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A Fault Diagnosis Method for Smart Meters via Two-layer Stacking Ensemble Optimization and Data Augmentation

Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1272-1284页

作者： Leijiao ge Tianshuo Du Zhengyang Xu Luyang Hou jun Yan Yuanliang Li School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China School of Computer Science(National Pilot Software Engineering School) Beijing University of Posts and TelecommunicationsBeijing 100876China Concordia Institute for Information Systems Engineering Concordia UniversityMontrealQC H3G 1M8Canada

The accurate identification of smart meter(SM)fault types is crucial for enhancing the efficiency of operationand maintenance(O&M)and the reliability of power ***,the intelligent classification of SM fault typesfaces significant challenges owing to the complexity of featuresand the imbalance between fault *** address these issues,this study presents a fault diagnosis method for SM incorporatingthree distinct *** first module employs acombination of standardization,data imputation,and featureextraction to enhance the data quality,thereby facilitating improvedtraining and learning by the *** enhance theclassification performance,the data imputation method considersfeature correlation measurement and sequential imputation,and the feature extractor utilizes the discriminative enhancedsparse *** tackle the interclass imbalance of datawith discrete and continuous features,the second module introducesan assisted classifier generative adversarial network,which includes a discrete feature generation ***,anovel Stacking ensemble classifier for SM fault diagnosis is *** contrast to previous studies,we construct a two-layerheuristic optimization framework to address the synchronousdynamic optimization problem of the combinations and hyperparametersof the Stacking ensemble classifier,enabling betterhandling of complex classification tasks using SM *** proposedfault diagnosis method for SM via two-layer stacking ensembleoptimization and data augmentation is trained and validatedusing SM fault data collected from 2010 to 2018 in Zhejiang Province,*** results demonstrate the effectivenessof the proposed method in improving the accuracyof SM fault diagnosis,particularly for minority classes.

关键词： Data augmentation fault diagnosis feature extraction smart meter Stacking ensemble optimization

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Asymmetrical Fault Current Calculation Method and Influencing Factors Analysis of Droop-Controlled Inverters

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 562-573页

作者： Huimin Zhao Zhikang Shuai jun ge An Luo Weimin Wu Z.John Shen College of Electrical and Information Engineering Hunan UniversityChangsha 410006China Electrical Engineering Department Shanghai Maritime UniversityShanghai 201306China Department of Electrical and Computer Engineering Ilinois Institute of TechnologyChicagoIL 60616 USA

Since the fault dynamic of droop-controlled inverter is different from synchronous generators (SGs), protection devices may become invalid, and the fault overcurrent may damage power electronic devices and threaten the safety of the microgrid. Therefore, it is imperative to conduct a comprehensive fault analysis of the inverter to guide the design of protection schemes. However, due to the complexity of droop control strategy, existing literatures have simplified asymmetric fault analysis of droop-controlled inverters to varying degrees. Therefore, accurate fault analysis of a droop-controlled inverter is needed. In this paper, by analyzing the control system, an accurate fault model is established. Based on this, a calculation method for instantaneous asymmetrical fault current is proposed. In addition, the current components and current characteristics are analyzed. It was determined that fault currents are affected by control loops, fault types, fault distance and nonlinear limiters. In particular, the influences of limiters on the fault model, fault current calculation and fault current characteristics were analyzed. Through detailed analysis, it was found that dynamics of the control loop cannot be ignored, the fault type and fault distance determine fault current level, and part of the limiters will totally change the fault current trend. Finally, calculation and experimental results verify the correctness of the proposed method.

关键词： Asymmetrical fault analysis droop control fault current calculation method limiter transient fault characteristics

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High-temperature wetting behavior between slag and refractory

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Journal of Iron and Steel Research International 2024年第6期31卷 1304-1319页

作者： Yong-xin Wang Ya-ge Li Ya-bo Gao Zhong Huang Hai-jun Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Slag corrosion is one of the main factors of the damage of refractory,and its primary manifestations involve the melting of refractory in slag and the slag penetration into refractory,both of which are highly related to the wetting behavior between slag and *** high-temperature wettability could be characterized by parameters including the surface tension,adhesion work,and spreading coefficient of the slag on refractory surface,and it could be suppressed by altering the slag/refractory interface,thus resulting in an improved anti-corrosion *** this,the key knowledges of the slag corrosion,theory of wetting behavior and test of high-temperature contact angle were firstly ***,the major factors influencing the high-temperature slag wetting behavior were discussed based on the aspects of slag composition,refractory composition,and surface ***,the future research direction was proposed in this field.

关键词： High-temperature wetting Refractory Slag corrosion Surface tension

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Knockout of a rice K5.2 gene increases Ca accumulation in the grain

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Journal of Integrative Plant Biology 2024年第2期66卷 252-264页

作者： Peitong Wang Naoki Yamaji Namiki Mitani-Ueno jun ge Jian Feng Ma National Key Laboratory of Crop genetics&germplasm Enhancement and Utilization College of Resources and Environmental SciencesNanjing Agricultural UniversityNanjing 210095China Institute of Plant Science and Resources Okayama UniversityKurashiki 710-0046Japan

Rice is a staple food for half of the world’s population,but it is a poor dietary source of calcium(Ca)due to the low *** is an important issue to boost Ca concentration in this grain to improve Ca deficiency risk,but the mechanisms underlying Ca accumulation are poorly ***,we obtained a rice(Oryza sativa)mutant with high shoot Ca *** mutant exhibited 26%-53% higher Ca in shoots than did wild-type rice(WT)at different Ca *** concentration in the xylem sap was 36% higher in the mutant than in the *** was no difference in agronomic traits between the WT and mutant,but the mutant showed 25% higher Ca in the polished grain compared with the ***-based cloning combined with a complementation test revealed that the mutant phenotype was caused by an 18-bp deletion of a gene,OsK5.2,belonging to the Shaker-like K+channel ***5.2 was highly expressed in the mature region of the roots and its expression in the roots was not affected by Ca levels,but upregulated by low *** showed that OsK5.2 was mainly expressed in the pericycle of the *** together,our results revealed a novel role for OsK5.2 in Ca translocation in rice,and will be a good target for Ca biofortification in rice.

关键词： accumulation biofortification calcium OsK5.2 pericycle rice translocation

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Influence of pore structure heterogeneity on channeling channels during hot water flooding in heavy oil reservoir based on CT scanning

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Petroleum Science 2024年第4期21卷 2407-2419页

作者： Qing-jun Du Hao-Yu Zheng Jian Hou Yong-ge Liu Jian-Fang Sun Dong Zhao State Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) School of Petroleum Engineering China University of Petroleum (East China) Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology Petroleum Exploration and Production Research Institute

Hot water flooding is an effective way to develop heavy oil reservoirs. However, local channeling channels may form, possibly leading to a low thermal utilization efficiency and high water cut in the reservoir. The pore structure heterogeneity is an important factor in forming these channels. This study proposes a method that mixes quartz sand with different particle sizes to prepare weakly heterogeneous and strongly heterogeneous models through which hot water flooding experiments are *** the experiments, computer tomography(CT) scanning identifies the pore structure and micro remaining oil saturation distribution to analyze the influence of the pore structure heterogeneity on the channeling channels. The oil saturation reduction and average pore size are divided into three levels to quantitatively describe the relationship between the channeling channel distribution and pore structure heterogeneity. The zone where oil saturation reduction exceeds 20% is defined as a channeling *** scanning area is divided into 180 equally sized zones based on the CT scanning images, and threedimensional(3D) distributions of the channeling channels are developed. Four micro remaining oil distribution patterns are proposed, and the morphology characteristics of micro remaining oil inside and outside the channeling channels are analyzed. The results show that hot water flooding is more balanced in the weakly heterogeneous model, and the oil saturation decreases by more than 20% in most zones without narrow channeling channels forming. In the strongly heterogeneous model, hot water flooding is unbalanced, and three narrow channeling channels of different lengths form. In the weakly heterogeneous model, the oil saturation reduction is greater in zones with larger pores. The distribution range of the average pore size is larger in the strongly heterogeneous model. The network remaining oil inside the channeling channels is less than outside the channeling channels,

关键词： Heavy oil Hot water flooding Pore structure Channeling channels CT scanning

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Enhanced Cooling Efficiency of Urban Trees on Hotter Summer Days in 70 Cities of China

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Advances in Atmospheric Sciences 2024年第11期41卷 2259-2275页

作者： Limei YANG jun ge Yipeng CAO Yu LIU Xing LUO Shiyao WANG Weidong GUO School of Atmospheric Sciences Nanjing UniversityNanjing 210023China Joint International Research Laboratory of Atmospheric and Earth System Sciences Nanjing UniversityNanjing 210023China Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjing 210023China

Increasing the urban tree cover percentage(TCP) is widely recognized as an efficient way to mitigate the urban heat island effect. The cooling efficiency of urban trees can be either enhanced or attenuated on hotter days, depending on the physiological response of urban trees to rising ambient temperature. However, the response of urban trees' cooling efficiency to rising urban temperature remains poorly quantified for China's cities. In this study, we quantify the response of urban trees' cooling efficiency to rising urban temperature at noontime [~1330 LT(local time), LT=UTC+8] in 17summers(june, July, and August) from 2003–19 in 70 economically developed cities of China based on satellite observations. The results show that urban trees have stronger cooling efficiency with increasing temperature, suggesting additional cooling benefits provided by urban trees on hotter days. The enhanced cooling efficiency values of urban trees range from 0.002 to 0.055℃ %-1 per 1℃ increase in temperature across the selected cities, with larger values for the lowTCP-level cities. The response is also regulated by background temperature and precipitation, as the additional cooling benefit tends to be larger in warmer and wetter cities at the same TCP level. The positive response of urban trees' cooling efficiency to rising urban temperature is explained mainly by the stronger evapotranspiration of urban trees on hotter *** results have important implications for alleviating urban heat risk by utilizing urban trees, particularly considering that extreme hot days are becoming more frequent in cities under global warming.

关键词： urban trees cooling efficiency China's cities evapotranspiration summer hot days

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Design study of charge-stripping scheme of heavy ion beams for HIAF-BRing

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Nuclear Science and Techniques 2024年第5期35卷 30-41页

作者： jun-Jie Zhang Zhi-You Xu Jin-Quan Zhang Wen-Wen ge Liang-Ting Sun Huan-Yu Zhao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Charge strippers play an essential role in heavy-ion accelerators by stripping the projectile ions to higher charge states to enhance the acceleration efficiency downstream of the *** the high-energy mode of the booster ring(BRing)of the high-intensity heavy-ion accelerator facility,the pre-accelerated ions from the iLinac will be stripped by a carbon foil to higher charge states and then injected into the *** key parameters of the stripper and stripped ions were calculated,and the influence of stripping on the beam quality was *** get high stripping efficiencies,the foil thicknesses and resultant charge state distributions for the typical ions were determined by the code *** equilibrium thickness was obtained for the U beam,while the stripper thicknesses for the Xe and Kr beams were determined based on a compromise between the stripped charge states and the stripping *** energy loss,energy straggling,and emittance growth due to stripping have a non-negligible impact on the transport of the stripped beams and the injection of the ***,these parameters were simulated by *** addition,the foil’s temperature evolution,which greatly affects the foil lifetime,was simulated by *** maximum temperature of the foil bombarded by the U and Xe beams with the nominal parameters will exceed the safe value in terms of the impact of evaporation on the foil’s *** the foil temperature constraint,the highest tolerable beam intensity and the injected ion number into the ring were derived for different beam *** results of this paper will present important reference data for the optimization design and commissioning of the beamline and injection to the BRing for the stripped ions.

关键词： High-intensity heavy-ion accelerator facility Charge stripper Energy spread Thermal analysis Emittance growth Injection turns

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Periplaneta americana extract promotes infectious diabetic ulcers wound healing by downregulation of LINC01133/SLAMF9

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Chinese Journal of Natural Medicines 2024年第7期22卷 608-618页

作者： YANG Yuhang HUANG jun LI Xintian LIN Renjing WANG Xiaoyan XIAO ge ZENG Juanni WANG Zhenquan Department of Anorectal Disease 1 The Second Affiliated Hospital of Hunan University of Traditional Chinese MedicineChangsha 410005China Department of Anorectal Disease 3 The Second Affiliated Hospital of Hunan University of Traditional Chinese MedicineChangsha 410005China Laboratory of Vascular Biology and Translational Medicine Medical SchoolHunan University of Chinese Medicine/Hunan Provincial Key Laboratory of Vascular Biology and Translational MedicineChangsha 410208China

Wound healing in diabetic ulcers remains a significant clinical challenge,primarily due to bacterial infection and impaired *** americana extract(PAE)has been widely used to treat diabetic wounds,yet its underlying mechanisms are not fully *** study aimed to elucidate these mechanisms by analyzing long non-coding RNA(lncRNA)expressions in the wound tissues from diabetic anal fistula patients treated with or without PAE,using high-throughput *** blood monocytes from patients were differentiated into M0 macrophages with human macrophage colony-stimulating factor(hMCSF)and subsequently polarized into M1 macrophages with *** results indicated that LINC01133 and SLAMF9 were downregulated in wound tissues of patients treated with ***,PAE suppressed M1 macrophage polarization and enhanced human umbilical vein endothelial cell(HUVEC)proliferation,migration,and *** effects were diminished when LINC01133 or SLAMF9 were ***,LINC01133 was shown to upregulate SLAMF9 through interaction with *** of SLAMF9 reversed the effects of LINC01133 silencing on macrophage polarization and HUVEC *** conclusion,PAE facilitates the healing of infected diabetic ulcers by downregulating the LINC01133/SLAMF9 pathway.

关键词： Periplaneta americana extract Infectious diabetic ulcers M1 macrophage polarization LINC01133 SLAMF9

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Enantioselective Synthesis of Benzimidazole Atropisomers Featuring a N-N Axis

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Chinese Journal of Chemistry 2024年第7期42卷 711-718页

作者： Fang-Bei ge Qi-Kun Yin Chuan-jun Lu Xuan Xuan Jia Feng Ren-Rong Liu College of Chemistry and Chemical Engineering Qingdao UniversityQingdaoShandong 266071China School of Pharmacy Key Laboratory of Molecular Pharmacology and Drug EvaluationMinistry of EducationYantai UniversityYantaiShandong 264005China

Atroposelective synthesis of N-N atropisomers is an emerging area but remains underexplored;in particular,the synthesis of N-N benzimidazole atropisomers is still ***,the first enantioselective synthesis of N-N benzimidazole atropisomers via the palladium-catalyzed de novo construction of benzimidazole skeleton is *** readily available palladium catalyst and biphosphine ligand,a broad range of nonbiaryl benzimidazole and indole-benzimidazole atropisomers were conveniently ac-cessed in high yields and with excellent ***,these N-N benzimidazole atropisomers showed great anti-tumor activity and selectivity to breast cancer MCF-7 *** simple catalytic system,broad substrate scope,high enantioselectivi-ty,and good bioactivity make this approach highly attractive.

关键词： Asymmetric synthesis Atropisomerism Palladium Benzimidazole Antitumor

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Laser powder bed fusion of NiTiFe shape memory alloy via premixed powder:microstructural evolution,mechanical and functional properties

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Rare Metals 2024年第5期43卷 2300-2316页

作者： Bo Yuan Jin-Guo ge Liang Zhang Hong-jun Chen Long-Sha Wei Yu-Duo Zhou Run-Hua Song Institute of Intelligent Manufacturing Technology Shenzhen PolytechnicShenzhen 518055China School of Mechanical and Electrical Engineering Guilin University of Electronic TechnologyGuilin 541004China Guangdong Advanced Polymer Composite Engineering Technology Research Center Shenzhen Academy of Aerospace TechnologyShenzhen 518057China Jihua Laboratory Testing Center Jihua LaboratoryFoshan 528000China

High-cost pre-alloyed powder is the bottleneck problem that limits the widespread application of additivemanufactured shape memory *** this work,the lowcost ternary NiTiFe shape memory alloy is fabricated by laser powder bed fusion(LPBF)technique via mechanically mixed pre-alloy NiTi powder and varying contents pure Fe powder(1,2,3 wt%).All NiTiFe alloys show a relative density of up to 99.8%by optimizing the LPBF processing *** to the heterogeneous nucleation effect of micron-sized Fe particles,both grain refinement and texture weakening are generated in the NiTiFe alloys,accompanied by the reduction of dislocation *** the room-temperature mechanical properties,the NiTi-3Fe alloy shows the highest microhardness of HV370,but the fracture strength and elongation reduce to1701 MPa and 23%*** evolution of mechanical properties is attributed to the high internal defects,low dislocation density and the incoherent ***,the NiTi-3Fe alloy shows the quasi-linear superelasticity behavior;the superelastic recoverable strain of NiTi-1Fe and NiTi-2Fe decreased with the increase in Fe *** study provided a new-fangled insight for the development of multi-component NiTi-based shape memory alloys by additive manufacturing.

关键词： Additive manufacturing Shape memory alloy Metal matrix composite Microstructure Mechanical properties

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