Наноалмазы как идеальные наноносители для циансодежащих цитостатиков

Цианосодержащие цитостатики - новый класс открытых нами лекарств, которые благодаря цианогруппам хорошо закрепляются на наноалмазах, с увеличением активности

Development of technology for obtaining electrodes based on copper wire using in the manufacture of solar modules

To optimize the technological process of manufacturing copper wire coated with solder of the POIN-52 grade, the optimal modes for the tinning temperature, linear velocity, diameter of the diamond die and flux were identified. It was found that the best wire tinning process is achieved when cleaning the surface of a copper wire by the method of electrochemical degreasing. The results of the tests showed that, in terms of mechanical and electrical parameters wire meets the require-ments for electrodes in the manufacture of solar modules. The results of climatic tests of solar modules  showed a high degree of reliability with a power loss of 0.86% and thermal cycling tests with a power loss of 0.4%, which is within tolerance

Structure and Hardness Variations Through Section of Hot-Forged Pipe Billet from PT-1M Alloy

In this paper structure and hardness variations through the section of the hot-forged pipe billet from the PT-1M alloy were studied by the methods of macro, micro, X-ray structural and durometric analyzes. A coarse nonuniform structure through sections of the pipe billet and the relationship between the structure and the hardness were established.     Keywords: titanium alloy PT-1M, hot deformation, macrostructure, microstructure, hardness

Relationship Between Structure and Properties of the Large-Size Billet of Titanium Alloy PT-7M

In this paper the interrelation between the structure, hardness and strain resistance at 875 ∘C of the hot-forged pipe billet of the titanium alloy PT-7M (Ti-2.2Al-2.5Zr) was studied by the methods of macro, micro, XRDA, durometric analyzes and hot upsetting operation at 875 ∘C. It was found, that the volume fraction of the large grains reduced and recrystallized from the center to the surface of the pipe billet. As a result, hardness and strain resistance grew at 875 ∘C from the center to the surface of the billet.     Keywords: titanium alloy PT-7M, hot deformation, phase composition, structure, texture, hardness, strain resistance

Structure and Properties of the Billet of PT-1M Alloy after Expanding

In this paper the macro-, microstructure, the hardness and the modulus of elasticity for the billet of the PT-1M alloy after expanding was studied. It was shown the expanding resulted to grain refinement near inner surface of the billet due to the recrystallization. The relationship between the structure through sections, the hardness and the modulus of elasticity was established.     Keywords: titanium alloy PT-1M, expanding, macrostructure, microstructure, hardness, modulus of elasticit

Counter-Pandemic Vector of Remote Learning for University Students: Risks and Benefits of Educational Process Large-Scale Digitalization

The relevance of this study is due to the challenges of the global pandemic, which has led to the large-scale development of education digitalization. In this regard, this article is devoted to revealing the features of remote learning in the context of a global pandemic, identifying the risks and benefits of digital learning. The article reveals the discursive content of the counter-pandemic vector of distance learning for University students; defines the classification of risks and advantages of large-scale digitalization of students’ remote learning. Based on the results of the study, the authors justified the consolidated model of students distance learning, the counter-pandemic vector of which is a large-scale digitalization of the University educational process. The effectiveness of the model is proved by the results of its use in the process of large-scale digitalization of students’ remote learning in the context of a global pandemic. The materials of the article have practical application and can be useful in the development and implementation of digital educational complexes. They are recommended to teachers and students of the University, methodologists, curators, Tutors

Влияние структурно-фазового состояния на физико-механические свойства горячепрессованных труб из титанового сплава Ti–3Al–2,5V

This study investigates the impact the hot extrusion process variables on the physical and mechanical properties of Ti–3Al–V alloy The research examines four tube segments extracted from various hot-extruded tubes of Ti–3Al–2.5V alloy, with an outer diameter (OD) of 90 mm and a wall thickness of 20 mm. The manufacturing process involves expanding sleeves with a horizontal hydraulic press to achieve an OD of 195 mm, followed by heating to 850–865 °C prior to extrusion. The tube segments are labeled as 1, 2, 3, and 4, corresponding to their order of production. Our findings demonstrate that an increase in the number of extrusions in the α + β area from tube 1 to tube 4 leads to a reduction in the primary α-phase volume fraction and an increase in the β-transformed structure volume fraction. These changes are attributed to the higher final extrusion temperature resulting from more intense deformation heating during hot tooling (die and mandrel) processes. Additionally, elevating the final extrusion temperature from tube 1 to tube 4 leads to a notable decrease in the residual β-solid solution volume fraction and a reduction in the “sharpness” of the α-phase tangent-oriented texture. The alterations in the structural and phase state of the alloy from tube 1 to tube 4 are found to influence the contact modulus of elasticity and microhardness. These identified relationships can be utilized to optimize the process variables for the extrusion of multiple Ti–3Al–2.5V alloy tubes.Исследовано влияние изменения  параметров  горячего  прессования  на  физико-механические  свойства  труб  из сплава Ti–3Al–2,5V. Материалом для исследования служили  четыре  патрубка,  отобранные  от  разных  горячепрессованных труб из сплава Ti–3Al–2,5V с внешним диаметром 90 мм и толщиной стенки 20 мм, полученных из экспандированных гильз с внешним диаметром 195 мм на горизонтальном гидравлическом прессе. Экспандированные гильзы перед прессованием  нагревались до температуры 850–865 °С. Образцам исследуемых горячепрессованных труб присвоены номера 1, 2, 3 и 4 согласно последовательности  их  получения  в  промышленных  условиях.  Показано,  что  увеличение  количества  проведенных  прессовок в α + β-области от трубы 1 к трубе 4 приводит к закономерному уменьшению объемной доли первичной α-фазы в их структуре, а также к росту объемной доли β-превращенной структуры вследствие повышения температуры окончания прессования, вызванного более активным деформационным разогревом из-за увеличения температуры инструмента (матрицы и иглы). Обнаружено, что фиксируемое структурно повышение температуры окончания прессования от 1-й трубы к 4-й влечет за собой характерное уменьшение объемной  доли  остаточного  β-твердого  раствора  и  снижение  «остроты»  наблюдаемой  тангенциальной текстуры α-фазы. Установлено, что выявленные изменения структурно-фазового состояния сплава от 1-й трубы к 4-й оказывают закономерное влияние на получаемый в них уровень свойств – контактного модуля упругости и микротвердости. Полученные  закономерности  необходимо  учитывать  при  разработке  технологического  режима   многоразового   прессования труб из сплава Ti–3Al–2,5V

ФОРМИРОВАНИЕ СТРУКТУРЫ, ХИМИЧЕСКОГО И ФАЗОВОГО СОСТАВОВ В СОЕДИНЕНИИ ИЗ КОРРОЗИОННО-СТОЙКИХ СПЛАВОВ

By means of methods of scanning electron microscopy, microhardness, X-ray and electron microscope analysis were studied changes of structure, chemical and phase composition for gradient of oldering by silver solder joint «titanium alloy-stainless». There wasdemonstrated that owing to interdiffusion of chemical elements, containing in solder (Ag, Cu) and alloy PT3V (Ti, Al, V) is formed diffusion zone with structure of eutectoid type (α + Ti2(Ag, Cu) intermetallide) with microhardness characteristic with close to the basic metal PT3V. On the side of stainless 18Cr10NiTi is formed diffusion zone with following layers: solder layer Ag–Cu, with depleted copper layer, and particles of intermetallide TiAg; layer on the base of intermetallic compound Ti (CuFe); layer on the base of intermetallic compound Ti (FeNi); layer on the base of intermetallic compound Ti (Fe, Cr)2; layer from tertiary compounds Ti5Cr8Fe16 of variable solubility; layer of steel, enriched by chromium, with three phase structure α + γ + σ. Availability of intermetallic compounds in diffusion zone from the side of steel contributed to increasing of microhardness in comparison with the basic metal 18Cr10NiTi.Методами растровой электронной микроскопии, микродюрометрии, рентгеноструктурного и микрорентгеноспектрального анализов изучено изменение структуры, химического и фазового составов по сечению паяного серебряным припоем соединения «титановый сплав – нержавеющая сталь». Показано, что за счет взаимной диффузии химических элементов, входящих в припой (Ag, Cu) и сплав ПТ3В (Ti, Al, V), формируется диффузионная зона со структурой эвтектоидного типа (α + интерметаллид Ti2(AgCu)) с дюрометрическими характеристиками, близкими к основному металлу ПТ3В. Со стороны нержавеющей стали Х18Н10Т образуется диффузионная зона с характерными слоями: слой припоя Ag–Cu, обедненный медью, с частицами интерметаллида TiAg; слой на основе комплексного интерметаллида Ti(CuFe); слой на основе комплексного интерметаллида Ti(FeNi); слой на основе интерметаллида Ti(Fe, Cr)2; слой из тройного соединения Ti5Cr8Fe16 переменной растворимости; слой стали, обогащенный по хрому, с трехфазной α + γ + σ-структурой. Наличие интерметаллидных соединений в диффузионной зоне со стороны стали способствовало повышению микродюрометрических характеристик по сравнению с основным металлом Х18Н10Т