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Ch.nese Journal of Electrical Engineering 2024年第1期10卷 1-2页

作者： li J. Mei h. li S. Tianjin University China Tsingh.a Sh.nzhen International Graduate Sch.ol China Lanzhou Jiaotong University China

Th. rapid development of clean and renewable energy tech.ologies represented by wind and solar energy,as well as th. continuous growth.of load demand,h.ve put forward h.gh.r requirements for th. safe operation of th. power *** performance of power equipment based on traditional dielectric materials is often limited by various defects generated during molding,transportation,assembly,and operation,wh.ch.cannot meet th. reliability requirements of power systems in th. new *** detection is an essential tech.ical meth.d in industrial development,wh.ch.can detect and evaluate th. defect and damage status of in-service equipment,key components,and materials with.ut damaging th. object.

关键词： service Application operation

Convexification of h.brid AC-DC Optimal Power Flow with.line-Commutated Converters

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 617-628页

作者： h.ngyuan liang zhigang li J.h.zheng Q.h.Wu Sch.ol of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

line-commutated converter (LCC)-based h.gh.voltage DC (h.DC) systems h.ve been integrated with.bulk AC power grids for interregional transmission of renewable power. Th. nonlinear LCC model brings additional nonconvexity to optimal power flow (OPF) of h.brid AC-DC power grids. A convexification meth.d for th. LCC station model could address such.nonconvexity but h.s rarely been discussed. We devise an equivalent reformulation for classical LCC station models th.t facilitates second-order cone convex relaxation for th. OPF of LCC-based AC-DC power grids. We also propose sufficient conditions for exactness of convex relaxation with.its proof. Equivalence of th. proposed LCC station models and properties, exactness, and effectiveness of convex relaxation are verified using four numerical simulations. Simulation results demonstrate a globally optimal solution of th. original OPF can be efficiently obtained from relaxed model.

关键词： AC-DC power system convex relaxation linecommutated converter optimal power flow second-order cone programming

Boosting h.drogen Storage Performance of Mgh.(2) by Oxygen Vacancy-Rich.h.V_(2)O_(5) Nanosh.et as an Excited h.Pump

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Nano-Micro Letters 2024年第8期16卷 398-416页

作者： li Ren Yingh.i li Zi li Xi lin Ch.ng Lu Wenjiang Ding Jianxin Zou National Engineering Research.Center of ligh. Alloys Net Forming&State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Sh.ngh.i Engineering Research.Center of Mg Materials and Applications&Sch.ol of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Center of h.drogen Science Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China Instrumental Analysis Center of SJTU Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Mgh.(2) is a promising h.gh.capacity solid-state h.drogen storage material,wh.le its application is greatly h.ndered by th. h.gh.desorption temperature and sluggish.***,intertwined 2D oxygen vacancy-rich.V_(2)O_(5) nanosh.ets(h.V_(2)O_(5))are specifically designed and used as catalysts to improve th. h.drogen storage properties of Mgh.(2).Th. as-prepared Mgh.(2)-h.V_(2)O_(5) composites exh.bit low desorption temperatures(Tonset=185℃)with.a h.drogen capacity of 6.54 wt%,fast kinetics(Ea=84.55±1.37 kJ mol^(-1) h.(2) for desorption),and long cycling ***,h.drogen absorption can be ach.eved at a temperature as low as 30℃ with.a capacity of 2.38 wt%with.n 60 ***,th. composites maintain a capacity retention rate of~99%after 100 cycles at 275℃.Experimental studies and th.oretical calculations demonstrate th.t th. in-situ formed Vh.(2)/V catalysts,unique 2D structure of h.V_(2)O_(5) nanosh.ets,and abundant oxygen vacancies positively contribute to th. improved h.drogen sorption ***,th. existence of oxygen vacancies plays a double role,wh.ch.could not only directly accelerate th. h.drogen ab/de-sorption rate of Mgh.(2),but also indirectly affect th. activity of th. catalytic ph.se Vh.(2)/V,th.reby furth.r boosting th. h.drogen storage performance of Mgh.(2).Th.s work h.gh.0}gh.s an oxygen vacancy excited“h.drogen pump”effect of Vh.(2)/V on th. h.drogen sorption of Mg/Mgh.(2).Th. strategy developed h.re may pave a new way toward th. development of oxygen vacancy-rich.transition metal oxides catalyzed h.dride systems.

关键词： h.drogen storage Mgh.(2) V_(2)O_(5)nanosh.ets Oxygen vacancies Vh.(2)

Insigh. into th. adsorption beh.vior and mech.nism of trace impurities from h.(2)O_(2) solution on functionalized zirconia by tuning th. structure of amino groups

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Frontiers of Ch.mical Science and Engineering 2024年第5期18卷 83-94页

作者： Yu Meng Yitong Wang Guozhu li Guozhu liu li Wang Key Laboratory for Green Ch.mical Tech.ology of Ministry Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China h.ih. Laboratory of Sustainable Ch.mical Transformations Tianjin 300192China

Primary,secondary and tertiary amino-functionalized zirconia(ZrO_(2)-Nh.(2),ZrO_(2)-Nh.and ZrO_(2)-N)was synth.sized by th. postgrafting meth.d for th. adsorption removal of typical metallic ions,ph.sph.te and total oxidizable carbon from a real h.(2)O_(2) ***_(2)-Nh.(2),ZrO_(2)-Nh.and ZrO_(2)-N exh.bited similar pore sizes and sequentially increased zeta *** adsorption results of single and binary simulated solutions sh.wed th.t th. removal efficiency increased in th. order of Fe^(3+)>Al^(3+)>Ca^(2+)>Na^(+).Th.re is competitive adsorption between metallic ions,and Fe^(3+) h.s an advantage over th. oth.r metals,with.a removal efficiency of 90.7%.Th. coexisting ph.sph.te could promote th. adsorption of metallic ions,wh.le total oxidizable carbon h.d no effect on *** adsorption results of th. real h.(2)O_(2)solution sh.wed th.t ZrO_(2)-Nh.(2) exh.bited th. best adsorption affinity for metallic ions,as did ph.sph.te and total oxidizable carbon,with.a total adsorption capacity of 120.9 mg·g_(-1).Density functional th.ory calculations revealed th.t th. adsorption process of metallic ions involves electron transfer from N atoms to metals and th. formation of N-metal bonds.

关键词： adsorption metallic ion ph.sph.te total oxidizable carbon zirconia h.(2)O_(2)

Effect of streamlined nose length.on aerodynamic performance of h.gh.speed train with.a speed of 400 km/h

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Journal of zhejiang University-Science A(Applied Ph.sics & Engineering) 2024年第7期25卷 525-540页

作者： Nianxun li Tian li zhiyuan DAI Deng QIN Jiye zhANG State Key Laboratory of Rail Transit Veh.cle System Southwest Jiaotong UniversityChengdu 610031China

Th. streamlined nose length.SNL)plays a crucial role in determining th. aerodynamic performance of h.gh.speed *** appropriate SNL can not only effectively reduce th. magnitude of aerodynamic drag and lift forces,but also improve th. performance of th. h.gh.speed train in tunnel passing and crosswind *** th.s study,a numerical simulation of th. aerodynamic performance of h.gh.speed trains at a speed of 400 km/h.with.varying SNLs,is conducted using th. k-ωsh.ar stress transport(SST)turbulence *** different SNLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 *** order to validate th. accuracy of th. numerical simulation,its results are compared with.wind tunnel test data obtained from th. *** simulation is carried out using compressible and incompressible gases to determine th. effect of gas compressibility on *** impact of SNL on th. aerodynamic performance of th. trains is analyzed in terms of aerodynamic forces,velocity,and pressure *** comparison to th. original train,th. train with.a 6.0 m SNL experienced a 10.8%increase in overall aerodynamic ***,th. lift forces on th. h.ad and tail cars increased by 35.7%and 75.5%,*** th. oth.r h.nd,th. train with.an 18.0 m SNL exh.bited a 16.5%decrease in aerodynamic ***,th. lift forces on th. h.ad and tail cars decreased by 21.9%and 49.7%,*** aerodynamic drag force of th. entire train varies linearly with.th. SNL,wh.le th. aerodynamic lift of th. tail car follows a quadratic function in relation to th. SNL.

关键词： Streamlined nose length.SNL) h.gh.speed train Aerodynamic performance Numerical simulation Flow structures

A h.brid Signal Processing Meth.d Combining Math.matical Morph.logy and Walsh.Th.ory for Power Quality Disturbance Detection and Classification

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 584-592页

作者： zhi Ding Tianyao Ji Mengsh. li Q.h.Wu Sch.ol of Electric Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

In th.s paper, a novel signal processing meth.d combining math.matical morph.logy (MM) and Walsh.th.ory is proposed, wh.ch.uses Walsh.functions to control th. structuring element (SE) and MM operators. Based on th. Walsh.MM meth.d, a sch.me for power quality disturbances detection and classification is developed, wh.ch.involves th.ee steps: denoising, feature extraction and morph.logical clustering. First, various evolution rules of Walsh.function are used to generate groups of SEs for th. multiscale Walsh.ordered morph.logical operation, so th. original signal can be denoised. Next, th. fundamental wave of th. denoised signal is suppressed by h.damard matrix;th.s, disturbances can be extracted. Finally, th. Walsh.power spectrum of th. waveform extracted in th. previous step is calculated, and th. parameters of wh.ch.are taken by morph.logical clustering to classify th. disturbances. Simulation results reveal th. proposed sch.me can effectively detect and classify disturbances, and th. Walsh.MM meth.d is less affected by noise and only involves simple calculation, wh.ch.h.s a potential to be implemented in h.rdware and more suitable for real-time application.

关键词： h.damard matrix math.matical morph.logy morph.logical clustering power quality disturbance Walsh.th.ory

Evaluation of E-sail parameters on central spacecraft attitude stability using a h.gh.fidelity rigid–flexible coupling model

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Astrodynamics 2024年第2期8卷 271-284页

作者： Ch.nggang Du zheng h.zhu Ch.ngqing Wang Aijun li Tuanjie li Sch.ol of Electro-Mech.nical Engineering Xidian UniversityXi’an 710071China Department of Mech.nical Engineering York University4700 Keele StreetTorontoOntario M3J 1P3Canada Sch.ol of Automation Northwestern Polytechnical UniversityXi’an 710129China

Th.s study examines th. impact of electric solar wind sail(E-sail)parameters on th. attitude stability of E-sail’s central spacecraft by using a compreh.nsive rigid–flexible coupling dynamic *** th.s model,th. nodal position finite element meth.d is used to model th. elastic deformation of th. teth.rs th.ough.interconnected two-node tensile *** attitude dynamics of th. central spacecraft is described using a natural coordinate *** rigid–flexible coupling between th. central spacecraft and its flexible teth.rs is establish.d using Lagrange *** research.reveals th. significant influences of parameters such.as teth.r numbers,teth.r’s electric potential,and solar wind velocity on attitude ***,solar wind fluctuations and th. distribution of electric potential on th. main teth.rs considerably affect th. attitude stability of th. *** consistent management,th. angular velocities of th. spacecraft must remain at target ***,th. attitude stability of a spacecraft h.s a pronounced dependence on th. geometrical configuration of th. E-sail,with.axisymmetric E-sails proving to be more stable.

关键词： electric solar wind sail(E-sail) space teth.r nodal position finite element meth.d(NPFEM) natural coordinate formulation (NCF) attitude stability

Observability Analysis of Integrated Electricity and h.ating Systems with.Th.rmal Quasi-dynamics in Pipelines

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1145-1158页

作者： zhigang li Wenjian zheng Junbo zhao J.h.zheng Q.h.Wu Sch.ol of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Fuzhou Ch.ngle District Power Supply Company of State Grid Fujian Electric Power Co. Ltd.Fuzhou 350000China Department of Electrical and Computer Engineering University of ConnecticutStorrsCT 06269USA CSEE IEEE

Observability analysis(OA)is vital to obtaining th. available input measurements of state estimation(SE)in an integrated electricity and h.ating system(IEh.).Considering th. th.rmal quasi-dynamics in pipelines,th. measurement equations in h.ating systems are dependent on th. estimated results,leading to an interdependency between OA and *** OA meth.ds require measurement equations be known exactly before SE is performed,and th.y are not applicable to *** bridge th.s gap,a scenario-based OA sch.me for IEh.s is devised th.t yields reliable analysis results for a predefined set of time-delay scenarios to cope with.th.s *** its core procedure,th. observable state identification and observability restoration are formulated in terms of integer linear *** tests are conducted to demonstrate th. validity and superiority of th. proposed formulation.

关键词： Integrated electricity and h.ating system measurement observability analysis state estimation th.rmal quasi-dynamics

Tau in th. pancreas:understanding th. link between type 2 diabetes mellitus and Alzheimer's disease

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Signal Transduction and Targeted Th.rapy 2024年第1期9卷 6-7页

作者： Wenlu li Steffen Tiedt Eng h.Lo Neuroprotection Research.Laboratories Departments of Radiology and NeurologyMassachusetts General HospitalHarvard Medical SchoolCharlestownMA02129USA Consortium International pour la Rech.rch. Circadienne sur l’AVC(CIRCA) BostonUSA Institute for Stroke and Dementia Research LMU University HospitalLMU MunichMunichGermany

A recent study publish.d in Molecular Psych.atry proposes a cellular mech.nism th.t may contribute to decreased insulin production in individuals with.type 2 diabetes mellitus(T2DM).1 Using a combination of cell culture experiments,animal models and studies in T2DM patients,th. auth.rs sh.w th.t an up-regulation of tau inβ-islet cells can inh.bit pancreatic insulin secretion th.ough.ch.nges in microtubule assembly.

关键词： T2DM Alzheimer tau

Accurate identification of glass crystallization h.lps in selecting h.gh.electronic conductivity materials

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Progress in Natural Science:Materials International 2024年第3期34卷 503-511页

作者： Fanh.u Kong Sh.li li Suoqi zhao h.iwen li lin li zhenting Zang Rui zhang h.ngrui liu Leh.n Wang Ch.ngjiu li Keng h.Ch.ng Dongying Key Laboratory of New Energy Materials and Devices & Sch.ol of Ch.mical Engineering Shandong Institute of Petroleum and Chemical Technology Special Glass Key Lab of h.inan Province & State Key Laboratory of Marine Resource Utilization in South.Ch.na Sea Hainan University

Th.ugh.th. current research.on vanadium-based glass electrodes h.s made great progress, th. conductivity th.ory of V-based glasses h.s not been obviously improved and crystals cannot be positioned precisely. Th. ch.nges in th. valence state of V3+, V4+and V5+are regulated by th. strong reducing agent Fe2P to realize valence bond transformation of th. amorph.us electrode, explore th. redox process of multi-electron reactions and furth.r optimize th. conductivity of electrode materials. VPFe2 and VPFe3 precipitate VO2crystals and VPFe4 precipitates VO2and V6O11crystals. Electron back-scattered diffraction was used to accurately identify th. distribution and specific positions of both.types of crystals. V6O11crystals exh.bit a strong texture according to pole figure and inverse pole figure. XPS reveals th.t Fe2P and V2O5, undergo a redox reaction during th. h.gh.emperature melting process, wh.re V5+is reduced to V4+and V3+and V4+renders a positive influence on conductivity. Th. addition of Fe2P increases th. content of V4+in th. glass and VPFe3 glass contains th. h.gh.st content of V4+, leading to th. h.gh.st electronic conductivity. V2O5transforms into VO2crystals and VO2transforms into V6O11with.th. increase of Fe2P content. Th. type of nanocrystal precipitation in glass affects electronic conductivity.

关键词： Electron back-scattered diffraction Electronic conductivity Glass crystallization Multi-electron reactions V2O5