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A hybrid Signal Processing Method Combining Mathematical Morphology and Walsh Theory 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 Mengshi Li q.h.Wu School of Electric Power Engineering South China University of Technology(SCUT)Guangzhou 510641China

In this paper, a novel signal processing method combining mathematical morphology (MM) and Walsh theory is proposed, which uses Walsh functions to control the structuring element (SE) and MM operators. Based on the Walsh-MM method, a scheme for power quality disturbances detection and classification is developed, which involves three steps: denoising, feature extraction and morphological clustering. First, various evolution rules of Walsh function are used to generate groups of SEs for the multiscale Walsh-ordered morphological operation, so the original signal can be denoised. Next, the fundamental wave of the denoised signal is suppressed by hadamard matrix;thus, disturbances can be extracted. Finally, the Walsh power spectrum of the waveform extracted in the previous step is calculated, and the parameters of which are taken by morphological clustering to classify the disturbances. Simulation results reveal the proposed scheme can effectively detect and classify disturbances, and the Walsh-MM method is less affected by noise and only involves simple calculation, which has a potential to be implemented in hardware and more suitable for real-time application.

关键词： hadamard matrix mathematical morphology morphological clustering power quality disturbance Walsh theory

Thin Film of Mesoporous MCM-41 Grown on Indium-Tin-Oxide Glass Substrate

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Chinese Chemical Letters 1999年第4期10卷 335-338页

作者： Zhang, J Xiong, hM ding, h Cai, q Chen, JS Pang, Wq Jilin Univ Key Lab Inorgan Synthesis & Preparat Chem Changchun 130023 Peoples R China Jilin Univ Dept Chem Changchun 130023 Peoples R China Chongqing Teachers Coll Dept Chem Yongchuan 402168 Peoples R China

From a basic solution containing celyltrimethylammonium cations as the template, thin film of mesoporous MCM-41 has been grown on the surface of a pre-treated indium-tin-oxide conducting glass substrate. The channel axis of the film is oriented parallel with the surface plane of the substrate, and the film is stable after careful removal of template in vacuum.

关键词： mesoporous MCM-41 film ITO glass substrate basic medium synthesis

Magnetic/Magnetostrictive Properties Together with Resistivity and Corrosion Behaviors of CoFe_2 and Its Composite with CoFe_2N

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Journal of Materials Science & Technology 2017年第7期33卷 744-750页

作者： B.q.Geng Y.q.Ma M.Wang Z.L.ding W.h.Song B.C.Zhao Key Laboratory of Materials Physics Institute of Solid State Physics Chinese Academy of Sciences Hefei 230031 China

The CoFe_2alloy（CF） was prepared by reducing CoFe_2O_4 in the h_2 ambient. Subsequently the CF sample was nitrided in the Nh_3 atmosphere to produce the composite of CoFe_2N and CoFe_2. The magnetostriction, thermal expansion, resistivity and corrosion resistance of CF sample and the nitrided sample（CFN）at 1000？C were investigated. The saturation magnetostriction coefficiency λ_s and thermal expansion coefficient ？ at 300 K for the nitrided CFN were 50 ppm and 10 ppm/K, respectively, approximately equal to those for the CF sample. however, compared with CF, CFN presents a decrease in temperature coefficient R_λ（300 K） of magnetostriction by 11%. The smaller resistivity and improved corrosion resistance in the h_2SO_4 solution may expand the applications of the CoFe_2 in the fields needing lower resistivity or in the acidic environment.

关键词： CoFe alloy CoFe_2N alloy Magnetostriction Resistivity Corrosion resistance

PLASMA SPRAYED Ti AND hA COATINGS: A COMPARATIVE STUDY BETWEEN APS AND VPS

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 339-344页

作者： X.B.Zheng h.Ji J.q.huang C.X.ding ShanghaiInstituteofCeramics TheChineseAcademyofSciencesShanghai200050China

Titanium (Ti) and hydroxyapatite (hA) coatings have been prepared via air (APS) and vacuum plasma spraying (VPS), and then their composition, structure, bonding strength and bioactivity were examined. The results obtained reveal that in APS process many of Ti were oxidized, but in VPS the oxidization was avoided. VPS T i coating possesses better bonding condition than APS Ti coating. As for hA coat ing, higher crystallinity has been obtained while the coating was deposited by V PS as compared with APS. The simulated body fluid (SBF) tests show that both of APS and VPS hA coatings possess good bioactivity. As compared with APS, VPS is r ecommended as a better method to deposit Ti and hA coatings that can be applied as hard tissue replacement implants.

关键词： vacuum plasma spray Ti hA biocoating

Enhancing strength and ductility of AlSi10Mg fabricated by selective laser melting by TiB_(2)nanoparticles

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Journal of Materials Science & Technology 2022年第14期109卷 254-266页

作者： Y.K.Xiao h.Chen Z.Y.Bian T.T.Sun h.ding q.Yang Y.Wu q.Lian Z.Chen h.W.Wang State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240China School of Materials Science&Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In the metallic components fabricated by the emerging selective laser melting(SLM)technology,most strategies used for strengthening the materials sacrifice the ductility,leading to the so-called strengthductility *** the present study,we report that the strength and ductility of materials can be enhanced simultaneously by introducing nanoparticles,which can break the trade-off of the metallic *** the case of in-situ nano-TiB_(2)decorated AlSi10Mg composites,the introduced nanoparticles lead to columnar-to-equiaxed transition,grain refinement and texture *** increasing content of nanoparticles,the strength increases ***,the ductility first increases and then *** results show that the ductility is controlled by the competition between the crack-induced catastrophic fracture and ductile fracture associated with dislocation *** first increase of ductility is mainly attributed to the suppression of crack-induced catastrophic fracture when TiB_(2)nanoparticles *** the further increase of TiB_(2)nanoparticles,the subsequent decrease of ductility is mainly controlled by dislocation ***,the materials will exhibit the optimum strength and ductility combination in a certain range of TiB_(2)*** study clarifies the physical mechanism controlling ductility for nano-TiB_(2)decorated Al Si10Mg composites,which provides the insights for the design of structural materials.

关键词： Selective laser melting Aluminium matrix composites Ductility Mechanical behavior Dislocations Cracks

Reserve Constrained Dynamic Economic Dispatch with Valve-point Effect:A Two-stage Mixed Integer Linear Programming Approach

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CSEE Journal of Power and Energy Systems 2017年第2期3卷 203-211页

作者： Zhaolong Wu Jianying ding q.h.Wu Zhaoxia Jing Jiehui Zheng School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China Power Generation Commercial Division Guangdong Yudean Group Co.LTDGuangzhou 510630China

This paper proposes a deterministic two-stage mixed integer linear programming(TSMILP)approach to solve the reserve constrained dynamic economic dispatch(DED)problem considering valve-point effect(VPE).In stage one,the nonsmooth cost function and the transmission loss are piecewise linearized and consequently the DED problem is formulated as a mixed integer linear programming(MILP)problem,which can be solved by commercial *** stage two,based on the solution obtained in stage one,a range compression technique is proposed to make a further exploitation in the subspace of the whole solution *** to the linear approximation of the transmission loss,the solution obtained in stage two dose not strictly satisfies the power balance ***,a forward procedure is employed to eliminate the *** simulation results on four test systems show that TSMILP makes satisfactory performances,in comparison with the existing methods.

关键词： Dynamic economic dispatch mixed integer linear programming valve-point effect spinning reserve transmission loss non-convex optimization

MODELING OF DYNAMIC RECRYSTALLIZATION OF Ti6A14V ALLOY USING A CELLULAR AUTOMATON APPROACh

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 260-268页

作者： J.W. Zhao h. ding W.J. Zhao F.R. Cao h.L. hou Z.q. Li School of Materials and Metallurgy Northeastern University Shenyang 110004 China Beijing Aeronautical Manufacturing Technology Research Institute Beijing 100024 China

A cellular automaton （CA） model is established to simulate dynamic recrystallization （DRX） in the β single-phase field of Ti6Al4 V alloy, and the kinetics during DRX processing has been analyzed. The model employed considers the influences of dynamic recovery, nucleation rate, strain rate and dislocation density on DRX, and practical deformation parameters, such as temperature, strain and strain rate on DRX have been considered in the simulation. The simulated DRX grain size and DRX grain shape agree well with the experimental results, which shows the availability and lea- sibility of the cellular automaton method for the simulation of DRX. The result of kinetics analysis of DRX reveals that the Avrami exponent is variable ranging from 2.4 to 2.9, which increases with the increase of strain rate.

关键词： Ti6A4 V alloyi Dynamic recrystallization Kinetics Modeling Cellular automaton

A FLOW STRESS MODEL FOR AZ61 MAGNESIUM ALLOY

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Acta Metallurgica Sinica(English Letters) 2004年第2期17卷 155-160页

作者： h.T.Zhou X.q.Zeng q.D Wang W.J.ding State Key Laboratory of Metal Matrix Composite,Shanghai Jiaotong University,Shanghai 200030,China State Key Laboratory of Metal Matrix Composite Shanghai Jiaotong UniversityShanghai 200030China

The flow stress behaviors of AZ61 alloy has been investigated at temperature rangefrom 523 to 673K with the strain rates of 0.001-1s^(-1). It is found that the averageactivation energy, strain rate sensitive exponent and stress exponent are different atvarious deformation conditions changing from 143.6 to 176.3kJ/mol, 0.125 to 0.167and 6 to 8 respectively. A flow stress model for AZ61 alloy is derived by analyzingthe stress data based on hot compression test. It is demonstrated that the flow stressmodel including strain hardening exponent and strain softening exponent is suitableto predicate the flow stress. The prediction of the flow stress of AZ61 alloy has shownto be good agreement with the test data. The maximum differences of the peak stressescalculated by the model and obtained by experiment is less than 8%.

关键词： magnesium alloy flow stress model hot deformation straion softening

Solid solution strengthening of high-entropy alloys from first-principles study

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Journal of Materials Science & Technology 2022年第26期121卷 105-116页

作者： h.L.Zhang D.D.Cai X.Sun h.huang S.Lu Y.Z.Wang q.M.hu L.Vitos X.D.ding State Key Laboratory for Mechanical Behavior of Materials Frontier Institute of Science and TechnologyXi’an Jiaotong UniversityXi’an 710049China Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research College of StomatologyXi’an Jiaotong UniversityXi’an 710049China Department of Materials Science and Engineering The Ohio State University2041 College RoadColumbusOH 43210United States Institute of Metal Research Chinese Academy of SciencesShenyang 110016China Science and Technology on Surface Physics and Chemistry Laboratory Jiangyou 621908China Applied Materials Physics Department of Materials Science and EngineeringRoyal Institute of TechnologyStockholm SE-10044Sweden

Solid solution strengthening(SSS)is one kind of strengthening mechanisms and plays an important role in alloy design,in particular for single-phase alloys including high-entropy alloys(hEAs).The classical Labusch–Nabarro model and its expansions are most widely applicable to treating SSS of solid solution alloys including both conventional alloys(CAs)and *** this study,the SSS effects in a series of Febased CAs and hEAs are investigated by using the classical Labusch–Nabarro model and its *** size misfit and shear modulus misfit parameters are derived from first-principles *** on available experimental data in combination with empirical SSS model,we propose fitting constants(i.e.,the ratio between experimental hardness and predicted SSS effect)for these two families of *** predicted host/alloy family-dependent fitting constants can be used to estimate the hardness of these SSS *** agreement between predicted and measured hardness values is satisfactory for both CAs and hEAs,implying that the proposed approach is reliable and successful.

关键词： Alloys Solid solution strengthening hardness Size misfit parameter Shear modulus misfit parameter First-principles calculations