检索结果-南通市图书馆

Improving flangeability of multiphase steel by increasing microstructural homogeneity

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第7期31卷 1736-1745页

作者： Xiao-yu yang Yong-gang yang Xing Fang Han-long Zhang Zhen-li Mi Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Engineering TechnologyUniversity of Science and Technology BeijingBeijing 100083China Shanghai Baosteel Group Corp.Technology Center Shanghai 201900China

Multiphase microstructure significantly increases the strength,usually at the expense of flangeability because of lacking microstructure *** further improve the strength-flangeability of multiphase steel,the microstructural homogeneity was advanced by adjusting the hard martensite/austenite(M/A)*** strength-flangeability was measured via uniaxial tensile tests and hole expansion *** microstructures were characterized using a scanning electron microscope equipped with an electron backscatter diffraction detector and a transmission electron *** tests were supplementally used to quantitatively reveal the microstructural homogeneity of the *** show that the adjusted multiphase steel achieves an excellent ultimate tensile strength(~800 MPa)and flangeability(~135%hole expansion ratio).A promising homogeneous multiphase microstructure was obtained by controlling undercooled austenite transformed at about 600℃.This microstructure consists of soft polygonal ferrite,blocky bainitic ferrite,and hard M/A *** volume fraction of M/A islands is around 5%,and the average size is less than l *** nanoindentation analysis indicated that the participation of M/A islands impressively influenced the microstructural *** strain partition and better mechanical compatibility were present in the adjusted multiphase steel since the plasticity initiation started late,which resulted in a positive ***,avoiding M/A islands distributed in the chain along the rolling direction on the matrix hindered the possibility of voids coalescing into cracks and stabilized the flanging performance.

关键词： Multiphase steel Flangeability Martensite/austenite island-Microstructural homogeneity-Microstructure Compact strip production process

Self-assembly Induced by Complexation of Diblock Copolyelectrolytes and Oppositely Charged Homopolymers

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 Journal of Polymer Science 2024年第9期42卷 1321-1332,I0006页

作者： Ling Zhao Zhi-Yuan Yin Jia-Di Jiang er-Qiang Chen Shuang yang Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCenter for Soft Mater Science and EngineeringCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China

We investigate the solution self-assembly of a mixture of positively charged homopolymers and AB diblock copolymers,in which the A blocks are negatively charged,and the B blocks are *** electrostatic complexation between oppositely charged polymers drives the formation of many ordered *** microstructures and phase diagrams are calculated using self-consistent field theory(SCFT)based on an ion-pair model with an equilibrium constant K to characterize the strength of binding between positively and negatively charged *** effects of the charge ratio,representing the ratio of charges from the homopolymer over all charges from polymers in the system,on the ordered structure are systematically studied,both for hydrophobic and hydrophilic A *** charge ratio plays an important role in determining the phase boundaries in the phase diagram of salt concentration versus polymer *** also provide information about the varying tendency of the domain spacing and core size of the spherical phase when the charge ratio is changed,and the results are in good agreement with *** studies provide a deep understanding of the self-assembled microstructures of oppositely charged diblock copolymer-homopolymer systems.

关键词： Self-assembly Polyelectrolyte complexation Self-consistent field theory Ion-pair

Linear Viscoelasticity of ABA-type Vitrimer Based on Dioxaborolane Metathesis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第10期42卷 1495-1504页

作者： Shi-long Wu Huan-Huan yang Quan Chen State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Science University of Science and Technology of China

In this study, we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct. The vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the crosslinks. When the average number of A monomers per end moiety m=1.1, the crosslinker can only extend the chain but not crosslink the chain. When m becomes 2.8 or higher, introducing a crosslinker first leads to the gelation, whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol regime. Surprisingly, a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABAtype ionomers. We attribute this difference to the distinct relaxation mechanisms:the relaxation of the vitrimer samples is based on relatively independent exchange reactions, which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.

关键词： ABA-type vitrimer Kinetics and thermodynamics Linear viscoelasticity Polymer rheology Relaxation mechanism

Phase-field simulation of precipitation kinetics and creep properties of Ni-Al-Cr/Ta superalloys

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第4期67卷 1139-1150页

作者： yang ShuaiGe ZHANG Zan ZHUO JiCheng long HongLi LI YongSheng National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

The precipitation kinetics ofγ'-Ni_(3)(Al,Ta)phase and creep properties of Ni-15Al-x Ta at.%superalloys are investigated by the crystal plasticity phase-field *** results show that the high Ta content brings a lower creep strain for the deceleration and steady creep stage,while the creep lifetime is *** large external strain intensifies the creep damage and shortens the creep life of Ni-15Al-3Ta at.%*** kinetics evolution and elements distribution are revealed in the quaternary Ni-10Al-8.5Cr-xT a(x=1.5 at.%,2.0 at.%,2.5 at.%)superalloys by the multi-component phase-field *** anti-phase boundary(APB)changes the coarsening mechanism ofγ'phase,and Ta promotes the precipitation ofγ'phase with an increasing volume fraction and particle *** composition difference betweenγ'andγphases increases with the rising of Ta content,the strong partitioning of Ta toγ'phase strengthens the partitioning of Ni and Cr toγmatrix,and Ta shows a superiority than Al in the lattice site occupation of L1_(2)-Ni_(3)(Al,X)*** an importantγ'phase forming element,the optimization of Ta content is essential for improving the mechanical properties of Ni-based superalloys.

关键词： Ni-Al-Ta alloys creep properties kinetics phase-field

Effects of rafting on the meso deformation and fracture behaviour of a Ni-based single crystal superalloy at room temperature: In-situ observation and simulation

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第7期67卷 2133-2146页

作者： TAN long yang XiaoGuang SHI DuoQi FAN YongSheng SHI Yi School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 102206China School of Materials Science&Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Microstructural rafting of Ni-based single-crystal(SC) superalloys is inevitable at elevated temperatures during long-term service with mechanical loading, which significantly affects the mechanical behaviour of the material. In this study, the effects of rafting on the mesodeformation and fracture behaviour of a Ni-based SC superalloy under cyclic and tensile loads were investigated using in situ scanning electron microscopy(SEM), digital image correlation(DIC), and crystal plasticity finite element method(CP-FEM) simulations. The results indicated that the tensile strength decreased significantly in the rafted specimens. In the cyclic tests, both the virgin and rafted specimens showed an increase in the maximum shear strain with cycle number. The interaction of cross-slip bands was captured by in situ SEM-DIC around the micro-notch of the virgin specimens during the tensile test, while a more homogeneous local deformation field was observed in the rafting specimens. In addition,the fracture behaviour was strongly influenced by the rafting morphology. The crack exhibited instantaneous and long-range fracture features along the octahedral plane as it propagated in the rafting specimen, whereas it deflected over a short distance between the crystallographic planes at an early stage in the virgin specimen, which is consistent with the CP-FEM ***, the CP-FEM results for the crack initiation direction on(111) dominant slip plane were consistent with the in situ SEM observations.

关键词： in-situ SEM-DIC Ni-based SC superalloys microstructural rafting deformation crack path CP-FEM

Visual Semantic Segmentation Based on Few/Zero-Shot Learning:An Overview

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1106-1126页

作者： Wenqi Ren yang Tang Qiyu Sun Chaoqiang Zhao Qing-long Han Key Laboratory of Smart Manufacturing in Energy Chemical Process Ministry of EducationEast China University of Science and TechnologyShanghai 200237China National Key Laboratory of Air-Based Information Perception and Fusion Aviation Industry Corporation of ChinaLuoyang 471000China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia

Visual semantic segmentation aims at separating a visual sample into diverse blocks with specific semantic attributes and identifying the category for each block,and it plays a crucial role in environmental *** learning-based visual semantic segmentation approaches count heavily on largescale training data with dense annotations and consistently fail to estimate accurate semantic labels for unseen *** obstruction spurs a craze for studying visual semantic segmentation with the assistance of few/zero-shot *** emergence and rapid progress of few/zero-shot visual semantic segmentation make it possible to learn unseen categories from a few labeled or even zero-labeled samples,which advances the extension to practical ***,this paper focuses on the recently published few/zero-shot visual semantic segmentation methods varying from 2D to 3D space and explores the commonalities and discrepancies of technical settlements under different segmentation ***,the preliminaries on few/zeroshot visual semantic segmentation,including the problem definitions,typical datasets,and technical remedies,are briefly reviewed and ***,three typical instantiations are involved to uncover the interactions of few/zero-shot learning with visual semantic segmentation,including image semantic segmentation,video object segmentation,and 3D ***,the future challenges of few/zero-shot visual semantic segmentation are discussed.

关键词： Visual segmentation separating

A Simple-Prepared and Multi-Reusable Adhesive Based on Epoxy Vitrimer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第10期42卷 1589-1594页

作者： Yu-Ting Wang Huan Liang Yen Wei Jian-long Wang Xiang-Ming He yang yang Institute of Nuclear and New Energy Technology Tsinghua University The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education) Department of Chemistry Tsinghua University

Adhesives play an important role in modern society's production and daily life. Developing robust and sustainable adhesives remains a great challenge. Here we report a sustainable epoxy-vitrimer adhesive with high adhesive strength (about 10 MPa) and reusability (82%strength after 3 times). This adhesive can be fabricated from commercially available products through a straightforward hot-pressing method without the need of solvents. The adhesive process is also simple, requiring only 30 min at 180°C. In addition, the vitrimer adhesive has the advantages of both erasability for reuse and excellent water resistance. This work provides a facile strategy to fabricate high-strength adhesive that ensures reusability, recyclability, low cost of raw materials, and simple processing technology. Simultaneously, it expands the range of potential applications for epoxy vitrimers.

关键词： Adhesive Epoxy Reusable Sustainable Vitrimer

Disposal of zinc extraction residues via iron ore sintering process:an innovative resource utilization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第7期31卷 1636-1645页

作者： Chun-long Fan Cheng-yi Ding Tao yang Yun-fei Luo Yi-fan Wang Qian Li Hong-ming long School of Metallurgical Engineering Anhui University of TechnologyMa'anshan 243002AnhuiChina Zhongye Changtian International Engineering Co. Ltd.Changsha 410205HunanChina Key Laboratory of Metallurgical Emission Reduction and Resources Recycling(Ministry of Education) Anhui University of TechnologyMa'anshan 243002AnhuiChina

Zinc extraction residue,a solid waste generated from the treatment of zinc-containing dust in rotary kilns,is commonly stockpiled in steel companies for extended *** poses significant disposal challenges and environmental pollution *** far,research on the treatment of zinc extraction residues has been slow,inadequate,and *** this gap,a novel approach was proposed to effectively treat the zinc extraction residue via the iron ore sintering *** was feasible to add 1 wt.%of zinc extraction residues to the sintering raw *** more adequate mineralization reaction resulted in higher yield and tumbler indexes,despite a slight decrease in sintering *** this may result in a slight decrease in sintering speed,the more complete mineralization reaction leads to improved sintering yield and tumbler ***,the addition of zinc extraction residues reduced the CO and NO_(x) concentrations in the sintering flue ***,the iron ore sintering process provided a viable solution for resource utilization and environmentally friendly treatment of zinc extraction residues.

关键词： Zinc extraction residue Iron ore sintering Co-processing Waste utilization Gas pollutant reduction

Visible Light-Induced[3+2]Annulation Reaction of Alkenes with Vinyl Azides:Direct Synthesis of Functionalized Pyrroles

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 Journal of Chemistry 2024年第2期42卷 151-156页

作者： Ming yang Xin-Yu Wang Jie Wang Yu-long Zhao Jilin Province Key Laboratory of Organic Functional Molecular Design&Synthesis Faculty of ChemistryNortheast Normal UniversityChangchunJilin 130024China

A photocatalytic[3+2]annulation of alkenes with vinyl azides was developed under irradiation by visible light in the presence of organic dye *** substrate scope and high functional group tolerance were demonstrated by more than 50 *** reaction provides a novel and efficient method for the synthesis of polyfunctionalized pyrroles under very mild metal-free conditions without other additives.

关键词： Photocatalysis Vinyl azides Alkenes Pyrroles Annulation Radical reactions