Properties of nanostructured diamond-silicon carbide composites sintered by high pressure infiltration technique

A high-pressure silicon infiltration technique was applied to sinter diamond–SiC composites with different diamond crystal sizes. Composite samples were sintered at pressure 8 GPa and temperature 2170 K. The structure of composites was studied by evaluating x-ray diffraction peak profiles using Fourier coefficients of ab initio theoretical size and strain profiles. The composite samples have pronounced nanocrystalline structure: the volume-weighted mean crystallite size is 41–106 nm for the diamond phase and 17–37 nm for the SiC phase. The decrease of diamond crystal size leads to increased dislocation density in the diamond phase, lowers average crystallite sizes in both phases, decreases composite hardness, and improves fracture toughness

Issues of Strategic Legal Regulation of the Implementation of Digital Technologies in Transport

Despite the awareness of the importance of digital transformation of highways as the basis for life safety, social and economic development of the country, the issues of technical, legal and financial regulation of the digitalization of the transport complex at the federal and regional levels, a detailed assessment of the impact of digital technologies in transport on social and economic processes in modern Russian society. In the Russian doctrine in recent years, research has been carried out in general on the formation and development of the digital economy in Russia, in which intelligent transport systems are mentioned pointwise and only in general terms without their comprehensive analysis. Based on the assessment of the current state and trends in the development of info-communication transport infrastructure in Russia, foreign experience, potential problems of the implementation of digital technologies in transport in the socioeconomic and legal dimension were identified, specific proposals were formulated on the legal and financial regulation of issues and minimization of the risks of liability for harm in conditions development of information transport systems. The role of the programs “Digital Economy of the Russian Federation” and “Safe and High-Quality Roads” in the development of intelligent transport systems has been analyzed, and as a result, promising areas for the use of unmanned vehicles to improve the quality of life of people, develop entrepreneurship, high-tech industries, and increase the investment attractiveness of Russia have been identified. and strengthening its position in the international arena. The study used the following methodological principles: objectivity; determinism; historicism; integrity; consistency; structure; functionality; hierarchy; pluralism of explanation and understanding of law; comparative studies. The study uses private methods: legal analytics, legislative techniques, legal comparative studies, expert assessments. As the main results of the study, the features of the legal regulation of new and promising relations arising in the digital economy have been identified. This is a strategic legal planning and legal experiment. Taking into account this conclusion, a system of prerequisites for the development of intelligent transport systems was formulated based on the analysis of national programs. The system of prerequisites includes three levels: technological prerequisites, infrastructural and regulatory

ИЗНОСЫ В ПЯТНИКОВЫХ УЗЛАХ ЦИСТЕРН

Structural elements of the rolling stock are of great importance for the safety of passengers and freightage, especially it concerns friction units, because some of them are operated under rude conditions. The presence of abrasives, absence of lubricant, specific spectrum of absorbed load provoke severe wear of contact surface.Численный анализ узлов трения вагонных конструкций в условиях эксплуатации, особенности трибологических свойств разного вида цистерн. Для анализа износов в пятниковых узлах с использованием полученных уравнений была разработана программа с учетом не только распределения контактного давления, но и нагрузок в местах сопряжения. Полученные результаты показали, что износы зависят от пробега вагона, радиусов кривых рельсового пути и типа вагонной конструкции, прежде всего ее базы. В пятниковых узлах тележек 8-осной цистерны износ меньше, зато в узлах между ее котлом и соединительными балками – наибольший. Интенсивный износ характерен и для кривых малого радиуса. Всем этим случаям в статье дается свое объяснение

H216O line list for the study of atmospheres of Venus and Mars

IR spectroscopy is an important method of remote measurement of H216O content in planetary atmospheres with initial spectroscopic information from the HITRAN, GEISA, etc., databases adapted for studies in the Earth’s atmosphere. Unlike the Earth, the atmospheres of Mars and Venus mainly consist of carbon dioxide with a CO2 content of about 95%. In this paper, the line list of H216O is obtained on the basis of the BT2 line list (R.J. Barber, J. Tennyson, G.J. Harris, et al., Mon. Not. R. Astron. Soc. 368, 1087 (2006)). The BT2 line list containing information on the centers, intensities, and quantum identification of lines is supplemented with the line contour parameters: the self-broadening and carbon dioxide broadening coefficients and the temperature dependence coefficient at 296 K in the range of 0.001–30000 cm−1. Transitions with intensity values 10−30, 10−32, and 10−35 cm/molecule, the total number of which is 323310, 753529, and 2011072, respectively, were chosen from the BT2 line list

КОНТАКТНЫЕ ДАВЛЕНИЯ НА ЦИЛИНДРИЧЕСКИХ ПОВЕРХНОСТЯХ ПЯТНИКОВОГО УЗЛА

Contact pressure is one of main factors that influence level and character of wear and tear of center plate arrangement. Distribution of contact pressure over the contact zone in the case of cylindrical surfaces is unbalanced. A software was developed in order to numerically analyze the influence of different diameters of top (pivot block) and bottom center plate (end thrust bearing) on changing of monitored values. The obtained results have shown that the values of contact pressure depend on clearance between top and bottom parts of center plate arrangement. At the initial stage of operation the values of contact pressure for nominal values of diameters of both top and bottom part of center plate are lower than when they are manufactured with admissible departure.Одним из основных факторов, влияющих на величину и характер износа, является контактное давление в зоне сопряжения. В случае цилиндрических поверхностей распределения контактных давлений по зоне сопряжения неравномерны. Для проведения численного анализа влияния различных диаметров пятника и подпятника на изменение контролируемых величин была разработана компьютерная программа. Полученные результаты показали, что величины контактных давлений зависят от зазора между пятником и подпятником. В начальный момент эксплуатации они для номинальных значений диаметров пятника и подпятника меньше, чем при изготовлении их с допустимыми отклонениями