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Power supply arm protection scheme of high-speed railway based on wide-area current differential

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Railway Engineering Science 2023年第3期31卷 281-292页

作者： Guosong Lin Bin Hong Zefang Wu Xuguo Fu School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China

When fault occurs on cross-coupling autotransformer(AT)power supply traction network,the up-line and down-line feeder circuit breakers in the traction substation trip at the same time without selectivity,which leads to an extended power failure.Based on equivalent circuit and Kirchhoff’s current law,the feeder current characteristic in the substation,AT station and sectioning post when T-R fault,F-R fault,and T-F fault occur are analyzed and their expressions are obtained.When the traction power supply system is equipped with wide-area protection measurement and control system,the feeder protection device in each station collects the feeder currents in other two stations through the wide-area protection channel and a wide-area current differential protection scheme based on the feeder current characteristic is proposed.When a short-circuit fault occurs in the power supply arm,all the feeder protection devices in each station receive the feeder currents with time stamp in other two stations.After data synchronous processing and logic judgment,the fault line of the power supply arm can be identified and isolated quickly.The simulation result based on MATLAB/Simulink shows that the power supply arm protection scheme based on wide-area current differential has good fault discrimination ability under different fault positions,transition resistances,and fault types.The verification of measured data shows that the novel protection scheme will not be affected by the special working conditions of the electrical multiple unit(EMU),and reliability,selectivity,and rapidity of relay protection are all improved.

关键词： Cross-coupling AT power supply Wide-area current differential Power supply arm protection Equivalent circuit High-Speed railway

Improved fault location method for AT traction power network based on EMU load test

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Railway Engineering Science 2022年第4期30卷 532-540页

作者： Guosong Lin Xuguo Fu Wei Quan Bin Hong School of Electrical Engineering Southwest Jiaotong UniversityChengdu 611756China

The autotransformer(AT)neutral current ratio method is widely used for fault location in the AT traction power network.With the development of high-speed electrified railways,a large number of data show that the relation between the AT neutral current ratio and the distance from the beginning of the fault AT section to the fault point(Q-L relation)is mostly nonlinear.Therefore,the linear Q-L relation in the traditional fault location method always leads to large errors.To solve this problem,a large number of load-related current data that can be used to describe the Q-L relation are obtained through the load test of the electric multiple unit(EMU).Thus,an improved fault location method based on the back propagation(BP)neural network is proposed in this paper.On this basis,a comparison between the improved method and the traditional method shows that the maximum absolute error and the average absolute error of the improved method are 0.651 km and 0.334 km lower than those of the traditional method,respectively,which demonstrates that the improved method can effectively eliminate the influence of nonlinear factors and greatly improve the accuracy of fault location for the AT traction power network.Finally,combined with a shortcircuit test,the accuracy of the improved method is verified.

关键词： Fault location EMU load test BP neural network AT traction power network High-speed electrified railway

Optimizing intrinsic cocatalyst activity and light absorption efficiency for efficient hydrogen evolution of 1D/2D ReS_(2)-CdS photocatalysts via control of ReS_(2)nanosheet layer growth

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Journal of Materials Science & Technology 2024年第1期168卷 103-113页

作者： Ghufran Aulia bin Azizar Jong Wook hong Department of Chemistry University of UlsanUlsan 44610Korea

The visible-light-driven hydrogen evolution is extremely important,but the poor charge transfer capa-bility,a sluggish evolution rate of hydrogen,and severe photo-corrosion make photocatalytic hydrogen evolution impractical.In this study,we present 1D/2D ReS_(2)-CdS hybrid nanorods for photocatalytic hy-drogen evolution,comprised of a ReS_(2)nanosheet layer grown on CdS nanorods.We found that precise control of the contents of the ReS_(2)nanosheet layer allows for manipulating the electronic structure of Re in the ReS_(2)-CdS hybrid nanorods.The ReS_(2)-CdS hybrid nanorods with optimal ReS_(2)nanosheet layer content dramatically improve photocatalytic hydrogen evolution activity.Notably,photocatalytic hydro-gen evolution activity(64.93 mmol g^(−1)h^(−1))of ReS_(2)-CdS hybrid nanorods with ReS_(2)nanosheet layers(Re/Cd atomic ratio of 0.051)is approximately 136 times higher than that of pure CdS nanorods under visible light irradiation.Furthermore,intimated coupling of the ReS_(2)nanosheet layer with CdS nanorods reduced the surface trap-site of the CdS nanorods,resulting in enhanced photocatalytic stability.The de-tailed optical and electrical investigations demonstrate that the optimal ReS_(2)nanosheet layer contents in the ReS_(2)-CdS hybrid nanorods can provide improved charge transfer capability,catalytic activity,and light absorption efficiency.This study sheds light on the development of photocatalysts for highly efficient photocatalytic hydrogen evolution.

关键词： Photocatalyst Hydrogen evolution reaction ReS_(2)-CdS heterostructure Control of ReS_(2)nanosheet layer growth Optimization of cocatalyst activity and light absorption

Grain refinement of 5A06 aluminum alloy welds caused by tungsten inert gas welding arc characteristics under Ar-He alternating gas supply conditions:a coupled method of water-cooled copper plate test/numerical simulation

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Journal of Iron and Steel Research(International) 2024年第3期31卷 767-777页

作者： hong-bin Dai Jian Miao Jia-xin Lin School of Materials Science and Engineering Harbin University of Science and TechnologyHarbin 150040HeilongjiangChina

The welding arc,as a carrier for the conversion of electrical energy to thermal energy,has a direct impact on the quality of welding by its properties and states.In the tungsten inert gas(TIG)welding process under the condition of Ar-He alternating gas supply,the arc is alternately converted between Ar arc and He arc with an alternating gas supply cycle,which has obvious arc change characteristics.The FLUENT software was used to numerically simulate the characteristics of the TIG arc under the condition of alternating gas supply,and the arc temperature field,arc pressure,electric potential and current density distribution under the condition of alternating gas supply were obtained.Combined with the real-time data of arc pressure measured by the water-cooled copper plate with holes,it is proved that the TIG arc has obvious dynamic characteristics under the condition of Ar-He alternating gas supply.This unique dynamic TIG arc acts on the 5A06 aluminum alloy weld,causing the molten pool to stir,resulting in uniform microstructure and grain refinement at the weld,and thereby improving the mechanical properties of the welded joint.

关键词： Alternating gas supply Grain refinement Numerical simulation Tungsten argon arc morphology Microstructure Mechanical property

Review of sentiment analysis: An emotional product development view

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Frontiers of Engineering Management 2022年第4期9卷 592-609页

作者： hong-bin YAN Ziyu LI School of Business East China University of Science and TechnologyShanghai 200237China

Conveying consumers’specific emotions in new products,referred to as emotional product development or emotional design,is strategically crucial for manufacturers.Given that sentiment analysis(SA)can extract and analyze people’s opinions,sentiments,attitudes,and perceptions regarding different products/services,SA-based emotional design may provide manufacturers with real-time,direct,and rapid decision support.Despite its considerable advancements and numerous survey and review articles,SA is seldom considered in emotional design.This study is among the first efforts to conduct a thorough review of SA from the view of emotional design.The comprehensive review of aspect-level SA reveals the following:1)All studies focus on extracting product features by mixing technical product features and consumers’emotional perceptions.Consequently,such studies cannot capture the relationships between technical and emotional attributes and thus cannot convey specific emotions to the new products.2)Most studies use the English language in SA,but other languages have recently received more interest in SA.Furthermore,after conceptualizing emotion as Kansei and introducing emotional product development and Kansei Engineering,a review of the data-driven emotional design is then conducted.A few efforts start to study emotional design with the help of SA.However,these studies only focus on either analyzing consumers’preferences on product features or extracting emotional opinions from online reviews,thus cannot realize data-driven emotional product development.Finally,some research opportunities are provided.This study opens a broad door to aspect-level SA and its integration with emotional product development.

关键词： sentiment analysis emotion product development Kansei Engineering

Effects of relativistic parameter sets on tidal deformabilities and f-mode oscillations of neutron stars

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Communications in Theoretical Physics 2022年第6期74卷 87-102页

作者： Bin Hong Xue-Ling Mu School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210023China College of Electronic Information and Electrical Engineering Chengdu UniversityChendu 610106China

The implications of relativistic parameter sets established at saturation density on the tidal deformabilities and f-mode oscillations of neutron stars(NSs)are examined using constraints from the gravitational wave(GW)event GW170817 and NICER.According to our findings,the isovector saturation parameters have a greater impact on the radii and tidal deformabilities of NSs than the isoscalar saturation parameters.Our analysis also examines the impact of saturation properties on f-mode frequencies and finds that f-mode frequencies with 1.4 M⊙(solar mass)are roughly between 1.95 and 2.15 kHz.These findings could be confirmed by future advanced GW detectors.A good linear parameter-independent correlation between f-mode frequencies inferred from saturation parameters in the entire region is also observed,and we attempt to fit an updated version of this universal relationship.Furthermore,we used chiral effective theory(χEFT)together with the multi-messenger astronomy constraints to further reinforce the rationality of the conclusions we have reached.

关键词： neutron stars nuclear astrophysics massive stars

Decomposition of oil cleaning agents from nuclear power plants by supercritical water oxidation

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Nuclear Science and Techniques 2022年第4期33卷 83-95页

作者： Shi-bin Li Xiao-bin Xia Qiang Qin Shuai Wang hong-Jun Ma Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

Oil cleaning agents generated from nuclear power plants(NPPs)are radioactive organic liquid wastes.To date,because there are no satisfactory industrial treatment measures,these wastes can only be stored for a long time.In this work,the optimization for the supercritical water oxidation(SCWO)of the spent organic solvent was investigated.The main process parameters of DURSET(oil cleaning agent)SCWO,such as temperature,reaction time,and excess oxygen coefficient,were optimized using response surface methodology,and a quadratic polynomial model was obtained.The determination coefficient(R^(2))of the model is 0.9812,indicating that the model is reliable.The optimized process conditions were at 515 C,66 s,and an excess oxygen coefficient of 211%.Under these conditions,the chemical oxygen demand removal of organic matter could reach 99.5%.The temperature was found to be the main factor affecting the SCWO process.Ketones and benzene-based compounds may be the main intermediates in DURSET SCWO.This work provides basic data for the industrialization of the degradation of spent organic solvents from NPP using SCWO technology.

关键词： Supercritical water oxidation Oil cleaning agent Nuclear power plants Response surface methodology

Effects of oxidants on the degradation of tributyl phosphate under supercritical water oxidation conditions

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Nuclear Science and Techniques 2022年第3期33卷 160-171页

作者： Qiang Qin Xiao-bin Xia Shi-bin Li Shuai Wang hong-Jun Ma Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The effects of additional oxidants,such as NaNO_(3),Na_(2)S_(2)O_(3),KClO_(4),and K_(2)Cr_(2)O_(7),on the supercritical water oxidation(SCWO)of tributyl phosphate(TBP)were studied.The coupling of an ionic oxidant with SCWO can effectively enhance the oxidative degradation ability of the system,thus increasing its organic-matter-removal efficiency at a reduced reaction temperature.Moreover,the addition of NaNO_(3),KClO_(4),or K_(2)Cr_(2)O_(7)could improve this efficiency at a reaction temperature of 500℃compared with that of the original system at 550℃.Additionally,based on the conditions adopted in this study,the addition of either of these oxidants could reduce the final total organic carbon(TOC)of the effluent from~500 to99%.The effects of the ionic oxidants on the gas products,including CO_(2),CO,H_(2),and CH_(4),as well as other organic gases,have also been studied.Among these gas products,CO_(2)accounted for the main gas product with a proportion of more than half.At<500℃,temperature significantly affected the as products(CO,H_(2),CH_(4),and other organic gases).However,the gas product was mainly CO_(2)when the temperature was increased to≥500℃.This study initially revealed the enhancement effect of ionic oxidants on SCWO,which still requires further research.

关键词： Supercritical water oxidation Ionic oxidant Organic wastes

The vital role of CovS in the establishment of Streptococcus equi subsp.zooepidemicus virulence

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Journal of Integrative Agriculture 2023年第2期22卷 568-584页

作者： XU bin MA Zhe ZHOU hong LIN Hui-xing FAN hong-jie MOE Joint International Research Laboratory of Animal Health and Food Safety College of Veterinary MedicineNanjing Agricultural UniversityNanjing 210095P.R.China Key Laboratory of Veterinary Biological Engineering and Technology of Ministry of Agriculture and Rural Affairs National Research Center of Veterinary Biologicals Engineering and TechnologyInstitute of Veterinary MedicineJiangsu Academy of Agricultural SciencesNanjing 210014P.R.China Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses Yangzhou UniversityYangzhou 225009P.R.China

Streptococcus equi subsp.zooepidemicus(SEZ)is an important zoonotic agent.Here,a virulence-attenuated strain M35246 derived from natural variation of wild-type SEZ ATCC35246 was found.M35246 showed a deletion of 25contiguous genes as well as a loss-of-function mutation in covS.Subsequently,a 25-gene-deleted strain(ΔPI),a covS-mutant strain(Mcov S),and relevant complementary strains were constructed and investigated.M35246 and Mcov S were significantly less encapsulated and exhibited poorer anti-phagocytic capacity compared to wild-type SEZ.McovS was significantly more sensitive toβ-lactams,aminoglycosides,macrolides,and lincosamides than wild-type SEZ.M35246,McovS,andΔPI exhibited an increase in median lethal dose(LD_(50))in mice by 10~5,10~5,and 5 times when compared to wild-type SEZ,respectively.Neither M35246 nor McovS were isolated from mice 48 h after being challenged with approximately 2000 times the LD_(50)of wild-type SEZ.Transcriptome analysis showed that 668 significantly differentially expressed genes existed between McovS and wild-type SEZ.Numerous virulence factor-encoding genes and anabolicrelated genes in McovS that were involved in anti-phagocytosis,capsule formation,pathogenicity,and antibiotic resistance were downregulated significantly relative to the wild-type strain.This study revealed that the CovS plays a vital role in the establishment of SEZ virulence.

关键词： Streptococcus equi subsp.zooepidemicus covS natural variation virulence regulation