МАТЕМАТИКА И ЕСТЕСТВЕННЫЕ НАУКИ

Самоучитель по новейшим реализациям пакета визуального блочного имитационного моделирования Simulink матричной системы MATLAB. Подробно описаны библиотека блоков Simulink, методика подготовки диаграмм моделей, их редактирование, настройка и запуск на исполнение. Дано описание наиболее важных пакетов расширения Simulink инструментального ящика Blockset, в том числе SimPowerSystems, SimMechanics, Aerospace, Stateflow, Signal Processing, Telecommunication, Video and Image Processing и др. Отражены средства виртуальной реальности. Описаны сотни наглядных примеров применения этих средств. Издание предназначено для студентов, преподавателей и аспирантов вузов и университетов, инженеров и научных работников.

Это пособие рассматривает часть тем, входящих в учебную программу англоязычного курса «Mathematical Foundations of Information Security». Пособие знакомит читателя с вопросами количественного измерения информации, сжатия данных, помехоустойчивого кодирования данных и обеспечения конфиденциальности данных. Теоретический материал полностью соответствует известным публикациям по изучаемым вопросам. Отличительной особенностью пособия является большое количество практических примеров, иллюстрирующих теоретические положения, а также большой набор задач для самоконтроля студентов.

Обработка больших данных с каждым днем приобретает все большее значение. В этой книге подробно рассматривается организация обработки больших данных с использованием аналитической операционной системы Apache Spark. Тщательно описываются процессы потребления, преобразования и публикации результатов обработки данных; продемонстрированы возможности Apache Spark при работе с разнообразными форматами исходных данных (текст, JSON, XML, СУРБД и многими другими) и при публикации результатов в разнообразных форматах. Особое внимание уделяется обработке потоковых данных, что весьма важно в современных условиях. Подробно рассмотрены организация и архитектура кластера Spark. В приложениях представлена обширная справочная информация, необходимая каждому разработчику, использующему Spark. Книга содержит множество иллюстраций и примеров исходного кода на языке Java с подробными комментариями.

Самоучитель по новейшим реализациям пакета визуального блочного имитационного моделирования Simulink матричной системы MATLAB. Подробно описаны библиотека блоков Simulink, методика подготовки диаграмм моделей, их редактирование, настройка и запуск на исполнение. Дано описание наиболее важных пакетов расширения Simulink инструментального ящика Blockset, в том числе SimPowerSystems, SimMechanics, Aerospace, Stateflow, Signal Processing, Telecommunication, Video and Image Processing и др. Отражены средства виртуальной реальности. Описаны сотни наглядных примеров применения этих средств. Издание предназначено для студентов, преподавателей и аспирантов вузов и университетов, инженеров и научных работников.

Цель учебного пособия – развитие профессиональной иноязычной коммуникативной компетенции студентов. Работа с предлагаемым учебным пособием даст студентам возможность совершенствовать профессиональную компоненту образования в области системного анализа и управления при изучении дисциплины «Иностранный язык для профессиональных целей». Данное учебное пособие также может быть использовано студентами других направлений подготовки и специальностей, широким кругом лиц, имеющих достаточный уровень сформированности лингвистической компетенции, интересующихся проблемами системного анализа и управления.

Composite materials based on wood filler are promising materials that are actively conquering the market. This is due to the advantages of using these materials in various fields: weather resistance and environmental compatibility, easy machining and possibility of recycling. Furthermore, it is sustainable use of wastes of timber sawing and furniture and woodworking industries, as well as low-grade wood. Wood powder is also known to be one of the components of consumables used in additive 3D printing technologies. Over the last decade, the commercial use of 3D printers has increased rapidly due to the fact that it allows creating prototype objects of complex shape based on a computer model. Experimental studies were carried out to determine the tensile strength and rheological properties of a composite made of polylactide 4043D, untreated wood powder brand 140 and wood powder thermally modified at 200 and 240 °C. The composite is intended for creation of three-dimensional objects by extrusion using a 3D printer. It was found that with an increase in the amount of filler in the composite, the tensile strength decreases. Also, samples with thermally modified filler show an increase in tensile strength in comparison with samples with untreated filler. Prototypes of 3D threads with different composition were obtained, during the study of which the melt flow index was examined. It was found that with increasing temperature of wood filler treatment the melt flow index increases. With a lower content of wood powder in the melt composition, there is a 2-fold increase in the melt flow index. The knowing of the rheological properties of the resulting compositions will allow achieving maximum performance and reduction of energy and production costs. For citation: Sabirova G.A., Safin R.R., Galyavetdinov N.R., Shaikhutdinova A.R., Khayrullin R.Z. Studying the Rheological Properties of a Polylactide Melt Mixed with Wood Filler. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 1, pp. 173–179. DOI: 10.37482/0536-1036-2021-1-173-179 Funding: The reported study was funded by RFBR, project number 19-33-90249
Композиционные материалы на основе древесного наполнителя, являясь перспективными, активно завоевывают рынок. это связано с преимуществами применения данных материалов в различных областях: стойкость к атмосферным воздействиям и экологичность, легкость механической обработки и возможность утилизации отходов. Кроме того, это и рациональное использование низкосортной древесины, а также отходов лесопиления, мебельной и деревообрабатывающей промышленности. Известно применение древесной муки в качестве одного из компонентов в аддитивных технологиях 3D-печати. За последнее десятилетие коммерческое использование 3D-принтеров возросло благодаря тому, что они позволяют создавать объекты-прототипы сложной формы на основе компьютерной модели. Проведены экспериментальные исследования по определению предела прочности на разрыв и реологических свойств композита из полилактида 4043D и термически обработанной при температуре 200 и 240 °С и необработанной древесной муки марки 140, предназначенного для создания трехмерных объектов методом экструзии с помощью 3D-принтера. Установлено, что с увеличением количества наполнителя в композите уменьшается предел прочности при растяжении, а также что по сравнению с образцами из необработанного наполнителя у образцов из термически модифицированного наполнителя наблюдается возрастание предела прочности. Получены опытные образцы различных по составу 3D-нитей, для которых был исследован показатель текучести расплава. Показано, что с ростом температуры обработки древесного наполнителя этот показатель повышается. При меньшем содержании древесной муки в составе расплава отмечается его увеличение в 2 раза. Знание реологических свойств получаемых композиций позволит достигнуть максимальной производительности, снизить энергозатраты и себестоимость готовой продукции. Для цитирования: Sabirova G.A., Safin R.R., Galyavetdinov N.R., Shaikhutdinova A.R., Khayrullin R.Z. Studying the Rheological Properties of a Polylactide Melt Mixed with Wood Filler // Изв. вузов. Лесн. журн. 2021. № 1. С. 173–179. DOI: 10.37482/0536-1036-2021-1-173-179 Финансирование: Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 19-33-90249.

A study of the scale effect on the reservoir permeability and porosity over a wide range of the void structure appears to be a significant research task. In this work, we aimed to investigate the scale effect over a wide range of alternating reservoir properties, depending on changes in the void structure, as well as to assess the feasibility of using a whole core with a retained drilling diameter in determining the permeability and porosity of complex reservoirs. For the first time, core samples are proposed to be selected on the basis of space zoning, which takes into consideration the void structure and the scale effect. Filtration studies using such samples are expected to correctly reflect the physical and hydrodynamic characteristics of the reservoir, thus being valuable for calculating reserves and designing project documentation. Based on the performed linear discriminant analysis, the practical problem of dividing the D3fm object of the Tedinskoye oil field by the type of productive sediment reservoir is solved. In addition, an analysis of the results of physical and hydrodynamic studies confirmed the significance of the scale effect when studying the porosity and permeability properties of complex reservoirs. A significant effect of the void structure on the value of residual water-oil saturation is demonstrated. The feasibility of using whole core samples is substantiated, taking into account the quantitative measure of the scale effect differentiated over a wide range of porosity and permeability when determining the boundary values of porosity for carbonate deposits of the D3fm object of the Tedinskoye oil field. The obtained results show that the calculation of geological and recoverable reserves should take into account both the scale effect and the structural features of the void.

The article provides information on the outcrops of the Neogene-Quaternary riverine sediments of the North-Western Black Sea coastal area. A description of five outcrops of fluvial deposits located on the territory of the modern basins of the Dniester and Prut rivers is given. Based on the granulometric composition of the sediments and the presence in them of the fossil shells of freshwater bivalve mollusks (Bivalvia: Unionoida), an assumption has been made about the characteristics of the ancient river ecosystems of the Dniester and Prut on different Pliocene and Pleistocene time sections. A review of the data in the body of literature on the geological age of the studied outcrops was undertaken. The localities considered provide information on the sedimentation conditions in this region from the Pliocene to the Late Pleistocene. Previously, various approaches were used for dating such rocks and for determining the stratigraphic position of fossil material found in them. The article considers the method of amino acids racemization as one of the approaches. Racemization allows to obtain new data on the stratigraphy of Neogene-Quaternary riverine sediments and to solve the problem of their dating. The sampling principles of carbonate material for the analysis of amino acids from the mollusk shells and features of sample preparation are described. Five amino acids were used: aspartic acid (Asp), glutamic acid (Glu), leucine (Leu), phenylalanine (Phe) and isoleucine (Ile). The D/L ratios were analyzed (amino acid racemization (or AAR) is the interconversion of amino acids from one chiral form (the L – (laevo) amino acids which are the building blocks of proteins) to a mixture of L- and D- (dextro) forms. The extent of racemization is measured by the ratio of D/L isomers (it increases as a function of time and temperature and can be used for geochronology) from the same group of fossils (genera), which were preserved under similar environmental conditions, inorganic geochemistry and thermal histories. Based on the obtained values, it can be concluded that the analysis of the racemization of amino acids is useful for determining the geological age of fossil shells of freshwater bivalve mollusks, but there are limitations regarding age. In the shells of the Pliocene sites, the values of some amino acids are close to one, indicating that the racemization took place. D/L values in shells from Pleistocene localities allowed the determination of their stratigraphic position.

Phytoplankton constitutes a key part of all aquatic ecosystems. It produces organic matter, thus forming the first level of food chains in water bodies. In addition, phytoplankton plays a major role in the water quality formation. The studies of algocoenosis always remain relevant, since the obtained data provides important information on the ecological status of water bodies. This information can subsequently be used for planning and implementing environmental measures, which are particularly significant for water bodies located in specially protected areas. National parks existing for the purposes of nature preservation, education and research are also designed for tourism, which makes their ecosystems more vulnerable. Population residing in such territories and its economic activity may also carry some environmental risks, which necessitates regular complex observations. This paper covers the state of spring phytoplankton community of Lake Kenozero in 2018, its qualitative and quantitative characteristics (species composition, abundance and biomass). In the course of research, we identified 70 phytoplankton taxa belonging to seven divisions: Bacillariophyta, Dinophyta, Chlorophyta, Cyanophyta, Chrysophyta, Xanthophyta and Euglenophyta. The dominant species complex included diatoms (Asterionella formosa, Melosira granulata, Tabellaria fenestrata), representatives of Dinophyta (Gymnodinium sp.), as well as small euglenoids. Species diversity was estimated using the Shannon-Weaver index. Aquatic environment contamination was assessed, i.e. the saprobity index was calculated and the class of surface water quality was determined. According to the water quality classification of water bodies and watercourses by hydrobiological indicators, Lake Kenozero was assigned the second class of water quality (moderately polluted).

Phytoplankton constitutes a key part of all aquatic ecosystems. It produces organic matter, thus forming the first level of food chains in water bodies. In addition, phytoplankton plays a major role in the water quality formation. The studies of algocoenosis always remain relevant, since the obtained data provides important information on the ecological status of water bodies. This information can subsequently be used for planning and implementing environmental measures, which are particularly significant for water bodies located in specially protected areas. National parks existing for the purposes of nature preservation, education and research are also designed for tourism, which makes their ecosystems more vulnerable. Population residing in such territories and its economic activity may also carry some environmental risks, which necessitates regular complex observations. This paper covers the state of spring phytoplankton community of Lake Kenozero in 2018, its qualitative and quantitative characteristics (species composition, abundance and biomass). In the course of research, we identified 70 phytoplankton taxa belonging to seven divisions: Bacillariophyta, Dinophyta, Chlorophyta, Cyanophyta, Chrysophyta, Xanthophyta and Euglenophyta. The dominant species complex included diatoms (Asterionella formosa, Melosira granulata, Tabellaria fenestrata), representatives of Dinophyta (Gymnodinium sp.), as well as small euglenoids. Species diversity was estimated using the Shannon-Weaver index. Aquatic environment contamination was assessed, i.e. the saprobity index was calculated and the class of surface water quality was determined. According to the water quality classification of water bodies and watercourses by hydrobiological indicators, Lake Kenozero was assigned the second class of water quality (moderately polluted). Citation: Otchenash NG, Dvoryankin GA, Imant EN (2019) State of spring phytoplankton and quality of the Kenozero waters in 2018. Arctic Environmental Research 19(1): 43–48. https://doi.org/10.3897/issn2541-8416.2019.19.1.43

The objective of the research is to identify the main patterns of spatial distribution of natural and anthropogenic radionuclides (RN) in Naryan-Mar. Urban soils are formed by means of natural soil transformation with the participation of technogenic sedimentogenesis, which leads to disturbance of natural RN migration processes and contributes to the complex structure of natural and anthropogenic RNs contamination of tundra soils. The specific activity of anthropogenic (134Cs, 137Cs) and natural (226Ra, 232Th, 40K) RNs in Naryan-Mar soil was determined. The local low-intensity anomalies (LLIA) of anthropogenic RNs result from transboundary transfer; 134Cs and 137Cs are concentrated in soils with a well-shaped vegetable layer. 226Ra and 232Th LLIAs are confined to regions with stone buildings. 40K LLIAs are conditioned by high density of grassland vegetation involving 40K in the biological cycle. The statistical manipulation of the acquired data involved correlation and factor analysis techniques. The statistical analysis demonstrated a moderate and salient correlation between the content of 232Th and 40K in the soils of the areas built up with wooden houses and the soils of the recreation area, respectively. There is a salient correlation between the content of 134Cs and 40K as well as between 134Cs and 232Th in the soils of the recreation area. The area occupied by technological buildings demonstrates salient and high negative correlations between the content of 226Ra and radionuclides of 40K and 234Th. The multidirectional nature of the 226Ra and 232Th accumulation processes can be explained by their different mobility in the environment. A factor analysis of the specific activities of the radionuclides in the soils (based on the varimax method) revealed that the strongest factor (28%) conjointly regulates the 134Cs and 40K content, which testifies to their affiliation to non-mobile cationogenic elements. The second factor (25%) identified through an analysis of the overall data array may signify that organic matter plays a major role in the 137Cs retention.

The problem of semigroups approximation with respect to various predicates has been investigated by many scientists. Some necessary and sufficient conditions for the semigroups approximation with respect to such predicates as “equality”, “membership of an element to a subsemigroup”, “regular conjugation relation”, “Green ratio of L-, R-, H- and D-equivalence”, “membership of an element to a monogenic subsemigroup”, etc. were obtained. However, there were practically no results on the conditions of approximation with respect to the predicate of membership of an element to a subgroup of a given semigroup. The paper presents the necessary and sufficient condition for approximation with respect to this predicate. We constructed a special semigroup acting the role of a minimal approximation semigroup for many predicates. This semigroup has neither identity nor additive identity. It contains an infinite number of idempotents, and the presence of each idempotent is mandatory. By this semigroup, we have successfully solved the problem of approximation with respect to the predicate of membership of an element to a subsemigroup. A class of semigroups is also described, for which it is the minimal approximation semigroup. We obtained a criterion for the approximation of a semigroup with respect to the Green H-equivalence. The problem of algebraic systems approximating with respect to a predicate consists of three components: a set of algebraic systems (groups, semigroups, etc.); set of predicates; set of functions (homomorphisms, continuous mappings, etc.). The change of one of these components determines a new line of research.

A detailed investigation of the IVC breakpoint and the breakpoint region width gives important information concerning the peculiarities of stacks with a finite number of intrinsic Josephson junctions. The current-voltage characteristics for a stack of n Josephson junctions is defined from solving the system of n nonlinear differential equations. The current voltage characteristic has the shape of a hysteresis loop. On the back branch of the Hysteresis loop, near the breakpoint Ib, voltage V (I) decreases to zero rapidly. The goal of this work is to accelerate the computation of IVC based on numerical solution of the system. A numericalanalytical method was proposed in. This method showed perfect results in IVC calculations for a stack of 9 and 19 intrinsic Josephson junctions and the computation time reduced by five times approximately. The question of choosing a change-over point from “analytical” to numerical calculation was open. In testing computations the change-over point was taken equal to 2Ib. In the case of periodic boundary conditions an equation, determining the approximate location of Ib, was obtained. This moment we succeeded to develop an algorithm determining the approximate value Ib in more complicated technically case of non-periodic boundary conditions with γ = 1. All calculations were performed using the REDUCE 3.8 system.

This book is the second in the series. It contains lecture notes of the Second Yaroslavl Summer School on Discrete and Computational Geometry that took place in July and August of 2013. We hope this volume will be useful to all students and post graduates interested in the state-of-the-art in this field. Funded by Russian Government Grant 220 Contract 11.G34.31.0053

Путем синтеза получены S-амиды сульфосалициловой кислоты, которые дают яркие люминесцентные реакции с ионами тербия. Подобраны оптимальные условия комплексообразования и предложены высокочувствительные методы определения тербия.

Как производят и где применяют кристаллы карбида кремния.