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Unmanned Aerial Vehicles General Aerial Person-Vehicle Recognition Based on Improved YOLOv8s Algorithm

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Computers, Materials & Continua 2024年第3期78卷 3787-3803页

作者： Zhijian liu School of Electrical Engineering and Electronic Information Xihua UniversityChengdu610036China

Considering the variations in imaging sizes of the unmanned aerial vehicles(UAV)at different aerial photography heights,as well as the influence of factors such as light and weather,which can result in missed detection and false detection of the model,this paper presents a comprehensive detection model based on the improved lightweight You Only Look Once version 8s(YOLOv8s)algorithm used in natural light and infrared scenes(L_YOLO).The algorithm proposes a special feature pyramid network(SFPN)structure and substitutes most of the neck feature extraction module with the Special deformable convolution feature extraction module(SDCN).Moreover,the model undergoes pruning to eliminate redundant ***,the non-maximum suppression algorithm of intersection-union ratio based on minimum point distance(MPDIOU_NMS)algorithm has been integrated to eliminate redundant detection boxes,and a comprehensive validation has been conducted using the infrared aerial dataset and the Visdrone2019 *** comprehensive experimental results demonstrate that when the number of parameters and floating-point operations is reduced by 30%and 20%,respectively,there is a 1.2%increase in mean average precision at a threshold of 0.5(mAP(0.5))and a 4.8%increase in mAP(0.5:0.95)on the infrared ***,the mAP on the Visdrone2019 dataset has experienced an average increase of 12.4%.The accuracy and recall rates have seen respective increases of 9.2%and 3.6%.

关键词： YOLOv8s SPFN SDCN pruning MPDIOU_NMS

Fully automatic AI segmentation of oral surgery-related tissues based on cone beam computed tomography images

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International Journal of Oral Science 2024年第3期16卷 413-424页

作者： Yu liu Rui Xie Lifeng Wang Hongpeng liu Chen liu Yimin Zhao Shizhu Bai Wenyong liu Beijing Yakebot Technology Co. Ltd.BeijingChina School of Mechanical Engineering and Automation Beihang UniversityBeijingChina State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration National Clinical Research Center for Oral DiseasesShaanxi Key Laboratory of StomatologyDigital CenterSchool of StomatologyThe Fourth Military Medical UniversityXi’anChina Key Laboratory of Biomechanics and Mechanobiology of the Ministry of Education Beijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijingChina

Accurate segmentation of oral surgery-related tissues from cone beam computed tomography(CBCT)images can significantly accelerate treatment planning and improve surgical *** this paper,we propose a fully automated tissue segmentation system for dental implant ***,we propose an image preprocessing method based on data distribution histograms,which can adaptively process CBCT images with different *** on this,we use the bone segmentation network to obtain the segmentation results of alveolar bone,teeth,and maxillary *** use the tooth and mandibular regions as the ROI regions of tooth segmentation and mandibular nerve tube segmentation to achieve the corresponding *** tooth segmentation results can obtain the order information of the *** corresponding experimental results show that our method can achieve higher segmentation accuracy and efficiency compared to existing *** average Dice scores on the tooth,alveolar bone,maxillary sinus,and mandibular canal segmentation tasks were 96.5%,95.4%,93.6%,and 94.8%,*** results demonstrate that it can accelerate the development of digital dentistry.

关键词： surgery CBCT beam

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线性变换的值域与核互为正交补的条件

太原师范学院学报（自然科学版） 2009年第3期8卷 21-22,25页

作者：张姗梅刘耀军太原师范学院数学系山西太原030012 太原师范学院计算机科学与技术系山西太原030012

借助线性变换的核与值域的维数关系,给出有限维欧氏空间的线性变换的值域与核互为正交补的几个充分条件和充要条件.

关键词：欧氏空间正交补值域核

Optimization performance of quantum endoreversible Otto machines with dual-squeezed reservoirs

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Chinese Physics B 2024年第10期33卷 198-204页

作者： Haoguang liu College of Science and Technology Nanchang Aeronautical UniversityNanchang 332020China

We consider a quantum endoreversible Otto engine cycle and its inverse operation-Otto refrigeration cycle,employing two-level systems as the working substance and operating in dual-squeezed *** demonstrate that the efficiency of heat engines at maximum work output and the coefficient of performance for refrigerators at the maximum c criterion will degenerate toη-=η_(C)/(2-η_(C))andε-=(√9+8ε_(C)-3)/2 when symmetric squeezing is satisfied,*** also investigated the influences of squeezing degree on the performance optimization of quantum Otto heat engines at the maximum work output and refrigerators at the maximum X *** analytical results show that the efficiency of heat engines at maximum work output and the coefficient of performance for refrigerators at the maximum X criterion can be improved,reduced or even inhibited in asymmetric ***,we also find that the efficiency of quantum Otto heat engines at maximum work output is lower than that obtained from the Otto heat engines based on a single harmonic oscillator ***,the coefficient of performance of the corresponding refrigerator is higher.

关键词： quantum Otto heat engine quantum Otto refrigerator optimization performance dual-squeezed reservoirs

A Hierarchical Modeling Framework for Electrochemical Behaviors in Lithium-Ion Batteries with Detailed Structures

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Energy & Environmental Materials 2024年第5期7卷 81-89页

作者： Binghe liu Xin liu Huacui Wang Jie Li Jun Xu College of Mechanical and Vehicle Engineering Chongqing University State Key Laboratory of Intelligent Vehicle Safety Technology Department of Mechanical Engineering University of Delaware Energy Mechanics and Sustainability Laboratory (EMSLab) University of Delaware

The accurate representation of lithium plating and aging phenomena has posed a persistent challenge within the battery research community. Empirical evidence underscores the pivotal role of cell structure in influencing aging behaviors and lithium plating within lithium-ion batteries (LIBs). Available lithium-ion plating models often falter in detailed description when integrating the structural intricacies. To address this challenge, this study proposes an innovative hierarchical model that intricately incorporates the layered rolling structure in cells. Notably, our model demonstrates a remarkable capacity to predict the non-uniform distribution of current density and overpotential along the rolling direction of LIBs. Subsequently, we delve into an insightful exploration of the structural factors that influence lithium plating behavior,leveraging the foundation laid by our established model. Furthermore, we easily update the hierarchical model by considering aging factors. This aging model effectively anticipates capacity fatigue and lithium plating tendencies across individual layers of LIBs, all while maintaining computational efficiency.

关键词： aging model battery design hierarchical modeling lithium plating lithium-ion battery

Stable hydrogen-bonded organic frameworks and their photo-and electro-responses

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Nano Research 2024年第8期17卷 7675-7699页

作者： Ying Hou Xin-Song Huang Sheng-Hao Gong Chen liu Yangyang liu Tian-Fu liu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Department of Chemistry and Biochemistry California State UniversityLos AngelesCalifornia 90032USA College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China

Hydrogen-bonded organic frameworks(HOFs)are a recent class of porous materials that have garnered considerable research interest owing to their distinctive *** can be constructed through judicious selection of H-bonding motifs,which are further enforced by other weak intermolecular interactions such asπ–πstacking,van der Waals forces,and framework *** advantage of these interactions,we can expand the functional field of HOFs by introducing active ***,researchers have made substantial advancements in using HOFs for chemical sensing,catalysis,proton conduction,biological applications,and *** low bonding energy of H-bonds allows for precise control over the concentration of ligands in solvents,forming diverse HOF *** varied structures offer significant advantages for producing HOFs with photo-responsive and electro-responsive ***,the presence of H-bonds in HOFs results in their inherent lower stability compared to metal-organic frameworks(MOFs)and covalent-organic frameworks(COFs)formed via coordination and covalent bonds,*** a result,the pursuit of stable and innovative HOF materials with novel functional sites remains an ongoing *** review provides an overview of recent research progress in the development of new strategies for stable HOF synthesis and applications of HOFs with stimuli-responsive *** first classified all synthetic methods reported to date and discussed the stable HOFs synthesized,as well as their unique properties and *** addition,we summarized the applications of HOFs utilizing their synergistic responses to external stimuli,including photo,electrical,pressure,and chemical *** systematically reviewed stable HOF synthesis and applications,which may lead to a deeper understanding of the structure–activity relationship for these materials and guide future HOF design.

关键词： stable hydrogen-bonded organic frameworks(HOFs) photo-response electro-response photoelectric synergistic response

降雨侵蚀过程中红壤坡耕地地表微地貌演变特征

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水土保持研究 2018年第6期25卷 15-21页

作者：张利超葛佩琳李朝霞刘窑军喻荣岗江西省水土保持科学研究院江西省土壤侵蚀与防治重点实验室南昌330029 华中农业大学农业部长江中下游耕地保育重点实验室武汉430070

以第四纪红黏土母质红壤和泥质页岩母质红壤等典型南方红壤为例,选取典型红壤坡耕地的野外原位试验小区,控制土表相同初始条件,分别在两种雨强下进行连续三场降雨,同时采用毫米级高精度激光扫描和计算机数字图像处理相结合的方法,研究... 详细信息

以第四纪红黏土母质红壤和泥质页岩母质红壤等典型南方红壤为例,选取典型红壤坡耕地的野外原位试验小区,控制土表相同初始条件,分别在两种雨强下进行连续三场降雨,同时采用毫米级高精度激光扫描和计算机数字图像处理相结合的方法,研究了在降雨侵蚀过程中红壤坡耕地地表微地貌的演变特征,探讨了地表糙度、洼地蓄积量相关规律。结果表明:(1)连续降雨的进行,雨滴打击和径流搬运的联合作用导致地表糙度降低。第一场降雨带来糙度的迅速下降,第二、三场降雨对糙度的影响较小。在2mm/min雨强下,第二、三场降雨过程中,3种红壤糙度都有不同程度的少量提高,结皮倾向于降低糙度,细沟倾向于提高糙度,地表糙度的变化取决于两者之间的平衡。糙度下降幅度表现为坡上部>坡中部>坡下部、团聚体水稳性低的土壤>团聚体水稳性高的土壤;(2)洼地蓄积量在连续降雨过程中总体呈下降趋势。在1mm/min雨强下,红壤团聚体和结皮越稳定,洼地蓄积量下降幅度越小。在2mm/min雨强下,雨强是影响洼地蓄积量变化的主导因素,不同红壤的差异不明显;(3)洼地蓄积量与地表糙度之间呈线性关系,所有处理的R2均达到了0.9以上。1mm/min雨强下洼地蓄积量对地表糙度的敏感性比2mm/min雨强大。对南方红壤区坡耕地坡面水蚀过程地表微地貌研究、红壤区坡耕地水土流失防治与水土保持规划设计具有一定的借鉴意义。

关键词：水土保持微地貌激光扫描糙度红壤

Joint alignment and steering to manage interference

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Digital Communications and Networks 2024年第2期10卷 429-438页

作者： Zhao Li Xiujuan Liang Yinghou liu Jia liu Zheng Yan School of Cyber Engineering Xidian UniversityXi'an710126China Technol.on Commun.Net.Lab. The 54th Research Inst.of China Elec.Technol.Group Corp.Shijiazhuang050081China School of Computer Science and Technology Xidian UniversityXi'an710126China The Department of Communications and Networking(Comnet) Aalto University02150EspooFinland

In wireless communication networks,mobile users in overlapping areas may experience severe interference,therefore,designing effective Interference Management(IM)methods is crucial to improving network ***,when managing multiple disturbances from the same source,it may not be feasible to use existing IM methods such as Interference Alignment(IA)and Interference Steering(IS)*** is because with IA,the aligned interference becomes indistinguishable at its desired Receiver(Rx)under the cost constraint of Degrees-of-Freedom(DoF),while with IS,more transmit power will be consumed in the direct and repeated application of IS to each *** remedy these deficiencies,Interference Alignment Steering(IAS)is proposed by incorporating IA and IS and exploiting their advantages in *** IAS,the interfering Transmitter(Tx)first aligns one interference incurred by the transmission of one data stream to a one-dimensional subspace orthogonal to the desired transmission at the interfered Rx,and then the remaining interferences are treated as a whole and steered to the same subspace as the aligned ***,two improved versions of IAS,i.e.,IAS with Full Adjustment at the Interfering Tx(IAS-FAIT)and Interference Steering and Alignment(ISA),are *** former considers the influence of IA on the interfering user-pair's *** orthogonality between the desired signals at the interfered Rx can be maintained by adjusting the spatial characteristics of all interferences and the aligned interference components,thus ensuring the Spectral Efficiency(SE)of the interfering communication *** ISA,the power cost for IS at the interfered Tx is minimized,hence improving SE performance of the interfered *** the proposed methods are realized at the interfering and interfered Txs cooperatively,the expenses of IM are shared by both *** in-depth simulation results show that joint use of IA and

关键词： Interference Interference management Interference alignment Interference steering Spectral efficiency

Contact engineering for temperature stability improvement of Bi-contacted MoS2 field effect transistors

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Science China(Information Sciences) 2024年第6期67卷 172-179页

作者： Zizheng liu Qing ZHANG Xiaohe HUANG Chunsen liu Peng ZHOU State Key Laboratory of Integrated Chip and Systems School of MicroelectronicsZhangjiang Fudan International Innovation CenterFudan University Frontier Institute of Chip and System Shanghai Key Lab for Future Computing Hardware and SystemFudan University Shaoxin Laboratory

Semimetallic bismuth（Bi） is one of the most effective strategies for reducing the contact resistance of two-dimensional transition metal dichalcogenide field effect transistors（FETs）. However, the low melting point of Bi contact（271.5℃） limits its reliable applications. In this study, we demonstrated that the temperature stability of Bi-contacted electrodes could be improved by inserting a high-melting point semimetallic antimony（Sb） between the Bi contacting layer and the gold（Au） capping layer. The proposed Bi/Sb/Au contact electrodes tended to form a metal mixture with a continuous surface during the heating process（Voids appeared on the surface of the Bi/Au contact electrodes after heating at 120℃）. Because of the improved contacting layer formed by the semimetal Bi/Sb alloy, the fabricated Bi/Sb/Au-contacted molybdenum sulfide（MoS2） FETs with different gate lengths demonstrated higher on-state current stability after heating treatment than the Bi/Au contact. Because of the Bi/Sb/Au contact and poly（methyl methacrylate） package, the MoS2FETs demonstrated time stability of at least two months from the almost unchanged transfer characteristics. The electrical stability indicates that the insertion of semimetallic Sb is a promising technology for reliable Bi-based contact.

关键词： temperature stability semimetallic bismuth contact semimetallic antimony contact MoS$_{2}$ FETs time stability