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Design,fabrication,and characterization of hierarchical mechanical metamaterials

Frontiers of Mechanical Engineering 2024年第1期19卷 73-83页

作者： Jian SONG junfei YAN Bengang YI Automotive Engineering Research Institute BYD Auto Industry Co.Ltd.Shenzhen 518000China College of Civil and Transportation Engineering Shenzhen UniversityShenzhen 518060China

Natural mechanical materials,such as bamboo and bone,often exhibit superior specific mechanical properties due to their hierarchical porous *** the principle of hierarchy as inspiration can facilitate the development of hierarchical mechanical metamaterials(HMMs)across multiple length scales via 3D *** this work,we propose self-similar HMMs that combine octet-truss(OCT)architecture as the first and second orders,with cubic architecture as the third or more *** HMMs were fabricated using stereolithography 3D printing,with the length sizes ranging from approximately 200µm to the centimeter *** compressive stress–strain behaviors of HMMs exhibit a zigzag characteristic,and the toughness and energy absorption can be significantly enhanced by the hierarchical *** compressive moduli are comparable to that of natural materials,and the strengths are superior to that of most polymer/metal foams,alumina hollow/carbon lattices,and other natural ***,the flexural stress–strain curves exhibit a nonlinear behavior,which can be attributed to the hierarchical architecture and local damage *** relatively high mechanical properties can be attributed to the synergistic effect of the stretch-dominated OCT architecture and the bending-dominated cube ***,an ultralight HMM-integrated unmanned aerial vehicle(HMM-UAV)was successfully designed and *** HMM-UAV is~85%lighter than its bulk counterpart,remarkably extending the flight duration time(~53%).This work not only provides an effective design strategy for HMMs but also further expands the application benchmark of HMMs.

关键词： 3D printing mechanical metamaterials hierarchical architecture mechanical behavior unmanned aerial vehicle(UAV)

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A hybrid attention model based on first-order statistical features for smoke recognition

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Science China(Technological Sciences) 2024年第3期67卷 809-822页

作者： GUO Nan LIU JiaHui DI KeXin GU Ke QIAO junfei Beijing Laboratory of Smart Environmental Protection Beijing Key Laboratory of Computational Intelligence and Intelligent SystemBeijing Artificial Intelligence InstituteBeijing 100124China Faculty of Information Technology Beijing University of TechnologyBeijing 100124China

Smoke and fire recognition are of great importance on foreseeing fire disasters and preventing environmental pollution by monitoring the burning process of objects(e.g., straw, fuels). However, since fire images suffer from problems like the variability of the features, complexity of scenarios, interference from background, changeable weather conditions as well as image quality problems, identifying smoke and fire accurately and promptly from a given image still remains a substantial challenge. Automatically learning the features of smoke images by CNNs has improved the target recognition ability compared to traditional approaches,nonetheless, convolutions and pooling operations in CNNs may cause severe information loss which may lead to *** tackle the above problems, this paper proposed a hybrid attention model based on the characteristics of smoke images. This model adopted multiple optimized attention mechanism in several stages to quickly and precisely capture the important features,achieving state-of-the-art performance on smoke and fire recognition in terms of accuracy and speed. Our proposed module mainly consists of two stages: pooling and attention. In the first stage, we conducted several newly proposed first-order pooling methods. Through traversing the data space in a larger scope, features are better reserved, thus constructing a more intact feature space of smoke and fire in an image. In the second stage, feature maps are aggregated together to perform channel and spatial attention. The channel and spatial dependencies allow us to quickly catch the important features presented in an image. By fully exploring the feature space and prominent salient features, characteristics of smoke and fire are better presented so as to obtain better smoke and fire detection results. Experiments have been conducted on public smoke detection dataset and new proposed fine-grained smoke and fire detection database. Experimental results revealed that the propose

关键词： hybrid attention first-order pooling smoke and fire detection deep convolutional neural networks

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Semantic-aware entity alignment for low resource language knowledge graph

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Frontiers of Computer Science 2024年第4期18卷 97-106页

作者： junfei TANG Ran SONG Yuxin HUANG Shengxiang GAO Zhengtao YU Faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China Yunnan Key Laboratory of Artificial Intelligence Kunming University of Science and TechnologyKunming 650500China

Entity alignment(EA)is an important technique aiming to find the same real entity between two different source knowledge graphs(KGs).Current methods typically learn the embedding of entities for EA from the structure of KGs for *** EA models are designed for rich-resource languages,requiring sufficient resources such as a parallel corpus and pre-trained language ***,low-resource language KGs have received less attention,and current models demonstrate poor performance on those low-resource ***,researchers have fused relation information and attributes for entity representations to enhance the entity alignment performance,but the relation semantics are often *** address these issues,we propose a novel Semantic-aware Graph Neural Network(SGNN)for entity ***,we generate pseudo sentences according to the relation triples and produce representations using pre-trained ***,our approach explores semantic information from the connected relations by a graph neural *** model captures expanded feature information from *** results using three low-resource languages demonstrate that our proposed SGNN approach out performs better than state-of-the-art alignment methods on three proposed datasets and three public datasets.

关键词： graph neural network knowledge graph entity alignment low-resource language

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High-performance formaldehyde prediction for indoor air quality assessment using time series deep learning

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Building Simulation 2024年第3期17卷 415-429页

作者： Liu Lu Xinyu Huang Xiaojun Zhou junfei Guo Xiaohu Yang Jinyue Yan School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’anChina Department of Building Environment and Energy Engineering The Hong Kong Polytechnic UniversityKowloonHong KongChina Future Energy Profile School of BusinessSocietyand EngineeringMälardalen UniversityVästeråsSweden

Indoor air pollution resulting from volatile organic compounds(VOCs),especially formaldehyde,is a significant health concern needed to predict indoor formaldehyde concentration(Cf)in green intelligent building *** study develops a thermal and wet coupling calculation model of porous fabric to account for the migration of formaldehyde molecules in indoor air and cotton,silk,and polyester fabric with heat flux in Harbin,Beijing,Xi’an,Shanghai,Guangzhou,and Kunming,*** time-by-time indoor dry-bulb temperature(T),relative humidity(RH),and Cf,obtained from verified simulations,were collated and used as input data for the long short-term memory(LSTM)of the deep learning model that predicts indoor multivariate time series Cf from the secondary source effects of indoor fabrics(adsorption and release of formaldehyde).The trained LSTM model can be used to predict multivariate time series Cf at other emission times and *** LSTM-based model also predicted Cf with mean absolute percentage error(MAPE),symmetric mean absolute percentage error(SMAPE),mean absolute error(MAE),mean square error(MSE),and root mean square error(RMSE)that fell within 1.%,1.%,0.5,0.5,and 0.8,*** addition,the characteristics of the input dataset,model parameters,the prediction accuracy of different indoor fabrics,and the uncertainty of the data set are *** results show that the prediction accuracy of single data set input is higher than that of temperature and humidity input,and the prediction accuracy of LSTM is better than recurrent neural network(RNN).The method’s feasibility was established,and the study provides theoretical support for guiding indoor air pollution control measures and ensuring human health and safety.

关键词： multivariate time series formaldehyde concentration deep learning heat-humidity coupling mass transfer secondary source effect

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High-dimensional uncertainty quantification of projectile motion in the barrel of a truck-mounted howitzer based on probability density evolution method

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Defence Technology（防务技术） 2024年第2期32卷 209-221页

作者： Mingming Wang Linfang Qian Guangsong Chen Tong Lin junfei Shi Shijie Zhou Nanjing University of Science and Technology Nanjing 210094JiangsuChina Northwest Institute of Mechanical and Electrical Engineering Xianyang 712099ShaanxiChina Nanjing Vocational University of Industry Technology Nanjing 210023JiangsuChina

This paper proposed an efficient research method for high-dimensional uncertainty quantification of projectile motion in the barrel of a truck-mounted ***,the dynamic model of projectile motion is established considering the flexible deformation of the barrel and the interaction between the projectile and the ***,the accuracy of the dynamic model is verified based on the external ballistic projectile attitude test ***,the probability density evolution method(PDEM)is developed to high-dimensional uncertainty quantification of projectile *** engineering example highlights the results of the proposed method are consistent with the results obtained by the Monte Carlo Simulation(MCS).Finally,the influence of parameter uncertainty on the projectile disturbance at muzzle under different working conditions is *** results show that the disturbance of the pitch angular,pitch angular velocity and pitch angular of velocity decreases with the increase of launching angle,and the random parameter ranges of both the projectile and coupling model have similar influence on the disturbance of projectile angular motion at muzzle.

关键词： Truck-mounted howitzer Projectile motion Uncertainty quantification Probability density evolution method

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Plasma characteristics and material erosion mechanism in multi-channel wire electrical discharge machining

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Chinese Journal of Aeronautics 2024年第10期37卷 508-525页

作者： Guokang SU Chuanyun ZHANG junfei LI Xiaolei CHEN Guixian LIU Yongjun ZHANG State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of Advanced Manufacturing Technology of Marine Energy Equipment Guangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Nontraditional Machining Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China School of Mechanical Engineering Xi’an Technological UniversityXi’an 710021China

Multi-channel wire electrical discharge machining(MC-WEDM)is an advanced and high-efficiency machining technology,but its material erosion mechanism remains *** this study,dual-channel wire electrical discharge machining was utilized as a case study to investigate the impact of the plunging current on both the plasma characteristics and material erosion under complex discharge *** analysis was conducted on the charged particles in the plasma,revealing that the plunging current can influence the trajectory of the plasma by modifying the selfmagnetic *** particle tracking method was employed to simulate the motion of electrons,revealing that in MC-WEDM,electrons exhibited a larger and more uniform *** evolution of the plasma within a single-pulse discharge was observed using high-speed photography technology,and the discharge signals collected from different channels were *** was observed that the plasma in MC-WEDM experienced more intense back-and-forth sweeping on the workpiece surface,facilitating the ejection of molten metal from the molten *** oscillating plasma exhibits a larger processing area and a more uniform distribution of energy,resulting in the formation of larger and shallower discharge ***,the influence of the amplitude and time point of the plunging current on the volume and area of the discharge craters was ***,MC-WEDM significantly reduced the occurrence of holes and micro-cracks and exhibited a thinner recast layer in the continuous discharge experiment.

关键词： Multi-channel WEDM Discharge observation Plunging current Plasma characteristics Material erosion Discharge crater

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Hydrophobic tagging-induced degradation of NAMPT in leukemia cells

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Chinese Chemical Letters 2024年第9期35卷 214-218页

作者： Menglu Guo Ying-Qi Song junfei Cheng Guoqiang Dong Xun Sun Chunquan Sheng Department of Natural Medicine School of PharmacyFudan UniversityShanghai 201203China School of Pharmaceutical Sciences Hainan UniversityHaikou 570228China School of Pharmacy Second Military Medical UniversityShanghai 200433China

Nicotinamide phosphoribosyl transferase(NAMPT)is considered as a promising target for cancer therapy to its crucial role in cancer *** the therapeutic potential of NAMPT enzymatic inhibitors,their effectiveness is limited by dose-related toxicity and the inability to suppress nonenzymatic functions of extracellular NAMPT(e NAMPT).Herein,we designed and synthesized the first hydrophobic tagging NAMPT *** them,compound NH-1. selectively degraded NAMPT in leukemia cells through the ubiquitin-proteasome *** NH-1. effectively induced apoptosis and showed low toxicity to normal cells,representing a promising anti-leukemia lead compound.?2024 Published by Elsevier *** behalf of Chinese Chemical Society and Institute of Materia Medica,Chinese Academy of Medical Sciences.

关键词： NAMPT Hydrophobic tagging Leukemia Degradation Anti-cancer

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Postbiotics from Saccharomyces cerevisiae fermentation stabilize microbiota in rumen liquid digesta during grain-based subacute ruminal acidosis(SARA) in lactating dairy cows

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Journal of Animal Science and Biotechnology 2024年第5期15卷 2059-2080页

作者： junfei Guo Zhengxiao Zhang Le Luo Guan Ilkyu Yoon Jan C.Plaizier Ehsan Khafipour Department of Animal Science University of ManitobaWinnipegMB R3T 2N2Canada Present Address:College of Food and Biological Engineering Jimei UniversityXiamenFujian 361021China Department of Agriculture Food and Nutrition DepartmentUniversity of AlbertaEdmontonAB T6G 2R3Canada Faculty of Land and Food Systems University of British ColumbiaVancouverBC V6T 1Z4Canada Diamond V Cedar RapidsIA 52404United States Present Address:Cargill Animal Nutrition 15407 McGinty Road WestWayzataMN 55391USA

Background Subacute ruminal acidosis(SARA)is a common metabolic disorder of high yielding dairy cows,and it is associated with dysbiosis of the rumen and gut microbiome and host *** study evaluated the impact of two postbiotics from Saccharomyces cerevisiae fermentation products(SCFP)on rumen liquid associated microbiota of lactating dairy cows subjected to repeated grain-based SARA challenges.A total of 32 rumen cannulated cows were randomly assigned to 4 treatments from 4 weeks before until 1. weeks after *** groups included a Control diet or diets supplemented with postbiotics(SCFPa,1. g/d Original XPC;SCFPb-1.,1. g/d Nutri Tek;SCFPb-2X,38 g/d Nutri Tek,Diamond V,Cedar Rapids,IA,USA).Grain-based SARA challenges were conducted during week 5(SARA1.and week 8(SARA2)after parturition by replacing 20%DM of the base total mixed ration(TMR)with pellets containing 50%ground barley and 50%ground *** DNA from rumen liquid samples was subjected to V3–V41.S r RNA gene amplicon *** of rumen microbiota were compared among treatments and SARA *** Both SARA challenges reduced the diversity and richness of rumen liquid microbiota,altered the overall composition(β-diversity),and its predicted functionality including carbohydrates and amino acids metabolic *** SARA challenges also reduced the number of significant associations among different taxa,number of hub taxa and their composition in the microbial co-occurrence *** with SCFP postbiotics,in particular SCFPb-2X,enhanced the robustness of the rumen *** SCFP supplemented cows had less fluctuation in relative abundances of community members when exposed to SARA *** SCFP supplementation promoted the populations of lactate utilizing and fibrolytic bacteria,including members of Ruminococcaceae and Lachnospiraceae,and also increased the numbers of hub taxa during non-SARA and SARA *** with S

关键词： Postbiotics Rumen microbiota Saccharomyces cerevisiae fermentation products SARA

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The pathogenesis of chronic subdural hematoma in the perspective of neomembrane formation and related mechanisms

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BIOCELL 2024年第6期48卷 889-896页

作者： MINGYUE HUANG junfei DAI XIANLIANG ZHONG JIN WANG JIANZHONG XU BO DU School of Medicine Southern University of Science and TechnologyShenzhen518055China Department of Emergency Shenzhen People’s HospitalThe Second Clinical Medical College of Jinan UniversityThe First Affiliated Hospital of Southern University of Science and TechnologyShenzhen518055China

Chronic subdural hematoma(CSDH)is a disease characterized by capsuled blood products that progressively occupy the intracranial space,causing intracranial hypertension and compression in the *** frequently occurs in all demographics,especially in the elderly,but the pathogenesis of CSDH remains *** this review,we discuss the origin,development,and current treatment strategies of *** theﬁrst time,we analyzed the cellular and molecular compositions of hematoma membranes with a focus on neomembrane formation,a complex early-stage interactive event in hematoma *** hypothesize that in patients with CSDH,dural border cells(DBCs)might be induced to synthesize collagen or serum proteins might accumulate at the dura and arachnoid layers at the site of injury,thereby encapsulating the *** formation may trigger inﬂammatory responses after subdural hemorrhage,promotingﬁbroblast-involved extracellular matrix(ECM)deposition and aberrant angiogenesis within the outer ***,ECM deposition and angiogenesis mutually inﬂuence each other and are modulated by inﬂammatory *** illustrating the complex and interactive mechanism of neomembrane formation,we aim to provide a novel insight into CSDH pathogenesis and propose directions for future research as well as advancements in treatment strategies for this disease.

关键词： Chronic subduralhematoma Inflammation Angiogenesis Extracellular matrix Hyperfibrinolysis

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Multifunctional cellular carbon foams derived from chitosan toward self-cleaning, thermal insulation, and highly efficient microwave absorption properties

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Nano Research 2024年第3期17卷 927-938页

作者： Beibei Zhan Yanling Hao Xiaosi Qi Yunpeng Qu junfei Ding Jing-liang Yang Xiu Gong Yanli Chen Qiong Peng Wei Zhong College of Physics Guizhou Province Key Laboratory for Photoelectrics Technology and ApplicationGuizhou UniversityGuiyang 550025China Minzu Normal University of Xingyi Xingyi 562400China National Laboratory of Solid State Microstructures and Jiangsu Provincial Laboratory for NanoTechnology Nanjing UniversityNanjing 210093China

To adapt the practical demand,designing and constructing the multifunctional microwave absorbers(MAs)is the key future direction of research and ***,effective integrating the multiple functions into a single material remains a huge ***,cellular carbon foams(CCFs)with different porous structures were elaborately designed and fabricated in high efficiency through a facile continuous freeze-drying and carbonization processes using a sustainable biomass chitosan as the *** obtained results revealed that the thermal treated temperature and g-C_(3)N_(4) amount played a great impact on the carbonization degrees,pore sizes,and morphologies of CCFs,which led to their tunable electromagnetic(EM)parameters,improved conduction loss,and polarization loss *** to the special cellular structure,the designed CCFs samples simultaneously displayed the strong absorption capabilities,broad absorption bandwidths,and thin matching ***,the as-prepared CCFs exhibited the strong hydrophobicity and good thermal insulation,endowing its attractive functions of self-cleaning and thermal ***,our findings not only presented a facile approach to produce different porous structures of CCFs,but also provided an effective strategy to develop multifunctional high-performance MAs on basis of three-dimensional CCFs.

关键词： multifunctional microwave absorbers carbon foams cellular structure self-cleaning thermal insulation

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