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Multi-physics multi-scale simulation of unique equiaxed-to-columnar-to-equiaxed transition during the whole solidification process of Al-Li alloy laser welding

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Journal of Materials Science & Technology 2024年第4期171卷 235-251页

作者： Chu han Ping jiang Shaoning Geng liangyuan Ren School of Mechanical Science and Engineering Huazhong University of Science&Technology(HUST)Wuhan430074China

In this study,a novel multi-physics multi-scale model with the dilute multicomponent phase-field method in three-dimensional(3D)space was developed to investigate the complex microstructure evolu-tion in the molten pool during laser welding of Al-Li *** accurately compute mass data within both two and three-dimensional computational domains,three efficient computing methods,including central processing unit parallel computing,adaptive mesh refinement,and moving-frame algorithm,were *** was placed on the distinctive equiaxed-to-columnar-to-equiaxed transition phenomenon that occurs during the entire solidification process of Al-Li alloy laser *** results indi-cated that the growth distance of columnar grains that epitaxially grew from the base metal(BM)de-creased as the nucleation rate *** the nucleation rate increased,the morphology of the newly formed grains near the fusion boundary(FB)changed from columnar to equiaxed,and newly formed equiaxed grains changed from having high-order dendrites to no obvious dendrite *** the nucleation rate was sufficiently high,non-dendritic equiaxed grains could directly form near the FB,and there was nearly no epitaxial growth from the ***,simulation results illustrated the com-petition among multiple grains with varying orientations that grow in 3D space near the ***,how equiaxed grain bands develop was *** equiaxed band not only hindered the growth of early columnar grains but also some of its grains could grow epitaxially to form new columnar *** predicted results were in good agreement with experimental measurements and observations.

关键词： Laser welding Al-Li alloy Equiaxed-to-columnar-to-equiaxed transition Multi-physics multi-scale model Multicomponent alloys 3D phase-field model

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Simultaneously optimizing exciton diffusion length and nonradiative energy loss in organic solar cells via ternary strategy

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Science China Chemistry 2024年第9期67卷 3004-3011页

作者： Huanxiang jiang Hao Lu Zezhou liang Yonghai Li Guangliu Ran Chenyu han Yuqiang Liu Hongxiang Li Xichang Bao Zhishan Bo College of Textiles and Clothing State Key Laboratory of Bio-fibers and Eco-textilesQingdao UniversityQingdao 266071China Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of SciencesQingdao 266101China Key Laboratory for Physical Electronics and Devices of the Ministry of Education&Shaanxi Key Lab of Photonic Technique for InformationSchool of Electronics Science&EngineeringFaculty of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China Department of Physics and Applied Optics Beijing Area Major Laboratory Center for Advanced Quantum StudiesBeijing Normal UniversityBeijing 100875China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Laboratory of Solar Energy Shandong Energy InstituteQingdao 266101China

Significant nonradiative energy loss and short exciton diffusion length in organic solar cells(OSCs)are two major obstacles to achieving state-of-the-art *** is crucial to conduct a study on the intensive mechanism and improvement strategies for future breakthroughs in the efficiency of *** this work,nonradiative energy loss and exciton diffusion length are optimized simultaneously by incorporating a guest acceptor(LA15)to construct ternary OSC(D18:L8-BO:LA15).Firstly,LA15 exhibits excellent compatibility with the host acceptor L8-BO,and effectively improves the fluorescence quantum efficiency(FLQY),resulting in suppressed non-radiative energy ***,LA15 effectively prolongs the fluorescent lifetime of the acceptor phase from 0.85 to 1.12 ns,leading to larger exciton diffusion length,which is beneficial for reducing geminate ***,the addition of LA15 optimizes the crystallinity of the active layer with amplified charge transport *** a result,the optimized D18:L8-BO:LA15 device achieves ultralow nonradiative energy loss of 0.18 e V and improved fill factor(FF)with high efficiency up to 19.13%.These results highlight the crucial roles of regulating FLQYand exciton lifetime in achieving highefficiency OSCs.

关键词： organic solar cells nonradiative energy loss exciton lifetime exciton diffusion length

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A Survey on Event Tracking in Social Media Data Streams

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Big Data Mining and Analytics 2024年第1期7卷 217-243页

作者： Zixuan han Leilei Shi Lu Liu liang jiang Jiawei Fang Fanyuan Lin Jinjuan Zhang John Panneerselvam Nick Antonopoulos School of Computer Science and Communication Engineering and jiangsu Key Laboratory of Security Technology for Industrial Cyberspace Jiangsu UniversityZhenjiang 212013China School of Computing and Mathematical Sciences University of LeicesterLeicesterLE17RHUK Ocean College Jiangsu University of Science and TechnologyZhenjiang 212100China University Executive Office Edinburgh Napier UniversityEdinburghEH114BNUK

Social networks are inevitable parts of our daily life,where an unprecedented amount of complex data corresponding to a diverse range of applications are *** such,it is imperative to conduct research on social events and patterns from the perspectives of conventional sociology to optimize services that originate from social *** tracking in social networks finds various applications,such as network security and societal governance,which involves analyzing data generated by user groups on social networks in real ***,as deep learning techniques continue to advance and make important breakthroughs in various fields,researchers are using this technology to progressively optimize the effectiveness of Event Detection(ED)and tracking *** this regard,this paper presents an in-depth comprehensive review of the concept and methods involved in ED and tracking in social *** introduce mainstream event tracking methods,which involve three primary technical steps:ED,event propagation,and event ***,we introduce benchmark datasets and evaluation metrics for ED and tracking,which allow comparative analysis on the performance of mainstream ***,we present a comprehensive analysis of the main research findings and existing limitations in this field,as well as future research prospects and challenges.

关键词： Event Detection(ED) event propagation event evolution social networks

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Research on Optimal Preload Method of Controllable Rolling Bearing Based on Multisensor Fusion

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3329-3352页

作者： Kuosheng jiang Chengrui han Yasheng Chang School of Mechanical and Electrical Engineering Anhui University of Science and TechnologyHuainan232001China School of Optical and Electronic Information Suzhou City University&Suzhou Key Laboratory of BiophotonicsSuzhou215104China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an710054China

Angular contact ball bearings have been widely used in machine tool spindles,and the bearing preload plays an important role in the performance of the *** order to solve the problems of the traditional optimal preload prediction method limited by actual conditions and uncertainties,a roller bearing preload test method based on the improved D-S evidence theorymulti-sensor fusion method was ***,a novel controllable preload system is proposed and ***,multiple sensors are employed to collect data on the bearing parameters during preload ***,a multisensor fusion algorithm is used to make predictions,and a neural network is used to optimize the fitting of the preload *** limitations of conventional preload testing methods are identified,and the integration of complementary information frommultiple sensors is used to achieve accurate predictions,offering valuable insights into the optimal preload *** results demonstrate that the multi-sensor fusion approach outperforms traditional methods in accurately measuring the optimal preload for rolling bearings.

关键词： Multi-sensor information fusion neural network preload force

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Traditional Chinese Medicine in the treatment of recurrent respiratory tract infections in children: an overview of systematic reviews and Meta-analyses

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Journal of Traditional Chinese Medicine 2024年第5期44卷 871-884页

作者： DENG Yasheng han Siyin XI Lanhua HUANG Hui liang Tianwei ZHENG Yiqing FAN Yanping LIN jiang School of Basic Medical Sciences Guangxi University of Chinese Medicine School of Basic Medical Sciences Guangxi University of Chinese MedicineGuangxi Key Laboratory of Marine Drugs Department of Pharmacy Hainan Traditional Chinese Medicine Hospital

OBJECTIVE: To evaluate and summarise the evidence from published Meta-analyses/systematic reviews(MAs/SRs) of Traditional Chinese Medicine(TCM) in the treatment of recurrent respiratory tract infections(RRTIs) and to provide a scientific basis for the clinical treatment of RRTIs with TCM. METHODS: Studies were retrieved from Chinese and English databases including the China National Knowledge Infrastructure, Wanfang database, China Science and Technology Journal Database, SinoM ed, PubM ed, Web of Science, the Cochrane Library and EMbase from their establishment date to March 2023. Involved studies were screened, extracted, and evaluated for quality by two researchers independently. The a measurement tool to assess systematic reviews(AMSTAR) 2 scale was used for methodological quality evaluation, as well as the preferred reporting items for systematic reviews and Meta-analyses(PRISMA) 2020 statement for report quality evaluation, the risk of bias in systematic reviews(ROBIS) tool for risk of bias, and the grading of recommendations, assessment, development and evaluation(GRADE) quality assessment tool for evidence quality. RESULTS: Twenty MAs/SRs studies were included, including analyses of 274 original studies involving 38 335 patients with RRTIs. The AMSTAR 2 scale evaluation results showed that 19 studies were of very low quality and one of moderate quality. The ROBIS evaluation results showed that 11 MAs/SRs were at high risk and nine at low risk of bias. The PRISMA 2020 report quality showed the included studies had scores between 23.5 and 35.5, among them one with high quality, 17 with moderate quality and two with low quality. The GRADE system results showed that among 126 outcome indicators, only 17 had moderate quality of evidence, 27 had low quality, 82 had very low quality, and none had high quality. CONCLUSIONS: The MAs/SRs methodological quality of using TCM for treatment RRTIs is generally poor, the quality of reports as well as of evidence is generall

关键词： Meta-analysis child medicine, Chinese traditional randomized controlled trial respiratory tract infections systematic review

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Insights into the provenance implication of leaf wax n-alkanes along the lower Yellow River

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Science China Earth Sciences 2024年第6期67卷 2001-2018页

作者： liang ZhanG Jinzhao LIU Chong jiang Fei ZhanG Zhisheng AN School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710054China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China National Observation and Research Station of Earth Critical Zone on the Loess Plateau of Shaanxi Xi’an 710061China

Serving as one of the largest rivers in terms of both sediment and organic carbon transport fluxes in the world,the Yellow River plays a crucial role in regional biogeochemical process as well as in the global carbon ***,although a large number of studies have been carried out on the flux,composition,source and seasonal variation of total particulate organic carbon in the Yellow River so far,studies on molecular biomarkers at different spatial and temporal scales are still *** this study,we focus on the molecular and hydrogen isotopic properties of leaf wax n-alkanes among different types of samples which obtained from different seasons(flood ***-flood)along the lower Yellow *** molecular distribution of n-alkanes show that the riparian topsoils are subject to inputs from the overlying vegetation,while the suspended sediments from the flood season are characterized by the mixing of soil materials which originate from various stratigraphy with different ages on the Chinese Loess *** to the contrasting hydrodynamic conditions,the n-alkanes in suspended sediments also show distinct molecular composition between flood and non-flood ***,considering the effect of climatic factors,the proportion of monocots in flood-season suspended sediments is calculated from a semi-quantitative perspective using δ^(2)H_(wax).Our findings may bring to light new considerations for the interpretation of leaf wax proxies in studies of organic matter sources of Yellow River.

关键词： Molecular distribution Hydrogen isotopic composition Leaf wax n-alkanes Suspended sediments Lower Yellow River

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Response of ocean acidification to atmospheric carbon dioxide removal

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Journal of Environmental Sciences 2024年第6期140卷 79-90页

作者： Jiu jiang Long Cao Xiaoyu Jin Zechen Yu han Zhang Jianjie Fu Guibin jiang School of Environment Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Geoscience Big Data and Deep Resources of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhou 310058China Zhejiang Climate Center Hangzhou 310052China

Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate *** we use an Earth system model to examine the response of ocean acidification to idealized atmospheric CO_(2)removal *** our simulations,atmospheric CO_(2)is assumed to increase at a rate of 1%per year to four times its pre-industrial value and then decreases to the pre-industrial level at a rate of 0.5%,1%,2%per year,*** results show that the annual mean state of surface ocean carbonate chemistry fields including hydrogen ion concentration([H^(+)]),pH and aragonite saturation state respond quickly to removal of atmospheric CO_(2).However,the change of seasonal cycle in carbonate chemistry lags behind the decline in atmospheric CO_(2).When CO_(2)returns to the pre-industrial level,over some parts of the ocean,relative to the pre-industrial state,the seasonal amplitude of carbonate chemistry fields is substantially *** results also show that changes in deep ocean carbonate chemistry substantially lag behind atmospheric CO_(2)*** CO_(2)returns to its pre-industrial value,the whole-ocean acidity measured by[H^(+)]is 15%-18%larger than the pre-industrial level,depending on the rate of CO_(2)*** study demonstrates that even if atmospheric CO_(2)can be lowered in the future as a result of net negative CO_(2)emissions,the recovery of some aspects of ocean acidification would take decades to centuries,which would have important implications for the resilience of marine ecosystems.

关键词： Carbon dioxide removal Net negative CO_(2)emission Ocean acidification Climate change Earth system modeling

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Incorporating metapath interaction on heterogeneous information network for social recommendation

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Frontiers of Computer Science 2024年第1期18卷 33-48页

作者： Yanbin jiang Huifang MA Xiaohui ZhanG Zhixin LI liang ChanG College of Computer Science and Engineering Northwest Normal UniversityLanzhou 730070China Guangxi Key Lab of Multi-source Information Mining and Security Guangxi Normal UniversityGuilin 541001China Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China

Heterogeneous information network(HIN)has recently been widely adopted to describe complex graph structure in recommendation systems,proving its effectiveness in modeling complex graph *** existing HIN-based recommendation studies have achieved great success by performing message propagation between connected nodes on the defined metapaths,they have the following major *** works mainly convert heterogeneous graphs into homogeneous graphs via defining metapaths,which are not expressive enough to capture more complicated dependency relationships involved on the ***,the heterogeneous information is more likely to be provided by item attributes while social relations between users are not adequately *** tackle these limitations,we propose a novel social recommendation model MPISR,which models MetaPath Interaction for Social Recommendation on heterogeneous information ***,our model first learns the initial node representation through a pretraining module,and then identifies potential social friends and item relations based on their similarity to construct a unified *** then develop the two-way encoder module with similarity encoder and instance encoder to capture the similarity collaborative signals and relational dependency on different *** experiments on five real datasets demonstrate the effectiveness of our method.

关键词： heterogeneous information network social reco-mmender system metapath interaction attention mechanism

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Shock-induced chemical reaction characteristics of PTFE-Al-Bi_(2)O_(3)reactive materials

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Defence Technology（防务技术） 2024年第6期36卷 1-12页

作者： Chunlan jiang Rong Hu Jingbo Zhang Zaicheng Wang liang Mao State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

A ternary system of PTFE/Al/Bi_(2)O_(3)is constructed by incorporating PTFE-based reactive material and thermite for enhancing the energy release of the PTFE-based reactive *** effects of Bi_(2)O_(3)in the PTFE/Al/Bi_(2)O_(3)on both mechanical properties and the energy release were investigated through various tests such as thermogravimetry-differential scanning calorimetry,adiabatic oxygen bomb test and split Hopkinson pressure bar *** microstructure observed through scanning electron microscope and Xray diffraction results are used to analyze the ignition and reaction mechanism of PTFE/Al/Bi_(2)O_(3).The results indicate that the PTFE/Al/Bi_(2)O_(3)are capable of triggering the exothermic reaction of molten PTFE/Bi_(2)O_(3)and Al/Bi_(2)O_(3)over the PTFE/Al reactive materials,thereby promoting *** excessive aluminum in the ternary system is beneficial for increasing energy *** ignition of shock-induced chemical reactions in PTFE/Al/Bi_(2)O_(3)is closely related to the material *** dominant mechanism for hot-spot generation under Split Hopkinson Pressure Bar test is the frictional temperature rise at the microcrack after failure.

关键词： PTFE/Al/Bi_(2)O_(3) Shock-induced chemical reaction Energy release

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Characterization and Analysis of Inconel 718 Alloy Ground at Different Speeds

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 137-149页

作者： Hao Liu Huili han Qinghong jiang Minglin He Bi Zhang Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHong KongChina

Inconel 718(IN718)alloy is widely applied to fabricate high temperature resistant or corrosion resistant parts due to its excellent mechanical ***,the machining of IN718 alloy is difficult as it may cause serious tool wear and poor surface quality(SQ)of the *** this work,grinding experiments on IN718 alloy at different speeds were conducted by using a CBN grinding *** relationship between grinding speed,SQ and subsurface damage(SSD)was well *** increasing grinding speed,surface roughness decreased,and SQ was greatly ***,the microhardness of the grinding surface declined as the grinding speed *** SSD depth was almost unchanged when the grinding speed was lower than 15 m/s,then it decreased with higher grinding *** was attributed to the mechanical-thermal synergistic effect in the grinding *** results indicated that increasing grinding speed can effectively improve the SQ and reduce the SSD of IN718 *** conclusion in the work may also provide insight into processing other hard-to-machining materials.

关键词： Surface integrity Grinding speed IN718 alloy Precision machining CBN grinding wheel

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