检索结果-南通市图书馆

Interpretation of the Habit Plane of d Precipitates in Superalloy Inconel 718

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2018年第2期31卷 113-126页

作者： wen-Sheng Xu Xiao-Peng Yang wen-zheng zhang Key Laboratory of Advanced Materials (MOE) School of Materials Science and Engineering Tsinghua University Beijing 100084 China Oxford Instruments Beijing Office Beijing 100085 China

A calculation method based on a combination of Dg parallelism rule, good matching site（GMS） analysis, CSL/DSCL（coincidence site lattice/displacement shift complete lattice） and the O-lattice theory has been applied to interpret the observation of the habit plane（HP） of the d precipitates and the linear defects in the HP in an Inconel 718 superalloy. The small scattering in the HP orientation around an ideal rational plane is interpreted by the existence of a mixture of two types of steps with different heights and inclinations. These steps play a significant role to enhance the degree of matching in the HP. They are associated with secondary dislocations, with Burgers vectors of 1/6 （1 1 2）y/1/3（0 0 1）, and with a direction parallel to a near-invariant line along （110）y. The spacing of the secondary dislocations projected on the terrace plane is around 6.3 nm. The calculated dislocation structure is in good agreement with the observation.

关键词： Good matching site Dislocation Orientation relationship Interfacial structure Coincident site lattice

Structures and energetics of semicoherent interfaces of precipitates in hcp/bcc systems:A molecular dynamics study

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第8期67卷 50-60页

作者： Jin-Yu zhang Fu-Zhi Dai Zhi-Peng Sun wen-zheng zhang Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610041China

α/β(hcp/bcc)interfaces are of great importance in the microstructure development and the mechanical properties of titanium and zirconium *** work contributes to the study of interface energetics and interfacial structures of the precipitate in the hcp/bcc system based on a simulation study using molecular statics(MS)and molecular dynamics(MD).The input orientation relationship(OR)was calculated based on the O-line *** on the energy of the interfaces containing the invariant line(IL),two preferred facets were determined by the Wulff construction,which explained the observed orientations of the habit plane(HP)and the side facet(SF).The deviation of the observed precipitate morphology from the equilibrium shape was discussed in terms of interface *** structures of the interfaces surrounding a three-dimensional(3 D)precipitate,including the preferred facets and the end face,were obtained at the atomic *** simulated dislocation structures and atomic structures in these interfaces are in good agreement with those of the experimental observations for Ti-Cr alloys.A method was suggested for modifying the O-cell structure with the guidance of the relaxed structure,yielding consistency between the calculated dislocation structure based on the generalized O-element approach and the simulation results.

关键词： Interface Misfit dislocation Precipitate

钢渣沥青混凝土在二广高速公路养护工程中的应用

在线全文

学校读者我要写书评

暂无评论

建材世界 2024年第2期45卷 69-71页

作者：余鸿孟靖郑文章荆州市路桥投资开发有限公司荆州434000 湖北天浩公路工程有限公司荆州434000 湖北省交通规划设计院股份有限公司武汉430051

以二广高速公路路面专项养护工程为例,进行了不同钢渣掺量AC-13C沥青混凝土和配合比设计,采用高温车辙试验、冻融劈裂试验和间接拉伸试验等评价其路用性能,发现钢渣粗集料掺量为100%时,其高温抗变形性能、水稳定性能和抗裂性能均较好。... 详细信息

以二广高速公路路面专项养护工程为例,进行了不同钢渣掺量AC-13C沥青混凝土和配合比设计,采用高温车辙试验、冻融劈裂试验和间接拉伸试验等评价其路用性能,发现钢渣粗集料掺量为100%时,其高温抗变形性能、水稳定性能和抗裂性能均较好。试验段检测结果显示,其抗滑性能优越,且渗水系数、压实度均能满足规范要求。

关键词：道路工程钢渣沥青混凝土路用性能

维普期刊数据库博看期刊

Faceted interfaces: a key feature to quantitative understanding of transformation morphology

在线全文

学校读者我要写书评

暂无评论

npj Computational Materials 2016年第1期2卷 44-57页

作者： wen-zheng zhang Xin-Fu Gu Fu-Zhi Dai School of Materials Science and Engineering Tsinghua UniversityBeijingChina Institute for Materials Research Tohoku UniversitySendaiJapan Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijingChina

Faceted interfaces are a typical key feature of the morphology of many microstructures generated from solid-state phase ***,prediction and simulation of this faceted morphology remain a challenge,especially for systems where irrational orientation relationships(ORs)between two phases and irrational interface orientations(IOs)are *** terms of structural singularities,this work suggests an integrated framework,which possibly encompasses all candidates of faceted *** structural singularities are identified from a matching pattern,a dislocation structure and/or a ledge *** resultant singular interfaces have discrete IOs,described with low-index g’s(rational orientations)and/orΔg’s(either rational or irrational orientations).Various existing models are grouped according to their determined results regarding the OR and IO,and the links between the models are clarified in the integrated *** of defect types as far as possible in a dominant singular interface often exerts a central restriction on the *** irrational IO is usually due to the elimination of dislocations in one direction,i.e.,an O-line *** methods using both three-dimensional and two-dimensional models for quantitative determinations of O-line interfaces are reviewed,and a detailed example showing the calculation for an irrational interface is *** association between structural singularities and local energy minima is verified by atomistic calculations of interfacial energies in fcc/bcc alloys where it is found that the calculated equilibrium cross-sections are in a good agreement with observations from selected alloys.

关键词： transformation rational interface

A molecular dynamics study on formation of the self-accommodation microstructure during phase transformation

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

Journal of Materials Science & Technology 2019年第11期35卷 2638-2646页

作者： Zhi-peng Sun Jin-yu zhang Fu-zhi Dai Ben Xu wen-zheng zhang Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing100076China

Self-accommodation microstructure,a typical crystallographic texture developed from phase transformation,is often observed in various *** this work,a molecular dynamics simulation was conducted to reveal the fine details of self-accommodation microstructure evolution during the phase transformation from austenite to ferrite in pure *** growth and shrinkage of ferrite grains with different orientation relationships(ORs)are interpreted based on the analysis combining the elastic interaction energy and the interfacial *** was found that the strain energy determines the priority of potential ORs,while the interfacial energy selects the specific preferred ORs to *** present atomistic process and energetic interpretation of the self-accommodation microstructure provide helpful insight into phase transformation textures observed in various alloys.

关键词： Self-accommodation microstructure Molecular dynamics Orientation relationship Elastic interaction energy Interfacial energy

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2019年第6期32卷 669-676页

作者： Zhi-Peng Sun Fu-Zhi Dai Ben Xu wen-zheng zhang Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials and Processing TechnologyBeijing 100076China

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix *** a key feature of microstructure,the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial *** letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics *** found that the ferrite grain tends to grow into an elongated plate-like shape,independent of its initial confi *** fi nal shape of the ferrite is closely related to the misfi t between the two phases,with the longest direction and the broad facet of the plate being,respectively,consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC)*** strain energy calculation in the framework of Eshelby’s inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically *** is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.

关键词： Coherent ferrite Anisotropic growth Molecular dynamics simulation Burgers vector content Eshelby’s inclusion theory

ASYMPTOTIC THEORY FOR THE CIRCUIT ENVELOPE ANALYSIS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第4期42卷 955-978页

作者： Chunxiong zheng Xianwei wen Jinyu zhang Zhenya Zhou College of Mathematics and Systems Science Xinjiang UniversityUrumqi 830046China Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China Empyrean Software Empyrean Technology Co.Ltd.Beijing 100102China

Asymptotic theory for the circuit envelope analysis is developed in this paper.A typical feature of circuit envelope analysis is the existence of two significantly distinct timescales:one is the fast timescale of carrier wave,and the other is the slow timescale of modulation *** first perform pro forma asymptotic analysis for both the driven and autonomous *** resorting to the Floquet theory of periodic operators,we make a rigorous justification for first-order asymptotic *** turns out that these asymptotic results are valid at least on the slow *** speed up the computation of asymptotic approximations,we propose a periodization technique,which renders the possibility of utilizing the NUFFT *** experiments are presented,and the results validate the theoretical findings.

关键词： Asymptotic analysis Circuit envelope analysis Floquet theory Singularly perturbed problem

Performance improvement of β-Ga2O3 SBD-based rectifier with embedded microchannels in ceramic substrate

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

Science China(Information Sciences) 2024年第5期67卷 341-342页

作者： wen HONG Chao zhang Fang zhang Xuefeng zheng Xiaohua MA Yue HAO State Key Laboratory of Wide-Bandgap Semiconductor Devices and Integrated Technology School of MicroelectronicsXidian University

With the development of integrated circuits, there is a growing demand for higher power devices [1]. Gallium oxide（Ga2O3） holds promise for high power devices due to its wide bandgap and high breakdown electric field strength [2].However, its low thermal conductivity induces severe selfheating effects, limiting its performance and ***, effective thermal management techniques are urgently needed for Ga2O3devices.

关键词： Gallium compounds

FedQMIX:Communication-efficient federated learning via multi-agent reinforcement learning

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

High-Confidence Computing

High-Confidence Computing 2024年第2期4卷 96-104页

作者： Shaohua Cao Hanqing zhang Tian wen Hongwei Zhao Quancheng zheng Weishan zhang Danyang zheng Qingdao Institute of Software College of Computer Science and TechnologyChina University of Petroleum(East China)Qingdao 266580China School of Computing and Artificial Intelligence Xipu CampusSouthwest Jiaotong UniversityChengdu 611756China

Since the data samples on client devices are usually non-independent and non-identically distributed(non-IID),this will challenge the convergence of federated learning(FL)and reduce communication *** paper proposes FedQMIX,a node selection algorithm based on multi-agent reinforcement learning(MARL),to address these ***,we observe a connection between model weights and data distribution,and a clustering algorithm can group clients with similar data distribution into the same ***,we propose a QMIX-based mechanism that learns to select devices from clustering results in each communication round to maximize the reward,penalizing the use of more communication rounds and thereby improving the communication efficiency of ***,experiments show that FedQMIX can reduce the number of communication rounds by 11%and 30%on the MNIST and CIFAR-10 datasets,respectively,compared to the baseline algorithm(Favor).

关键词： Communication efficient Federated learning MARL