motivation in learning was strongly leveled off in students with high anxiety level.Было изучено влияние индивидуально-психологических факторов на формирование мотивации учения у 53 студентов I и II курсов медицинского вуза. Для изучения индивидуальных, психических особенностей применялись методики, которые используются в современных психологических исследованиях. Показатели тревожности у студентов в среднем находились в пределах среднего уровня, хотя были несколько выше у студентов I курса. У студентов с высоким уровнем тревожности была резко снижена мотивация учения

Structural features of metals and alloys formed in the process of selective laser melting

The features of the structure formed during selective laser melting (SLM) on the example of austenitic steel Fe-17%Cr-12%Ni-0.02%C (316L) and nickel alloy Ni-11%Cr-5%Co-6%Al-3%Ti-4%Mo-5%W-0.16%C-0.02%B are considered in this work. The structure formation occurs under conditions of ultrafast cooling rates from the region of the melt during laser treatment and subsequent thermal cycling during solidification of material adjacent regions. The following structural features are considered: hierarchical structure, heterogeneity of the alloying elements distribution, dislocation structure, macrostresses and crystallographic texture. © Published under licence by IOP Publishing Ltd

Структура и термическая стабильность аустенитной стали Fe-17%Cr-12%Ni-2%Mo-0.02%C, синтезированной методом селективного лазерного плавления

It was identified the features of cell structure in the austenitic steel formed in the process of selective laser melting (SLM). It was established that cell's boundaries present volume dislocation plexuses in which atomic segregations of alloying elements and gas impurities are present. It was showed that the cell structure in the austenitic steel keeps its stability up to annealing temperature of 800C and then recrystallization processes start.Выявлены важные особенности ячеистой структуры аустенитного сплава, сформированной в процессе селективного лазерного плавления (СЛП): установлено, что границы ячеек кристаллизации представляют собой объемные сплетения дислокаций, на которых присутствуют сегрегации атомов легирующих элементов и газовых примесей. Показано, что ячеистая структура в аустенитном сплаве сохраняет свою стабильность до температуры отжига 800 С, после чего начинаются процессы рекристаллизации

Mechanical and Electrochemical Behavior of Austenite Alloy Synthesized by Selective Laser Melting Method

Abstract: We have studied the mechanical and electrochemical properties of austenite Fe–12%Ni–17%Cr–2%Mo–0.02%C alloy obtained by selective laser melting (SLM), as well by SLM with subsequent annealing in a broad temperature interval. The studied characteristics are compared with the characteristics of the hardened alloy. © 2020, Pleiades Publishing, Ltd

A newly identified mutation in the JAK3 gene in a child with severe combined immune insufficiency

At present, molecular-genetic methods of investigation are more and more widely used in paediatric practice. In a child with clinical-anamnestic and laboratory signs of severe combined immune insufficiency, two heterozygous mutations were found in the JAK3 gene using next-generation sequencing. A mutation in exon 3, chr19:17954586 C>T, has been recorded in ClinVar as likely pathogenic. A mutation in exon 9, chr19:17951085 C>T, has not been previously described. In the patient's mother, using the method of simple sequencing a chr19:17951085 C>T mutation in exon 9 was found in a heterozygous state, no chr19:17954586 C>T mutation in exon 3 was found in the patient's mother. The child's father refused genetic testing. The described case might be regarded as evidence of the pathogenicity of mutations of the JAK3 gene chr19:17951085 C>T and chr19:17954586 C>T. © 2018 Dynasty Publishing House. All rights reserved