bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical work principles of digital computational synthesizers of multiphase signals
Authors: Ryabov I V , Nikitin P V , Bazhenov R I , Kurileva N V , Gorokhova R I 
Published: January 2021

Abstract
Modern systems of radio engineering systems are very widely used in radar and radio communications. An important component of the work of radio systems is the creation of diagnostic equipment with high resolution, noise immunity, improved security and reliability, which become more accessible with the advent of digital computer frequency synthesizers. Digital computer synthesizers using the direct digital signal synthesis method are the main nodes of modern diagnostic equipment for radar and radio communication systems. The article considers a number of advantages of digital computing synthesizers, which include a wide range of synthesized frequencies, an extremely small step of the frequency grid, extremely fast frequency tuning speed, phase continuity during frequency tuning, low phase noise, a simple algorithm for generating complex signals, the possibility of independent amplitude control, phase and frequency of the synthesized signal. The principles of construction and structural and circuitry solutions of digital computational synthesizers based on the method of direct digital synthesis of frequencies and signals are given. The principle of constructing structures of digital multiphase signal synthesizers is proposed, in which the initial phases of the synthesized signals can be set in software. Structural diagrams of digital computational synthesizers based on digital code storage devices and with an M-shaped law of frequency variation which allow synthesizing signals with amplitude, frequency and phase modulation in the frequency range from 0.001 to 400 MHz are presented.
Using high accuracy geodetic measurements to fix the main bases of the ship in shipbuilding and ship-repairing
Authors: Palkin P O , Kuzin A A 
Published: January 2021

Abstract
The article presents the coordinate method of determination and fixes the courses of main bases of the ship. All the methods that are used according to regulatory documents were analyzed, and their advantages and drawbacks were described. The real measurements were made using a total station and a laser tracker. The accuracy of this method was determined. Based on this analysis, it was concluded that surveying methods, among others, could be used to fix the course of main bases of the ship.
Optimization of transient well test technology for low permeability complex reservoir
Authors: Palyanitsina A N , Akhmedova A N 
Published: January 2021

Abstract
This paper summarizes the experience of conducting hydrodynamic studies on transient filtration modes (pressure build up method) using an example of a low-permeable formation with a complex structure. Such objects are distinguished by a high degree of differentiation of reservoirs by filtration-capacitive properties, which affects the design of ongoing research. The relevance of the work is due to the need to justify the optimal research time for reservoirs with the considered properties in terms of obtaining high-precision data and minimizing oil production losses. In order to fulfill these tasks, it is urgent to develop a design for hydrodynamic research of wells. Research modeling was performed using the Kappa Saphir software product. The design will provide an integrated approach to modeling the process of conducting research and forecasting the data obtained. The design will optimize research time. Based on the calculation results, the duration of the effect of the wellbore effect and the time of the beginning of the boundary effect were analyzed. The reasons for the long exit to the pseudoradial flow regime were considered. In order to optimize the research process, an analysis of the error in determining the pressure was made, depending on the duration of the study. Taking into account the error, the optimal time for registering the PBU is proposed.
Designing of distributed systems of hydrolithosphere processes parameters control for the efficient extraction of hydromineral raw materials
Authors: Pershin I M , Kukharova T V , Tsapleva V V 
Published: January 2021

Abstract
Using methods developed for systems with distributed parameters allows us to optimize processes of hydromineral raw materials production in practice. In accordance with the theory of distributed systems, formation of control actions on each well of a complex of production wells requires taking into account a state of the entire complex of wells, which ensures better dynamics and accuracy of a control process. The methodology of constructing distributed control systems for controlling the entire complex of wells involves the use of dynamic and static characteristics of an exploited aquifer. In this connection, a problem of mathematical description (identification) of the processes under consideration arises, which can be realized, for example, using the methods and formulas of Theis-Jacob. Using the Theis-Jacob formulas for the identification of the processes under consideration assumes an availability of information about parameters of hydrolytosphere processes (piezoelectric conductivity, overflow coefficients, etc.). The calculation of the considered parameters is a rather laborious task. The article proposes a methodology for constructing approximation models of the processes under consideration based on experimental studies using 2 wells of a field. Based on the obtained approximation model, a synthesis of the system for the hydrolytosphere processes parameters control was implemented.
Application of qualimetric methods for assessing quality of complex products
Authors: Pudovkin O P 
Published: January 2021

Abstract
For the final product high-quality assessment in any application field, it is necessary to choose the optimal method and suitable measuring instruments for the right conditions. The paper reflects theoretical information about the atomic emission spectrometer, the advantages of using this device in the quantitative chemical analysis when monitoring surface waters. In addition, information on methods for evaluating such complex products as the atomic emission spectrometer is provided. The paper presents expert and mixed methods of qualimetry, describes their advantages and disadvantages. Based on them, a new method for evaluating the quality of the atomic emission spectrometer has been developed, which includes elements of the expert method, differential and complex, as well as a method for determining the consistency of experts. In addition, the methodology sets out requirements for experts who are members of the expert group. It is designed such factors as: individual and group weighting factor, assessment of the consistency of experts with the help of the coefficient of concordance, relative indicator of quality, the product quality level, the weighted average arithmetic. Based on the assessment of the last indicator, you can conclude that this product is better or worse than the basic one, or rank several products. Three atomic emission spectrometers were selected for testing this technique. One of them was selected as the base sample, with which the two evaluated samples were compared. They were ranked from best to worst, and their example shows the efficiency of this method.
Modelling of a hydroacoustic modem for underwater communications
Authors: Tokmachev D A , Chensky A G , Zolotarev N S , Poletaev A S 
Published: January 2021

Abstract
The paper discusses results of designing of an underwater communication device. The MSK modulation type is more preferable as it provides with narrow spectrum density of signals. The article describes a simulation program that allows one to model signal distortions and choose the best-fit method of detection. Three demodulation algorithms are tested. Simulation of signal propagating in underwater medium showed that the most effective is cross correlation detecting for which bit error rate was 5·10–4 at signal-to-noise ratio of 6 dB. Signal distortions were modelled with additive white noise, phase drift and superimposed re-reflections. For a piezoceramic antenna with a resonant frequency of 55 kHz and 6 kHz bandpass, the transmission frequencies of “0” and “1” are defined as 54 kHz and 56 kHz respectively, bitrate is 4000 bauds. During experimental testing in conditions of a natural reservoir all electronic devices demonstrated stability, the maximum range of reliable transmitting was 250 m.
Comparative assessment of documentation referred to surface roughness measurement
Authors: Vinogradova A A , Grichukha M I , Smirnova E E 
Published: January 2021

Abstract
The research relates to the field of metrological supervision, specifically to the control of surface roughness parameters. The authors analyzed the following regulatory documents: GOST R ISO 4287-2014 “Geometrical product specifications (GPS). Surface texture. Profile method. Terms, definitions and surface texture parameters”, GOST 25142-82 “Surface roughness. Terms and definitions”, GOST 2789-73 “Surface roughness. Parameters and characteristics”, GOST 9378-93 (ISO 2632-1-85, ISO 2632-2-85) “Roughness comparison specimens. General technical conditions”, GOST 27964-88 (ST SEV 6134-87, ISO 4287 / 2-84) “Measurement of roughness parameters. Terms and definitions”, GOST 19300-86 “Instruments for measurement of surface roughness by the profile method. Contact profilographs and profilometers. Types and main parameters”, GOST R 8.651-2009 ISO “State system for ensuring the uniformity of measurements. Contact (stylus) instruments for the measurement of surface roughness. Procedure of calibration”, GOST 9847-79 “Optical instruments for surface roughness parameters measuring. Basis parameters and types”, GOST R 8.700-2010 “State system for ensuring the uniformity of measurements. Method of surface roughness effective height measurements by means of scanning probe atomic force microscope”, which regulate the measured parameters of the surface roughness, instruments that measure these parameters. In the course of a comparative analysis of the values of the parameters of existing devices and the values of the parameters of devices prescribed in the standards, a summary table was formed, and the problem of controlling nanoparameters and nanocoatings was also identified. The existing instrument base for monitoring surface roughness allows measuring parameters with high accuracy and within wide limits, but the regulatory framework on the territory of the Russian Federation is outdated and does not allow the use of some modern types of instruments. In this regard, it is necessary to update the requirements of GOSTs for the modern capabilities of technology and control over roughness parameters.
Modelling the movement of slurry in the channel of a nature-like pump used for the safety laying of the worked out space
Authors: Vasilyeva M A , Yusupov G A , Nagornov D O , Puskarev A E 
Published: January 2021

Abstract
The most important task of the production of the mineral raw materials industry is to increase the efficiency of the equipment and infrastructure in operation. In particular, this also applies to the need to create transport systems with high productivity while reducing the cost of transporting mineral raw materials and waste from its processing. Particular attention is paid to the use of hydraulic filling systems as a measure to prevent man-made tectonic earthquakes during prolonged and continuous development of deposits. In this paper, we consider the problem aimed at solving the fundamental problems of developing effective methods for controlling the flow of pasty substances in pipelines of variable cross-section, intended for the production of pumping equipment and used in such industries as mining, chemical, food, etc.
Improving the competitiveness of Russian industry in the production of measuring and analytical equipment
Authors: Repinskiy O D , Konyukhov V Yu , Bovkun A S , Schupletsov A F 
Published: January 2021

Abstract
The creation of a high-tech competitive industry in the production of measuring and analytical equipment in Russia in a highly competitive environment is impossible without the development and implementation of innovative products. The vast majority of Russian enterprises invest their funds in the purchase of imported innovations instead of investing in creation of their own R & d/D (Research, Development and Engineering). Such path of development of Russian enterprises is seems / seems to be a dead end. One can observe a growing trend in the share of R & d/D expenditures on the global market. Nowadays the leading countries of the world industry such as the United States, China, Japan and Germany invest much bigger than over countries/invest in science more than over countries. Large-scale development and innovation implementation can be realised under creation of the system based on interconnected elements “industry-innovation-science-education”. Expansion and intensification of fundamental and applied research, improvement quality of teaching mathematics, physics and engineering disciplines in higher and secondary educational institutions are seemed to be necessary/seem to lead to better results. Large industrial Russian companies, leaders in certain sectors of industry with a powerful modern production infrastructure and huge financial capacity should act as a driving motive of the mentioned system. The state should provide support by means of legislative activity aimed to create an industrial and innovation policy providing production of innovative items which will be able to compete in high-tech segments of the world market.
Numerical Analysis of Microstructure Development during Laser Welding Nickel-based Single-crystal Superalloy Part III: Nonequilibrium Solidification Behavior
Authors: Gao Zhiguo 
Published: January 2021

Abstract
The thermal-metallurgical modeling of primary γ gamma phase nonequilibrium solidification behavior during laser welding nickel-based single-crystal superalloy is further developed through coupling of heat transfer model, multicomponent dendrite growth model and nonequilibrium solidification model to evaluate solidification cracking susceptibility and advance the understanding of the material weldability. The useful relationship among welding conditions (laser power, welding speed and welding configuration), weld pool geometry, dendrite selection, dendrite growth, solidification temperature range, solidification cracking susceptibility and weldability are established for welding conditions optimization and microstructure control. It is indicated that for (001) and [100] welding configuration, solidification cracking susceptibility along the solid/liquid interface is symmetrically distributed about the weld pool centerline. It is crystallographically favorable for mitigation of solidification cracking with bimodal distribution of solidification temperature range. By contrast, for (001) and [110] welding configuration, solidification cracking susceptibility is asymmetrically distributed. The solidification cracking susceptibility of the unfavorable [100] dendrite growth region on the right side of the weld pool is higher than that of [010] dendrite growth region on the left side due to the enlargement of solidification temperature range. The mechanism of asymmetrical crystallography-dependent solidification cracking is proposed. Asymmetrical dendrite growth region induces asymmetrical solidification behavior and solidification cracking susceptibility along the solid/liquid interface, although heat transfer is symmetrical. The overall solidification temperature range of (001) and [100] welding configuration is beneficially narrower than that of (001) and [110] welding configuration throughout the weld pool regardless of heat input. The theoretical predictions agree well with the experiment results. In addition, the promising model is also applicable to other single-crystal superalloys with similar metallurgical properties during laser welding or laser cladding.
Preparation and Characterization of Polyimide/TiO2 Nano-composites for Non-lethal Weapon
Authors: Cui Xiaoping 
Published: January 2021

Abstract
A series of Polyimide/TiO2 (PI/TiO2) nano-composites were successfully prepared by incorporating different nano-sized TiO2 contents into PI which derived from pyromellitic dianhydride (PMDA) and a flexible diamine 4,4-bis(3-aminophenoxy)biphenyl (4,3-BAPOBP) via in-situ polymerization and a thermal imidization method. The micromorphology, chemical structure of samples were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR). The SEM results show that when the content of nano-TiO2 is lower, the nano-TiO2 can be distributed uniformly in the matrix by the method of this experiment scheme, and signs of agglomeration have begun to appear when the TiO2 content is 12 wt.%. XRD patterns reveal the crystal structure of TiO2 remains unchanged and stable after being doped into PI matrix, and the TiO2 nano-particles have good compatibility with PI matrix
Influence of shape on power conversion efficiency of Ni-Zn ferrite/piezoelectric magnetoelectric gyrator
Authors: Zhang Jitao , Wang Zhen , Zhang Qingfang , Zhao Hewei , Wu Jie , Tao Jiagui , Jiang Liying , Cao Lingzhi 
Published: January 2021

Abstract
Reducing the demagnetization effects via shape optimization in tri-layer magnetoelectric (ME) composite is an effective way to improve its power transfer conditions. To accomplish this goal, enhanced dynamic piezomagnetic coefficient of Ni0.7Zn0.3Tb0.02Fe1.98O4 ferrite, the tri-layer Ni0.7Zn0.3Tb0.02Fe1.98O4/PZT/Ni0.7Zn0.3Tb0.02Fe1.98O4 ME composites under different L/W ratios with coil wound around for gyrator fabrication were systematically characterized. Measurements of resonance ME responses were carried out for samples with the varying L/W ratio, the weak demagnetization field occurs at the sample with highest L/W ratio, yielding a stronger ME coupling. Experiment results of PE characterizations demonstrated that maximum of 91.3% was achieved under optimum bias and EMR driving in sample with higher L/W=17.5. Therefore, the higher PE is originated from strong dynamic magneto-mechanical response under the shape optimizations. These findings provide the possibility of ME gyrator in high energy conversion power electronics devices.
Model of Optimization solution Based on Generalized Evidence Theory
Authors: Ying Wu 
Published: January 2021

Abstract
In order to solve the application of generalized evidence theory in Engineering, a new generalized basic probability assignment GBPA generation method is proposed in this paper. And on this basis, the selection model of civil aircraft optimization scheme is constructed. Then, taking the optimization scheme of a civil aircraft as an example, it is proved that the method is simple in calculation and clear in physical meaning, which is more suitable for practical application
Physical processes driving intensification of future precipitation in the mid- to high latitudes
Authors: Poujol B , Mooney P A , Sobolowski S P 
Published: January 2021

Abstract
Precipitation is changing as the climate warms, and downpours can become more intense due to the increased water holding capacity of the atmosphere. However, the exact nature of the precipitation response and its characteristics is still not well understood due to the complex nature of the physical processes underlying the formation of clouds and precipitation. In this study, present and future Norwegian climate is simulated at convection-permitting scales with a regional climate model. The future climate is a high emission scenario at the middle of the century. Hourly precipitation is separated into three categories (convective, stratiform, and orographically enhanced stratiform) using a physically-based algorithm. We investigate changes in the frequency, intensity and duration of precipitation events for each category, delivering a more nuanced insight into the precipitation response to a changing climate. Results show very strong seasonality, with significant intensification of autumn precipitation. An increase in convective precipitation frequency and intensity dominates the climate change signal regardless of season. While changes in winter and summer are well explained by thermodynamical theory, the precipitation response in autumn and spring deviates from the idealised thermodynamic response, partly owing to changes in cloud microphysics. These results show that changes in the precipitation distribution are affected in complex ways by the local climatology, terrain, seasonality and cloud processes. They illustrate the need for further and more detailed investigations about physical processes underlying projected precipitation changes and their seasonal and regional dependence.
Mathematical, detailed and parametric modelling for smart spinal orthoses
Authors: Murzac R , Doicin C V , Ulmeanu M E , Ţurcanu T 
Published: January 2021

Abstract
The paper presents a mathematical model and the design details to manufacture a prototype of a smart orthosis for posture correction while sitting on a chair at your office or at home. The global geometry for developing the mathematical model was obtained by direct measuring a human 3D model, developed by scanning one of the authors’ body and 3D printing it. Based on the mathematical model, the detailed design for the entire product was performed in accordance with the product architecture. The stages of detailed design for the critical systems within the final assembly are also presented in the paper. The posture correction orthosis must be customized for each user, thus, once the design for the critical components has been validated, a parametric design has been generated to facilitate the manufacturing process. The technical solutions are generated and analysed for a vertebral element of the orthosis, representing the critical component of the product. The vertebral element is subject to mechanical stresses, so that a finite element analysis was performed. The geometry of the component and its material were validated by using FEA on the CAD model of the vertebral element. The further work will include research regarding the changes needed for transforming the orthosis into a medical device for spinal column illnesses.
Chemical and mechanical tests on the SiO2-ZnO materials for protective coatings of industrial use
Authors: Mocioiu A M , Băilă D I , Mocioiu O C 
Published: January 2021

Abstract
Many industrial processes, such as chemical process and pharmaceuticals, use aggressive acidic and caustic solution which may result in an early failure of the components of plant. The various corrosion processes in harsh environments could be uniform corrosion, localized corrosion, galvanic corrosion, etc. In order to extend the life of components, a proper material selection is necessary. This direction is intended to address the behaviour of materials due to exposure in harsh environments. The main objective is to develop new vitreous coatings for different kind of materials as metals or glasses in order to protect them against acid attack. SiO2-ZnO materials were prepared by chemical route in order to be used as protective coatings. The SiO2-ZnO materials were investigated by infrared spectroscopy and differential thermal analysis in order to determine their structure and thermal characteristics. SEM and EDS measurements were performed to investigate their structure and morphology. The chemical resistance tests in acid media (HCl and HF) were followed based on STAS and ISO standards and the extraction solutions were tested by ICP-MS in order to identify elements lost during tests. Mechanical tests were performed.