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Effect of Ni content on the wear behavior of Al-Si-Cu-Mg-Ni/SiC particles composites

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 374-383页

作者： yanyu Liu Lina jia Wenbo Wang Zuheng Jin hu Zhang School of Materials Science and Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315100China Qingdao Research Institute of Beihang University Qingdao 266000China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

In recent years,the addition of Ni has been widely acknowledged to be capable of enhancing the mechanical properties of Al-Si ***,the effect of Ni on the wear behaviors of Al-Si alloys and Al matrix composites,particularly at elevated temperat-ures,remains an understudied *** this study,Al-Si-Cu-Mg-Ni/20wt%SiC particles(SiCp)composites with varying Ni contents were prepared by using a semisolid stir casting *** effect of Ni content on the dry sliding wear behavior of the prepared compos-ites was investigated through sliding tests at 25 and 350℃.Results indicated that theθ-Al_(2)Cu phase gradually diminished and eventually disappeared as the Ni content increased from 0wt%to 3wt%.This change was accompanied by the formation and increase inδ-Al_(3)CuNi andε-Al_(3)Ni phases in *** hardness and ultimate tensile strength of the as-cast composites improved,and the wear rates of the composites decreased from 5.29×10^(−4)to 1.94×10^(−4)mm^(3)/(N∙m)at 25℃and from 20.2×10^(−4)to 7×10^(−4)mm^(3)/(N∙m)at 350℃with the increase in Ni content from 0wt%to 2wt%.The enhancement in performance was due to the presence of strengthening network structures and additional Ni-containing phases in the ***,the wear rate of the 3Ni composite was approximately two times higher than that of the 2Ni composite due to the fracture and debonding of theε-Al_(3)Ni *** wear,delamination wear,and oxidation wear were the predominant wear mechanisms of the investigated composites at 25℃,whereas delamination wear and oxid-ation wear were dominant during sliding at 350℃.

关键词： Al matrix composite microstructure sliding test high temperature wear mechanism

PAPS: Progressive Attention-Based Pan-sharpening

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 391-404页

作者： yanan jia Qiming hu Renwei Dian jiayi Ma Xiaojie Guo College of Intelligence and Computing Tianjin UniversityTianjin 300350 China IEEE School of Robotics Hunan UniversityChangsha 410082China Electronic Information School Wuhan UniversityWuhan 430072China

Pan-sharpening aims to seek high-resolution multispectral(HRMS) images from paired multispectral images of low resolution(LRMS) and panchromatic(PAN) images, the key to which is how to maximally integrate spatial and spectral information from PAN and LRMS images. Following the principle of gradual advance, this paper designs a novel network that contains two main logical functions, i.e., detail enhancement and progressive fusion, to solve the problem. More specifically, the detail enhancement module attempts to produce enhanced MS results with the same spatial sizes as corresponding PAN images, which are of higher quality than directly up-sampling LRMS *** a better MS base(enhanced MS) and its PAN, we progressively extract information from the PAN and enhanced MS images, expecting to capture pivotal and complementary information of the two modalities for the purpose of constructing the desired HRMS. Extensive experiments together with ablation studies on widely-used datasets are provided to verify the efficacy of our design, and demonstrate its superiority over other state-of-the-art methods both quantitatively and qualitatively. Our code has been released at https://***/jiayN1/PAPS.

关键词： High-resolution multispectral image image fusion pan-sharpening progressive enhancement

Triple signal amplification electrochemical sensing platform for Hg^(2+) in water without direct modification of the working electrode

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Frontiers of Environmental Science & Engineering 2024年第7期18卷 157-167页

作者： Liuyin hu jiahua Cui Tao Lu yalin Wang Jinping jia School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China International Copper Association Ltd.Shanghai 200020China

An ultrasensitive electrochemical biosensor to detect trace Hg^(2+)in environmental samples was developed utilizing nanogold-decorated magnetic reduced graphene oxide(MrGO-AuNPs),exonuclease III-assisted target cycle(Exo Ⅲ-ATC)and hybridization chain reaction(HCR)synergistic triple signal *** MrGO-AuNPs is a superior carrier for capture DNA(cDNA)and acts as magnetic media for automatic separation and *** innovative utilization of the magnetism and improved sensing efficiency obviates the need for direct modification and repeated polishing of the working ***,the three DNA hairpins(cDNA,methylene blue(MB)labeled HP1 and HP2)further contribute to biosensor specificity and *** cDNA captures Hgt,it activates Exo Ⅲ-ATC due to the formation of a sticky end in the DNA stem via thymine-Hig-thymidine(T-Hg^(2+)-T),this leads to the hydrolysis of self-folded DNA by Exo Ⅲ-ATC to form"key"DNA(kDNA).The kDNA subsequently initiates HCR,resulting in massive super-sandwich structures(kDNA-[HP1/HP2])carrying signaling molecules on MrGO-AuNPs,and this overall structure serves as a signal probe(SP).Leveraging magnetic adsorption,the SP was automatically adsorbed onto the magneto-glass carbon electrode(MGCE),generating an amplified *** biosensor's detection limit(LOD)was 3.14 pmol/L,far below the limit of 10 nmol/L for mercury in drinking water set by the US *** biosensor also showed excellent selectivity when challenged by interfering ions,and the results of its application in actual samples indicate that it has good potential for practical applications in environmental monitoring.

关键词： Electrochemical sensing Hg^(2+) Amplification Graphene Hybridization chain reaction Exonuclease Ⅲ

Significant improvement after sensory tricks and trunk strength training for Parkinson’s disease with antecollis and camptocormia:A case report

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World Journal of Clinical Cases 2024年第2期12卷 443-450页

作者： jia-Ren Wang yue hu Department of Neurology and Neurological Rehabilitation Shanghai Yangzhi Rehabilitation Hospital(Shanghai Sunshine Rehabilitation Center)Shanghai 201619China

BACKGROUND Patients with Parkinson's disease(PD)exhibit symptoms such as antecollis(AC)and camptocormia(CC).The pathology of these two conditions is ***,standard treatment methods have not been *** article reports the case of a 65-year-old female patient with AC and CC who was treated with central and peripheral interventions to alleviate *** SUMMARy We present the case of a 65-year-old female PD patient with AC and *** course of the disease was 5 *** was treated with rehabilitation strategies such as sensory tricks and trunk strength *** the inpatient period,we compared and analyzed the patient's gait,rehabilitation assessment scale score,and angles of her abnormal trunk posture in the first week,the third week,and the fifth *** patient's stride length increased,indicating that the patient's walking ability was *** Unified Parkinson's Disease Scale Part Three score and CC severity score ***,the score of the other scale *** addition,the patient showed significant improvements in AC,upper CC,and lower CC *** This case study suggested that sensory tricks and trunk strength training are beneficial and safe for patients with AC and CC.

关键词： Antecollis Camptocormia Parkinson's disease Sensory tricks Trunk strength training Case report

Flow characterization of macroporous W-4.8 vol.%ZrO2 alloy during hot deformation with improved constitutive equation and processing maps

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Tungsten 2024年第3期6卷 610-620页

作者： jia-Hao ye Liu-Jie Xu Ji-Kang hu School of Materials Science and Engineering Henan University of Science and Technology National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials Henan University of Science and Technology

In this work,isothermal compression experiments of macroporous W-4.8 vol.%ZrO2（W-4.8ZrO2） at 1300-1600℃ and strain rate of 0.005-1 s-1were carried out on a Gleeble-1500D thermo-mechanical *** dynamic recovery of W-4.8ZrO2is the main "softening" *** the basis of Arrhenius model,the initial constitutive equation is established by exploring the influence of temperature,strain rate and rheological *** on Arrhenius model,the relationship between flow stress,strain rate and deformation temperature is *** the influence of strain,the improved constitutive equation and the law of material constant changing with the strain are *** that,the hot processing maps were drawn on the basis of the dynamic material model,which is used to analyze the instability mechanism of the W-4.8ZrO2,and determine the appropriate hot working process parameters(temperature:1350-1450℃,strain rate:0.1-1 s-1).

关键词： Tungsten alloy Flow characteristics Constitutive equation Hot processing maps

Influence of human Activity Intensity on Habitat Quality in Hainan Tropical Rainforest National Park,China

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Chinese Geographical Science 2024年第3期34卷 519-532页

作者： HAN Nianlong yU Miao jia Peihong ZHANG yucheng hu Ke School of Geography and Tourism Huizhou UniversityHuizhou 516007China School of Public Administration Hainan Uni-versityHaikou 570228China Department of Land Surveying and Geo-Informatics The Hong Kong Polytechnic UniversityHong KongChina School of Geographic Sciences and Remote Sensing Guangzhou UniversityGuangzhou 510006China School of Public Administration Nanjing Agricultural UniversityNanjing 210095China

Due to long-term human activity interference,the Hainan Tropical Rainforest National Park(HTRNP)of China has experienced ecological problems such as habitat fragmentation and biodiversity loss,and with the expanding scope and intensity of human activity impact,the regional ecological security is facing serious challenges.A scientific assessment of the interrelationship between human activity intensity and habitat quality in the HTRNP is a prerequisite for achieving effective management of ecological disturbances caused by human activities and can also provide scientific strategies for the sustainable development of the *** on the land use change data in 2000,2010,and 2020,the spatial and temporal variations and the relationship between habitat quality(HQ)and human activity intensity(HAI)in the HTRNP were explored using the integrated valuation of ecosystem services and trade-offs(InVEST)*** dynamics and land use simulation models were also combined to conduct multi-scenario simulations of their *** results showed that during 2000–2020,the habitat quality of the HTRNP improved,the intensity of human activities decreased each year,and there was a negative correlation between the ***,the system dynamic model could be well coupled with the land use simulation model by combining socio-economic and natural *** simulation scenarios of the coupling model showed that the harmonious development(HD)scenario is effective in curbing the increasing trend of human activity intensity and decreasing trend of habitat quality,with a weaker trade-off between the two compared with the baseline development(BD)and investment priority oriented(IPO)*** maintain the authenticity and integrity of the HTRNP,effective measures such as ecological corridor construction,ecological restoration,and the implementation of ecological compensation policies need to be strengthened.

关键词： human activity intensity(HAI) habitat quality(HQ) bivariate spatial autocorrelation system dynamics model integrated valuation of ecosystem services and trade-offs(InVEST)model Hainan Tropical Rainforest National Park(HTRNP)of China

Characteristics and Influencing Factors of Microplastics in Snow in the Inner Mongolia Plateau, China

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Engineering 2024年第6期37卷 69-77页

作者： Hongwei yu Junrong Shao huawei jia Diga Gang Baiwen Ma Chengzhi hu State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Changjiang Survey PlanningDesign and Research Co.Ltd.Wuhan 430010China

Microplastics(MPs;<5 mm)have become one of the most prominent global environmental pollution *** can spread to high altitudes through atmospheric transport and can be deposited by rainfall or snowfall,potentially thre... 详细信息

Microplastics(MPs;y rainfall or snowfall,potentially threatening the structure and function of natural *** in terrestrial and aquatic ecosystems alter the growth and functional characteristics of ***,little attention has been given to the possible harm associated with MPs deposited in snow,particularly in the context of global climate *** collected from surface snow in the Inner Mongolia Plateau,China,were used for quantitative analysis and *** results showed that MPs were easily detected,and the related concentration was approximately(68±10)–(199±22)MPsL1 in snow *** were the most common morphology,the polymer composition was largely varied,and the abundance and composition of MPs were linked to human activity to a great ***-throughput sequencing results showed that the composition and abundance of microorganisms also differed in snow samples from areas with different MP pollution characteristics,indicating a considerable difference in microbial functional *** may have an interference effect on the individual growth and functional expression of microorganisms in *** addition,the results showed that functional living areas(e.g.,landfills and suburban areas)in cities play an important role in the properties of *** instance,the highest abundance of MPs was found in thermal power plants,whereas the abundance of polymers per sample was significantly lower in the suburban *** MP contaminants hidden in snow can alter microbial structure and function and are therefore a potential threat to ecosystem health.

关键词： human activities Snow Microplastics Microbial community Urban function Environmental effect

Predication of Selective Ring-opening Hydrogenolysis for Furfuryl Alcohol to Produce Pentanediol over Dual-atom Catalysts

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Chemical Research in Chinese Universities 2024年第1期40卷 55-63页

作者： WANG Tingting WANG jia XI yongjie hu Bin LI Fuwei State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China

Selective activation of C-O bond is of fundamental importance in the precise conversion of oxygenates into value-added compounds in an atom-economic and sustainable manner, and meanwhile, the structurally well-defined dual-atoms catalysts (DACs) have been scarcely investigated in this field. In this study, a series of transition metal DACs anchored on nitrogen-doped graphene (TM2/NC, TM=Pt, Ir, Rh, Pd, Ru, Co, Ni and Cu) was constructed to make a comprehensive investigation of their selectivity in the hydrogenative transformation of furfuryl alcohol (FAL), an important biomass platform molecule, to 1,2-pentanediol (1,2-PeD) via selective cleavage of furanic C5-O bond, by density functional theory (DFT) calculations and microkinetic modeling. We found that Ir2/NC demonstrated a high selectivity for the cleavage of furanic C5-O bond to produce 1,2-PeD, while the production of THFAL or 1,5-pentanediol (1,5-PeD) on other TM2/NC catalysts are more favorable. Furthermore, we found that the selective C-O bond cleavage of FAL furan ring is affected by the orbital overlap between the d-orbitals of the anchored metal atoms and the p-orbitals of the adsorbed C atom in FAL, suggesting that the selectivity of the C-O bond cleavage is inextricably related with the electronic property of the anchored metals.

关键词： Furfuryl alcohol Hydrogenation Dual-atom catalyst Density functional theory(DFT)calculation

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： yong-Chao Li Rui-Sheng jia ying-Xiang hu Hong-Mei Sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and Jhu-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning