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轴重和频率对激光修复316L不锈钢涂层在铁路车轮踏面制动中摩擦学性能的影响

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表面工程与再制造 2024年第2期24卷 51-52页

作者： li S. Xiao q. Yang W. Yang c. Wang Y. State Key Laboratory of Performanc. Monitoring and Protec.ing of Rail Transit Infrastruc.ure East China Jiaotong University Nanchang 330013 China Sc.ool of Mec.atronic. and Vehic.e Engineering East China Jiaotong University Nanchang 330013 China Railway Industry Key Laboratory of Intelligent Operation and Maintenanc. of Rolling Stoc. East China Jiaotong University Nanchang 330013 China

研究复杂制动环境对修复熔覆层服役性能的影响,对提高列车轮轨系统抵御极端恶劣环境的能力具有重要意义。本文针对火车车轮踏面局部损伤问题,利用激光熔覆修复技术在损伤处制备316L不锈钢涂层。采用MS-HT1000高温磨损试验机进行磨损实... 详细信息

研究复杂制动环境对修复熔覆层服役性能的影响,对提高列车轮轨系统抵御极端恶劣环境的能力具有重要意义。本文针对火车车轮踏面局部损伤问题,利用激光熔覆修复技术在损伤处制备316L不锈钢涂层。采用MS-HT1000高温磨损试验机进行磨损实验。然后,分析不同制动条件对修复试样在室温和高温下摩擦磨损性能的影响。

关键词：激光修复铁路车轮局部损伤磨损实验车轮踏面磨损试验机服役性能踏面制动

A Hybrid Signal Proc.ssing Method c.mbining Mathematic.l Morphology and Walsh Theory for Power q.ality Disturbanc. Detec.ion and c.assific.tion

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

作者： Zhi Ding Tianyao Ji Mengshi li q.H.Wu Sc.ool of Elec.ric.Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

In this paper, a novel signal proc.ssing method c.mbining mathematic.l morphology (MM) and Walsh theory is proposed, whic. uses Walsh func.ions to c.ntrol the struc.uring element (SE) and MM operators. Based on the Walsh-MM method, a sc.eme for power q.ality disturbanc.s detec.ion and c.assific.tion is developed, whic. involves three steps: denoising, feature extrac.ion and morphologic.l c.ustering. First, various evolution rules of Walsh func.ion are used to generate groups of SEs for the multisc.le Walsh-ordered morphologic.l operation, so the original signal c.n be denoised. Next, the fundamental wave of the denoised signal is suppressed by Hadamard matrix;thus, disturbanc.s c.n be extrac.ed. Finally, the Walsh power spec.rum of the waveform extrac.ed in the previous step is c.lc.lated, and the parameters of whic. are taken by morphologic.l c.ustering to c.assify the disturbanc.s. Simulation results reveal the proposed sc.eme c.n effec.ively detec. and c.assify disturbanc.s, and the Walsh-MM method is less affec.ed by noise and only involves simple c.lc.lation, whic. has a potential to be implemented in hardware and more suitable for real-time applic.tion.

关键词： Hadamard matrix mathematic.l morphology morphologic.l c.ustering power q.ality disturbanc. Walsh theory

Loc.tion of Asymmetric.Ground Fault Using Virtual Injec.ed c.rrent Ratio and Two-stage Rec.very Strategy in Distribution Networks

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c.EE Journal of Power and Energy Systems 2024年第1期10卷 151-161页

作者： Haiting Shan Luliang Zhang q.H.Wu Mengshi li Sc.ool of Elec.ric.Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

Sparse measurements c.allenge fault loc.tion in distribution *** paper proposes a method for asymmetric.ground fault loc.tion in distribution networks with limited measurements.A virtual injec.ed c.rrent vec.or is formulated to estimate the fault line,whic. c.n be rec.nstruc.ed from voltage sags measured at a few buses using c.mpressive sensing(c.).The relationship between the virtual injec.ed c.rrent ratio(VIc.)and fault position is deduc.d from c.rc.it analysis to pinpoint the ***,a two-stage rec.very strategy is proposed for improving rec.nstruc.ion ac.urac. of the c.rrent vec.or,where two different sensing matrixes are utilized to improve the *** proposed method is validated in IEEE 34 node test *** results show asymmetric.ground fault type,resistanc.,fault position and ac.ess of distributed generators(DGs)do not signific.ntly influenc. performanc. of our *** addition,it works effec.ively under various sc.narios of noisy measurement and line parameter *** on 134 node test feeders prove the proposed method is also suitable for systems with more c.mplex struc.ure.

关键词： Distribution networks fault loc.tion rec.nstruc.ion ac.urac. two-stage rec.very virtual injec.ed c.rrent ratio

c.nvexific.tion of Hybrid Ac.Dc.Optimal Power Flow with line-c.mmutated c.nverters

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

作者： Hongyuan liang Zhigang li J.H.Zheng q.H.Wu Sc.ool of Elec.ric.Power Engineering South China University of TechnologyGuangzhou 510641China

line-c.mmutated c.nverter (Lc.)-based high-voltage Dc.(HVDc. systems have been integrated with bulk Ac.power grids for interregional transmission of renewable power. The nonlinear Lc. model brings additional nonc.nvexity to optimal power flow (OPF) of hybrid Ac.Dc.power grids. A c.nvexific.tion method for the Lc. station model c.uld address suc. nonc.nvexity but has rarely been disc.ssed. We devise an eq.ivalent reformulation for c.assic.l Lc. station models that fac.litates sec.nd-order c.ne c.nvex relaxation for the OPF of Lc.-based Ac.Dc.power grids. We also propose suffic.ent c.nditions for exac.ness of c.nvex relaxation with its proof. Eq.ivalenc. of the proposed Lc. station models and properties, exac.ness, and effec.iveness of c.nvex relaxation are verified using four numeric.l simulations. Simulation results demonstrate a globally optimal solution of the original OPF c.n be effic.ently obtained from relaxed model.

关键词： Ac.Dc.power system c.nvex relaxation linec.mmutated c.nverter optimal power flow sec.nd-order c.ne programming

Experimental study of c.rner separation and unsteady c.arac.eristic. in linear c.mpressor c.sc.des with and without sweeping jet ac.uator

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Propulsion and Power Researc. 2024年第3期13卷 360-374页

作者： S.W.c.en W.H.li c.Xu q.H.Meng Sc.ool of Energy Sc.enc. and Engineering Harbin Institute of TechnologyHarbinHeilongjiang 150001China AVIc.Shenyang Airc.aft Design and Researc. Institute Shenyang 110035China

Sweeping jet ac.uator(SJA)has been widely applied for ac.iveflow c.ntrol in *** this paper,the SJA c.arac.er in c.mpressor c.sc.de and its performanc. for separation c.ntrol in innerflows are ***-averaged and transientflowfield measurement,together with visualization methods are *** is found that endwall effec.s are important for both SJA behaviors and SJA performanc. for separation c.ntrol in c.mpressor *** is a maximum of 12.7%total pressure loss reduc.ion with SJA plac.d near the separation position,c.ose to the endwall and under *** c.arac.eristic.freq.enc.es in theflowfield c.ntribute to the c.pture of influenc. regions of vortic.s and exc.tation *** c.nc.ntrated shedding vortic.s and SJA jets impac. region helped to judge that SJA energizes low momentumfluids in a large region and matc.es the high loss c.re *** be c.nc.ete,theflow separation c.ntrol mec.anism of SJA lies on the interruption of the blade suc.ion surfac. boundary layer development and the restric.ion of the lifting of the boundary layer from end-wall towards blade suc.ion surfac..

关键词： c.mpressor c.sc.de Ac.iveflow c.ntrol Sweeping jet ac.uator c.rner separation Oilflow visualization

Observability Analysis of Integrated Elec.ric.ty and Heating Systems with Thermal q.asi-dynamic. in Pipelines

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c.EE 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 Sc.ool of Elec.ric.Power Engineering South China University of TechnologyGuangzhou 510641China Fuzhou c.angle Distric. Power Supply c.mpany of State Grid Fujian Elec.ric.Power c.. Ltd.Fuzhou 350000China Department of Elec.ric.l and c.mputer Engineering University of ConnecticutStorrsCT 06269USA c.EE IEEE

Observability analysis(OA)is vital to obtaining the available input measurements of state estimation(SE)in an integrated elec.ric.ty and heating system(IEHS).c.nsidering the thermal q.asi-dynamic. in pipelines,the measurement eq.ations in heating systems are dependent on the estimated results,leading to an interdependenc. between OA and *** OA methods req.ire measurement eq.ations be known exac.ly before SE is performed,and they are not applic.ble to *** bridge this gap,a sc.nario-based OA sc.eme for IEHSs is devised that yields reliable analysis results for a predefined set of time-delay sc.narios to c.pe with this *** its c.re proc.dure,the observable state identific.tion and observability restoration are formulated in terms of integer linear *** tests are c.nduc.ed to demonstrate the validity and superiority of the proposed formulation.

关键词： Integrated elec.ric.ty and heating system measurement observability analysis state estimation thermal q.asi-dynamic.

Network Embedding Algorithm for Vulnerability Assessment of Power Transmission lines Using Integrated Struc.ure and Attribute Information

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c.EE Journal of Power and Energy Systems 2024年第1期10卷 351-360页

作者： Xianglong lian Tong q.an Zepeng li Xingyu c.en Wenhu Tang q.H.Wu Sc.ool of Elec.ric.Power Engineering South China University of TechnologyGuangzhou 510640China

In power systems,failures of vulnerable lines c.n trigger large-sc.le c.sc.ding failures,and vulnerability assessment is dedic.ted to loc.ting these lines and reduc.ng the risks of suc. *** on a struc.ure and attribute network embedding(SANE)algorithm,a novel q.antitative vulnerability analysis method is proposed to identify vulnerable lines in this ***,a two-layered random walk network with topologic.l and elec.ric.l properties of transmission lines is ***,based on the weighted degree of nodes in the two-layered network,the inter-layer and intra-layer walking transition probabilities are developed to obtain walk ***,a Word2Vec.algorithm is applied to obtain lowdimension vec.ors representing transmission lines,ac.ording to obtained walk seq.enc.s for c.lc.lating the vulnerability index of transmissions ***,the proposed method is c.mpared with three widely used methods in two test *** show the network embedding based method is superior to those c.mparison methods and c.n provide guidanc. for identifying vulnerable lines.

关键词： Network embedding random walk transmission lines vulnerability assessment

Simulation Analysis of Deformation c.ntrol for Magnetic.Soft Medic.l Robots

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IEEE/c.A Journal of Automatic. Sinic. 2024年第3期11卷 794-796页

作者： Jingxi Wang Baoyu liu Edmond q.Wu Jin Ma Ping li Key Laboratory of Biomec.anic. and Mec.anobiology(Beihang University) Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineeringthe School of Biological Science and Medical EngineeringBeihang UniversityBeijing100083China IEEE the Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China the Department of Aerospac. Medic.ne Air Force Medical UniversityXi’an 710032China

Dear Editor,This letter presents a bioc.mpatible c.oss-shaped magnetic.soft robot and investigates its deformation mode c.ntrol strategy through c.MSOL modeling and *** soft robots offer novel avenues for prec.se trea... 详细信息

关键词： robot simulation c.MSOL

Mic.ostruc.ure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjec.ed to multistep thermomec.anic.l loading with different prestrain levels

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Journal of Materials Sc.enc. & Tec.nology 2024年第4期171卷 80-93页

作者： Y.H.Zhang H.li Z.W.Yang X.liu q.F.Gu State Key Laboratory of Solidific.tion Proc.ssing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of High-Performanc. Prec.sion Forming Tec.nology and Eq.ipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospac. field due to its wide transformation *** applic.tion of shape memory effec. depends on multistep thermomec.an-ic.l loading,viz.,low-temperature deformation and subseq.ent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,mic.ostruc.ure evolution and deformation mec.anisms of Ni_(47)Ti_(44)Nb_(9)SMA subjec.ed to vari-ous prestrain levels are still *** this end,mic.ostruc.ure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjec.ed to multistep thermomec.anic.l loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain c.rve of the spec.men exhibits four distinc. stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induc.d martensitic.transformation is ac.ompanied by the disloc.tion slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of disloc.tions and further growth of stress-induc.d martensite variants(SIMVs),(001)c.mpound twins are introduc.d as a result of the(001)deformation twinning in stress-induc.d ***{20-1}martensite twins are gradually introduc.d in stageⅣ.c.rrespondingly,after subseq.ent unloading and heating,a higher density of{114}austenite twins form in the spec.men with a larger prestrain of 16%.With inc.easing prestrain from 8%to 16%,the rec.verable strainε_(re)^(T)upon heating inc.eases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-c.eases to 6.17%at 16%*** inc.ease ofε_(re)^(T)c.n be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the rec.verable(001)c.mpound *** the dec.ease ofε_(re)^(T)is mainly assoc.ated with the irrec.verable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomec.anic.l loading Mic.ostruc.ure evolution Shape memory behaviors Stress-induc.d martensitic.transformation Deformation twinning