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Arc and Droplet Behaviors in Horizontal Short-Arc Pulsed Gas Metal Arc Welding of 9%Ni Steel with ERNiCrMo-3 Welding Wire

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Journal of Shanghai Jiaotong university(Science) 2024年第2期29卷 361-376页

作者：刘轶玮华学明吴东升李芳蔡艳王欢杨修荣 Shanghai Key Laboratory of Material Laser Processing and Modification Shanghai Jiao Tong UniversityShanghai 200240China Hudong-Zhonghua Shipbuilding(Group)co. Ltd.Shanghai 200129China Zhuhai co.in Welding Equipment&co.sumables co. Ltd.Zhuhai 519015GuangdongChina

Short-arc pulsed gas metal arc welding(P-GMAW)was used to solve the dificulties of molten pool spreading and droplet transfer of Ni-based welding *** of short-circuit current was used to reduce *** length stabilizer was used to acquire a proper and stable arc length maintained at the critical position where short circuit starts to ***-arc P-GMAW with or without arc length stabilizer was *** droplet transfer,arc behaviors and weld bead profiles were investigated and co.pared based on the high-speed photography and observation of weld *** the arc length stabilizer was deactivated,the arc length was unstable and too *** droplet transfer mode was mainly short circuit partial transfer,with only a small part of the droplet transferred into the molten pool,with the characteristics of no obvious necking,a few spatters,small droplet impact,long short circuit duration and high short-circuit *** was also a small proportion of short circuit co.plete transfer with obvious necking,larger droplet impact,shorter short-circuit duration and lower short-circuit *** arc length stabilizer,droplet transfer modes were short circuit co.plete transfer and spray *** spray transfer had the largest droplet impact,no short circuit and no *** the arc length stabilizer activated,a deep penetration,a high penetration ratio,a small reinforcement and a large reinforcement factor were *** provides an innovative method to solve the difficulties of droplet transfer and molten pool spreading and eliminate the inco.plete fusion in the GMAW of 9%Ni steel with nickel-based alloy welding wire.

关键词： droplet transfer arc behaviors weld bead formation short-arc pulsed gas metal arc welding(P-GMAW) high nickel alloy 9%Ni steel

Machine learning methods for predicting the uniaxial co.pressive strength of the rocks:a co.parative study

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Frontiers of Earth Science 2024年第2期18卷 400-411页

作者： Tao WEN Decheng LI Yankun WANG Mingyi HU Ruixuan TANG School of Geosciences Yangtze UniversityWuhan 430100China Badong National observation and Research Station of Geohazards China University of GeosciencesWuhan 430074China Jiacha co.nty Branch of Hubei Yangtze University Technology Development co. LtdShannan 856499China

The uniaxial co.pressive strength(UCS)of rocks is a critical index for evaluating the mechanical properties and co.struction of an engineering rock mass classification *** most co.monly used method for determining the UCS in laboratory settings is expensive and *** this reason,UCS can be estimated using an indirect determination method based on several simple laboratory tests,including point-load strength,rock density,longitudinal wave velocity,Brazilian tensile strength,Schmidt hardness,and shore *** this study,six data sets of indices for different rock types were utilized to predict the UCS using three nonlinear co.bination models,namely back propagation(BP),particle swarm optimization(PSO),and least squares support vector machine(LSSVM).Moreover,the best prediction model was examined and selected based on four performance prediction *** results reveal that the PSO–LSSVM model was more successful than the other two models due to its higher performance *** ratios of the predicted UCS to the measured UCS for the six data sets were 0.954,0.982,0.9911,0.9956,0.9995,and 0.993,*** results were more reasonable when the predicted ratio was close to a value of approximately 1.

关键词： uniaxial co.pressive strength particle swarm optimization least squares support vector machine prediction model prediction performance

Experimental realization of deterministic joint remote preparation of an arbitrary two-qubit pure state via GHZ states

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Science China(Information Sciences) 2024年第3期67卷 317-318页

作者： Nachuan LI Lu XU Jin-Ming LIU State Key Laboratory of Precision Spectrosco.y School of Physics and Electronic ScienceEast China Normal University Hefei Origin Quantum co.puting Technology co. Ltd.

Quantum teleportation(QT) [1] enables secure transfer of an unknown quantum state between remote locations without physically transmitting the initial state. Unlike QT,with the sender possessing co.plete knowledge of the initial state, remote state preparation(RSP) [2] exhibits a tradeoff between the amount of the entanglement resource used and the classical co.munication co.t.

关键词： Quantum co.munication

Regression Method for Rail Fastener Tightness Based on Center-Line Projection Distance Feature and Neural Network

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 356-371页

作者： Yuanhang Wang Duxin Liu Sheng Guo Yifan Wu Jing Liu Wei Li Hongjie Wang Robotics Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China China co.struction Industrial&Energy Engineering Group co. Ltd.Nanjing 210023China

In the railway system,fasteners have the functions of damping,maintaining the track distance,and adjusting the track ***,routine maintenance and inspection of fasteners are important to ensure the safe operation of track ***,assessment methods for fastener tightness include manual observation,aco.stic wave detection,and image *** are limitations such as low accuracy and efficiency,easy interference and misjudgment,and a lack of accurate,stable,and fast detection *** at the small deformation characteristics and large elastic change of fasteners from full loosening to full tightening,this study proposes high-precision surface-structured light technology for fastener detection and fastener deformation feature extraction based on the center-line projection distance and a fastener tightness regression method based on neural ***,the method uses a 3D camera to obtain a fastener point cloud and then segments the elastic rod area based on the iterative closest point algorithm *** co.ponent analysis is used to calculate the normal vector of the segmented elastic rod surface and extract the point on the centerline of the elastic *** point is projected onto the upper surface of the bolt to calculate the projection ***,the mapping relationship between the projection distance sequence and fastener tightness is established,and the influence of each parameter on the fastener tightness prediction is ***,by setting up a fastener detection scene in the track experimental base,co.lecting data,and co.pleting the algorithm verification,the results showed that the deviation between the fastener tightness regression value obtained after the algorithm processing and the actual measured value RMSE was 0.2196 mm,which significantly improved the effect co.pared with other tightness detection methods,and realized an effective fastener tightness regression.

关键词： Railway system Fasteners Tightness inspection Neural network regression 3D point cloud processing

Isolation,identification,and virulence gene analysis of pathogenic Aeromonas dhakensis in Macrobrachium rosenbergii and histopathological observation

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Journal of Oceanology and Limnology 2024年第2期42卷 664-675页

作者： Xin PENG Haihui TU Xinyi YAO Xuan LAN Zhenxiao ZHONG Jinping LUO Qiongying TANG Shaokui YI Zhenglong XIA Guoliang YANG Zhejiang Provincial Key Laboratory of Aquatic Resources co.servation and Development College of Life SciencesHuzhou UniversityHuzhou 313000China Jiangsu Shufeng Prawn Breeding co. Ltd.Gaoyou 225654China

To identify the cause of mass mortality of adult Macrobrachium rosenbergii in a farm in Gaoyou City,Jiangsu Province,China,a dominant strain named DKQ-1 was isolated from the hepatopancreas of dying *** and identified as Aeromonas dhakensis by purification culture,biochemical characterization,and 16S rRNA and gyrB gene sequence *** results of the challenge test revealed that the strain was highly pathogenic and the 50%lethal dose(LD_(50))in 72 h to *** was 1.54×10^(5)CFU/*** amplification results of virulence genes show that strain DKQ-1 carried 9 virulence genes,including ascV,aexT,aer,act,lip,ompAI,gcaT,acg,and exu,supporting the strong virulence of strain DKQ-1 to *** observation of the hepatopancreas,gills,and intestines indicated that DKQ-1 injection into *** co.ld cause serious tissue damage,which further supported the strong virulence of this *** addition,a drug susceptibility test revealed that strain DKQ-1 was sensitive to 16 kinds of antibiotics,resistant to 9 kinds of antibiotics,and had intermediate resistance to spectinomycin and *** study is the first report of *** isolated from *** and provided a reference for the pathogen identification of bacterial diseases in ***,and for the prevention and treatment caused by ***.

关键词： Aeromonas dhakensis histopathology virulence gene gyrB drug susceptibility test Macrobrachium rosenbergii

State of the art in movement around a remote point:a review of remote center of motion in robotics

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Frontiers of Mechanical Engineering 2024年第2期19卷 1-28页

作者： Wuxiang ZHANG Zhi WANG Ke MA Fei LIU Pengzhi CHENG Xilun DING School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315832China Intelligent Aerospace Manufacturing Engineering Technology co. Ltd.Beijing 100191China

The co.cept of remote center of motion(RCM)is pivotal in a myriad of robotic applications,enco.pa-ssing areas such as medical robotics,orientation devices,and exoskeletal *** efficacy of RCM technology is a determining factor in the success of these robotic *** paper offers an exhaustive review of RCM technologies,elaborating on their various methodologies and practical *** delves into the unique characteristics of RCM across different degrees of freedom(DOFs),aiming to distill their fundamental *** addition,this paper categorizes RCM approaches into two primary classifications:design based and co.trol *** are further organized acco.ding to their respective DOFs,providing a co.cise summary of their co.e *** upon the understanding of RCM’s versatile capabilities,this paper then transitions to an in-depth exploration of its applications across diverse robotic *** this review,we critically analyze the existing research challenges and issues that are inherently present in both RCM methodologies and their *** discussion is intended to serve as a guiding framework for future research endeavors and practical deployments in related areas.

关键词： remote center of motion mechanism robotics medical robot orientation device exoskeleton

Effects of Enclosure on Grassland Eco.ogical and Eco.omic Benefits in Northern China

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Chinese Geographical Science 2024年第1期34卷 67-78页

作者： HU Bo WEN Qingke XI Fengjiang LI Mengyao WANG Libing REN Yuejuan Aerospace Information Research Institute Chinese Academy of SciencesBeijing100094China University of Chinese Academy of Sciences Beijing100049China Inner Mongolia remote Sensing Center co. Ltd.Huhhot010000China Xilinhot the Maodeng pasture Xilinhot026000China China University of Mining and Technology Xuzhou221116China Shanxi Provincial Key Lab of Resources Environment and Disaster MonitoringCoal Geological Geophysical Exploration Surveying&Mapping Institute of Shanxi ProvinceJinzhong030600China

Grasslands in northern China serve the co.ntry as both an eco.ogical barrier and a livestock production ***,installing enclosures has been beco.ing the major grassland restoration measure adopted by many local ***,the effects of restoration on both eco.ogical and production benefits of grassland remain unclear for implemented grassland restoration ***,a representative rangeland in northern China,the Maodeng pasture in Inner Mongolia Autonomous Region was selected as the study area,and remote sensing monitoring analyses were carried out to quantify the eco.ogical benefits and eco.omic benefits from 2015 to *** results showed that:1) in terms of eco.ogical benefits,the grassland area with a grassland co.erage rate of more than 60% acco.nts for 32.3% of the regional area,and 86.4% of its grassland grew significantly better than the same period in2015,showing a significant improvement in grassland *** the average amount of carbon per unit area as the eco.ogical benefit evaluation index,it increased by 27.1% to 32.48Tg C/yr from 2015 to 2021.2) In terms of eco.omic benefits,both theoretical grass production and livestock carrying capacity increased from 2015 to *** to 2015,the theoretical grass production in 2021 increased by 24.8% to 71 900 *** livestock carrying capacity reached 52 100 sheep units in 2021,nearly 11 000 sheep units more than that in *** the study period,multiple eco.omic indicators(on a per capita basis of permanent residents) for the pastoral area of Xilinhot City to which the Maodeng pasture belongs,have grown *** capita total inco.e rose from 29 630 yuan(RMB) in2015 to 62 859 yuan(RMB) in *** on grassland resources to develop the pastoral eco.ogy also broadens the potential eco.omic development ***,the establishment of the reserve and the experiment of implanting an enclosure policy have had a significant and positive impact on Maodeng pasture’s develo

关键词： enclosure grassland eco.ogical benefit eco.omic benefit Maodeng pasture Inner Mongolia northern China

FaultMonitoring Strategy for PV System Based on I-V Feature Library

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Energy Engineering 2024年第3期121卷 643-660页

作者： Huaxing Zhao Yanbo Che Gang Wen Yijing Chen School of Electrical and Information Engineering Tianjin UniversityTianjin300000China State Grid Shuozhou Electric Power Supply co.pany Shuozhou036000China China Huaneng Clean Energy Research lnstitute Technology co. Ltd.Beijing102209China

Long-term use in challenging natural co.ditions is possible for photovoltaic modules,which are extremely prone to *** to diagnose and address faults in Photovoltaic(PV)power systems in a timely manner can cause permanent damage to PV modules and,in more serious cases,***,research into photovoltaic module defect detection techniques is crucial for the growth of the photovoltaic sector as well as for maintaining national eco.omic prosperity and ensuring public *** the drawbacks of the current real-time and historical data-based methods for monitoring distributed PV systems,this paper proposes a method for monitoring PV systems at the module or string level that can be achieved by monitoring only electrical *** approach doesn’t need a lot of tests to get the operational data of PV modules beforehand and only requires theoretical feature libraries of PV modules through panel parameter *** present operating co.ditions and the open-circuit and short-circuit faults can be precisely identified by co.paring the observed open-circuit voltage and short-circuit current with the co.responding data in the theoretical feature *** that,by co.paring the measured maximum power point voltage and current with the co.responding data in the theoretical feature library through the threshold method,aging and shadowing faults can be accurately *** testing was done to see whether the suggested method was *** results show that the proposed technique is able to diagnose open-circuit faults,short-circuit faults,aging faults,and shadowing faults with shadow occlusion above 20%.

关键词： PV system lambert W function threshold method

Very Short-Term Forecasting of Distributed PV Power Using GSTANN

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CSEE Journal of Power and Energy Systems 2024年第4期10卷 1491-1501页

作者： Tiechui Yao Jue Wang Yangang Wang Pei Zhang Haizhou Cao Xuebin Chi Min Shi co.puter Network Information Center of the Chinese Academy of Sciences Beijing 100190China University of Chinese Academy of Sciences Beijing 100190China School of Electrical Engineering Beijing Jiaotong UniversityBeijing 100044China State Grid Hebei Electric Power co. Ltd.Shijiazhuang 050000China

Photovoltaic(PV)power forecasting is essential for secure operation of a power *** prediction of PV power can improve new energy co.sumption capacity,help power system planning,promote development of smart grids,and ultimately support co.struction of smart energy ***,different from centralized PV power forecasts,three critical challenges are enco.ntered in distributed PV power forecasting:1)lack of on-site meteorological observation,2)leveraging extraneous data to enhance forecasting performance,3)spatial-temporal modelling methods of meteorological information around the distributed PV *** address these issues,we propose a Graph Spatial-Temporal Attention Neural Network(GSTANN)to predict the very short-term power of distributed ***,we use satellite remote sensing data co.ering a specific geographical area to supplement meteorological information for all PV ***,we apply the graph co.volution block to model the non-Euclidean local and global spatial dependence and design an attention mechanism to simultaneously derive temporal and spatial ***,we propose a data fusion module to solve the time misalignment between satellite remote sensing data and surrounding measured on-site data and design a power approximation block to map the co.version from solar irradiance to PV *** co.ducted with real-world case study datasets demonstrate that the prediction performance of GSTANN outperforms five state-of-the-art baselines.

关键词： Distributed photovoltaic power forecasting graph co.volutional networks satellite images spatial-temporal attention