检索结果-南通市图书馆

Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 925-931页

作者： dong-xu qiao Hui Jiang Wen-Na Jiao Yi-Ping Lu Zhi-Qiang Cao Ting-Ju Li Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province) School of Materials Science and EngineeringDalian University of TechnologyDalian 116024China College of Mechanical and Electronic Engineering Shandong University of Science and TechnologyQingdao 266590China

A series of Ti2ZrHf0.5VNbx( x = 0, 0.25, 0.5, 0.75 and 1.0) refractory high-entropy alloys were prepared to investigate the alloying effect of Nb on the microstructures and mechanical *** the alloys displayed a simple BCC *** microstructures of the alloys changed from the initial single-phase columnar structure( x = 0) to dendrite microstructure( x > 0).At room temperature, all the alloys exhibited high ductility(with the compressive strains of more than 50%).With the increase in Nb content, the yield strength slightly decreased from 1160 to 980 MPa and the hardness dropped from 338 to 310 ***, the alloys exhibited low density from 6.47 to 6.84 g/cm3 and high specific yield strength(SYS) from 143 to 179 kPa m3/*** comprehensive performance of ductility and SYS was superior to most of the reported highentropy *** yield strength of the alloys increased from 405 to 859 MPa and from 85 to 195 MPa with the addition of Nb element at 873 K and 1073 K, respectively.

关键词： Specific yield strength Refractory metals Structure Mechanical properties

Synthesis and characterization of iron clusters with an icosahedral [Fe@Fe12]16+ Core

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第4期11卷 123-129页

作者： Gan xu Yun-Shu Cui xue-Lian Jiang Cong-qiao xu Jun Li xu-dong Chen Jiangsu Collaborative Innovation Center of Biomedical Functional Materials and Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials Science Nanjing Normal University Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry Southern University of Science and Technology Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education Tsinghua University State Key Laboratory of Coordination Chemistry Nanjing University

Iron-metal clusters are crucial in a variety of critical biological and material systems,including metalloenzymes,catalysts,and magnetic storage ***,a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron *** this work,we have synthesized,crystallized,and characterized a（Tp*）4W4S12(Fe@Fe12) cluster(Tp*=tris（3,5-dimethyl-1-pyrazolyl）borate（1-）),which features a rare trideca-nuclear,icosahedral[Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron（Fei） and peripheral irons（Fep）,as well as Fep…Fepferromagnetic *** chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+core,assisted by its bonding interactions with the peripheral tridentate [（Tp*）WS3]4-ligands which possess both S→Fe donation and spin-polarized Fe-Wσ *** ground-state electron spin is theoretically predicted to be S=32/2 for the *** existence of low oxidation-state（OS～+1.23） iron in this compound may find interesting applications in magnetic storage,spintronics,redox chemistry,and cluster catalysis.

关键词： Fe13 cluster iron-sulfur cluster low-valence iron iron−iron bond high spin complex

GPa-level pressure-induced enhanced corrosion resistance in TiZrTaNbSn biomedical high-entropy alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 265-275页

作者： Xiao-hong Wang Yu-lei Deng qiao-yu Li Zhi-xin xu Teng-fei Ma Xing Yang Duo dong dong-dong Zhu Xiao-hong Yang Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou UniversityQuzhou 324000ZhejiangChina School of Materials Science and Engineering Taizhou UniversityTaizhou 318000ZhejiangChina

TiZrTaNb-based high-entropy alloys(HEAs)are research frontier of biomedical materials due to their high hardness,good yield strength,excellent wear resistance and corrosion ***,as an essential trace element in the human body that plays a significant role in physiological *** has stable chemical properties and a low elastic *** this study,a new material,TiZrTaNbSn HEAs,was proposed as a potential biomedical *** Ti_(35)Zr_(25)Ta_(15)Nb_(15)Sn_(10)biomedical high-entropy alloys(BHEAs)were successfully prepared through an arc melting furnace and then remelted using a German high-temperature and high-pressure apparatus under GPa-level(4 GPa and 7 GPa).The precipitation behavior of the needle-like HCP-Zr_(5)Sn_(3)phase that precipitates discontinuously at the grain boundary was successfully *** phase constitution,microstructure,and corrosion resistance of the alloy were *** results show that the needle-like HCP-Zr_(5)Sn_(3)phase is eliminated and the(Zr,Sn)-rich nano-precipitated phase is precipitated in the microstructure under high pressure,which leads to the narrowing of grain boundaries and consequently improves the corrosion resistance of the *** addition,the formation mechanisms of(Zr,Sn)-rich nanoprecipitates in BHEAs were *** Zr and Sn dissolve in the matrix due to the effect of high pressure,during the cooling process,they precipitate to form a(Zr,Sn)-rich nano-precipitated phase.

关键词： biomedical HEAs precipitation grain boundary corrosion resistance TiZrTaNbSn

Effects of cooling rate on microstructure and microhardness of directionally solidified Galvalume alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 213-220页

作者： Ji-peng Li De-gao qiao Jian Li Xiao-yang Luo Peng Peng Xian-tao Yan xu-dong Zhang Gansu Jiu Steel Group Hongxing Iron and Steel Co. Ltd.Jiayuguan 735111GansuChina School of Materials and Energy Lanzhou UniversityLanzhou 730000China

The influences of cooling rate on the phase constitution,microstructural length scale,and microhardness of directionally solidified Galvalume(Zn-55Al-1.6Si)alloy were investigated by directional solidification experiments at different withdrawal speeds(5,10,20,50,100,200,and 400μm·s^(-1)).The results show that the microstructure of directionally solidified Galvalume alloys is composed of primary Al dendrites,Si-rich phase and(Zn-Al-Si)ternary eutectics at the withdrawal speed ranging from 5 to 400μm·s^(-1).As the withdrawal speed increases,the segregation of Si element intensifies,resulting in an increase in the area fraction of the Si-rich *** addition,the primary Al dendrites show significant refinement with an increase in the withdrawal *** relationship between the primary dendrite arm spacing(λ_(1))and the thermal parameters of solidification is obtained:λ_(1)=127.3V^(-0.31).Moreover,as the withdrawal speed increases from 5 to 400μm·s^(-1),the microhardness of the alloy increases from 90 HV to 151 *** is a combined effect of grain refinement and second-phase strengthening.

关键词： Galvalume alloy directional solidification microstructure length scale microhardness

Heteroatom doping regulates the catalytic performance of singleatom catalyst supported on graphene for ORR

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第3期17卷 1086-1093页

作者： Ji-Kai Sun Yu-Wei Pan Meng-Qian xu Lei Sun Shaolong Zhang Wei-qiao Deng dong Zhai Institute of Molecular Sciences and Engineering Institute of Frontier and Interdisciplinary ScienceShandong UniversityQingdao 266237China College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China

Replacing fossil fuels with fuel cells is a feasible way to reduce global energy shortages and environmental ***,the oxygen reduction reaction(ORR)at the cathode has sluggish kinetics,which limits the development of fuel *** is significant to develop catalysts with high catalytic activity of *** single-atom catalysts(SACs)of Pt supported on heteroatom-doped graphene are potential candidates for *** we studied the SACs of Pt with different heteroatoms doping and screened out Pt-C_(4) and Pt-C_(3)O_(1) structures with only 0.13 V overpotential for ***,it is found that B atoms doping could weaken the adsorption capacity of Pt,while N or O atoms doping could enhance *** regularity was verified on Fe *** the electronic interaction analysis between Pt and adsorbate,we explained the mechanism of this regularity and further proposed a new descriptor named corrected d-band center(ε_(d-corr))to describe *** descriptor is an appropriate reflection of the number of free electrons of the SACs,which could evaluate its adsorption *** work provides a purposeful regulatory strategy for the design of ORR catalysts.

关键词： single-atom catalyst(SAC) oxygen reduction reaction(ORR) heteroatom doping corrected d-band center descriptor

Large Tunneling Magnetoresistance and Perfect Spin Filtering Effect in van der Waals Cu/FeX_(2)/h-BN/FeX_(2)/Cu(X=Cl,Br,I)Magnetic Tunnel Junctions

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 Physics Letters 2024年第10期41卷 112-118页

作者： Xinlong dong Xiaowen Shi Dan qiao Zeyu Li Yuhao Bai Zhenhua qiao Xiaohong xu College of Physics and Information Engineering Shanxi Normal UniversityTaiyuan 030031China Key Laboratory of Magnetic Molecules and Magnetic Information Materials of the Ministry of Education Research Institute of Materials ScienceShanxi Normal UniversityTaiyuan 030031China International Center for Quantum Design of Functional Materials University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

The two-dimensional magnetic van der Waals heterojunctions have opened unprecedented opportunities to explore new physics due to their potential for spintronic ***,combing density functional theory with non-equilibriu... 详细信息

关键词： technique. resistance Perfect

Towards robustness and generalization of point cloud representation:A geometry coding method and a large-scale object-level dataset

在线全文

学校读者我要写书评

暂无评论

Computational Visual Media 2024年第1期10卷 27-43页

作者： Mingye xu Zhipeng Zhou Yali Wang Yu qiao Guangdong-Hong Kong-Macao Joint Laboratory of Human-Machine Intelligence-Synergy Systems Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen518000China University of Chinese Academy of Sciences Beijing065001China Shanghai AI Laboratory Shanghai200001China SIAT Branch Shenzhen Institute of Artificial Intelligence and Robotics for SocietyShenzhen518000China Alibaba DAMO Academy Hangzhou242332China

Robustness and generalization are two challenging problems for learning point cloud *** tackle these problems,we first design a novel geometry coding model,which can effectively use an invariant eigengraph to group points with similar geometric information,even when such points are far from each *** also introduce a large-scale point cloud dataset,*** consists of 184 categories and 51,915 synthetic objects,which brings new challenges for point cloud classification,and provides a new benchmark to assess point cloud cross-domain ***,we perform extensive experiments on point cloud classification,using ModelNet40,ScanObjectNN,and our PCNet184,and segmentation,using ShapeNetPart and *** method achieves comparable performance to state-of-the-art methods on these datasets,for both supervised and unsupervised *** and our dataset are available at https://***/Mingyexu/PCNet184.

关键词： geometry coding self-supervised learning point cloud classification segmentation 3D analysis

New insights into the effects of APP gene dose on synapse in Down syndrome

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

Neural Regeneration Research 2024年第5期19卷 961-962页

作者： xu-qiao Chen Xinxin Zuo Department of Neurosciences University of California San DiegoLa JollaCAUSA

Synaptic dysfunction:Alzheimer’s disease(AD)is a prevalent form of dementia,affecting over 35 million people worldwide(Tzioras et al.,2023).A synapse serves as the connection point between neurons,facilitating the transmission of information from one neuron to *** alterations in synapses,known as synaptic plasticity,play a pivotal role in cognitive processes such as learning and *** loss has been identified as a key contributor to cognitive decline in AD *** have shown that the soluble forms of amyloid-beta(Aβ)and tau proteins are toxic to synapses,leading to cognitive impairment in animal models(Spires-Jones and Hyman,2014).Additionally,the formation of oligomers of tau and Aβcan spread pathology through synaptic connections in the brain,emphasizing the vital role of synapses in disease progression.

关键词： alterations Aβ tau

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第3期18卷 227-229页

作者： Qianwen GOU Yunwei dong YuJiao WU qiao KE School of Computer Science Northwestern Polytechnical UniversityXi’an 710129China School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an 710129China

1 Introduction Program retrieval aims to enable the flexible retrieval of program snippets based on a natural language query,significantly accelerating software development *** shows that over 60%of developers perform program retrieval daily[1].Recent years have witnessed an increasing interest in deep learning-based program retrieval,which aims to construct embedding representations for program snippets and ***,the distribution of natural languages and programs is inconsistent,resulting in a semantic *** critical challenge is to bridge the semantic gap between the programming language and natural language,and accurately measure their similarity.

关键词： semantic similarity retrieval

Atomistic study of inverse size effect induced by interfacial plasticity in pearlitic multi-principal element alloy

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

Rare Metals 2024年第7期43卷 3341-3355页

作者： Chen Yang qiao-Sheng Xia Cun-Hong Yin dong-Peng Hua College of Mechanical Engineering Guizhou UniversityGuiyang 550025China Key Laboratory of Advanced Manufacturing Technology Ministry of EducationGuizhou UniversityGuiyang 550025China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China

Owing to the fine nano-laminated structure,the pearlitic multi-principal element alloy(PMPEA) exhibits excellent mechanical and tribological ***,the incomplete understanding of the size effect of its lamella thickness and the unclear understanding of the plasticity-interface interaction mechanism limit further optimization of *** this study,the FeCoNi/Ni_3Ti interface-mediated plastic deformation behavior in PMPEA and the variation of mechanical and tribological properties with lamella thickness within the nanoscale range using molecular dynamics(MD) simulation were *** results indicate that the mechanical and tribological properties of the PMPEA with lamella thicknesses below 10 nm have a significant inverse size effect,i.e.,the smaller the lamella thickness,the weaker the *** is because the plastic carrier-interface interaction mechanism changes from a strengthening mechanism that hinders dislocations to a weakening mechanism that promotes dislocations with the decreases in the lamella thickness,and the weakening effect becomes more pronounced as the lamella thickness decreases and the number of interfaces *** particular,the deformation behavior of Ni_3Ti lamellae changes from crystal-like to amorphous-like with decreasing ***,in the sample with larger lamella thickness,the occurrence of hierarchical slips in the body-centered cubic(BCC) phase due to the multiprincipal elements effect can better alleviate the stress concentration caused by the dislocation accumulation at the interface,so that the phase interface exhibits outstanding load-bearing *** the dislocation pattern in BCC phase shows a firm high-density cell,which makes the substrate exhibit a stable tribological response.

关键词： Multi-principal element alloy Nano-laminated structure Molecular dynamics simulation Nanoindentation and nanoscratch