检索结果-南通市图书馆

Precise measurement of geometric and physical quantities in cutting tools inspection and condition monitoring: A review

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

Chinese Journal of Aeronautics 2024年第4期37卷 23-53页

作者： Wenqi WANG Wei LIU yang zhang yang LIU Peidong zhang Zhenyuan JIA State Key Laboratory of High-Performance Precision Manufacturing Dalian University of TechnologyDalian 116024China

As one of the most important terminals in machining, cutting tools have been widely used for components manufacturing in aerospace and other industries. The quality of these components and processing efficiency are closely linked to the performance of cutting tools. Therefore, it is essential and critical to inspect the cutting tools and monitor the condition during the stage of manufacturing and machining. This review aims to discuss and summarize the key problems, methods,and techniques from the perspective of the tool geometric and the physical quantities measurement,including machine vision, physical sensors and data processing. It is worth mentioning that we focus on the topic of precision measurement methods and discuss universal solutions by identifying the common characteristics of the measured quantities. Eventually, the challenges and future trends for the development of in-depth research and practical applications are concluded. The research and application of precise measurement techniques for geometric and physical quantities will better promote the development of intelligent manufacturing.

关键词： Cutting tools Mechanical measurement Machine vision Physical sensors Tool condition monitoring

Fixed-Time Sliding Mode Control With Varying Exponent Coefficient for Modular Reconfigurable Flight Arrays

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 514-528页

作者： Jianquan yang Chunxi yang Xiufeng {2. Jing Na Faculty of Mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming 650500 Yunnan International Joint Laboratory of Intelligent Control and Aoolication of Advanced Equipment Kunming 650500China IEEE

The modular system can change its physical structure by self-assembly and self-disassembly between modules to dynamically adapt to task and environmental requirements. Recognizing the adaptive capability of modular systems, we introduce a modular reconfigurable flight array(MRFA) to pursue a multifunction aircraft fitting for diverse tasks and requirements,and investigate the attitude control and the control allocation problem by using the modular reconfigurable flight array as a platform. First, considering the variable and irregular topological configuration of the modular array, a center-of-mass-independent flight array dynamics model is proposed to allow control allocation under over-actuated situations. Secondly, in order to meet the stable, fast and accurate attitude tracking performance of the MRFA, a fixed-time convergent sliding mode controller with state-dependent variable exponent coefficients is proposed to ensure fast convergence rate both away from and near the system equilibrium point without encountering the singularity. It is shown that the controller also has fixed-time convergent characteristics even in the presence of external disturbances. Finally,simulation results are provided to demonstrate the effectiveness of the proposed modeling and control strategies.

关键词： Control allocation dynamic model fixed-time stabilization modular reconfigurable flight array(MRFA) sliding mode

Recent progress on copper catalysts with different surface states for CO_(2.electroreduction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第1期88卷 10-27,I0001页

作者： Wenjun zhang yang yang Donggang Guo Lu Liu Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China Shanxi Laboratory for Yellow River College of Environment and ResourceShanxi UniversityTaiyuan 030006ShanxiChina

The electrochemical carbon dioxide reduction reaction(eCO_(2.RR),which converts CO_(2.into various hydrocarbons or alcohols,has been extensively researched because it promises a sustainable energy ***,only copper(Cu)can currently achieve stable and efficient hydrocarbon conversion in the eCO_(2.***,understanding the catalytic mechanisms and summarizing the research progress on synthesis strategies of Cu catalysts are essential for the eCO_(2.*** paper reviews Cu catalysts with different surface states of Cu catalysts:oxide-derived Cu,Cu nanoparticles,Cu single atoms,and Cu *** then reviews the development and progress of different Cu-catalyst preparation methods in recent years,focusing on the activity and selectivity of *** revealing the tendencies of catalytic selection and deep reactive mechanisms of Cu catalysts with four different surface states,this review can guide the subsequent construction of catalysts and provides an understanding of catalytic mechanisms.

关键词： eCO_(2.RR Oxide-derived Cu Cu nanoparticles Cu single atoms Cu nanoclusters

Prediction of lime utilization ratio of dephosphorization in BOF steelmaking based on online sequential extreme learning machine with forgetting mechanism

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 508-517页

作者： Runhao zhang Jian yang Han Sun Wenkui yang State Key Laboratory of Advanced Special Steel School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The machine learning models of multiple linear regression(MLR),support vector regression(SVR),and extreme learning ma-chine(ELM)and the proposed ELM models of online sequential ELM(OS-ELM)and OS-ELM with forgetting mechanism(FOS-ELM)are applied in the prediction of the lime utilization ratio of dephosphorization in the basic oxygen furnace steelmaking *** ELM model exhibites the best performance compared with the models of MLR and ***-ELM and FOS-ELM are applied for sequential learning and model *** optimal number of samples in validity term of the FOS-ELM model is determined to be 1500,with the smallest population mean absolute relative error(MARE)value of 0.0582.6 for the *** variable importance analysis reveals lime weight,initial P content,and hot metal weight as the most important variables for the lime utilization *** lime utilization ratio increases with the decrease in lime weight and the increases in the initial P content and hot metal weight.A prediction system based on FOS-ELM is applied in actual industrial production for one *** hit ratios of the predicted lime utilization ratio in the error ranges of±1%,±3%,and±5%are 61.16%,90.63%,and 94.11%,*** coefficient of determination,MARE,and root mean square error are 0.8670,0.0682.,and 1.42.5,*** system exhibits desirable performance for applications in actual industrial pro-duction.

关键词： basic oxygen furnace steelmaking machine learning lime utilization ratio dephosphorization online sequential extreme learning machine forgetting mechanism

α-Synuclein pathology from the body to the brain:so many seeds so close to the central soil

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1463-1472页

作者： Yunying yang Zhentao zhang Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina TaiKang Center for Life and Medical Sciences Wuhan UniversityWuhanHubei ProvinceChina

α-Synuclein is a protein that mainly exists in the presynaptic *** folding and accumulation of α-synuclein are found in several neurodegenerative diseases,including Parkinson’s *** and highly phospho rylated a-synuclein constitutes the main component of Lewy bodies in the brain,the pathological hallmark of Parkinson s *** decades,much attention has been focused on the accumulation of α-synuclein in the brain parenchyma rather than considering Parkinson s disease as a systemic *** evidence demonstrates that,at least in some patients,the initial α-synuclein pathology originates in the peripheral organs and spreads to the *** of α-synuclein preformed fibrils into the gastrointestinal tra ct trigge rs the gutto-brain propagation of α-synuclein ***,whether α-synuclein pathology can occur spontaneously in peripheral organs independent of exogenous α-synuclein preformed fibrils or pathological α-synuclein leakage from the central nervous system remains under *** this review,we aimed to summarize the role of peripheral α-synuclein pathology in the pathogenesis of Parkinson’s *** also discuss the pathways by which α-synuclein pathology spreads from the body to the brain.

关键词： aggregation autonomic nervous system barrier receptors body fluid circulation in situ generation Parkinson’s disease phosphorylation propagation synucleinopathies α-synuclein α-synuclein fibrils

A multi-scale second-order autoregressive recursive filter approach for the sea ice concentration analysis

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第3期43卷 115-126页

作者： Lu yang Xuefeng zhang School of Marine Science and Technology Tianjin UniversityTianjin 300072China

To effectively extract multi-scale information from observation data and improve computational efficiency,a multi-scale second-order autoregressive recursive filter(MSRF)method is *** second-order autoregressive filter used in this study has been attempted to replace the traditional first-order recursive filter used in spatial multi-scale recursive filter(SMRF)*** experimental results indicate that the MSRF scheme successfully extracts various scale information resolved by ***,compared with the SMRF scheme,the MSRF scheme improves computational accuracy and efficiency to some *** MSRF scheme can not only propagate to a longer distance without the attenuation of innovation,but also reduce the mean absolute deviation between the reconstructed sea ice concentration results and observations reduced by about 3.2.compared to the SMRF *** the other hand,compared with traditional first-order recursive filters using in the SMRF scheme that multiple filters are executed,the MSRF scheme only needs to perform two filter processes in one iteration,greatly improving filtering *** the two-dimensional experiment of sea ice concentration,the calculation time of the MSRF scheme is only 1/7 of that of SMRF *** means that the MSRF scheme can achieve better performance with less computational cost,which is of great significance for further application in real-time ocean or sea ice data assimilation systems in the future.

关键词： second-order auto-regressive filter multi-scale recursive filter sea ice concentration three-dimensional variational data assimilation

Public transport inclusion and active aging: A systematic review on elderly mobility

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 312-347页

作者： Na zhang Qi yang School of Humanities Chang'an UniversityXi'an 710064China School of Transportation Engineering Chang'an UniversityXi'an 710064China School of Economics and Management Chang'an UniversityXi'an 710064China

Global aging has brought attention to addressing the elderly mobility dilemma,and a commitment to address inclusive transport in *** inclusion for older adults aims at establishing an age-friendly transport *** a direct policy goal and promoting active aging as an indirect social goal,to help older populations gain access to transport and social *** on the analysis of scientific knowledge mapping over the past 30 years,this study visualizes the hotspots and trends in elderly mobility *** a qualitative analysis of 138 papers,this paper reviews the theoretical foundations for transport inclusion and three themes of elderly mobility research,proposes a framework for public transport(PT)inclusion research as well as future research *** study suggests that transport inclusion can help enhance elderly health,social participation,and subjective *** can improve their travel opportunities for active aging in four ways:opportunity accessibility,physical accessibility,age-friendly informationalization,and cost *** research should pay attention to examining the mechanism of perceived transport inclusion on active aging,expanding the multilevel research space of the capability approach(CA),and exploring the subjectiveobjective integrated research model for PT *** research contributes to the overall knowledge of the theoretical and empirical researches on PT inclusion for the elderly and promotes the integrated application of interdisciplinary knowledge in the field.

关键词： Transportation engineering Elderly mobility Transport-related social exclusion Transport inclusion Active aging

The role of innate immunity in diabetic nephropathy and their therapeutic consequences

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2024年第1期14卷 39-51页

作者： Min yang Chun zhang Department of Nephrology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China

Diabetic nephropathy (DN) is an enduring condition that leads to inflammation and affects a substantial number of individuals with diabetes worldwide. A gradual reduction in glomerular filtration and emergence of proteins in the urine are typical aspects of DN, ultimately resulting in renal failure. Mounting evidence suggests that immunological and inflammatory factors are crucial for the development of DN. Therefore, the activation of innate immunity by resident renal and immune cells is critical for initiating and perpetuating inflammation. Toll-like receptors (TLRs) are an important group of receptors that identify patterns and activate immune responses and inflammation. Meanwhile, inflammatory responses in the liver, pancreatic islets, and kidneys involve inflammasomes and chemokines that generate pro-inflammatory cytokines. Moreover, the activation of the complement cascade can be triggered by glycated proteins. This review highlights recent findings elucidating how the innate immune system contributes to tissue fibrosis and organ dysfunction, ultimately leading to renal failure. This review also discusses innovative approaches that can be utilized to modulate the innate immune responses in DN for therapeutic purposes.

关键词： Innate immunity Diabetic nephropathy Inflammation Toll-like receptor Inflammasomes

Rapid report of source parameters of 2.2. M6.2.Jishishan,Gansu earthquake sequence

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

Earth and Planetary Physics 2024年第2期8卷 436-443页

作者： ZhiGao yang Jie Liu YingYing zhang Wen yang XueMei zhang China Earthquake Networks Center Beijing 100045China

The M6.2.earthquake in Jishishan,Gansu Province,on December 18,2.2.,caused extraordinary earthquake *** was located in the northern part of the north−south seismic zone,which is a key area for earthquake monitoring in *** newly built dense strong motion stations in this area provide unprecedented conditions for high-precision earthquake relocation,especially the earthquake focal *** paper uses the newly built strong motion and traditional broadband seismic networks to relocate the source locations of the M3.0 and above aftershocks and to invert their focal *** horizontal error of earthquake location is estimated to be 0.5−1 km,and the vertical error is 1−2.*** focal depth range of aftershocks is 9.6−14.6 km,distributed in a 12.km-long strip with SSE *** in the south are more concentrated horizontally and vertically,while aftershocks in the north are more *** focal mechanisms of the main shock and aftershocks are relatively consistent,and the P-axis orientation is consistent with the regional strain *** is a seismic blank area of M3.0 and above,about 3−5 km between the main shock and *** is suggested that the energy released by the main shock rupture is concentrated in this *** on the earthquake location and focal mechanism of the main shock,it is inferred that the Northern Lajishan fault zone is the seismogenic structure of the main shock,and the main shock did not occur on the main fault,but on a secondary *** initial rupture depth and centroid depth of the main shock were 12.8 and 14.0 km,*** source rupture depth may not be the main reason for the severe earthquake disaster.

关键词： Jishishan earthquake earthquake relocation focal mechanism strong motion data