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Consideration of the influence of supports in modeling the electromagnetic fields of 25 kV traction networks under emergency conditions

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Global Energy Interconnection 2024年第4期7卷 528-540页

作者： Konstantin Suslov Andrey Kryukov Ekaterina Voronina pavel Ilyushin Department of Hydropower and Renewable Energy National Research UniversityMoscow Power Engineering InstituteMoscow 11250Russia Department of Power Supply and Electrical Engineering Irkutsk National Research Technical UniversityIrkutsk 664074Russia Department of Transport Electric Power Irkutsk State Transport UniversityIrkutsk 664074Russia Department of Research on the Relationship between Energy and the Economy Energy Research Institute of the Russian Academy of SciencesMoscow 117186Russia

Single-phase 25 kV traction networks of electrified alternating current(AC)railways create electromagnetic fields(EMFs)with significant levels of *** most intense magnetic fields occur when short circuits exist between the contact wire and rails or *** the short duration of exposure,they can adversely affect electronic devices and induce significant voltages in adjacent power lines,which is dangerous for operating *** numerous investigations have focused on modeling the EMF of traction networks and power lines,the challenge of determining the three-dimensional electromagnetic fields near metal supports during the flow of a short-circuit current through them is yet to be *** this case,the field has a complex spatial structure that significantly complicates the calculations of *** study proposes a methodology,algorithms,software,and digital models for determining the EMF in the described emergency *** the modeling process,the objects being studied were represented by segments of thin wires to analyze the distribution of the electric charge and calculate the intensities of the electric and magnetic *** approach was implemented in the Fazonord software,and the modeling results show a substantial increase in EMF levels close to the support,with a noticeable decrease in the levels as the distance from it *** procedure implemented in the commercial software Fazonord is universal and can be used to determine electromagnetic fields at any electrical power facility that includes live parts of limited *** on the proposed procedure,the EMF near the supports of overhead power lines and traction networks of various designs could be determined,the EMF levels at substations can be calculated,and the influence of metal structures located near traction networks,such as pedestrian crossings at railway stations,can be considered.

关键词： Power supply systems AC railways Emergency conditions Electromagnetic fields near supports Modeling Electromagnetic safety

Thermogravimetric,kinetic study and gas emissions analysis of the thermal decomposition of waste-derived fuels

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Journal of Environmental Sciences 2024年第3期137卷 155-171页

作者： Vadim V.Dorokhov Galina S.Nyashina pavel A.Strizhak Heat and Mass Transfer Laboratory National Research Tomsk Polytechnic University30 Lenin AvenueTomsk 634050Russia

A wide range of wastes can potentially be used to generate thermal and electrical *** co-combustion of several types of waste as part of water-containing waste-derived fuels is a promising method for their *** this research,we use thermogravimetric analysis and differential scanning calorimetry to study the thermal behavior and kinetics of coal slime,biomass,waste oils,and blends on their *** also analyze the concentrations of gaseous *** results show that biomass,oils,and coal slime significantly affect each other in the course of their co-combustion when added to slurry *** preparation of coal-water slurry based on slime and water reduced the ignition and burnout temperature by up to 16%.Adding biomass and waste oils additionally stimulated the slurry ignition and burnout,which occurred at lower *** to dry coal slime,threshold ignition temperatures and burnout temperatures decreased by 6%–9%and 17%–25%,***,the use of biomass and waste oils as part of slurries inhibited NOхand SO_(2)emission by 2.75 *** to the kinetic analysis,added biomass and waste turbine oil provide a 28%–51%reduction in the activation energy as compared to a coal-water slurry without additives.

关键词： Coal-water slurry Water-containing composite fuels Combustion Emission Kinetic TGA-DSC

Plasticity of photorespiratory carbon concentration mechanism in Sedobassia sedoides(Pall.)Freitag&*** under elevated CO_(2)concentration and salinity

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Journal of Arid Land 2024年第7期16卷 963-982页

作者： Zulfira RAKHMANKULOVA Elena SHUYSKAYA Maria PROKOFIEVA Kristina TODERICH pavel VORONIN Timiryazev Institute of Plant Physiology Russian Academy of SciencesMoscow 127276Russia Graduate School of Bioresources Mie University1577 KurimamachiyaTsu 514-8507Japan

Rising atmospheric CO_(2)(carbon dioxide)concentrations and salinization are manifestations of climate change that affect plant growth and *** with an intermediate C_(3)-C_(4)type of photosynthesis live in a wide range of precipitation,temperature,and soil quality,but are more often found in warm and dry *** of the intermediate C_(3)-C_(4)photosynthetic type is C_(2)photosynthesis with a carbon concentration mechanism(CCM)that reassimilates CO_(2)released via ***,the ecological significance under which C_(2)photosynthesis has advantages over C_(3)and C_(4)plants remains largely *** tolerance and functioning of CCM were studied in plants from two populations(P1 and P2)of Sedobassia sedoides(Pall.)Freitag&*** *** with C_(2)photosynthesis exposed to 4 d and 10 d salinity(200 mM NaCl)at ambient(785.7 mg/m^(3),aCO_(2)and elevated(1571.4 mg/m^(3),eCO_(2))CO_(2).On the fourth day of salinity,an increase in Na+content,activity catalase,and superoxide dismutase was observed in both populations.P2 plants showed an increase in proline content and a decrease in photosynthetic enzyme content:rubisco,phosphoenolpyruvate carboxylase(PEPC),and glycine decarboxylase(GDC),which indicated a weakening of C_(2)and C_(4)characteristics under *** under 10 d salinity led to an increased Na^(+)content and activity of cyclic electron flow around photosystem I(PSI CEF),a decreased content of K^(+)and GDC in both populations.P1 plants showed greater salt tolerance,which was assessed by the degree of reduction in photosynthetic enzyme content,PSI CEF activity,and changes in relative growth rate(RGR).Differences between populations were evident under the combination of eCO_(2)and *** long-term salinity and eCO_(2),more salt-tolerant P1 plants had a higher dry biomass(DW),which was positively correlated with PSI CEF *** less salt-tolerant P2 plants,DW correlated with transpiration and dark

关键词： photosystemsⅠandⅡ carbon-concentrating mechanism glycine decarboxylase rubisco phosphoenolpyruvate carboxylase(PEPC) cyclic electron flow salinity stress drylands

Population genetic structure in the paddyfield warbler （Acrocephalus agricola Jerd.）

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Current Zoology 2011年第1期57卷 63-71页

作者： pavel zehtindjiev Mihaela ILIEVA Bengt HANSSON Olga OPARINA Mihail OPARIN Staffan BENSCH Institute of Biodiversity and Ecosystem Research Bulgarian Academy of Sciences 2 Gagarin Street 1113 Sofia Bulgaria Department of Ecology Lund University Ecology Building SE-223 62 Lund Sweden A.N.Severtsov Institute of Ecology and Evolution Russian Academy of Sciences Saratov Branch 410028 Rabochaya Str.24 Saratov Russia

Resonantly enhanced second-and third-harmonic generation in dielectric nonlinear metasurfaces

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Opto-Electronic Advances 2024年第5期7卷 5-19页

作者： Ji Tong Wang pavel Tonkaev Kirill Koshelev Fangxing Lai Sergey Kruk Qinghai Song Yuri Kivshar Nicolae C.Panoiu Department of Electronic and Electrical Engineering University College LondonLondon WC1E 7JEUnited Kingdom Nonlinear Physics Center Research School of PhysicsAustralian National UniversityCanberra ACT 2601Australia Ministry of Industry and Information Technology Key Lab of Micro-Nano Optoelectronic Information System Guangdong Provincial Key Laboratory of Semiconductor Optoelectronic Materials and Intelligent Photonic SystemsHarbin Institute of TechnologyShenzhen 518055China Wuzhen Laboratory EGO Wuzhen Digital Economy Industrial ParkNo.925 Daole RoadTongxiangChina

Nonlinear dielectric metasurfaces provide a promising approach to control and manipulate frequency conversion optical processes at the nanoscale,thus facilitating both advances in fundamental research and the development of new practical applications in photonics,lasing,and ***,we employ symmetry-broken metasurfaces made of centrosymmetric amorphous silicon for resonantly enhanced second-and third-order nonlinear optical *** the rich physics of optical quasi-bound states in the continuum and guided mode resonances,we comprehensively study through rigorous numerical calculations the relative contribution of surface and bulk effects to second-harmonic generation(SHG)and the bulk contribution to third-harmonic generation(THG) from the ***,we experimentally achieve optical resonances with high quality factors,which greatly boosts light-matter interaction,resulting in about 550 times SHG enhancement and nearly 5000-fold increase of THG.A good agreement between theoretical predictions and experimental measurements is *** gain deeper insights into the physics of the investigated nonlinear optical processes,we further numerically study the relation between nonlinear emission and the structural asymmetry of the metasurface and reveal that the generated harmonic signals arising from linear sharp resonances are highly dependent on the asymmetry of the *** work suggests a fruitful strategy to enhance the harmonic generation and effectively control different orders of harmonics in all-dielectric metasurfaces,enabling the development of efficient active photonic nanodevices.

关键词： second-harmonic generation third-harmonic generation bound state in the continuum guided mode resonance all-dielectric metasurfaces nonlinear optics

Independent control of circularly polarized light with exceptional topological phase coding metasurfaces

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Photonics Research 2024年第6期12卷 534-542页

作者： YICHENG LI SHICHENG WAN SHAOXUAN DENG ZHENGWEI DENG BO LV CHUNYING GUAN JUN YANG ANDREY BOGDANOV pavel BELOV JINHUI SHI Key Laboratory of Photonic Materials and Devices Physics for Oceanic Applications Ministry of Industry and Information TechnologyCollege of Physics and Optoelectronic EngineeringHarbin Engineering UniversityHarbin 150001China Key Laboratory of In-Fiber Integrated Optics of Ministry of Education College of Physics and Optoelectronic EngineeringHarbin Engineering UniversityHarbin 150001China School of Physics and Engineering ITMO UniversitySt.Petersburg 197101Russia School of Information Engineering Guangdong University of TechnologyGuangzhou 510008China Qingdao Innovation and Development Center Harbin Engineering UniversityQingdao 266000China

Exceptional points,as degenerate points of non-Hermitian parity-time symmetric systems,have many unique physical *** to its flexible control of electromagnetic waves,a metasurface is frequently used in the field of *** this work,we developed a parity-time symmetric metasurface and implemented the 2πtopological phase surrounding an exceptional *** with Pancharatnam-Berry phase,the topological phase around an exceptional point can achieve independent regulation of several circular polarization *** combined the Pancharatnam-Berry phase with the exceptional topological phase and proposed a composite coding metasurface to achieve reflection decoupling of different circular *** work provides a design idea for polarimetric coding metasurfaces in the future.

关键词： properties. exceptional topological

Pulsed THz radiation under ultrafast optical discharge of vacuum photodiode

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Frontiers of Optoelectronics 2024年第2期17卷 99-112页

作者： Aleksandr Ushakov Kseniia Mamaeva Leonid Seleznev Georgy Rizaev Vladimir Bukin Timophey Dolmatov pavel Chizhov Vladimir Bagdasarov Sergey Garnov Prokhorov General Physics Institute of the Russian Academy of Sciences Moscow 119991Russia Physical Institute Russian Academy of SciencesMoscow 119991Russia Moscow Institute of Physics and Technology Dolgoprudny 141700Russia Russian Institute for Scientific and Technical Information Moscow 125190Russia

In this paper,we first present an experimental demonstration of terahertz radiation pulse generation with energy up to 5 pJ under the electron emission during ultrafast optical discharge of a vacuum *** use a femtosecond optical excitation of metallic copper photocathode for the generation of ultrashort electron bunch and up to 45 kV/cm external electric field for the photo-emitted electron *** of terahertz pulses energy as a function of emitted charge density,incidence angle of optical radiation and applied electric field have been *** and polarization characteristics of generated terahertz pulses have also been *** proposed semi-analytical model and simulations in COMSOL Multiphysics prove the experimental data and allow for the optimization of experimental conditions aimed at flexible control of radiation parameters.

关键词： Electron emission Vacuum photodiode Ultrafast excitation Terahertz

Adaptive Method’s Application for the Identification Systems in Dynamic Weighing

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Journal of Traffic and Transportation Engineering 2024年第4期12卷 175-186页

作者： pavel Shakun Transport and Telecommunication Institute RīgaLV-1019Latvia

In this work,the possibility of adaptive algorithm in WIM(weight-in-motion)systems,in which fibre optic sensors are used,is *** of dynamic weighing device consists in determining the weight and type of *** this work an algorithm for processing the input data and fiber optic sensor to create the database used in the algorithm is *** results of the algorithm for the identification of vehicles are *** conclusions are made and options of increasing the accuracy of the identification algorithm are considered.

关键词： Dynamic weighing adaptive filtering digital data processing

SPEED:an integrated,smartphone-operated,handheld digital PCR Device for point-of-care testing

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Microsystems & Nanoengineering 2024年第3期10卷 149-158页

作者： Haoqing Zhang Xiaocheng Liu Xinlu Wang Zhiqiang Yan Ying Xu Martina Gaňová TomášŘezníček Marie Korabečná pavel Neuzil Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’anShaanxi 710072PR China The Key Laboratory of Biomedical Information Engineering of the Ministry of Education School of Life Science and TechnologyXi’an Jiaotong UniversityXi’anShaanxi 710049PR China Bioinspired Engineering and Biomechanics Center(BEBC) Xi’an Jiaotong UniversityXi’an 710049PR China School of Marine Science and Technology Northwestern Polytechnical UniversityXi’anShaanxi 710072PR China Central European Institute of Technology Brno University of TechnologyPurkyňova 12361300 BrnoCzech Republic ITD Tech S.R.O Osvoboditelu100573581 BohumínCzech Republic Institute of Biology and Medical Genetics First Faculty of MedicineCharles University and General University Hospital of PragueAlbertov 412800 PragueCzech Republic

This study elaborates on the design,fabrication,and data analysis details of SPEED,a recently proposed smartphonebased digital polymerase chain reaction(dPCR)*** dPCR chips incorporate partition diameters ranging from 50μm to 5μm,and these partitions are organized into six distinct blocks to facilitate image *** to the superior thermal conductivity of Si and its potential for mass production,the dPCR chips were fabricated on a Si substrate.A temperature control system based on a high-power density Peltier element and a preheating/cooling PCR protocol user interface shortening the thermal cycle *** optical design employs four 470 nm light-emitting diodes as light sources,with filters and mirrors effectively managing the light emitted during *** algorithm is utilized for image processing and illumination nonuniformity correction including conversion to a monochromatic format,partition identification,skew correction,and the generation of an image correction *** validated the device using a range of deoxyribonucleic acid targets,demonstrating its potential applicability across multiple ***,we provide guidance and verification of the design and testing of the recently proposed SPEED device.

关键词： correction smart testing