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基于局部检测信息的电力系统时间同步攻击定位方法

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华北电力大学学报（自然科学版） 2024年第1期51卷 10-19页

作者：徐飞阳孔贺常乃超顾雷马婧薛安成新能源电力系统国家重点实验室(华北电力大学) 北京102206 国家电网有限公司国家电力调度控制中心北京100031 国家电网有限公司华北分部北京100053

卫星时间同步攻击可造成电力系统设备时间紊乱,PMU相角量测错误,危及系统安全运行。鉴于基于线路两端PMU数据的攻击检测方法无法判断线路哪端节点受到攻击,提出了一种基于局部攻击检测信息及同步区域搜索聚合的卫星时间同步攻击定位方... 详细信息

卫星时间同步攻击可造成电力系统设备时间紊乱,PMU相角量测错误,危及系统安全运行。鉴于基于线路两端PMU数据的攻击检测方法无法判断线路哪端节点受到攻击,提出了一种基于局部攻击检测信息及同步区域搜索聚合的卫星时间同步攻击定位方法。首先,结合同步攻击特性构建了电力系统等效图及邻接矩阵。其次,结合线路两端攻击检测信息,利用广度优先搜索获取报警线路分割形成的各内部同步的区域子系统。再次,根据子系统是否两两相连分为简单情形和复杂情形;针对复杂情形,结合相角差偏差估计与同步子系统聚合将其转化为简单情形。最后,基于正常节点数量占优假设定位受攻击节点。IEEE 39节点系统测试表明,该方法在不同攻击下可有效定位攻击,可区分受不同攻击的节点,对微小攻击的定位能力强。

关键词：时间同步攻击攻击定位卫星授时同步相量数据攻击检测

维普期刊数据库

Correction of Time-varying PMU Phase Angle Deviation with Unknown Transmission Line Parameters

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CSEE Journal of Power and Energy Systems 2023年第1期9卷 315-325页

作者： Ancheng Xue he kong Feiyang Xu Junbo Zhao Naichao Chang Joe H.Chow Haiyan Hong State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Department of Electrical and Computer Engineering University of ConnecticutStorrs06268USA National Electric Power Dispatching and Control Center Beijing 100031China Department of Electrical Computerand Systems EngineeringRensselaer Polytechnic Institute(RPI)TroyNY 12180USA

Phasor measurement units(PMUs)provide useful data for real-time monitoring of the smart ***,there may be time-varying deviation in phase angle differences(PADs)between both ends of the transmission line(TL),which may deteriorate application performance based on *** address that,this paper proposes two robust methods of correcting time-varying PAD deviation with unknown parameters of TL(ParTL).First,the phenomena of time-varying PAD deviation observed from field PMU data are *** general formulations for PAD estimation are then *** simplify the formulations,estimation of PADs is converted into the optimal problem with a single ParTL as the variable,yielding a linear estimation of *** latter is used by second-order Taylor series expansion to estimate PADs *** reduce the impact of possible abnormal amplitude data in field data,the IGG(Institute of Geodesy&Geophysics,Chinese Academy of Sciences)weighting function is *** using both simulated and field data verify the effectiveness and robustness of the proposed methods.

关键词： Correction line parameters parameter identification phasor measurement time-varying phase angle difference deviation

Electrolyte effect on electrochemical behaviors of manganese fluoride material for aqueous asymmetric and symmetric supercapacitors

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Rare Metals 2024年第3期43卷 1048-1061页

作者： Zheng-Hua he Jian-Fei Gao Ling-Bin kong State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals Lanzhou University of TechnologyLanzhou730050China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou730050China

Exploring wide voltage window materials is not only an available measure to enhance the energy density of hybrid supercapacitor(HSCs),but also avoids the dynamic mismatch caused by different energy storage mechanisms of two electrodes in assembled symmetrical ***,there are few reports about the wide potential window materials except Bi_(2)O_(3)and VO_(2).Therefore,the MnF_(2)synthesized by solvothermal reaction was served as the electrode for *** MnF_(2)exhibited electrochemical activity in alkaline solution in three-electrode system,especially with a wide potential window from-0.8 to+0.5 V in 2 mol·L^(-1)***,the assembled MnF_(2)//MnF_(2)symmetrical HSC had a potential window of 1.5 V,and it exhibited outstanding long-cycle ***,when MnF_(2)was taken as the negative and positive respectively,the potential windows of asymmetric devices CoMoO_(4)//MnF_(2)and MnF_(2)//Activated Carbon(AC)could reach 1.3 and 1.45 V,respectively,showing excellent cycle *** work shows that MnF_(2)material has great research value in HSC,and provides a new research direction for developing high-performance devices.

关键词： Manganese fluoride Potential window Hybrid supercapacitors Electrochemical performance

维普期刊数据库

Corrosion of Duplex Stainless Steel Manufactured by Laser Powder Bed Fusion: A Critical Review

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 587-606页

作者： Yiqi Zhou Decheng kong Ruixue Li Xing he Chaofang Dong Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing100083China Shanghai Key Laboratory of Advanced High-Temperature Materials and Precision Forming School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai200240China

Laser powder bed fusion (LPBF) is a commonly used additive manufacturing (AM) method for efficiently producing intricate geometric components. This investigation examines factors such as pores, cellular structure, grain size, and inclusions from the manufacturing process that contribute to the corrosion resistance of LPBF DSS. Furthermore, the as-built LPBF duplex stainless steel (DSS) is primarily ferrite due to the rapid cooling process. Therefore, the transformation of ferrite to austenite after various heat treatments in LPBF DSS and its corresponding corrosion resistance are presented. Additionally, a new mixed powder method is proposed to increase the austenite content in the as-built LPBF DSS. This review also focuses on the passivation capability and pitting corrosion performance in LPBF and conventional DSS. This article summarizes the variations in microstructure between as-built and heat-treated LPBF DSS, with their impacts on corrosion resistance, offering insights for manufacturing highly corrosion-resistant LPBF DSS.

关键词： Laser powder bed fusion Duplex stainless steel Microstructure heat treatment Passivation Pitting corrosion

An Underwater Target Detection Algorithm Based on Attention Mechanism and Improved YOLOv7

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Computers, Materials & Continua 2024年第2期78卷 2829-2845页

作者： Liqiu Ren Zhanying Li Xueyu he Lingyan kong Yinghao Zhang College of Information Science and Engineering Dalian Polytechnic UniversityDalian116034China

For underwater robots in the process of performing target detection tasks,the color distortion and the uneven quality of underwater images lead to great difficulties in the feature extraction process of the model,which is prone to issues like error detection,omission detection,and poor ***,this paper proposed the CER-YOLOv7(CBAM-EIOU-RepVGG-YOLOv7)underwater target detection *** improve the algorithm’s capability to retain valid features from both spatial and channel perspectives during the feature extraction phase,we have added a Convolutional Block Attention Module(CBAM)to the backbone *** Reparameterization Visual Geometry Group(RepVGG)module is inserted into the backbone to improve the training and inference *** Efficient Intersection over Union(EIoU)loss is also used as the localization loss function,which reduces the error detection rate and missed detection rate of the *** experimental results of the CER-YOLOv7 algorithm on the UPRC(Underwater Robot Prototype Competition)dataset show that the mAP(mean Average Precision)score of the algorithm is 86.1%,which is a 2.2%improvement compared to the *** feasibility and validity of the CER-YOLOv7 are proved through ablation and comparison experiments,and it is more suitable for underwater target detection.

关键词： Deep learning underwater object detection improved YOLOv7 attention mechanism

Force Compensation Control for Electro-Hydraulic Servo System with Pump-Valve Compound Drive via QFT-DTOC

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 228-246页

作者： Kaixian Ba Yuan Wang Xiaolong he Chunyu Wang Bin Yu Yaliang Liu Xiangdong kong hebei Provincial Key Laboratory of heavy Machinery Fluid Power Transmission and Control Qinhuangdao 066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China National Engineering Research Center for Local Joint of Advanced Manufacturing Technology and Equipment Yanshan UniversityQinhuangdao 066004China

Each joint of a hydraulic-driven legged robot adopts a highly integrated hydraulic drive unit(HDU),which features a high power-weight ***,most HDUs are throttling-valve-controlled cylinder systems,which exhibit high energy *** contrast,pump control systems offer a high ***,their response ability is *** fully utilize the advantages of pump and valve control systems,in this study,a new type of pump-valve compound drive system(PCDS)is designed,which can not only effectively reduce the energy loss,but can also ensure the response speed and response accuracy of the HDUs in robot joints to satisfy the performance requirements of ***,considering the force control requirements of energy conservation,high precision,and fast response of the robot joint HDU,a nonlinear mathematical model of the PCDS force control system is first *** addition,pressure-flow nonlinearity,friction nonlinearity,load complexity and variability,and other factors affecting the system are considered,and a novel force control method based on quantitative feedback theory(QFT)and a disturbance torque observer(DTO)is designed,which is denoted as QFT-DTOC *** method improves the control accuracy and robustness of the force control system,reduces the effect of the disturbance torque on the control performance of the servo motor,and improves the overall force control performance of the ***,experimental verification is performed using the PCDS performance test *** experimental results and quantitative data show that the QFT-DTOC proposed herein can significantly improve the force control performance of the *** relevant force control method can be used as a bottom-control method for the hydraulic servo system to provide a foundation for implementing the top-level trajectory planning of the robot.

关键词： Legged robot Pump-valve compound drive system(PCDS) Force compensation control Quantitative feedback theory(QFT) Disturbance torque observer(DTO)

Independent and Combined Associations of Sleep Duration, Bedtime, and Polygenic Risk Score with the Risk of hearing Loss among Middle-Aged and Old Chinese: The Dongfeng–Tongji Cohort Study

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Research 2024年第1期2023卷 721-733页

作者： Miao Liu Haiqing Zhang Zhichao Wang Tingting Mo Xuefeng Lai Yaling he Minghui Jiang Meian he Weijia kong Tangchun Wu Xiaomin Zhang Department of Occupational and Environmental health Ministry of Education Key Laboratory of Environment and Healthand State Key Laboratory of Environmental Health(Incubating)School of Public HealthTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina Department of Otorhinolaryngology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina Department of Epidemiology and Biostatistics School of Public HealthTongji Medical CollegeHuazhong University of Science and TechnologyWuhanHubeiChina

Evidence available on the independent and combined associations of sleep duration,bedtime,and genetic predisposition with hearing loss was *** present study included 15,827 participants from the Dongfeng–Tongji cohort *** risk was characterized by polygenic risk score(PRS)based on 37 genetic loci related to hearing *** conducted multivariate logistic regression models to assess the odds ratio(OR)for hearing loss with sleep duration and bedtime,as well as the joint association and interaction with *** showed that hearing loss was independently associated with sleeping≥9 h/night compared to the recommended 7 to9:00 *** 10:00 *** to those with bedtime>10:00 *** 11:00 p.m.,with estimated ORs of 1.25,1.27,and 1.16,respectively.

关键词： Middle hearing fen

Dietary Macleaya cordata extract supplementation improves the growth performance and gut health of broiler chickens with necrotic enteritis

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Journal of Animal Science and Biotechnology 2024年第1期15卷 374-395页

作者： Bochen Song Jie he Xue Pan Linglian kong Chuanpi Xiao Chake Keerqin Zhigang Song Key Laboratory of Efficient Utilization of Non‑Grain Feed Resources College of Animal Science and TechnologyShandong Agricultural UniversityTaian 271018ShandongChina Center for Mitochondria and healthy Ageing College of Life SciencesYantai UniversityYantai 264005ShandongChina Precision Livestock and Nutrition Unit University of LiègeGembloux Agro‑Bio TechGemblouxBelgium Phytobiotics(Jiangsu)Biotech Co. Ltd.Jintan 213200China

Background The poultry industry needs effective antibiotic alternatives to control outbreaks of necrotic enteritis(NE)caused by Clostridium *** The aim of this study was to investigate the effects of dietary supplementation with Macleaya cordata extract(MCE)on the immune function and gut microbiota of broilers with NE.A total of 2881-day-old broiler chicks were randomly assigned to a 2×2 factorial arrangement with two concentrations of dietary MCE supplementation(0 or 350 mg/kg of diet)and two disease challenge statuses(control or NE).Results The results revealed that NE significantly increased the feed conversion rate(FCR),mortality,intestinal lesion score,the levels of IL-1β,IL-17 and IFN-γ/IL-4 in serum and IL-17/IL-10 in the jejunal mucosa,m RNA levels of TLR2,IFN-γand p Ig R in the jejunum,and Clostridium perfringens concentrations in the *** significantly decreased the body weight(BW),body weight gain(BWG),jejunal villus height,V/C,m RNA level of AMPK-α1 in jejunum,IL-4 level in the jejunal mucosa and lactic acid bacteria abundance in the *** significantly increased BW,BWG,jejunal villus height,V/C,m RNA levels of occludin,ZO-1 and AMPK-α1 in the jejunum,the levels of Ig A and Ig G in serum and IL-10 in the jejunal mucosa and m RNA levels of NF-κB,IL-10 and MHC-II in the ***,MCE significantly decreased the FCR,mortality,intestinal lesion score,jejunal crypt depth,the levels of IFN-γand IL-17 in serum and IL-17/IL-10 in the jejunal mucosa,Clostridium perfringens concentrations in the cecum,and m RNA levels of IL-17/IL-10 in the ***,NE significantly increased the abundance of bacteria that are associated with inflammation,obesity and depression(Alistipes,Barnesiella,Intestinimonas,RF39 and UCG-005)and significantly decreased the abundance of short-chain fatty acid(SCFA)-producing bacteria(Anaerotruncus,Butyricicoccus and Bacteroides)in the *** significantly increased the abundance of SCFA-producing b

关键词： Broiler chicken Gut microbiota Immune function Macleaya cordata extract Necrotic enteritis

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Silver Ion-Induced Formation of Unprecedented Thorium Nonamer Clusters via Lacuna-Construction Strategy

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CCS Chemistry 2023年第5期5卷 1144-1153页

作者： Xiang-he kong Qun-Yan Wu Lei Mei Li-Wen Zeng Zhi-Wei Huang Ji-Pan Yu Chang-Ming Nie John KGibson Zhi-Fang Chai kong-Qiu Hu Wei-Qun Shi Laboratory of Nuclear Energy Chemistry Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049 School of Chemistry and Chemical Engineering University of South ChinaHengyang 421001 Chemical Sciences Division Lawrence Berkeley National Laboratory(LBNL)BerkeleyCalifornia 94720

herein,we report the synthesis and structures of two novel mixed-metal clusters denoted as Th_(9)Ag_(6)and Th_(9)Ag_(12).Both clusters feature unprecedented Th_(9)*** cores are tricapped trigonal prism moieties that are novel among *** alternative synthesis routes indicate that the Th_(9)clusters are accessible only through slow introduction of Ag_(+)into a solution containing a Th6 cluster modified with 2-picolinic *** rapid addition of Ag_(+)leads to dissociation of the Th6 cluster with formation of a high-purity(ThAg)_(∞)two-dimensional layered structure material.A mechanism for cluster dissociation and reassembly to yield Th_(9)from Th6 is proposed that is consistent with spectroscopic observations and computational *** of Ag⋯Ag andπ–πinteractions,the Th_(9)Ag_(12)cluster exhibits high stability in air,at elevated temperature,underγ-irradiation,and in common solvents.

关键词： thorium nonamer clusters silver ion lacuna-construction strategy dissociation and reassembly high stability