检索结果-南通市图书馆

A novel intrusion detection model for the CAN bus packet of in-vehicle network based on attention mechanism and autoencoder

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

Digital Communications and Networks 2023年第1期9卷 14-21页

作者： Pengcheng Wei Bo Wang Xiaojun Dai Li Li Fangcheng He school of Mathematics and Information engineering Chongqing University of EducationChongqingChina school of Automation Chongqing University of Posts and TelecommunicationsChongqingChina Department of modern Service Chongqing Energy Industry Technician CollegeChongqingChina College of Foreign Languages Literature Chongqing University of EducationChongqingChina

The attacks on in-vehicle Controller Area Network(CAN)bus messages severely disrupt normal communication between ***,researches on intrusion detection models for CAN have positive business value for vehicle security,and the intrusion detection technology for CAN bus messages can effectively protect the invehicle network from unlawful *** machine learning-based models are unable to effectively identify intrusive abnormal messages due to their inherent ***,to address the shortcomings of the previous machine learning-based intrusion detection technique,we propose a novel method using Attention Mechanism and AutoEncoder for Intrusion Detection(AMAEID).The AMAEID model first converts the raw hexadecimal message data into binary format to obtain better *** the AMAEID model encodes and decodes the binary message data using a multi-layer denoising autoencoder model to obtain a hidden feature representation that can represent the potential features behind the message data at a deeper ***,the AMAEID model uses the attention mechanism and the fully connected layer network to infer whether the message is an abnormal message or *** experimental results with three evaluation metrics on a real in-vehicle CAN bus message dataset outperform some traditional machine learning algorithms,demonstrating the effectiveness of the AMAEID model.

关键词： Controller area network bus packet In-vehicle network Attention mechanism Autoencoder

A robust and efficient algorithm for Chinese historical document analysis and recognition

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

National science Review 2023年第6期10卷 9-12页

作者： Chongyu Liu Cheng Jian Jiarong Huang Wentao Yang Yongxin Shi Qing Jiang Lianwen Jin school of Electronic and Information engineering South China University of Technology SCUT-Zhuhai Institute of modern Industrial Innovation

PROBLEM Historical documents,which contain valuable information on historical knowledge and literary arts,are important mediums for the inheritance of human ***,the preservation of historical documents is considered to be an urgent research *** efficient way is to develop a document digitization system,which requires accurate historical document recognition and *** the rapid development of optical character recognition techniques,historical document understanding has made great progress [1,2] and several benchmarkshave been established [3-5].

关键词：

Phase-field simulation of lack-of-fusion defect and grain growth during laser powder bed fusion of Inconel 718

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2224-2235页

作者： Miaomiao Chen Renhai Shi Zhuangzhuang Liu Yinghui Li Qiang Du Yuhong Zhao Jianxin Xie Beijing Advanced Innovation Center for Materials Genome engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory for Advanced Materials Processing(MOE) Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for modern Transportation Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China SINTEF industry Oslo 0314Norway school of Materials science and engineering North University of ChinaTaiyuan 030051China

The anisotropy of the structure and properties caused by the strong epitaxial growth of grains during laser powder bed fusion(L-PBF)significantly affects the mechanical performance of Inconel 718 alloy components such as turbine *** defects(lack-of-fusion Lo F)in components processed via L-PBF are detrimental to the strength of the *** purpose of this study is to investigate the effect of laser scanning parameters on the epitaxial grain growth and LoF formation in order to obtain the parameter space in which the microstructure is refined and LoF defect is *** temperature field of the molten pool and the epitaxial grain growth are simulated using a multiscale model combining the finite element method with the phase-field *** LoF model is proposed to predict the formation of LoF defects resulting from insufficient melting during *** mitigation and grain-structure control during L-PBF can be realized simultaneously in the *** simulation shows the input laser energy density for the as-deposited structure with fine grains and without LoF defects varied from 55.0–62.5 J·mm^(-3)when the interlayer rotation angle was 0°–90°.The optimized process parameters(laser power of 280 W,scanning speed of 1160 mm·s^(-1),and rotation angle of 67°)were computationally *** these conditions,the average grain size was 7.0μm,and the ultimate tensile strength and yield strength at room temperature were(1111±3)MPa and(820±7)MPa,respectively,which is 8.8%and10.5%higher than those of *** results indicating the proposed multiscale computational approach for predicting grain growth and Lo F defects could allow simultaneous grain-structure control and defect mitigation during L-PBF.

关键词： Inconel 718 alloy laser powder bed fusion scanning parameter optimization lack-of-fusion phase-field method finite element method

Effect of Electrical Current on the Tribological Behavior of the Cu-WS_2-G Composites in Air and Vacuum

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical engineering 2013年第2期26卷 384-392页

作者： QIAN Gang FENG Yi LI Bin HUANG Shiyin LIU Hongjuan DING Kewang school of Materials science and engineering Hefei University of Technology

As the traditional graphite-based composites cannot meet the requirement of rapid developing modern industry, novel sliding electrical contact materials with high self-lubricating performance in multiple environments are eagerly required. Herein a copper-based composite with WS2 and graphite as solid lubricant are fabricated by powder metallurgy hot-pressed method. The friction and wear behaviors of the composites with and without current are investigated under the condition with sliding velocity of 10 m/s and normal load of 2.5N/cm 2 in both air and vacuum. Morphologies of the worn surfaces are observed by optical microscope and compositions of the lubricating films are analyzed by XPS. Surface profile curves and roughness of the worn surfaces are obtained by 2205 surface profiler. The results of wear tests show that the friction coefficient and wear volume loss of the composites with current are greater than that without current in both air and vacuum due to the adverse effects of electrical current which damaged the lubricating film partially and roughed the worn surfaces. XPS results demonstrate that the lubricating film formed in air is composed of oxides of Cu, WS2 , elemental S and graphite, while the lubricating film formed in vacuum is composed of Cu, WS2 and graphite. Because of the synergetic lubricating action of oxides of Cu, WS2 and graphite, the composites show low friction coefficient and wear volume loss in air condition. Owing to the fact that graphite loses its lubricity which makes WS2 become the only lubricant, severe adhesive and abrasive wear occur and result in a high value of wear rate in vacuum condition. The formation of the lubricating film on the contact interface between the brush and ring is one of the factors which can greatly affect the wear performance of the brushes. The low contact voltage drop of the composites in vacuum condition is attributed to the high content of Cu in the surface film. This study fabricated a kind of new sli

关键词： Cu-WS2-G composites electrical current air and vacuum environments friction and wear contact voltage drop

Fluid characteristic of multiphase fluid in annular space between pump barrel and plunger

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2019年第5期26卷 1327-1341页

作者： XING Ming-ming ZHOU Li-li ZHAO Yan XUE Kai-feng ZHANG Cheng-mao school of Mechanical & Vehicle engineering Linyi UniversityLinyi 276000China Municipal modern Agriculture UAV engineering and Technological Research Centers Linyi 276000China school of Chemistry & Chemical engineering Linyi UniversityLinyi 276000China

The pump performance parameters,such as pump pressure,plunger friction and pump valve resistance,are fundamental parameters of optimal design of pump efficiency and sucker rod pumping system (SRPS).In this paper,considering the characteristic of geometrical nonlinear and rheology property of multiphase fluid,the pump performance parameters are ***,a dynamics model of annular fluid flow is *** the detail,a partial differential equation of annular fluid is established and a computing model of fluid pressure gradient is ***,the simulation models of plunger friction and hydraulic resistance of pump valve are ***,a novel simulation method of fluid pressure in annular space is proposed with software *** order to check up the correction of models proposed in this paper,the comparison curves of experiment and simulation results are *** on above model,the whole simulation model of plunger pump is simulated with Visual Basic *** results show that the fluid friction of pump plunger and instantaneous resistance of pump valve are *** impact factors of pump performance parameters are analyzed,and their characteristic curves are given,which can help to optimize the pump motion parameters and pump structural.

关键词： sucker rod pumping system (SRPS) pump pump plunger pump barrel performance parameter

Glutamine metabolism in Th17/Treg cell fate:applications in Th17 cell-associated diseases

在线全文

学校读者我要写书评

暂无评论

science China(Life sciences) 2021年第2期64卷 221-233页

作者： Guan Yang Yaoyao Xia Wenkai Ren Guangdong Laboratory of Lingnan modern Agriculture Guangdong Provincial Key Laboratory of Animal Nutrition ControlNational Engineering Research Center for Breeding Swine IndustryCollege of Animal ScienceSouth China Agricultural UniversityGuangzhou 510642China Department of Pathology Microbiology and ImmunologyVanderbilt University School of MedicineNashvilleTN 37232USA

Alteration in the Th17/Treg cell balance is implicated in various autoimmune diseases and these disease-associated *** investigations have shown that glutamine metabolism regulates the differentiation of Th17 and Treg *** we summarize the mechanisms by which glutamine metabolism regulates Th17/Treg cell *** examples of a glutamine metabolism-dependent modulation of the development and progression of several Th17/Treg cell-associated diseases are provided *** review will provide a comprehensive understanding of the importance of glutamine metabolism in the fate of Th17/Treg cell differentiation.

关键词： glutamine Th17 cells Treg cells mTOR UDP-GlcNAc

Top-level modeling theory of multi-discipline virtual prototype

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2012年第3期23卷 425-437页

作者： Tingyu Lin Xudong Chai Bohu Li school of Automatic science and Electrical engineering Beihang University Beijing 100191 P. R. China Beijing Simulation Center Second Academy of China Aerospace Science ＆ Industry Corporation Beijing 100854 P. R. China

Multi-disciplinary virtual prototypes of complex products are increasingly and widely used in modern advanced manufactur- ing. How to effectively address the problems of unified modeling, composition and reuse based on the multi-disciplinary heteroge- neous models has brought great challenges to the modeling and simulation （M＆S） science and technology. This paper presents a top-level modeling theory based on the meta modeling framework （M2F） of the COllaborative SIMulation （COSlM） theory of virtual prototyping to solve the problems. Firstly the fundamental prin- ciples of the top-level modeling theory are decribed to expound the premise, assumptions, basic conventions and special require- ments in the description of complex heterogeneous systems. Next the formalized definitions for each factor in top level modeling are proposed and the hierarchical nature of them is illustrated. After demonstrating that they are self-closing, this paper divides the top- level modeling into two views, static structural graph and dynamic behavioral graph. Finally, a case study is discussed to demon- strate the feasibility of the theory.

关键词： top-level modeling virtual prototype complex product multi-discipline modeling and simulation.

Efficient electrooxidation of biomass-derived aldehydes over ultrathin Ni V-layered double hydroxides films

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第3期78卷 412-421,I0012页

作者： Biying Liu Zhikeng Zheng Yaoyu Liu Man Zhang Yuchen Wang Yangyang Wan Kai Yan Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology School of Environmental Science and EngineeringSun Yat-sen UniversityGuangzhou 510275GuangdongChina Guangdong Laboratory for Lingnan modern Agriculture South China Agricultural UniversityGuangzhou 510642GuangdongChina Institute for Advanced Materials School of Materials Science and EngineeringJiangsu UniversityZhenjiang 212013JiangsuChina

Selective upgrading of C=O bonds to afford carboxylic acid is significant for the petrochemical industry and biomass *** we declared the efficient electrooxidation of biomass-derived aldehydes family over NiV-layered double hydroxides(LDHs) thin *** studies confirmed the hydroxyl active intermediate(-OH*) generated on the surface of NiV-LDHs films by employing electrochemical impedance spectroscopy and the electron paramagnetic resonance *** using advanced techniques,e.g.,extended X-ray absorption fine structure and high-angle annular dark-field scanning transmission electron microscopy,NiV-LDHs films with 2.6 nm could expose larger specific surface *** benzaldehyde as a model,high current density of 200 mA cm^(-2)at 1.8 V ***,81.1% conversion,77.6% yield of benzoic acid and 90.8% Faradaic efficiency were reached,which was superior to most of previous *** DFT analysis was well matched with experimental findings and documented that NiV-LDHs had high adsorption capacity for the aldehydes to suppress the side reaction,and the aldehydes were oxidized by the electrophilic hydroxyl radicals formed on *** findings offer a universal strategy for the robust upgrading of diverse biomass-derived platform chemicals.

关键词： NiV-LDHs Films Hydroxyl radicals Electrocatalytic oxidation Biomass-derived aldehydes

A novel vanadium complex VO(p-dmada)inhibits neuroinflammation induced by lipopolysaccharide

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第10期34卷 209-214页

作者： Zhijun He Xiaoqian Li Huajie Zhang Xin Liu Shuangxue Han Anwar Abdurahman Liming Shen Xiubo Du Nan Li Xiaoda Yang Qiong Liu Shenzhen Key Laboratory of Marine Biotechnology and Ecology College of Life Sciences and OceanographyShenzhen UniversityShenzhen 518055China National R&D Center for Se-rich Agricultural Products Processing Hubei Engineering Research Center for Deep Processing of Green Se-rich Agricultural ProductsSchool of Modern Industry for Selenium Science and EngineeringWuhan Polytechnic UniversityWuhan 430023China Shenzhen Bay Laboratory Shenzhen 518055China State Key Laboratories of Natural and Biomimetic Drugs Department of Chemical BiologySchool of Pharmaceutical SciencesPeking University Health Science CenterBeijing 100191China Department of Pharmacy Shenzhen People’s Hospital(The Second Clinical Medical CollegeJinan UniversityThe First Affiliated HospitalSouthern University of Science and Technology)Shenzhen 518020China Shenzhen-Hong Kong Institute of Brain science-Shenzhen Fundamental Research Institutions Shenzhen 518055China

Uncontrolled microglial activation is decisively involved in the neuroinflammatory pathogenesis of brain diseases. Consequently, suppression of microglial overactivation appears to be a strategy for the prevention of nerve injury. In this paper, a novel vanadium complex, vanadyl N-(p-N,Ndimethylaminophenylcarbamoylmethyl)iminodiacetate(VO(p-dmada)), was synthesized from vanadyl sulfate and N,N-dimethyl-p-phenylenediamine, which was structurally characterized by Fourier transform infrared spectrum and ESI-MS analysis. The effect of VO(p-dmada) on neuroinflammation was investigated by using the models of lipopolysaccharide(LPS)-induced BV2 microglial cells and BALB/c *** data demonstrated that VO(p-dmada) significantly suppressed microglial activation by downregulating inflammatory mediators and associated proteins, and inactivating nuclear factor-κ B(NF-κ B) signaling pathway. VO(p-dmada) also upregulated peroxisome proliferator activated receptor gamma(PPARγ) by reducing transglutaminase 2 and heat shock protein 60 expression. Co-treatment with PPARγ antagonist GW9662 significantly impeded the inhibitory effect of VO(p-dmada) on LPS-induced *** cumulative findings demonstrated that VO(p-dmada) is a potential new drug for the treatment of neuroinflammation-related neurodegenerative diseases.

关键词： Vanadium Vanadyl N-(p-N,Ndimethylaminophenylcarbamoylmethyl)iminodiacetate (VO(p-dmada)) Neuroinflammation Microglia Proteomics Peroxisome proliferator activated receptor gamma(PPARγ)