检索结果-南通市图书馆

Accuracy evaluation for in-situ ma.hining reference points binocular measurement based on credibility probability

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 472-486页

作者： Binchao YU Wei LIU Yanze ZHAnG Dazhi ma.Zhenyuan JIA Yi YUE Jiabo ZHAnG Key Laboratory for Precision and non-Traditional ma.hining Technology of the Ministry of Education Dalian University of TechnologyDalian 116024China Beijing spacecrafts China Academy of Space TechnologyBeijing 100081China

Passive binocular measurement systems are being increasingly utilized in the in-situ industries of automobiles,aviation,and aerospace,*** to their excellent qualities of accuracy,efficiency,and cost *** the barrier of evaluating the accuracy of measured objects resulted from the unequal equivalent focal length and quantization of pixels,has limited their further development and application of high requirements for in-situ ma.hining,e.g.,the measurement of ma.hining reference points for the positioning of robotic drilling in aerospace *** this paper,an accuracy evaluation method is proposed to address the ***,the unequal equivalent focal length is considered to improve the accuracy of 3D ***,the credibility probability model is developed to calculate the probability of the observed error in the public view of the binocular measurement system and indicates the direction of ***,the in-situ experiment is carried out to validate the method within the effective public view range of 300 mm×300 *** experiment results show that the RMss of observed errors are superior to 0.035 mm,and the credibility probabilities are all higher than 0.91;the ma.imum 3D reconstruction accuracy improvement is 60.3%,with the error reduced from 0.078 mm to 0.031 mm.

关键词： Aerospace ma.ufacturing Binocular vision Credibility probability Pixel quantization Unequal equivalent focal length

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

在线全文

学校读者我要写书评

暂无评论

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 Automa.ion Beihang UniversityBeijing 100191China ningbo Institute of Technology Beihang UniversityNingbo 315832China Intelligent Aerospace ma.ufacturing Engineering Technology co. Ltd.Beijing 100191China

The concept of remote center of motion(RCM)is pivotal in a myriad of robotic applications,encompa-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 prima.y classifications:design based and control *** are further organized according to their respective DOFs,providing a concise summa.y of their core *** 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

Investigation into the roles of interfacial H_(2)O structure in catalytic oxidation of HCHO and co over CuMnO_(2) catalysts

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2024年第3期137卷 310-320页

作者： Chunyan ma.Jushuang Pan Cheng Chen Yuanyuan Dong Feng Yao Fengbang Wang ma.yong song Key Laboratory of Environmental nanotechnology and Health Effects Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of sciences Beijing 100049China no.52 Institute of China north Industries Group Yantai Branch co.Ltd. Yantai 264000China

The rapid deactivation of cost-effective MnO_(2)-based catalysts in humid air limits their application in practice,and the identification of the role of water in an oxidation process is significant for developing water-resistant MnO_(2)-based ***,CuMnO_(2)showed a20.3%HCHO conversion in 10 hr at room temperature in humid air with relative humidity of 40%,but deactivated in 3 hr in dry *** excellent activity and stability of HCHO oxidation in humid air were attributed to the positive effect of H_(2)O on HCHO oxidation to the H_(2)O-HOCH_(2)OH supermolecule assemblies via hydrogen bonds formed on CuMnO_(2).H_(2)O-HOCH_(2)OH supermolecule assemblies tend to be oxidized to carbonate,which is further oxidized to co_(2).Furthermore,CuMnO_(2)exhibited a much poorer activity of co oxidation in humid air,but the co conversion was still 100%in 10 hr in dry air.H_(2)O showed a competitive adsorption effect to co on CuMnO_(2).CuMnO_(2)could be applied in HCHO elimination in humid air and co elimination in dry air.

关键词： H_(2)O-HOCH_(2)OH supermolecule HCHO oxidation Humid air CuMnO_(2) co oxidation

sTGnn-LMR:A spatial–Temporal Graph neural network Approach Based on sEMG Lower Limb Motion Recognition

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第1期21卷 256-269页

作者： Weifan ma. Bin ma.Zhao Li Jianxing Zhang Yizhou Lu Zhuting Yu Feng Zhang shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China University of Chinese Academy of sciences Beijing 101408China University of science and Technology of China Hefei 230026China shanghai Zhongyan Jiuyi Technology co. Ltd.Shanghai 201821China Academy of Military science Bejing 100091China

Lower limb motion recognition techniques commonly employ surface Electromyographic signal(sEMG)as input and apply a ma.hine learning classifier or Back Propagation neural network(BPnn)for ***,this artificial feature engineering technique is not generalizable to similar tasks and is heavily reliant on the researcher’s subject *** contrast,neural networks such as convolutional neural network(Cnn)and Long short-term Memory neural network(LsTM)can automa.ically extract features,providing a more generalized and adaptable approach to lower limb motion *** this approach overcomes the limitations of huma. feature engineering,it ma. ignore the potential correlation among the sEMG *** paper proposes a spatial–temporal graph neural network model,sTGnn-LMR,designed to address the problem of recognizing lower limb motion from multi-channel ***-LMR transforms multi-channel sEMG into a graph structure and uses graph learning to model spatial–temporal *** 8-channel sEMG dataset is constructed for the experimental stage,and the results show that the sTGnn-LMR model achieves a recognition accuracy of 99.71%.Moreover,this paper simulates two unexpected scenarios,including sEMG sensors affected by sweat noise and sudden failure,and evaluates the testing results using hypothesis *** to the experimental results,the sTGnn-LMR model exhibits a significant advantage over the control models in noise scenarios and failure *** experimental results confirm the effectiveness of the sTGnn-LMR model for addressing the challenges associated with sEMG-based lower limb motion recognition in practical scenarios.

关键词： Lower limb motion recognition Exoskeleton sEMG.Graph neural network noise sensor failure

sema.tic consistency and correctness Verification of Digital Traffic Rules

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2024年第2期33卷 47-62页

作者： Lei Wan Changjun Wang Daxin Luo Hang Liu sha ma.Weichao Hu Policy Standardand Patent DepartmentIntelligent Automotive Solution BUHuawei Technologies Co.Ltd.Beijing 100094China Research Institute for Road safety of the Ministry of Public security Beijing 100062China

The consensus of the automotive industry and traffic ma.agement authorities is that autonomous vehicles must follow the same traffic laws as huma. *** forma. or digital methods,natural language traffic rules can be translated into ma.hine language and used by autonomous *** this paper,a translation flow is *** the translation,a deeper examination is required,because the sema.tics of natural languages are rich and complex,and frequently contain hidden *** issue of how to ensure that digital rules are accurate and consistent with the original intent of the traffic rules they represent is both significant and *** response,we propose a method of forma. verification that combines equivalence verification with model *** and reassuring digital traffic rules can be obtained by utilizing the proposed traffic rule digitization flow and verification *** addition,we offer a number of simulation applications that employ digital traffic rules to assess vehicle *** experimental findings indicate that our digital rules utilizing metric temporal logic(MTL)can be easily incorporated into simulation platforms and autonomous driving systems(ADs).

关键词： Autonomous driving Traffic rules Digitization Forma.ization Verification

Growth performa.ce,serum parameters,inflamma.ory responses,intestinal morphology and microbiota of weaned piglets fed 18%crude protein diets with different ratios of standardized ileal digestible isoleucine to lysine

在线全文

学校读者我要写书评

暂无评论

Anima. nutrition 2024年第1期16卷 313-325页

作者： Jian Wang sujie Liu Jiayu ma.Xiaoli Dong shenfei Long Xiangshu Piao state Key Laboratory of Anima. nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China Beijing Jingwa Agricultural science and Technology Innovation Center Beijing101206China CJ International Trading co. LtdShanghai 201107China

The present study was to explore the Ile requirement of piglets fed 18%crude protein(CP)*** hundred and fifty 28-day-old Duroc×Landrace×Yorkshire piglets(8.37±1.92 kg)were randomly divided into 5 dietary treatments(10 piglets per replicate,5 barrows and 5 gilts per replicate)with 45%,50%,55%,60%,65%standardized ileal digestible(sID)Ile-to-Lys ratios,and the sID Lys was formulated to1.19%.The experimental design consisted of two phases(d 1 to 14 and d 15 to 28).Results showed that average daily gain(ADG)had a tendency to quadratically increase as the sID Ile-to-Lys ratio increased(P=0.09),and the optimum sID Ile-to-Lys ratios required to ma.imize ADG were 48.33%and 54.63%for broken-line linear model and quadratic polynomial model,*** sID Ile-to-Lys ratios had no significant effects on average daily feed intake and gain-to-feed *** ma.ter(Pss energy(Pnd organic ma.ter(Pstibility increased *** total cholesterol levels decreased linearly(P=0.01)and quadratically(Pspartate aminotransferase(Pnterleukin-1β(P=0.01),and tumor necrosis factor-a(Ps decreased quadratically;immunoglobulin G(P=0.03)and immunoglobulin M(P=0.01)concentrations increased *** ser levels decreased linearly(Pnd quadratically(P=0.01);Glu(P=0.02),Arg(P=0.05),and Thr(P=0.03)levels decreased quadratically;Gly(Pnd Leu(P=0.01)levels decreased linearly;Ile(Pconcentration increased *** villus height(Pnd villus height to crypt depth ratio(Pncreased *** deficiency or excess of Ile decreased short chain fatty acid-producing bacteria abundance and increased pathogenic bacteria ***,taking ADG as the effect index,the optimum sID Ile-to-Lys ratios of piglets offered 18%CP diets were 48.33%and 54.63%based on two different statistical models,respectively,and the deficiency or excess of lle negative

关键词： Weaned piglet Growth performa.ce Intestinal health Isoleucine Reduced crude protein diet

Chatter suppression techniques in milling processes:A state of the art review

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 1-23页

作者： Zhenmin LI Qinghua sOnG Peijian JIn Zhanqiang LIU Bing WAnG Haifeng ma Key Laboratory of High Efficiency and Clean Mechanical ma.ufacture Ministry of EducationSchool of Mechanical EngineeringShandong UniversityJinan 250061China national demonstration Center for Experimental Mechanical Engineering Education Shandong UniversityJinan 250061China

Chatter in the ma.hining system can result in a decrease in tool life,poor surface finish,conservative cutting parameters,*** ma.y review papers promoting the understanding and research of this area,chatter suppression techniques are generally discussed within limited pages in the framework of comprehensive chatter-related *** recent years,the developments of sma.t ma.erials,advanced sensing techniques,and more effective control strategies have led to some new progress in chatter ***,the widely used thin-walled parts present more and more severe ma.hining challenges in their milling *** the above deficiencies,this paper summa.izes the current state of the art in milling chatter *** classifications of chatter suppression techniques are proposed according to the working principle and control *** on the new classified framework,the mechanism and comparisons of different chatter suppression strategies are ***,the current challenges and potential tendencies of milling chatter suppression techniques are ***,integration,compactness,adaptability to workpiece geometry,and the collaboration of multiple control methods are predicted to be important trends in the future.

关键词： Active control Chatter suppression Damping Milling Regenerative effect

Effective peroxydisulfate activation by CQDs-MnFe_(2)O_(4)@ZIF-8 catalyst for complementary degradation of bisphenol A by free radicals and non-radical pathways

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第5期35卷 371-379页

作者： shuo Li Xinran Liu Yongjie Zheng Jun ma.shijie You Heshan Zheng college of Chemistry and Chemical Engineering Qiqihar UniversityQiqihar 161006China state Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

The present study reported fabrication of novel carbon quantum dots-MnFe_(2)O_(4)@ZIF-8(CQDs-MFO@ZIF-8)by using co-precipitation hydrotherma. method for activation of peroxydisulfate(PDs)to degrade bisphenol A(BPA),one of important emerging organic pollutants in water ***-MFO@ZIF-8 served as a highly efficient therma. activated PDs catalyst with high catalytic degradation efficiency,reusability and *** catalyst achieved almost completely removal of 20.0 mg/L BPA within 5.0 min,and the degradation efficiency rema.ned higher than 83%after 5 consecutive *** radicals(^(·)OH,sO_(4)^(·-)and^(·)O_(2)^(-))and non-free radicals((1)O_(2))were generated in the therma. PDs-activation system,in which singlet oxygen((1)O_(2))played a dominant role in the degradation of *** potential toxicity of BPA degradation intermediates was analyzed upon the culture of *** and Chlorella sorokiniana by using Ecological structure-Activity Relationship Model(EcosAR)*** catalytic performa.ces of BPA degradation by CQDs-MFO@ZIF-8 were evaluated for treatment of different practical water samples to further verify the feasibility of practical *** study provides proof-in-concept demonstration of new nanoma.erials for enhanced catalytic water decontamination.

关键词： Bisphenol A degradation Peroxydisulfate ^(1)O_(2) Toxicity analysis

Catalytic Reaction Kinetics of Propylene Dimerization to 4-Methyl-1-Pentene Using Cu-K/K_(2)co_(3) solid Base Catalyst

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 78-87页

作者： Jin Haibo Chai Jing Yang suohe He Guangxiang ma.Lei Guo Xiaoyan college of new ma.erials and Chemical Engineering Beijing Institute of Petrochemical Technology/Beijing Key Laboratory of Fuel Cleaning and Efficient Catalytic Emission Reduction TechnologyBeijing102617China

The catalysis technology of propylene dimerization to form 4-methyl-1-pentene(4MP1)using a Cu-K/K_(2)co_(3) solid base catalyst is a well-known heterogeneous catalytic *** this study,the intrinsic kinetics of propylene dimerization were studied in a fixed-bed continuous *** and external diffusion during the dimerization reaction experiments were eliminated by adjusting the flow rate of the carrier gas and the particle size of the catalyst ***,the concentration changes of each substance at the outlet of the catalyst bed under different residence times were ***,the suitable reaction kinetics equations was derived using the Langmuir Hinshelwood-Hougen-Watson kinetic ***,the activation energy for each reaction involved in the dimerization reaction was *** activation energies of 4MP1,branched by-products,and 1-hexene were 115.0,150.8,and 177.4 kJ/mol,*** effect of process conditions on propylene dimerization with solid base catalysts was studied through kinetic model *** comparing the theoretical values obtained from the simulation with the experimental results,the applicability and accuracy of the kinetic model were verified.

关键词： propylene dimerization 4-methyl-1-pentene intrinsic kinetics surface reaction