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A universal multifunctional dual cation doping strategy towards stabilized ultra-high nickel cobalt-free lithium layered oxide cathode

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Journal of Energy Chemistry 2024年第8期95卷 296-305,I0007页

作者： Yabin Shen Dongming Yin Limin Wang Gang Huang Yong Cheng henan institute of Advanced Technology Zhengzhou UniversityZhengzhou 450002HenanChina State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022JilinChina

Ultra-high nickel cobalt-free lithium layered oxides are promising cathode material for lithium-ion batteries(LIBs)because of their relatively high capacity and low ***,the high nickel content would induce bulk structure degradation and interfacial environment deterioration,and the absence of Co element reduces the lithium diffusion kinetics,severely limiting the performance liberation of this kind of ***,a multifunctional Ti/Zr dual cation co-doping strategy has been employed to improve the lithium storage performance of LiNi_(0.9)Mn_(0.1)O_(2)(NM91)*** the one hand,the Ti/Zr co-doping weakens the Li^(+)/Ni^(2+)mixing through magnetic interactions due to the inexistence of unpaired electrons for Ti^(4+)and Zr^(4+),increasing the lithium diffusion rate and suppressing the harmful coexistence of H1 and H2 *** the other hand,they enhance the lattice oxygen stability because of the strong Ti-O and Zr-O bonds,inhibiting the undesired H3 phase transition and lattice oxygen loss,improving the bulk structure and cathode-electrolyte interface *** a result,the Ti/Zr co-doped NM91(NMTZ)exhibits a 91.2%capacity retention rate after 100 cycles,while that of NM91 is only82.9%.Also,the NMTZ displays better rate performance than NM91 with output capacities of 115 and93 mA h g^(-1)at a high current density of 5 C,***,the designed NMTZ could enable the full battery to deliver an energy density up to 263 W h kg^(-1),making the ultra-high nickel cobaltfree lithium layered oxide cathode closer to practical applications.

关键词： Lithium-ion battery Ultra-high nickel cobalt-free cathode Ti/Zr co-doping Li^(+)/Ni^(2+)mixing Lattice oxygen stability

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A Hybrid Feature Fusion Traffic Sign Detection Algorithm Based on YOLOv7

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Computers, Materials & Continua 2024年第7期80卷 1425-1440页

作者： Bingyi Ren Juwei Zhang Tong Wang School of Mechanical Engineering Henan University of Science and TechnologyLuoyang471000China School of Information Engineering Henan University of Science and TechnologyLuoyang471000China School of Electronic Information Zhengzhou Institute of Aeronautical Industry ManagementZhengzhou450046China henan province New Energy Vehicle Power Electronics and Power Transmission Engineering Research Center Luoyang471000China

Autonomous driving technology has entered a period of rapid development,and traffic sign detection is one of the important *** target detection networks are difficult to adapt to scenarios where target sizes are seriously imbalanced,and traffic sign targets are small and have unclear features,which makes detection more ***,we propose aHybrid Feature Fusion Traffic Sign detection algorithmbased onYOLOv7(HFFTYOLO).First,a self-attention mechanism is incorporated at the end of the backbone network to calculate feature interactions within scales;Secondly,the cross-scale fusion part of the neck introduces a bottom-up multi-path fusion *** reuse paths at the end of the neck,paying particular attention to cross-scale fusion of highlevel *** addition,we found the appropriate channel width through a lot of experiments and reduced the superfluous *** terms of training,a newregression lossCMPDIoUis proposed,which not only considers the problem of loss degradation when the aspect ratio is the same but the width and height are different,but also enables the penalty term to dynamically change at different ***,our proposed improved method shows excellent results on the TT100K *** with the baseline model,without increasing the number of parameters and computational complexity,AP0.5 and AP increased by 2.2%and 2.7%,respectively,reaching 92.9%and 58.1%.

关键词： Small target detection YOLOv7 traffic sign detection regression loss

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Energy Efficiency Maximization in Mobile Edge Computing Networks via IRS assisted UAV Communications

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1865-1884页

作者： Ying Zhang Weiming Niu Supu Xiu Guangchen Mu School of Electronic Information Engineering Henan Institute of TechnologyXinxiang453003China Houde College Henan Institute of TechnologyXinxiang453003China Department of Science Henan Institute of TechnologyXinxiang453003China

In this paper,we investigate the energy efficiency maximization for mobile edge computing(MEC)in intelligent reflecting surface(IRS)assisted unmanned aerial vehicle(UAV)*** particular,UAVcan collect the computing tasks of the terrestrial users and transmit the results back to them after *** jointly optimize the users’transmitted beamforming and uploading ratios,the phase shift matrix of IRS,and the UAV trajectory to improve the energy *** formulated optimization problem is highly non-convex and difficult to be solved ***,we decompose the original problem into three *** first propose the successive convex approximation(SCA)based method to design the beamforming of the users and the phase shift matrix of IRS,and apply the Lagrange dual method to obtain a closed-form expression of the uploading *** the trajectory optimization,we propose a block coordinate descent(BCD)based method to obtain a local optimal ***,we propose the alternating optimization(AO)based overall algorithmand analyzed its complexity to be equivalent or lower than existing *** results show the superiority of the proposedmethod compared with existing schemes in energy efficiency.

关键词： Mobile edge computing(MEC) unmanned aerial vehicle(UAV) intelligent reflecting surface(IRS) energy efficiency

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Tuning microstructures of TC4 ELI to improve explosion resistance

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Defence Technology（防务技术） 2024年第3期33卷 78-99页

作者： Changle Zhang Yangwei Wang Lin Wang Zixuan Ning Guoju Li Dongping Chen Zhi-Wei Yan Yuchen Song Xucai Wang School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing 100081China State Key Laboratory of Explosive Science and Technology Beijing Institute of TechnologyBeijing 100081China Aerospace Information Research institute Chinese Academy of SciencesBeijing 100094China School of Aeronautical Engineering Zhengzhou University of AeronauticsHenan ProvinceZhengzhou 450046China Shanxi Jiangyang Chemical Co. Ltd.Shanxi ProvinceTaiyuan 030041China Shandong institute of Non-metallic Materials Shandong ProvinceJinan 250031China

A reasonable heat treatment process for TC4 ELI titanium alloy is crucial to tune microstructures to improve its explosion ***,there is limited investigation on tuning microstructures of TC4 ELI to improve explosion ***,the current challenge is quantifying microstructural changes'effects on explosion resistance and incorporating microstructural changes into finite element *** work aims to tune microstructures to improve explosion resistance and elucidate their anti-explosion mechanism,and find a suitable method to incorporate microstructural changes into finite element *** this work,we systematically study the deformation and failure characteristics of TC4 ELI plates with varying microstructures using an air explosion test and LS-DYNA finite element *** Johnson-Cook(JC)constitutive parameters are used to quantify the effects of microstructural changes on explosion resistance and incorporate microstructural changes into finite element *** of the heat treatment,one plate has equiaxed microstructure and the other has bimodal *** convex of the plate after the explosion has a quadratic relationship with the charge mass,and the simulation results demonstrate high reliability,with the error less than 17.5%.Therefore,it is feasible to obtain corresponding JC constitutive parameters based on the differences in microstructures and mechanical properties and characterize the effects of microstructural changes on explosion *** bimodal target exhibits excellent deformation *** response of bimodal microstructure to the shock wave may be more intense under explosive *** well-coordinated structure of the bimodal target enhances its resistance to deformation.

关键词： Microstructure Finite element modelling Parameter optimization Failure characteristics Explosion resistance

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Mechanism of slag pellets sticking on the wall of reduction pot in magnesium production by Pidgeon process

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Journal of Magnesium and Alloys 2024年第6期12卷 2397-2412页

作者： Jilei Xu Jinhui Liu Dong Guo Mao Chen Peixu Yang Rongbin Li Shaojun Zhang School of Materials Science and Engineering Zhengzhou UniversityZhengzhou 450001China henan province Industrial Technology Research institute of Resources and Materials Zhengzhou UniversityZhengzhou 450001China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In the preparation of magnesium by Pidgeon process,the phenomenon slag pellets sticking on the wall of reduction pot always appear,and the glaze sticking on the inner wall of the reduction pot is difficult to *** mechanism of this phenomenon is studied in this work by X-ray fluorescence spectrometer(XRF)measurement,electron probe microanalyzer scanning(EPMA)analysis,differential scanning calorimetry(DSC)analysis,and thermodynamic *** main components of the glaze are MgO,Ca_(12)Al_(14)F_(2)O_(32),CaF_(2),CaO,and a small amount of Ca_(4)Si_(2)O_(7)F_(2).The solid-liquid transition temperature of Ca_(12)Al_(14)F_(2)O_(32)and CaF_(2)is close to the production temperature of Pidgeon process,which leads to the bonding between the slag pellets and the pot *** loss of CaF_(2)in glaze layer will reduce the total amount of liquid phase and increase the temperature at which Ca_(12)Al_(14)F_(2)O_(32)is completely transformed into liquid phase,which causes glaze layer sticking on the inner wall of the reduction pot.

关键词： Pidgeon process Glaze Ca_(12)Al_(14)F_(2)O_(32) CaF_(2) Solid-liquid transition

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Research on the Assessment System of Computational Mechanics Courses Based on the TOPSIS Entropy Weight Model

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Journal of Contemporary Educational Research 2024年第6期8卷 166-182页

作者： Huijun Ning Ruhuan Yu Qianshu Wang Mingming Lin institute of Science and Technology Development Henan University of Science and TechnologyLuoyang 471000Henan ProvinceChina School of Civil Engineering and Architecture Henan University of Science and TechnologyLuoyang 471000Henan ProvinceChina International Education College Henan University of Science and TechnologyLuoyang 471000Henan ProvinceChina

This paper takes the assessment and evaluation of computational mechanics course as the background,and constructs a diversified course evaluation system that is student-centered and integrates both quantitative and qualitative evaluation *** system not only pays attention to students’practical operation and theoretical knowledge mastery but also puts special emphasis on the cultivation of students’innovative *** order to realize a comprehensive and objective evaluation,the assessment and evaluation method of the entropy weight model combining TOPSIS(Technique for Order Preference by Similarity to Ideal Solution)multi-attribute decision analysis and entropy weight theory is adopted,and its validity and practicability are verified through example *** method can not only comprehensively and objectively evaluate students’learning outcomes,but also provide a scientific decision-making basis for curriculum teaching *** implementation of this diversified course evaluation system can better reflect the comprehensive ability of students and promote the continuous improvement of teaching quality.

关键词： TOPSIS entropy weight model Computational mechanics Course assessment and evaluation system Assessment model

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Impact of stage-specific limb function exercises guided by a selfmanagement education model on arteriovenous fistula maturation status

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World Journal of Clinical Cases 2024年第14期12卷 2316-2323页

作者： Yi Li Li-Jun Huang Jian-Wen Hou Dan-Dan Hu Department of Nursing The People's Hospital of Jianyang CityJianyang 641400Sichuan ProvinceChina Department of Nephrology The People's Hospital of Jianyang CityJianyang 641400Sichuan ProvinceChina Department of Head and Neck Surgery Zhejiang Cancer HospitalHangzhou 310000Zhejiang ProvinceChina School of Nursing Shangqiu Institute of TechnologyShangqiu 476005Henan ProvinceChina

BACKGROUND The exercise of limb function is the most economical and safe method to promote the maturation of arteriovenous fistula(AVF).However,due to the lack of a uni-fied exercise standard in China,many patients have insufficient awareness of the importance of AVF,leading to poor effectiveness of limb function *** self-management education model can effectively promote patients to take pro-active health-related *** study focuses on the characteristics of patients during the peri-AVF period and conducts a phased limb function exercise under the guidance of the self-management education model to observe changes in fac-tors such as the maturity of *** To assess the impact of stage-specific limb function exercises,directed by a self-management education model,on the maturation status of *** This study is a randomized controlled trial involving 74 patients with forearm AVFs from the Nephrology Department of a tertiary hospital in Sichuan province,*** were randomly divided into an observation group and a control group using a random number table *** observation group underwent tailored stage-specific limb func-tion exercises,informed by a self-management education model which took into account the unique features of AVF at various stages,in conjunction with routine ***,the control group was given standard limb function exercises along with routine *** assessment involves the maturity of AVFs post-intervention,post-operative complications,and the self-management level of the fistula in both groups *** were conducted using SPSS version *** data were represented by frequency and percentage and subjected to chi-square test *** data adhering to a normal distribution were presented as mean±*** independent samples t-test was utilized for inter-group comparisons,while the paired t-test was used for intra-group *** measurement data not fitting a normal distr

关键词： Self-management Education model Stage-specific Limb function exercises Arteriovenous fistula Maturation status

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Characteristics and source apportionment of ambient volatile organic compounds and ozone generation sensitivity in urban Jiaozuo,China

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Journal of Environmental Sciences 2024年第4期138卷 607-625页

作者： Pengzhao Li Chun Chen Dan Liu Jie Lian Wei Li Chuanyi Fan Liangyu Yan Yue Gao Miao Wang Hang Liu Xiaole Pan Jing Mao State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials School of Materials Science and EngineeringZhengzhou UniversityZhengzhou 450001China henan Key Laboratory of Environmental Monitoring Technology Henan Ecological Environment Monitoring and Safety CenterZhengzhou 450046China Jiaozuo Ecological Environment Monitoring Center of henan province Jiaozuo 454003China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

In recent years,many cities have taken measures to reduce volatile organic compounds(VOCs),an important precursor of ozone(O_(3)),to alleviate O_(3) pollution in China.116 VOC species were measured by online and offline methods in the urban area of Jiaozuo from May to October in 2021 to analyze the compositional *** sources were analyzed by a positive matrix factorization(PMF)model,and the sensitivity of ozone generation was determined by ozone isopleth plotting research(OZIPR)*** results showed that the average volume concentration of total VOCs was 30.54 ppbv and showed a bimodal feature due to the rush-hour traffic in the morning and at *** most dominant VOC groups were oxygenated VOCs(OVOCs,29.3%)and alkanes(26.7%),and the most abundant VOC species were acetone and ***,based on the maximum incremental reactivity(MIR)method,the major VOC groups in terms of ozone formation potential(OFP)contribution were OVOCs(68.09μg/m^(3),31.5%),aromatics(62.90μg/m^(3),29.1%)and alkene/alkynes(54.90μg/m^(3),25.4%).This indicates that the control of OVOCs,aromatics and alkene/alkynes should take *** sources of VOCs were quantified by PMF,including fixed sources of fossil fuel combustion(27.8%),industrial processes(25.9%),vehicle exhaust(19.7%),natural and secondary formation(13.9%)and solvent usage(12.7%).The empirical kinetic modeling approach(EKMA)curve obtained by OZIPR on O_(3) exceedance days indicated that the O_(3) sensitivity varied in different *** results provide theoretical support for O_(3) pollution prevention and control in Jiaozuo.

关键词： Volatile organic compounds(VOCs) Online and offline measurement Ozone formation potential(OFP) Positive matrix factorization(PMF) Ozone isopleth plotting research(OZIPR) Jiaozuo

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Tunable magneto-Seebeck effect in Co_(2)FeSi/MgO/Co_(2)FeSi heterostructure via optimized interfacial engineering

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 128-135页

作者： Jingyu Li Xianbiao Shi Yurong Jin Le Ma Liuming Wei Chi Zhang Hang Li Peng-Fei Liu International Joint Research Laboratory of New Energy Materials and Devices of henan province School of Physics and ElectronicsHenan UniversityKaifeng 475004China institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Defence Industry Secrecy Examination and Certification Center Beijing 100089China School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Network Security Henan Police CollegeZhengzhou 450046China College of Electrical Engineering Henan University of TechnologyZhengzhou 450001China

Enhancing the tunneling magneto-Seebeck(TMS) ratio and uncovering its underlying mechanism are greatly demanded in spin *** magnitude and sign of the TMS effect depend on the type of atom and the stacking order of atoms at the ***,we demonstrate that TMS ratios can be effectively manipulated by altering heterogonous or homogeneous interface through decoration on the CoFeSi(001) surface inserted on the MgO insulating *** maximum TMS ratio of pure Co_(2)/O termination is 4565% at 800 ***,the TMS ratio of the FeSi/O termination has two peak values,of which the maximum could reach up to-3290% at 650 *** comparing two different atom arrangements at the interface,we reveal that the sign and symbol of the TMS ratio can be controlled by the temperature and different atomic configurations at the Co_(2)FeSi/MgO ***,the spin-Seebeck coefficient up to ~150 μV/K is also possible when we select suitable terminations and *** findings will provide useful insights into how to control the sign and symbol of the TMS ratio and accordingly stimulate the development field of magneto-thermoelectric power and spin caloritronic devices based on the magneto-Seebeck effect in Heusler-based metallic multilayers.

关键词： magneto-Seebeck effect interface spintronics electronic structure spin-Seebeck effect

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IRS Assisted UAV Communications against Proactive Eavesdropping in Mobile Edge Computing Networks

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工程与科学中的计算机建模(英文) 2024年第1期138卷 885-902页

作者： Ying Zhang Weiming Niu Leibing Yan School of Electronic Information Engineering Henan Institute of TechnologyXinxiang453003China Houde College Henan Institute of TechnologyXinxiang453003China

In this paper,we consider mobile edge computing(MEC)networks against proactive *** maximize the transmission rate,IRS assisted UAV communications are *** take the joint design of the trajectory of UAV,the transmitting beamforming of users,and the phase shift matrix of *** original problem is strong non-convex and difficult to *** first propose two basic modes of the proactive eavesdropper,and obtain the closed-form solution for the boundary conditions of the two *** we transform the original problem into an equivalent one and propose an alternating optimization(AO)based method to obtain a local optimal *** convergence of the algorithm is illustrated by numerical ***,we propose a zero forcing(ZF)based method as sub-optimal solution,and the simulation section shows that the proposed two schemes could obtain better performance compared with traditional schemes.

关键词： Mobile edge computing(MEC) unmanned aerial vehicle(UAV) intelligent reflecting surface(IRS) zero forcing(ZF)

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