9 research outputs found
Technical Physics V. 45, I. 05
No full textTechnical Physics -- May 2000
Volume 45, Issue 5, pp. 521-666
REVIEW
Development Prospects of the Commercial Production of Fullerenes
A. A. Bogdanov, D. Deininger, and G. A. Dyuzhev
pp. 521-527 Full Text: PDF (88 kB)
THEORETICAL AND MATHEMATICAL PHYSICS
Resonant Frequencies of Azimuthal-Homogeneous Oscillations of an Anisotropic Sphere
Yu. F. Filippov and Z. E. Eremenko
pp. 528-531 Full Text: PDF (58 kB)
ATOMS, SPECTRA, AND RADIATION
Temperature Dependence of an Electron Attachment to Chlorine Molecules
A. P. Golovitskii
pp. 532-537 Full Text: PDF (76 kB)
GASES AND LIQUIDS
Optimization of the Gas Outflow from a Ballistic Plasmatron Barrel
V. T. Volov, D. B. Volov, and V. M. Shmelev
pp. 538-542 Full Text: PDF (82 kB)
Electric Dispersion of Fluid under the Oscillatory Instability of Its Free Surface
A. I. Grigor'ev
pp. 543-548 Full Text: PDF (70 kB)
The Theory of Droplet Diffusiophoresis for Concentrated Solutions
Yu. I. Yalamov and E. Yu. Terekhina
pp. 549-553 Full Text: PDF (59 kB)
Parametric Identification of a Model for Hydrogen Transfer through Double-Layer Membranes
Yu. V. Zaika
pp. 554-562 Full Text: PDF (111 kB)
SOLIDS
The Effect of Space Charge and Crystallite Size on the Formation of Properties of Ferropiezoceramic Materials
A. Ya. Dantsiger, V. Z. Borodin, L. A. Reznitchenko, S. I. Dudkina, V. A. Servuli, S. V. Gavrilyatchenko, L. A. Shilkina, and V. A. Borodina
pp. 563-565 Full Text: PDF (46 kB)
Dynamics of Fluxons in Josephson Junctions under the Noise Current Action
F. Kh. Abdullaev, M. R. Jumaev, and É. N. Tsoi
pp. 566-570 Full Text: PDF (74 kB)
Differential Conductivity at the Transverse Runaway of Hot Electrons
Z. S. Kachlishvili, N. K. Metreveli, and F. G. Chumburidze
pp. 571-573 Full Text: PDF (42 kB)
Electron and Phonon Mechanisms of Friction in Crystalline Solids in Atomically Close Contact at Low Temperatures
V. L. Popov
pp. 574-583 Full Text: PDF (108 kB)
OPTICS, QUANTUM ELECTRONICS
Transformation of the Spectral Density of Intensity Fluctuations of the Pulsed Radiation from a Quasi-Single-Mode Heterolaser in an Optical Fiber
Yu. A. Morozov
pp. 584-590 Full Text: PDF (94 kB)
ELECTRON AND ION BEAMS, ACCELERATORS
Computation of the Tracking Force Acting on a Relativistic Electron Beam Propagating in a Conducting Waveguide under the Ohmic and Ion-Focused Regimes
E. K. Kolesnikov and A. S. Manuilov
pp. 591-596 Full Text: PDF (76 kB)
Forming a Beam of Ions Extracted from Glow-Discharge Plasma
N. V. Gavrilov and D. R. Emlin
pp. 597-604 Full Text: PDF (100 kB)
EXPERIMENTAL INSTRUMENTS AND TECHNIQUES
Dynamic Characteristics of Solids in Microvolumes: Modern Principles, Techniques, and Results of Investigation
Yu. I. Golovin, A. I. Tyurin, V. I. Ivolgin, and V. V. Korenkov
pp. 605-612 Full Text: PDF (151 kB)
X-ray Diffractometry Diagnosis of Laser Diffusion of Aluminum into Silicon
V. A. Bushuev and A. P. Petrakov
pp. 613-617 Full Text: PDF (67 kB)
A Computerized Complex for Recording and Processing of Reflected High-Energy Electron Diffraction Patterns
V. N. Petrov, V. N. Demidov, N. P. Korneeva, N. K. Polyakov, and G. É. Tsyrlin
pp. 618-622 Full Text: PDF (157 kB)
Superconducting Cluster in YBa2Cu3O7 – x Ceramic
D. R. Dzhuraev and B. Yu. Sokolov
pp. 623-626 Full Text: PDF (68 kB)
BRIEF COMMUNICATIONS
On the Mechanism of Explosive Etching of PMDA–ODA Film in Nonequilibrium Oxygen Plasmas
I. I. Amirov
pp. 627-629 Full Text: PDF (49 kB)
Determination of the Supercooling Dependence of the (211) Facet of BGO Crystal on Growth Rate from the Temporal Dependence of Supercooling at a Prescribed Melt-Cooling Rate
Ya. V. Vasiliev, V. D. Golyshev, M. A. Gonik, É. N. Kolesnikova, V. B. Tsvetovskii, V. N. Shlegel', and V. S. Yuferev
pp. 630-632 Full Text: PDF (93 kB)
Sensitivity to Initial Conditions and Lyapunov Exponent of a Quasiperiodic System
I. A. Khovanov, N. A. Khovanova, V. S. Anishchenko, and P. W. E. McClintock
pp. 633-635 Full Text: PDF (61 kB)
Optimization of a Semiconductor Lidar for Detecting Atmospheric Molecular Iodine and Hydrogen
R. N. Verem'ev, V. E. Privalov, and V. G. Shemanin
pp. 636-640 Full Text: PDF (47 kB)
Chromium as an Antidiffusion Interlayer in Higher Manganese Silicide–Nickel Contacts
L. I. Petrova, L. D. Dudkin, V. S. Khlomov, M. I. Fedorov, V. K. Zaitsev, and F. Yu. Solomkin
pp. 641-643 Full Text: PDF (174 kB)
A Stability Criterion for an Electroslag Process
D. A. Dudko, A. M. Pal'ti, V. A. Sevryukov, and A. A. Snarskii
pp. 644-645 Full Text: PDF (36 kB)
A Multifrequency Gyrotron
S. N. Vlasov
pp. 646-649 Full Text: PDF (52 kB)
Porous Gallium Arsenide with Arsenic Clusters
Yu. N. Buzynin, S. A. Gusev, Yu. N. Drozdov, and A. V. Murel
pp. 650-652 Full Text: PDF (77 kB)
Ferrite and High-Temperature Superconductor Targets for Sputtering
A. A. Lepeshev, V. N. Saunin, S. V. Telegin, K. P. Polyakova, V. A. Seredkin, and A. I. Polsky
pp. 653-655 Full Text: PDF (104 kB)
Effect of Technological Parameters on the Structure and Surface Morphology of Carbon Films
A. N. Gladkii, S. Yu. Suzdal'tsev, and R. K. Yafarov
pp. 656-658 Full Text: PDF (306 kB)
Anomalous Thermal Electromotive Force in Samarium Monosulfide
M. M. Kazanin, V. V. Kaminskii, and S. M. Solov'ev
pp. 659-661 Full Text: PDF (52 kB)
Interaction between Microwave Oscillation and a Photoionized Semiconductor Plasma in a Two-Layer Waveguide
V. V. Antonov and S. V. Ivanov
pp. 662-666 Full Text: PDF (64 kB)Archived web conten
Study of a new design of the steel ribs of a saw gin
No full textThe article presents a study of a new design of steel ribs of a saw gin. When assembling the rib grate from the ribs selected after rejection, the technological gaps in the working area fluctuate over a wide range. As a result, saw blades exert additional lateral pressure on the ribs, which leads to fiber damage and intense wear of the ribs. In the beam under consideration, bending movements play the main role. Displecements due to tension and shear are small compared to bending movements, as are the tension and shear energies compared to bending energy. Therefore, from the six Mohr integrals, one is taken for bending. For steel St.3 Е=2·1011 N/m2, I=6·10-10m4, l=0.084 m, P=40 N we have: θmax= – 0.00151 rad = – 5.21’; ymax= – 0.000088 m = – 0.0088 m. In general, the new design of the cantilever rib from St.3 has the maximum values of deflection θmax= –5.21’ and angle of rotation ymax = – 0.0088 m; the strength condition for normal πmax = 1.462 MPa >[σ]=110 MPa and shear πmax=0.6 МPа <[π]=50 MPa stresses under bending is fulfilled, moreover, with a large margin
Study of the dependence of the degree of disordering of the surface layers of Si(111) and Ge(111) single crystals upon bombardment with low-energy ions
Get PDFIn the presented article, samples were studied using Auger electron spectroscopy, recording the angular dependences of the coefficient of elastically reflected electrons η, and spectroscopy of elastically
reflected electrons. A change in the composition and degree of disorder of the surface layers of Si (111) was detected when bombarded with Ar+ and K+ ions with a change in energy E0 ∼ from 1 to 10 keV and ion dose from ∼ 1013 to 1017 cm−2. It was found that although the Ar and K atoms have the same masses, at the same ion energies, the degree of disordering of the near-surface Si(111) layer differs significantly. The observed effect is explained by the significant difference in their ionic radii. It is shown that at E0 ≥ 3 keV, the complete amorphization of near-surface layers occurs at relatively lower doses than surface amorphization
Некоторые психолого-педагогические принципы математического образования
Get PDFThe article deals with the construction of regular inscribed polygons, which are of great scientific and practical importance. As a result of solving such problems, new formations arise, new systems of connections are formed, new properties, qualities of the mind (flexibility, depth, awareness), which mark a progressive shift in mental development. This is why the effect of math training is directed at this side of the psyche. To increase its developing effect, it is necessary to take into account the specifics of thinking, the ratio of age and individual mental characteristics of schoolchildren. Let us now consider the problem of humanizing higher education. Humanitarianization presupposes, first of all, the introduction of a young person to the humanitarian culture of mankind. In other words, humanitarization is usually seen as an additional and necessary component of professional education. The author draws attention to the issues of humanitarization of mathematical education in Uzbekistan for further improving the system of teaching mathematical science at all levels of education, support the effective work of teachers, expand the scale and increase the practical significance of research, and strengthen ties with the international community.В статье рассматриваются вопросы построения правильных вписанных многоугольников, имеющие важное научное и практическое значение. В результате решения таких задач возникают новообразования, формируются новые системы связей, новые свойства, качества ума (гибкость, глубина, осознанность), знаменующие собой прогрессивный сдвиг в умственном развитии. Вот почему воздействие математического обучения направлено на эту сторону психики. Чтобы повысить его развивающий эффект, необходимо учитывать специфику мышления, соотношение возрастных и индивидуальных психических особенностей школьников. Рассмотрим теперь проблему гуманитаризации высшего образования. Гуманитаризация предполагает прежде всего приобщение молодого человека к гуманитарной культуре человечества. Другими словами, гуманитаризация обычно рассматривается как дополнительный и необходимый компонент профессионального образования. Автор обращает внимание на вопросы гуманитаризации математического образования Узбекистана в целях дальнейшего совершенствования системы преподавания математической науки на всех уровнях образования, поддержки эффективного труда педагогов, расширения масштаба и повышения практической значимости научно-исследовательских работ, укрепления связей с международным сообществом
Phase formation in the system Na+,Ca2+,Al3+|| SO42–,HCO3--H2O at 273 K
No full textThe article discusses the results of determining possible phase equilibria on geometric images of a five-component mutual water-salt system of sulfates, sodium bicarbonates, calcium and aluminum at 273 K, followed by the construction of its phase complex diagram. The patterns that determine the structure of the phase complex of this system are needed both to obtain scientific data used as reference material, as well as to create optimal conditions for the disposal of liquid waste from industrial aluminum production containing sulfate, bicarbonate salts of sodium, calcium and aluminum. To achieve this goal, we used the translation method, according to which the dimension of the geometric images of the diagram of the original (private) system, when adding a subsequent component to it, increases by one, i.e. the geometric images are transformed. Due to the fact that the studied five-component system consists of five particular four-component systems, the addition of a fifth component to any of them is accompanied by a transformation of the geometric images of all five four-component systems. Transformed geometric images, based on their topological properties, are translated (transferred) to the level of a five-component composition. At the level of a five-component composition, transformed and translated geometric images, observing the Gibbs phase rule, intersect and form geometric images of a given level of component. The study of the phase equilibria of a five-component water-salt mutual system of sulfates, sodium bicarbonates, calcium and aluminum and the construction of its phase complex diagram by the translation method at 273 K showed that it is characterized by the presence of twelve divariant fields, ten monovariant curves and three non-invariant points at this temperature. Based on the data obtained, a complete closed phase diagram of the studied system was constructed for the first time and, for ease of reading, fragmented along the divariant crystallization fields of equilibrium solid phases
Burden of disease attributable to high body mass index: an analysis of data from the Global Burden of Disease Study 2021
Get PDFBackground Obesity represents a major global health challenge with important clinical implications. Despite its recognized importance, the global disease burden attributable to high body mass index (BMI) remains less well understood. Methods We systematically analyzed global deaths and disability-adjusted life years (DALYs) attributable to high BMI using the methodology and analytical approaches of the Global Burden of Disease Study (GBD) 2021. High BMI was defined as a BMI over 25 kg/m2 for individuals aged ≥20 years. The Socio-Demographic Index (SDI) was used as a composite measure to assess the level of socio-economic development across different regions. Subgroup analyses considered age, sex, year, geographical location, and SDI. Findings From 1990 to 2021, the global deaths and DALYs attributable to high BMI increased more than 2.5-fold for females and males. However, the age-standardized death rates remained stable for females and increased by 15.0% for males. Similarly, the age-standardized DALY rates increased by 21.7% for females and 31.2% for males. In 2021, the six leading causes of high BMI-attributable DALYs were diabetes mellitus, ischemic heart disease, hypertensive heart disease, chronic kidney disease, low back pain and stroke. From 1990 to 2021, low-middle SDI countries exhibited the highest annual percentage changes in age-standardized DALY rates, whereas high SDI countries showed the lowest. Interpretation The worldwide health burden attributable to high BMI has grown significantly between 1990 and 2021. The increasing global rates of high BMI and the associated disease burden highlight the urgent need for regular surveillance and monitoring of BMI
Global burden of disease attributable to metabolic risk factors in adolescents and young adults aged 15-39, 1990-2021
No full textBACKGROUND: Metabolic risk factors are a significant cause of global burden among adolescents and young adults, but there is a lack of attention to the burden attributable to these metabolic risk factors globally.AIMS: This study aims to provide comprehensive estimates of five important metabolic risk factors and the attributable disease burden in people aged 15-39 years from 1990 to 2021, based on the Global Burden of Disease Study (GBD) database.METHODS: Global total deaths and disability-adjusted life years (DALYs) were used to describe the burden attributable to five common metabolic risk factors, including high fasting plasma glucose (FPG), high low-density lipoprotein cholesterol (LDL-C), high systolic blood pressure (SBP), high body mass index (BMI), and kidney dysfunction, in adolescents and young adults. The estimated annual percentage changes (EAPC) of DALYs were utilized to depict the trends from 1990 to 2021.RESULTS: From 1990 to 2021, the DALY rates attributable to all metabolic risk factors showed a globally significant upward trend, with EAPC reaching 33.0 % (27.4-38.7). Compared to females, males had a heavier burden and a more significant increase in deaths and DALYs attributable to metabolic risk factors. High BMI and high FPG have become the top two metabolic risk factors in 2021, with summary exposure variables (SEV) rising by 84.2 % and 53.6 %, respectively. Low-middle socio-demographic index (SDI), middle SDI, and high SDI regions experienced upward regional trends in DALY rates, while low SDI regions remained stable. Among 204 countries and territories, 101 (49.5 %) showed a significant increase in DALY rates, as indicated by the EAPC.CONCLUSIONS: There is a substantial global burden attributable to metabolic risk factors in adolescents and young adults in 2021, especially high BMI and high FPG. This calls for further investigation and intervention to address this emerging trend.</p
Влияние цифровизации на инвестиционный потенциал города
Get PDFThe digital transformation of all socio-economic spheres of the country determines the inclusion of digital factors in the assessment of investment potential. The aim of this paper is to justify the need to include digital factors in assessing the investment potential and the assessment of the digital potential of St. Petersburg. The study includes statistical methods of correlation analysis, average values, comparison, and grouping. This paper defines the concept of digital potential; highlights indicators of digital technology development; presents a methodology and assessment of the digital capacity of St. Petersburg compared with other cities of federal status through 2016–2018. The author features three key components of digital potential: information and communication technology (ICT) infrastructure, digital government, and e-business. The study shows that St. Petersburg’s digital potential is sustainably growing. The research reveals that the digital capacity of St. Petersburg is improving by boosting the “e-business” component which reflects the use of ERP and CRM systems by organizations, as well as by the e-commerce. The low level of the “digital government” component has a negative effect on the integral level of digital potential despite the ongoing digitization process in the public sector services. The conclusions of the study suggest that the use of digital channels to interact with public authorities, the digitization of businesses, as well as the implementation of electronic workflow processes will improve the digital potential of St. Petersburg. Taking digital factors into account as a part of the investment potential of a city will make it possible to accurately assess its investment attractiveness. The findings of the study may be useful to scientists, rating agencies, and government officials when making investment decisions. The prospects for future research on this topic consist of expanding its base, clarifying the components of the digital potential factors, and methods for assessing the investment attractiveness of a territorial entity.Цифровая трансформация всех сфер социально-экономического развития страны обусловливает актуальность включения цифровых факторов в оценку инвестиционного потенциала. Цель статьи — обоснование необходимости включения цифровых факторов в оценку инвестиционного потенциала и оценка цифрового потенциала города Санкт-Петербурга. Автор использует методы сравнения и группировки, обобщения и синтеза, индексный и корреляционный анализ. Определено понятие цифрового потенциала; предложены показатели, характеризующие развитие цифровых технологий; разработана методика и проведена оценка цифрового потенциала города Санкт-Петербурга в сравнении с другими городами федерального значения за период 2016–2018 гг. Выделены три ключевые компоненты цифрового потенциала: информационно-коммуникационная инфраструктура, цифровое правительство и электронный бизнес. Показано, что цифровой потенциал города Санкт-Петербурга имеет тенденцию к умеренному росту. Реализации цифрового потенциала Санкт-Петербурга способствует высокий уровень компоненты «электронный бизнес», который отражает использование организациями ERP и CRM-систем, а также продажи через сеть Интернет. Низкий уровень компоненты «цифровое правительство» отрицательно влияет на интегральный уровень цифрового потенциала, несмотря на продолжающиеся процессы цифровизации при оказании государственных услуг населению. Сделан вывод, что повышению цифрового потенциала Санкт-Петербурга будет способствовать использование цифровых каналов для осуществления взаимодействия с органами власти, интеграция информационных систем внутри организаций, а также активное использование электронного документооборота. Учет цифровых факторов в составе инвестиционного потенциала города позволит более точно оценить его инвестиционную привлекательность. Результаты исследования могут быть полезны ученым, рейтинговым агентствам и государственным служащим для принятия инвестиционных решений. Перспективы дальнейшего исследования данной тематики — в расширении ее базы, уточнении состава частных факторов цифрового потенциала и методики оценки инвестиционной привлекательности территориального образования
Статические характеристики преобразователей постоянного тока с магнитной модуляцией с аналоговым фильтром
Get PDFThe paper examines the most important requirements for current converters, the features of magnetic modulation converters, and identifies their fundamental and design features. The paper considers the principle of constructing converters for contactless DC measurement and their disadvantages of converters, methods of current measurement using magnetic modulation current converters, in which the magnetic permeability of a core made of ferromagnetic material is modulated. The influence of the parameters of the elements of a magnetic modulation current converter with an analog filter on their static characteristics and the influence of modulation on the static characteristics of the sensor have been determined. It has been revealed that the discrete operation of the magneto-modulation DC converter does not affect its static characteristics and the nonlinearity due to the type of modulation also does not affect the static characteristics of the sensor. The most important requirement for the operation of a magneto-modulation DC converter for autonomous power supplies with recharging buffer batteries is the formation of a static characteristic with the specified properties: linearity, sensitivity and the required range of operating currents. An analytical expression for the static characteristic is obtained in the form of the dependence of the output voltage on the values of T1 and T2 for the basic version of a magnetic modulation DC converter with an analog low-pass filter. Curves of the static characteristics of the magneto-modulation DC converter have been constructed for different values of the resistance of the ballast resistor R, as well as curves of the static characteristics of the magneto-modulation DC converter for different values of the supply voltage E. Analytical expressions for the static characteristics of a magneto-modulation DC converter based on magnetic transistor multivibrators with pulse-width modulation, curves of their characteristics and the output voltage of a magnetic modulation DC converter with a digital output and a discrete filter have been obtained.В данной статье рассматриваются важнейшие требования к преобразователям тока, особенности магнитомодуляционных преобразователей и выявлены их принципиальные и конструктивные особенности. Рассмотрены принцип построения преобразователей для бесконтактного измерения постоянного тока и основные недостатки преобразователей, методы измерения тока с помощью магнитомодуляционных преобразователей тока, в которых модулируется магнитная проницаемость сердечника из ферромагнитного материала. Определено влияние параметров элементов магнитомодуляционного преобразователя тока с аналоговым фильтром на их статические характеристики и влияние модуляции на статические характеристики датчика. Выявлено, что дискретность работы магнитомодуляционного преобразователя постоянного тока не оказывает влияния на его статические характеристики и нелинейность, обусловленную видом модуляции, а также не влияет на статические характеристики датчика. Важнейшим требованием к работе магнитомодуляционного преобразователя постоянного тока для автономных источников питания с подзарядом буферной аккумуляторной батарей является формирование статической характеристики с заданными свойствами: линейностью, чувствительностью и требуемым диапазоном рабочих токов. Получено аналитическое выражение статической характеристики в виде зависимости выходного напряжения от величины T1 и T2 для базового варианта магнитомодуляционного преобразователя постоянного тока с аналоговым фильтром нижних частот. Построены кривые статических характеристик магнитомодуляционного преобразователя постоянного тока при разных значениях сопротивления балластного резистора R, а также кривые статических характеристик магнитомодуляционного преобразователя постоянного тока при разных значениях напряжения питания E. Получены аналитические выражения статических характеристик магнитомодуляционного преобразователя постоянного тока на основе магнитно-транзисторных мультивибраторов с широтно-импульсной модуляцией, кривые их характеристик, выходное напряжение магнитомодуляционного преобразователя постоянного тока с цифровым выходом и с дискретным фильтром
