检索结果-南通市图书馆

Chinese Physics B 2017年第12期26卷 427-431页

作者： Sergey Konovalov dmitry zagulyaev 陈希章 Victor Gromov Yurii Ivanov Samara National Research University Samara 443086 Russia Wenzhou University Wenzhou 325035 China Siberian State Industrial University Novokuznetsk 654007 Russia Institute of High Current Electronics of the Siberian Branch of the Russia Academy of Sciences Tomsk 634055 Russia

Commercially pure polycrystalline aluminum of grade A85, as a test material, is investigated. Using scanning and transmission electron microscopy the aluminum fine structure and fracture surface are analyzed. Fractures are studied in the regime of creep with and without a simultaneous effect of 0.3-T magnetic field. It is found that the application of a magnetic field in a linear stage of creep leads to substructure imperfection increasing. Furthermore, the magnetic field effect on aluminum in the process of creep causes the average scalar density of dislocations to increase and induces the process of dislocation loop formation to strengthen. Fractographic investigation of the fracture surface shows that in the fibrous fracture zone the average size of plastic fracture pits decreases more than twice under creep in the condition of external magnetic field compared with in the conventional experimental condition. In a shear zone, the magnetic field causes the average size of fracture pits to decrease. Experimental data obtained in the research allow us to conclude that the magnetic field effect on aluminum in the process of creep leads to the fracture toughness value of the material decreasing, which will affect the state of defect substructure of the volume and surface layer of the material. The influence of the magnetic field is analyzed on the basis of the magneto-plasticity effect.

关键词： aluminum magnetic field creep structure

CHARACTERIZATIONS OF BALLS AND ELLIPSOIDS BY INFINITESIMAL HOMOTHETIC CONDITIONS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2025年第1期45卷 280-290页

作者： M.Angeles ALFONSECA dmitry RYABOGIN Alina STANCU Vladyslav YASKIN Department of Mathematics North Dakota State UniversityFargoND58018USA Department of Mathematical Sciences Mathematics and Computer ScienceKent State UniversityBuilding 233Summit StreetKentOH44242USA Department of Mathematics and Statistics Concordia University1455 Blvd.de Maisonneuve OuestMontrealQuebecH3G 1M8Canada Department of Mathematical and Statistical Sciences University of AlbertaEdmontonAlbertaT6G 2G1Canada

We prove that for a smooth convex body K⊂ℝd,d≥2,with positive Gauss curvature,its homothety with a certain associated convex body implies that K is either a ball or an ellipsoid,depending on the associated body consi... 详细信息

关键词： Busemann-Petty problem convex bodies dual mixed volumes floating body surface of centers

Light-activated tautomeric transition enhanced buried heterointerface for highly efficient and ultraviolet robust perovskite solar cells

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年第2期68卷 723-732页

作者： Sheng Jiang Shaobing Xiong Shuaifei Mao Yefan Zhang Dongyang Zhao Xiaomeng You Vladimir Gaishun dmitry Kovalenk Qinye Bao School of Physics and Electronic Science East China Normal UniversityShanghai 200241China Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception Institute of OptoelectronicsFudan UniversityShanghai 200433China Institute of Functional Nano&Soft Materials(FUNSOM) Soochow UniversitySuzhou 215123China Shanghai Key Laboratory of Magnetic Resonance East China Normal UniversityShanghai 200241China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Department of Physics and Information Technologies Francisk Skorina Gomel State UniversityGomel 246028Belarus

The buried heterointerface of perovskite solar cells(PSCs)suffers from serious nonradiative recombination and ultraviolet(UV)light stress,relentlessly limiting further increase in their power conversion efficiency and operational ***,we develop an emerging strategy of incorporating a thin UV-activated tautomeric transition layer onto underlying charge transport layer and then depositing perovskite layer to construct an efficient hole-selective buried *** is revealed that the UV-activated tautomeric transition interlayer not only improves upper perovskite crystallinity,diminishes thermionic loss for collecting hole and passivates defect site at such buried contact that significantly promote charge transport and suppress nonradiative recombination,but also effectively protects adjacent perovskite from UV degradation through“UV sunscreen”*** a result,we report a remarkably enhanced efficiency of 24.76%compared to 22.02%of the control *** importantly,the achieved high-efficiency PSC features excellent resistance against UV radiation at 365 nm of 100 and 850 mW cm^(−2),which are approximately 21 and 184 times of UV flux(4.6 mW cm^(−2))under AM 1.5G solar *** work provides a promising approach of strengthening buried heterointerface for simultaneous realization of highly efficient and UV robust PSCs.

关键词： buried heterointerface energetics nonradiative recombination ultraviolet resistance perovskite solar cell

Alternative Strategy for Development of Dielectric Calcium Copper Titanate‑Based Electrolytes for Low‑Temperature Solid Oxide Fuel Cells

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2025年第1期17卷 310-332页

作者： Sajid Rauf Muhammad Bilal Hanif Zuhra Tayyab Matej Veis MAKYousaf Shah Naveed Mushtaq dmitry Medvedev Yibin Tian Chen Xia Martin Motola Bin Zhu College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060People’s Republic of China Department of Inorganic Chemistry Faculty of Natural SciencesComenius University BratislavaIlkovicova684215 BratislavaSlovakia Energy Storage Joint Research Center School of Energy and EnvironmentSoutheast UniversityNanjing 210096People’s Republic of China Hydrogen Energy Laboratory Ural Federal University620002 EkaterinburgRussia Laboratory of Electrochemical Devices Based on Solid Oxide Proton Electrolytes Institute of High Temperature Electrochemistry620066 EkaterinburgRussia School of Microelectronics Hubei UniversityWuhan 430062People’s Republic of China

The development of low-temperature solid oxide fuel cells(LT-SOFCs)is of significant importance for realizing the widespread application of *** has stimulated a substantial materials research effort in developing high oxide-ion conductivity in the electrolyte layer of *** this context,for the first time,a dielectric material,CaCu_(3)Ti_(4)O_(12)(CCTO)is designed for LT-SOFCs electrolyte application in this *** individual CCTO and its heterostructure materials with a p-type Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ)(NCAL)semiconductor are evaluated as alternative electrolytes in LT-SOFC at 450–550℃.The single cell with the individual CCTO electrolyte exhibits a power output of approximately 263 mW cm^(-2) and an open-circuit voltage(OCV)of 0.95 V at 550℃,while the cell with the CCTO–NCAL heterostructure electrolyte capably delivers an improved power output of approximately 605 mW cm^(-2) along with a higher OCV over 1.0 V,which indicates the introduction of high hole-conducting NCAL into the CCTO could enhance the cell performance rather than inducing any potential short-circuiting *** is found that these promising outcomes are due to the interplay of the dielectric material,its structure,and overall properties that led to improve electrochemical mechanism in CCTO–***,density functional theory calculations provide the detailed information about the electronic and structural properties of the CCTO and NCAL and their heterostructure CCTO–*** study thus provides a new approach for developing new advanced electrolytes for LT-SOFCs.

关键词： LT-SOFCs Dielectric CaCu_(3)Ti_(4)O_(12) Semiconductor Ni_(0.8)Co_(0.15)Al_(0.05)LiO_(2−δ) Ionic conductivity Heterostructure electrolyte

Four-wave mixing in a laser diode gain medium induced by the feedback from a high-Q microring resonator

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2025年第1期13卷 59-68页

作者： DARIA M.SOKOL NIKITA YU DMITRIEV dmitry A.CHERMOSHENTSEV SERGEY N.KOPTYAEV ANATOLY V.MASALOV VALERY E.LOBANOV IGOR A.BILENKO ARTEM E.SHITIKOV Russian Quantum Center Moscow Institute of Physics and Technology (MIPT) Skolkovo Institute of Science and Technology Lebedev Physical Institute Russian Academy of Sciences Faculty of Physics M.V.Lomonosov Moscow State University

Laser diodes are widely used and play a crucial role in myriad modern applications including nonlinear optics and ***,we explore the four-wave mixing effect in a laser diode gain medium induced by the feedback from the high-Q microring *** phenomenon can be observed at a laser frequency scan close to the microresonator eigenfrequency,prior to the transition of the laser diode from a free-running to a self-injection locking *** effect opens up the possibility for generation of remarkably low-noise,stable,and adjustable microwave *** provide a detailed numerical study of this phenomenon proven with experimental results and demonstrate the generation of the signals in the GHz *** obtained results reveal the stability of such regime and disclose the parameter ranges enabling to achieve ***,our findings uncover,to our knowledge,a novel laser diode operation regime and pave the way for the creation of new types of chip-scale,low-noise microwave sources,which are highly demanded for diverse applications,including telecommunication,metrology,and sensing.

关键词： Four wave mixing

Choosing configurations of transmission line tower grounding by back flashover probability value

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers in Energy 2016年第2期10卷 213-226页

作者： dmitry KUKLIN Centre for Physical and Technological Problems of Energy in NorthemAreas Apatity 184209 Russia

There is a considerable number of works devoted to electrical characteristics of grounding. These characteristics are important in general. However, in application to grounding of transmission line towers they are not enough to determine what grounding construction is preferable in some particular case, because these characteristics are calculated or measured apart from the grounded object, and only limited number of current （or voltage） source waveforms is used. This paper indicates reasons in favor of the fact that to choose the optimum design of grounding, the calculation model should include the tower as it is. The probability of back flashover, which provides both qualitative and quantitative estimate of the grounding structure efficiency, can be taken as the criterion for the grounding design. The insulation flashover probability is calculated on the basis of engineering method, which evaluates breakdown strength of insulation for nonstandard waveshapes, and probability data on lightning currents. Different approaches are examined for identifying the back flashover probability, as not only amplitudes but also other parameters can be taken into account. Finite-difference time-domain method is used for calculations of transients. It is found that lightning current waveform can greatly influence calculated back flashover probability value.

关键词： grounding transmission line tower back flashover probability FDTD method

E-beam generation in discharges initiated by voltage pulses with a rise time of 200 ns at an air pressure of 12.5-100 kPa

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第4期21卷 52-60页

作者： Victor TARASENKO dmitry BELOPLOTOV Mikhail LOMAEV dmitry SOROKIN Institute of High Current Electronics Siberian Bran ch.Russian Academy of Sciences.Tomsk&34055.Russia National Research Tomsk State University.Tomsk 634050 Russia

The effect of air pressure(12.5,25,50,and 100 kPa)on the gen eration of runaway electron beams in a non-uniform electric field when applying voltage pulses(~35 kV)with a rise time of?200 ns has been *** results show that the discharge has various stages:streamer,diffuse,and ***,a wide streamer develops in the gap and a diffuse discharge is formed.A spark is formed u 100 ns after the *** current pulse of a supershort avalanche electron beam(SAEB)was measured with a collector at various pressures of *** show that there are two modes of generation of run away *** an air pressure of 25-100 kPa,a single SAEB current pulse with a full width at half-maximum(FWHM)of 120-140 ps is *** the air pressure of 12.5 kPa,two current pulses of the electron beam are *** of the first and second current pulses are ul40ps and u300 ps,*** current pulse amplitude of the second electron beam is higher than that of the first one,but the electron energy is less.

关键词： diffuse discharge runaway electrons streamer breakdown displacement current

Adhesion at friction and wear

在线全文

学校读者我要写书评

暂无评论

Friction 2022年第11期10卷 1859-1878页

作者： dmitry P.MARKOV Research Institute of Railway Transport Moscow 129851Russia

Our understanding of the surrounding world,from friction to the origin of life,depends on how we imagine the contact interaction of condensed *** are the forces acting in contact with solids?Do they attract(adhesive)or repel(dehesive)?Theory and research at the atomic–molecular level have shown that the force are adhesive,but everyday experiences cast doubt on this *** article addresses this issue by considering the mistakes made in experimental and theoretical tribology and surface *** into account the theories of hybridization and dehybridization of electron orbitals and valence bonds,the views on the structure of the surfaces of condensed bodies and the force arising during contact interaction are *** influence of van der Waals,hydrogen,covalent,metallic,and ionic bonds on the properties of lubricants is *** contours of the dehesive–deformation theory of friction and wear are also outlined.

关键词： atomic and molecular interactions adhesion cohesion dehesion friction wear

Positive and negative streamers in air and nitrogen in a sharply inhomogeneous electric field under conditions of runaway electron generation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2023年第3期8卷 527-537页

作者： dmitry Beloplotov Victor Tarasenko dmitry Sorokin Cheng Zhang Tao Shao Institute of High Current Electronics Siberian Branch of the Russian Academy of ScienceTomskRussia Beijing International S&T Cooperation Base for Plasma Science and Energy Conversion Institute of Electrical EngineeringChinese Academy of SciencesBeijingChina

The development of positive and negative streamers in a point-to-plane gap filled with air and nitrogen at various pressures(50-200 kPa)and voltages(8-25 kV)was studied.A four-channel intensified charge-coupled device(ICCD)and a streak-camera were *** parameters were measured with high resolution(10 GHz).An original method of measuring a displacement current caused by a streamer was *** was expected,positive streamer branches in nitrogen at low voltages and/or elevated pressures while a large-diameter streamer is formed in ***,at high voltages or negative polarity,the large-diameter streamer is formed both in nitrogen and air in the entire pressure *** was found that runaway electrons(REs)are generated in the very first picoseconds of gas ionisation near the pointed *** was assumed that REs can be generated near the pointed anode and produce bremsstrahlung radiation due to a sharply inhomogeneous distribution of electrical *** was found that in the final stage of negative streamer development in air and nitrogen,the gas between the streamer front and the opposite electrode is ionised almost simultaneously in the entire volume when the streamer diameter is almost equal to the interelectrode gap.

关键词： sharply inhomogeneous electrode

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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