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An object detection approach with residual feature fusion and second-order term attention mechanism

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CAAI Transactions on Intelligence Technology 2024年第2期9卷 411-424页

作者： Cuijin li Zhong qu Shengye Wang College of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqingChina College of Electronic Information Chongqing Institute of EngineeringChongqingChina

Automatically detecting and locating remote occlusion small objects from the images of complex traffic environments is a valuable and challenging *** the boundary box location is not sufficiently accurate and it is difficult to distinguish overlapping and occluded objects,the authors propose a network model with a second-order term attention mechanism and occlusion ***,the backbone network is built on *** a method is designed for the feature extraction network based on an item-wise attention mechanism,which uses the filtered weighted feature vector to replace the original residual fusion and adds a second-order term to reduce the information loss in the process of fusion and accelerate the convergence of the ***,an objected occlusion regression loss function is studied to reduce the problems of missed detections caused by dense *** experimental results demonstrate that the authors’method achieved state-of-the-art performance without reducing the detection *** mAP@.5 of the method is 85.8%on the Foggy_cityscapes dataset and the mAP@.5 of the method is 97.8%on the KITTI dataset.

关键词： artificial intelligence computer vision image processing machine learning neural network object recognition

Exploring non-invasive diagnostics for metabolic dysfunctionassociated fatty liver disease

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World Journal of Gastroenterology 2024年第28期30卷 3447-3451页

作者： Biao qu Zheng li Department of Clinical Pharmacology The Second Hospital of Anhui Medical UniversityHefei 230601Anhui ProvinceChina Jiangsu Engineering Research Center of Cardiovascular Drugs Targeting Endothelial Cells College of Health SciencesSchool of Life SciencesJiangsu Normal UniversityXuzhou 221000Jiangsu ProvinceChina

The population with metabolic dysfunction-associated fatty liver disease(MAFLD)is increasingly common *** of people at risk of progression to advanced stages is necessary to timely offer interventions and appropriate *** biopsy is currently considered the gold standard for the diagnosis and staging of MAFLD,but it has associated risks and *** has spurred the exploration of non-invasive diagnostics for MAFLD,especially for steatohepatitis and *** non-invasive approaches mostly include biomarkers and algorithms derived from anthropometric measurements,serum tests,imaging or stool metagenome ***,they still need rigorous and widespread clinical validation for the diagnostic performance.

关键词： Metabolic dysfunction-associated fatty liver disease Non-invasive diagnostics Circulating biomarkers Imaging biomarkers Stool microbial biomarkers

Plants affect the horizontal transmission of a new densovirus infecting the green peach aphid Myzus persicae by modulating honeydew production

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Insect Science 2024年第1期31卷 236-254页

作者： Ya Guo Yani Zhao Yang Yang yahong Zhang Yuying li Honggang Tian Tong-Xian liu Zhaofei li State Key Laboratory of Crop Stress Biology for Arid Areas Key Laboratory of Northwest Loess Plateau Crop Pest Management of Ministry of AgricultureCollege of Plant ProtectionNorthwest A&F UniversityYanglingChina Institute of Entomology and Institute of Plant Health&Medicine Guizhou UniversityGuiyangChina

In a tritrophic context of plant-insect-entomopathogen,plants play important roles in modulating the interaction of insects and their pathogenic ***,the influence of plants on the transmission of insect viruses has been mainly studied on baculoviruses and some RNA viruses,whereas the impact of plants on other insect viruses is largely ***,we identified a new densovirus infecting the green peach aphid Myzus persicae and tested whether and how host plants influence the transmission of the aphid *** complete single-stranded DNA genome of the virus,*** densovirus 2,is 5727 nt and contains inverted terminal *** and phylogenetic analysis indicated that the virus was distinct from other a few identified aphid *** virus abundance was detected highly in the intestinal tract of aphids,compared with the lower level of it in other tissues including head,embryo,and *** and pepper plants had no obvious effect on the vertical transmission and saliva-mediated horizontal transmission of the ***,the honeydew-mediated horizontal transmission among aphids highly depended on host plants(65%on cabbages versus 17%on peppers).Although the virus concentration in the honeydew produced by aphids between 2 plants was similar,the honeydew production of the infected aphids reared on peppers was dramatically *** together,our results provide evidence that plants influence the horizontal transmission of a new densovirus in an aphid population by modulating honeydew secretion of aphids,suggesting plants may manipulate the spread of an aphid-pathogenic densovirus in nature.

关键词： aphids densovirus host plants MpDV2 Myzus persicae transmission

Improving the high cycle fatigue property of Ti6Al4V Eli alloy by optimizing the surface integrity through electric pulse combined with ultrasonic surface rolling process

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Journal of Materials Science & Technology 2024年第3期170卷 103-121页

作者： Pengfei Sun Shengguan qu Chenfeng Duan Xiongfeng Hu Xiaoqiang li National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China School of Mechanical and Automotive Engineering South China University of TechnologyGuangzhou 510640China

To improve the surface integrity and high cycle fatigue property of Ti6Al4V Eli alloy,the electric pulse has been introduced into the ultrasonic surface rolling process(USRP),which is called electric pulse-assisted ultrasonic surface rolling process(EUSRP).With the help of“electroplasticity”of the electric pulse,the thickness of the surface gradient deformation layer was about three times of the USRP specimens by adjusting the pulse current ***,the surface hardness decreases due to the continuous effect of the pulse current and the“skin effect”during *** is worth noting that the higher the applied pulse current,the more severe the *** paradox causes the fatigue performance of EUSRP specimens lower than that of USRP *** break this paradox,the EUSRP treatment is followed by a USRP *** EUSRP-2(with a pulse current of 200 A)+USRP specimens exhibit excellent surface hardness,a gradient deformation layer thickness of about 400μm,low surface roughness and high compressive residual compressive ***,the hardening mechanisms of the different surface strengthening specimens have been quantitatively analyzed in combination with microstructure *** fatigue life of Ti6Al4V Eli alloy can be improved by about 25 times at 780 MPa using the EUSRP-2+USRP treatment,the main reason for the highest fatigue life is the deepest surface gradient layer and the deepest crack initiation *** fatigue limit of the EUSRP-2+USRP specimens is not the highest because too much surface hardening causes compressive residual stress relaxation during cycling and the beneficial effect of compressive residual stress is eliminated.

关键词： Ti6Al4V Eli alloy Combined surface treatment Transmission electron microscopy Residual stress Fatigue performance

Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine

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China Ocean Engineering 2024年第3期38卷 363-378页

作者： ZHAO Mi YU Wan-li WANG Pi-guang qu Yang DU Xiu-li Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China State Key Laboratory of Bridge Engineering Safety and Resilience Beijing University of TechnologyBeijing 100124China

A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic *** this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model.

关键词： computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field

Electrode/Electrolyte Interfacial Chemistry Modulated by Chelating Effect for High-Performance Zinc Anode

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Energy & Environmental Materials 2024年第3期7卷 93-99页

作者： Chuanlin li Guangmeng qu Xixi Zhang Chenggang Wang Xijin Xu School of Physics and Technology University of JinanJinan 250022China School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China

Although Zn metal has been regarded as the most promising anode for aqueous batteries,its practical application is still restricted by side reactions and dendrite ***,an in-situ solid electrolyte interphase(SEI)film formed on the interface of electrode/electrolyte during the plating/stripping of zinc anodes by introducing trace amounts of multidentate ligand sodium diethyldithiocarbamate(DDTC)additive into 1 M ZnSO_(4).The synergistic effect of in-situ solid electrolyte interphase forming and chelate effect endows Zn^(2+)with uniform and rapid interface-diffusion kinetics against dendrite growth and surface side *** a result,the Zn anode in 1 M ZnSO_(4)+DDTC electrolytes displays an ultra-high coulombic efficiency of 99.5%and cycling stability(more than 2000 h),especially at high current density(more than 600 cycles at 40 mA cm^(-2)).Moreover,the Zn//MnO_(2)full cells in the ZnSO_(4)+DDTC electrolyte exhibit outstanding cyclic stability(with 98.6%capacity retention after 2000 cycles at 10 C).This electrode/electrolyte interfacial chemistry modulated strategy provides new insight into enhancing zinc anode stability for high-performance aqueous zinc batteries.

关键词： chelating effect in-situ SEI ultra-high current density Zn anodes

TiN/Fe2N/C composite with stable and broadband high-temperature microwave absorption

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International Journal of Minerals, Metallurgy and Materials 2024年第11期31卷 2508-2517页

作者： Zhang, yahong Zhang, Yi liu, Huimin li, Dan Wang, Yibo Xu, Chunchao Tian, Yuping Meng, Hongjie College of Chemistry and Molecular Sciences Henan University Kaifeng China Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province Institute of Surface Micro and Nano Materials College of Chemical and Materials Engineering Xuchang University Xuchang China School of Energy Science and Technology Henan University Zhengzhou China

Facing the complex variable high-temperature environment, electromagnetic wave (EMW) absorbing materials maintaining high stability and satisfying absorbing properties is essential. This study focused on the synthesis and EMW absorbing performance evaluation of TiN/Fe2N/C composite materials, which were prepared using electrostatic spinning followed by a high-temperature nitridation process. The TiN/Fe2N/C fibers constructed a well-developed conductive network that generates considerable conduction loss. The heterogeneous interfaces between different components generated a significant level of interfacial polarization. Thanks to the synergistic effect of stable dielectric loss and optimized impedance matching, the TiN/Fe2N/C composite materials demonstrated excellent and stable absorption performance across a wide temperature range (293–453 K). Moreover, TiN/Fe2N/C-15 achieved a minimum reflection loss (RL) of −48.01 dB and an effective absorption bandwidth (EAB) of 3.64 GHz at 2.1 mm and 373 K. This work provides new insights into the development of high-efficiency and stabile EMW absorbing materials under complex variable high-temperature conditions.

关键词： high-temperature impedance matching stable permittivity dielectric loss

Earthquake potential across the North–South seismic belt of China

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Science Bulletin 2024年第2期69卷 179-182页

作者： Yanchuan li Xinjian Shan Chunyan qu Guohong Zhang Xiaogang Song State Key Laboratory of Earthquake Dynamics Institute of GeologyChina Earthquake AdministrationBeijing 100029China

The elastic rebound theory,which frames our understanding of earthquakes,suggests that the accumulated elastic strain on faults will ultimately be released through earthquakes[1].As such,identifying the location,rate,and accumulation of slip deficit on faults constitutes a basis for seismic potential assessment[2].Interseismic coupling(ISC)refers to the ratio of the slip deficit rate on a fault to the far-field loading rate,where full and no coupling correspond to 100%and 0%slip deficits,respectively.

关键词： seismic belt fault

Physical Layer Security Performance Analysis in Multi-Antenna NOMA-Based UAV Relay Networks

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China Communications 2024年第9期 98-108页

作者： Huang Haiyan Zhang Hongsheng liang linlin li yahong School of Electronic and Information Engineering Lanzhou Jiaotong University School of Cyber Engineering Xidian University

With the increasing number of communication devices and the complexity of communication environments,unmanned aerial vehicles(UAV),due to their flexible deployment and convenient networking capabilities,have shown significant advantages in tasks such as high-density communication areas and emergency rescue within special communication *** the openness of air-toground wireless communication,it is more susceptible to eavesdropping *** a result,the introduction of physical layer security(PLS) in UAV communication systems is crucial to safeguard the security of transmitted *** this paper,we investigate the PLS issues in a UAV cooperative communication system operating in Nakagami-m fading channels with the presence of friendly *** considers the effects of imperfect successive interference cancellation(i SIC) and power allocation coefficients on system performance based on non-orthogonal multiple access(NOMA) *** deriving closed-form expressions for the outage probabilities at the receiving users and the intercept probability of UAV eavesdropper(U-EAV),the performance of the considered cooperative UAV-assisted NOMA relay system with the presence of friendly interference is evaluated.

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