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Formation of diffuse and spark discharges between two needle electrodes with the scattering of particles

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Plasma Science and Technology 2024年第9期26卷 32-39页

作者： Victor F TArasENKO Dmitry V BELOPLOTOV Alexei N PANCHENKO Dmitry A SOROKIN institute of high current electronics Siberian BranchRussian Academy of SciencesTomsk 634055Russia National Research Tomsk State University Tomsk 634050Russia

The development of a nanosecond discharge in a pin-to-pin gap filled with air at atmospheric pressure has been studied with high temporal and spatial resolutions from a breakdown start to the spark *** and negative nanosecond voltage pulses with an amplitude of tens of kilovolts were ***-resolved images of the discharge development were taken with a fourchannel Intensified Charge Coupled Device(ICCD)*** minimum delay between the camera channels could be as short as≈0.1 *** made it possible to study the gap breakdown process with subnanosecond *** was observed that a wide-diameter streamer develops from the high-voltage pointed *** ionization processes near the grounded pin electrode started when the streamer crossed half of the *** bridging the gap by the streamer,a diffuse discharge was *** development of spark leaders from bright spots on the surface of the pointed electrodes was observed at the next *** was found that the rate of development of the spark leader is an order of magnitude lower than that of the wide-diameter *** thin luminous tracks were observed against the background of a discharge plasma *** has been established that the tracks are adjacent to brightly glowing spots on the electrodes and are associated with the flight of small particles.

关键词： needle electrodes short voltage pulses atmospheric air streamer breakdown diffuse and spark discharges scattering metal particles

Age and geochemical evolution of granite magmatism in Olkhon region from Caledonian syncollisional ore-free granite to the rare metal granite and pegmatite of Middle Paleozoic intraplate setting

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China Geology 2024年第1期7卷 63-79页

作者： Viktor Antipin Valentina Makrygina Larisa Kushch Nataliya Sheptyakova Vinogradov institute of Geochemistry SB RAS664033 IrkutskRussia

The detailed description of two granite complexes in the Olkhon subterrane is *** Early Paleozoic Sharanur complex was formed by granitization of gneisses of the Olkhon *** includes migmatites,granite-gneisses,granites and pegmatites of normal alkalinity;they belong to the type of syncollisional *** Middle Paleozoic Aya granite complex includes mother Aya massif of amazonite-bearing granites and several types of rare-metal *** have elevated alkalinity,low of Ba,Sr,and high LILE and HFSE elements *** Aya pegmatites lie in northwest cracks of stretching and associated with the rise of the territory under the influence of the North Asian *** cracks and pegmatites mark the beginning of a new intraplate geodynamic *** geochemical types are distinguished among the pegmatites of this *** are amazonite pegmatites of Li-F type with Ta mineralization and complex type pegmatite with Be-Rb-Nb-Ta and Li-F mineralization(the Ilixin vein).The Tashkiney pegmatite vein is similar to Ilixin,but lies in the gneisses of the Olkhon *** shows high concentrations of Be,Nb,Ta,as well as W,Sn,but lacks Li and F,due to a greater depth and higher temperature of the melt crystallization of this pegmatite.

关键词： Pegmatite Geochemistry Submantle plume Magmatism Caledonian collision Middle Paleozoic intraplate setting Be-Rb-Nb-Ta-Li-F mineralization Olkhon region Russia

Catalytic co-combustion of biomass and brown coal in a fluidized bed:Economic and environmental benefits

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Journal of Environmental Sciences 2024年第6期140卷 24-36页

作者： Yury V.Dubinin Nikolay A.Yazykov Petr M.Yeletsky Roman B.Tabakaev Aleksandra I.Belyanovskaya Vadim A.Yakovlev Federal Research Center Boreskov institute of Catalysis sb ras Lavrentiev Ave.5Novosibirsk630090Russia University of Tyumen Volodarskogo str.6Tyumen625003Russia

The work is devoted to the study of combustion of brown coal,pine sawdust,and their mixtures in a fluidized bed of catalyst at 600-750℃.It is shown that an increase in the content of sawdust in a mixture with brown coal leads to an increase in the burnout degree of solid fuel from 94.4%to 99.9%,while the emission of greenhouse gases in the form of CO_(2)CO and NOxis reduced(CO_(2)from the biomass is not included in the balance).The high content of alkaline earth metal oxides(CaO and MgO)in the mineral part of brown coal,sawdust,and their mixtures eliminates the emission of sulfur oxides and the slagging of heat-exchange surfaces during the combustion in a fluidized bed of *** optimal temperature,when the highest burnout degree of the above fuels is achieved in the combustion is 750℃.It is also shown that the increase in temperature and the content of sawdust in the composition of the fuel mixtures has a positive effect on the economic and environmental process indicators.

关键词： Co-combustion Fluidized catalyst bed Biomass Coal Economic effect Environmental impact

Numerical Simulation of Thermocapillary Convection with Evaporation Induced by Boundary Heating

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Fluid Dynamics & Materials Processing 2024年第7期20卷 1667-1686页

作者： O.N.Goncharova V.B.Bekezhanova Altai State University Institute of Mathematics and Information TechnologiesBarnaul656049Russia institute of Computational Modelling sb ras Department of Differential Equations of MechanicsKrasnoyarsk660036Russia

The dynamics of a bilayer system filling a rectangular cuvette subjected to external heating is *** influence of two types of thermal exposure on the flow pattern and on the dynamic contact angle is *** particular,the cases of local heating from below and distributed thermal load from the lateral walls are *** simulation is carried out within the frame of a two-sided evaporative convection model based on the Boussinesq approximation.A benzine–air system is considered as reference *** variation in time of the contact angle is described for both heating *** lateral heating,near-wall boundary layers emerge together with strong convection,whereas the local thermal load from the lower wall results in the formation of multicellular motion in the entire volume of the fluids and the appearance of transition regimes followed by a steady-state *** results of the present study can aid the design of equipment for thermal coating or drying and the development of methods for the formation of patterns with required structure and morphology.

关键词： Thermocapillary convection two-phase system numerical modeling contact angle

Analysis of the discrete contact characteristics based on the Greenwood-Williamson model and the localization principle

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Friction 2024年第5期12卷 1042-1056页

作者： Anastasiya A.YAKOVENKO Irina G.GORYACHEVA Ishlinsky institute for Problems in Mechanics ras Moscow119526Russia

The contact of a rigid body with nominally flat rough surface and an elastic half-space is *** solve the contact problem,the Greenwood-Williamson statistical model and the localization principle are *** developed contact model allows us to investigate the surface approach and the real contact area with taking into account the asperities *** is shown that the mutual influence of asperities changes not only contact characteristics at the macroscale,but also the contact pressure distribution at the *** follows from the results,the inclusion in the contact model of the effect of the mutual influence of asperities is especially significant for studying the real contact area,as well as the contact characteristics at high applied *** results calculated according to the proposed approach are in a good agreement with the experimentally observed effects,i.e.,the real contact area saturation and the additional compliance exhaustion.

关键词： surface roughness elasticity Greenwood-Williamson model localization principle asperity interaction

A muon high-resolution pseudorange measurement method: Application to muon navigation in confined spaces

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Chinese Journal of Aeronautics 2024年第4期37卷 391-404页

作者： Haoyang LI Chunxi ZHANG Xingming FAN Longjie TIAN Tianqi LI Yang PANG Yanqiang YANG institute of Optics and electronics School of Instrumentation Science and Optoelectronics EngineeringBeihang UniversityBeijing 100191China institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China

Confined spaces such as polar regions, deep earth and deep ocean are crucial navigation scenarios where traditional navigation techniques have difficulty in obtaining external signals for positioning. The cosmic ray muons, which carry the spatial and energetic information, are easy to penetrate these confined spaces. Therefore, the unique muon characteristic provides a new perspective to estimate detector position, which can be considered using in confined spaces *** this paper, a well-developed theory of muon navigation is established by combining a muon pseudorange measurement method. Moreover, an Equivalent Velocity Calculation Model(EVCM)and a Muon Sequence Matching Technology(MSMT) are proposed. The first model corrects flight pseudorange error caused by the relativistic energy loss and the second technology compensates the random error in pseudorange measurement. Further, a series of simulations are performed to analyze the muon events number which can be received by detector in different scenarios with the variations of zenith angle, detector area, varied detector plates gap, and muon flight ***, the simulation results demonstrate that the muon navigation update rate every 10 minutes can reach 5.989 in confined spaces at 100 m, and further pseudorange error analysis indicates that the meter-level positioning accuracy can be acquired. Finally, we construct a muon coincidence measurement scheme and verify that the laws of the muon positioning system for high-energy muons are consistent with the simulation results.

关键词： Muon navigation Cosmic ray muons Muon detection technology Muon transmission technology Pseudorange measurement

Scalable orthogonal delay-division multiplexed OEO artificial neural network trained for TI-ADC equalization

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Photonics Research 2024年第1期12卷 85-105页

作者： ANDREA ZAZZI ARKA DIPTA DAS LUKAS HüSSEN RENATO NEGRA JEREMY WITZENS institute of Integrated Photonics RWTH Aachen University52074 AachenGermany Chair of high-Frequency electronics RWTH Aachen University52074 AachenGermany

We propose a new signaling scheme for on-chip optical-electrical-optical artificial neural networks that utilizes orthogonal delay-division multiplexing and pilot-tone-based self-homodyne *** scheme offers a more efficient scaling of the optical power budget with increasing network *** simulations,based on220 nm silicon-on-insulator silicon photonics technology,suggest that the network can support 31×31 neurons,with 961 links and freely programmable weights,using a single 500 m W optical comb and a signal-to-noise ratio of 21.3 d B per ***,it features a low sensitivity to temperature fluctuations,ensuring that it can be operated outside of a laboratory *** demonstrate the network’s effectiveness in nonlinear equalization tasks by training it to equalize a time-interleaved analog-to-digital converter(ADC)architecture,achieving an effective number of bits over 4 over the entire 75 GHz ADC *** anticipate that this network architecture will enable broadband and low latency nonlinear signal processing in practical settings such as ultra-broadband data converters and real-time control systems.

关键词： network delay artificial

Changes in filtration and capacitance properties of highly porous reservoir in underground gas storage:CT-based and geomechanical modeling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2982-2995页

作者： Valerii Khimulia Vladimir Karev Yury Kovalenko Svyatoslav Barkov Ishlinsky institute for Problems in Mechanics ras Moscow119526Russia

The paper presents the results of comprehensive studies of filtration and capacitance properties of highly porous reservoir rocks of the aquifer of an underground gas storage *** geomechanical part of the research included studying the dependence of rock permeability on the stress-strain state in the vicinity of the wells,and physical modeling of the implementation of the method of increasing the permeability of the wellbore zone-the method of directional unloading of the *** digital part of the research included computed tomography(CT)-based computer analysis of the internal structure,pore space characteristics,and filtration properties before and after the *** to the results of physical modeling of deformation and filtration processes,it is found that the permeability of rocks before fracture depends on the stress-strain state insignificantly,and this influence is ***,when downhole pressure reaches 7-8 MPa,macrocracks in the rock begin to grow,accompanied by irreversible permeability ***,geodesic tortuosity and permeability values were obtained based on digital studies and numerical modeling.A weak degree of transversal anisotropy of the filtration properties of rocks was *** on the analysis of pore size distribution,pressure field and flow velocities,high homogeneity and connectivity of the rock pore space is *** absence of pronounced changes in pore space characteristics and pore permeability after non-uniform triaxial loading rocks was *** the basis of geometrical analysis of pore space,the reasons for weak permeability anisotropy were *** filtration-capacitance properties obtained from the digital analysis showed very good agreement with the results of field and laboratory *** physical modeling has confirmed the efficiency of application of the directional unloading method for the reservoir under *** necessary parameters of its application were calcu

关键词： Permeability anisotropy Reservoir porosity Rocks computed tomography(CT) Digital core analysis Filtration flow numerical modeling

Study of asphaltene reaggregation in toluene/heptane mixture by dynamic and static light scattering

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Petroleum Research 2024年第1期9卷 48-54页

作者： Vladimir N.Kuryakov Oil and Gas Research institute of ras(OGRI ras) Gubkina Str.3119333MoscowRussian Federation

This paper presents the study of the effect of multiple ultrasonic impacts on submicron asphaltene aggregates in a toluene/heptane solution,conducted with dynamic light scattering *** objects of the study were four samples of asphaltenes obtained from four different *** all samples,the change in the average size of the asphaltene submicron aggregates with time was measured after the addition of a precipitant(heptane)to a solution of asphaltenes in toluene at an amount above the threshold *** aggregates formed in solution after the addition of the precipitant and were subjected to ultrasonic treatment,which led to the destruction of the asphaltene *** of destroyed asphaltenes was *** kinetics of this aggregation were similar to the kinetics of aggregation of asphaltenes after the addition of a *** iterations of asphaltene aggregate destruction in the sample led to a significant change in the kinetics of aggregation:the growth of aggregates slowed and stabilized at a size of approximately 200 nm and 30 nm for the different studied samples.

关键词： Asphaltenes Aggregation Sonication Dynamic light scattering Re-aggregation Colloidal stability Resins