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Journal of Materials science & Technology 2022年第14期109卷 197-208页

作者： s.shuang q.Yua X.Gao q.F.he J.Y.Zhang s.q.shi Y.Yang Department of Mechanical Engineering City University of Hong KongKowloon TongKowloonHong KongChina Department of Mechanical Engineering Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of Materials science and Engineering City University of Hong KongKowloon TongKowloonHong KongChina

In this work,we demonstrate that the corrosion resistance of the FeCrNiCoNb_(0.5) eutectic high entropy alloy(EheA)can be tuned by controlling the size of its eutectic *** microstructure refinement,the EheA exhibits a superb corrosion resistance in 1 M NaCl in terms of a very low corrosion current density and an ultra-high transpassviation potential,which outperforms a variety of other heAs and conventional metals and *** the fundamental level,the microstructure refinement results in a rapid formation of a thick and compact passive film with less Cl-adsorption on the EheA,which results in significant enhancement in its corrosion *** outcome of our research provides important insights into the design of corrosion resistant chemically complex alloys.

关键词： Eutectic high entropy alloy Passivation Transpassivation potential Microstructure size

Elastoplastic homogenization of particulate composites complying with the Mohr–Coulomb criterion and undergoing isotropic loading

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Acta Mechanica sinica 2015年第3期31卷 392-405页

作者： D.Yang q.C.he school of Mechanical Engineering Southwest Jiaotong University Université Paris-Est Laboratoire Modélisation et Simulation Multi Echelle UMR 8208 CNRS

This work aims at determining the overall response of a two-phase elastoplastic composite to isotropic loading. The composite under investigation consists of elastic particles embedded in an elastic perfectly plastic matrix governed by the Mohr-Coulomb yield criterion and a non-associated plastic flow rule. The composite sphere assemblage model is adopted, and closed-form estimates are derived for the effective elastoplastic properties of the composite either under tensile or compressive isotropic loading. In the case when elastic particles reduce to voids, the composite in question degenerates into a porous elastoplastic material. The results obtained in the present work are of interest, in particular, for soil mechanics.

关键词： Composite Porous medium. Elastoplasticity Mohr-Coulomb yield criterion Non-associated flow rule Homogenization

IMPROVEMENT OF CARBIDE MORPHOLOGY ANDMECHANICAL PROPERTIEs OF Cr12MoV sTEELs

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Acta Metallurgica sinica(English Letters) 2000年第5期13卷 1053-1058页

作者： Cui, X.H. Jiang, q.C. Wang, s.q. he, Z.M. sch. of Mat. sci. and Eng. Jilin Univ. of Technol. Changchun 130025 China

Compared with conventional cast Cr12MoV steel and forged Cr12MoV steels, carbide morphology and properties of modified cast Cr12MoV steels were investigated by performing hardness test, impact test, fracture toughness test, fatigue crack propagation test, metallographic examination and quantitatively metallographic analysis. The results indicate that the carbide morphology in modified cast steel is characterized by uniformly-distributed granular carbide, which is different from that of conventional cast steel, but similar to that of forged steel. the impact toughness of modified cast steel is distinctly increased to 12.75 J/cm2 from 6.8 J/cm2 in the conventional cast steel with networked carbide, because of carbide granulation. Furthermore, The fracture toughness and fatigue-crack-propagation threshold of modified cast steel are not only higher than that of the conventional cast steel, but also higher than that of the forged steels.

关键词： Alloys Carbides Mechanical properties Morphology

EFFECT OF MODIFICATION ON CARBIDE GRANULATION AND ITs MECHANIsM

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Acta Metallurgica sinica(English Letters) 1999年第2期12卷 167-172页

作者： Wang, s.q. Jiang, q.C. Cui, X.H. he, Z.M. Jilin Univ of Technology Changchun China

By the modification, network carbide is disconnected at 1100 degree C through uneven dissolution at higher energy places in carbide, where there is twin or lattice distortion, and is granulated at 1130 degree C through element diffusion. The stability of M//7C//3 carbide is decreased because of the modification reducing the segregation of Cr and Mo, thus the temperature, at which uneven dissolution of carbide commenced, is decreased. Also lattice distortion or defect such as twin in carbide is increased by the modification, which prompts widespread disconnections in carbide. In addition, the modification prompts element diffusion to accelerate the kinetics process of carbide granulation. (Edited author abstract) 6 Refs.

关键词： Carbides Chromium alloys Granulation Modification Morphology

Analysis of extreme ultraviolet spectral profiles of laser-produced Cr plasmas

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Chinese Physics B 2019年第7期28卷 319-323页

作者： L Wu M G su q Min s q Cao s q he D X sun C Z Dong Key Laboratory of Atomic and Molecular Physics & Functional Material of Gansu Province College of Physics and Electronic EngineeringNorthwest Normal University

Radiation from laser-produced plasmas was examined as a potential wavelength calibration source for spectrographs in the extreme ultraviolet(EUV) ***, the EUV emission of chromium(Cr) plasmas was acquired via spatiotemporally resolved emission *** the aid of Cowan and flexible atomic code(FAC) structure calculations,and a comparative analysis with the simulated spectra, emission peaks in the 6.5–15.0 nm range were identified as 3 p–4 d, 5 d and 3 p–4 s transition lines from Cr5+–Cr10+ions.A normalized Boltzmann distribution among the excited states and a steady-state collisional-radiative model were assumed for the spectral simulations, and used to estimate the electron temperature and density in the *** results indicate that several relatively isolated emission lines of highly charged ions would be useful for EUV wavelength calibration.

关键词： laser-produced plasmas highly charged ions extreme ultraviolet wavelength calibration

Gradient microstructure,recrystallization and mechanical properties of copper processed by high pressure surface rolling

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Journal of Materials science & Technology 2022年第31期126卷 182-190页

作者： J.Guo q.Y.he q.s.Mei X.Huang G.L.Wu O.V.Mishin College of Materials science and Engineering Chongqing UniversityChongqing400045China southwest Technology and Engineering Research Institute Chongqing 400039China school of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Department of Mechanical Engineering Technical University of Denmark2800 Kgs.LyngbyDenmark

The microstructure,hardness and tensile properties have been studied in copper processed by high pressure surface rolling(HPsR)both in the as-deformed condition and after subsequent annealing at 150℃.It is found that a gradient structure with significant differences in the scale of microstructural features is formed by *** deformed microstructure varies from nano-and ultrafine-scale structures with a large fraction of high angle boundaries near the surface to lightly deformed grains at depths of 1-3 mm below the *** tests of 1-mm-thick specimens demonstrate that the asdeformed material has a high strength and a low uniform *** at 150℃results in partial recrystallization,which creates new through-thickness *** for the topmost layer and several bands in the adjacent layer,recrystallization is more pronounced close to the *** fraction recrystallized is at least 80%at depths of 60-300μm after annealing for 960 *** fraction recrystallized in the subsurface decreases with increasing depth,and the deformed layer at depths greater than 500μm re-mains largely non-recrystallized after *** partially recrystallized condition demonstrates an improved combination of strength and ductility.

关键词： High pressure surface rolling Copper Gradient microstructure Annealing Hardness strength Ductility

P-Distances, q-Distances and a Generalized Ekeland's Variational Principle in Uniform spaces

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Acta Mathematica sinica,English series 2012年第2期28卷 235-254页

作者： Jing Hui qIU Fei he school of Mathematical sciences Soochow UniversitySuzhou 215006 P.R.China school of Mathematical sciences Inner Mongolia UniversityHohhot 010021P.R.China

In this paper, we attempt to give a unified approach to the existing several versions of Ekeland＇s variational principle. In the framework of uniiorm spaces, we introduce p-distances and more generally, q-distances. Then we introduce a new type of completeness for uniform spaces, i.e., sequential completeness with respect to a q-distance （particularly, a p-distance）, which is a very extensive concept of completeness. By using q-distances and the new type of completeness, we prove a generalized Takahashi＇s nonconvex minimization theorem, a generalized Ekeland＇s variational principle and a generalized Caristi＇s fixed point theorem. Moreover, we show that the above three theorems are equivalent to each other. From the generalized Ekeland＇s variational principle, we deduce a number of particular versions of Ekeland＇s principle, which include many known versions of the principle and their improvements.

关键词： Ekeland's variational principle Takahashi's nonconvex minimization theorem Caristi'sfixed point theorem uniform space locally convex space p-distance q-distance

Generation of unsteady waves by concentrated disturbances in an inviscid fluid with an inertial surface

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Acta Mechanica sinica 2008年第3期24卷 267-275页

作者： D.q.Lu s.q.Dai shanghai Institute of Applied Mathematics and Mechanics Shanghai University200072 ShanghaiChina shanghai Key Laboratory of Mechanics in Energy and Environment Engineering 200072 ShanghaiChina

The surface waves generated by unsteady concentrated disturbances in an initially quiescent fluid of infinite depth with an inertial surface are analytically investigated for two- and three-dimensional cases. The fluid is assumed to be inviscid, incompressible and homogenous. The inertial surface represents the effect of a thin uniform distribution of non-interacting floating matter. Four types of unsteady concentrated disturbances and two kinds of initial values are considered, namely an instantaneous/oscillating mass source immersed in the fluid, an instantaneous/oscillating impulse on the surface, an initial impulse on the surface of the fluid, and an initial displacement of the surface. The linearized initial-boundary-value problem is formulated within the framework of potential flow. The solutions in integral form for the surface elevation are obtained by means of a joint Laplace-Fourier transform. The asymptotic representations of the wave motion for large time with a fixed distance- to-time ratio are derived by using the method of stationary phase. The effect of the presence of an inertial surface on the wave motion is analyzed. It is found that the wavelengths of the transient dispersive waves increase while those of the steady-state progressive waves decrease. All the wave amplitudes decrease in comparison with those of conventional free-surface waves. The explicit expressions for the freesurface gravity waves can readily be recovered by the present results as the inertial surface disappears.

关键词： Waves Inertial surface Concentrated disturbances Asymptotic representation

Multiple Tin Compounds Modified Carbon Fibers to Construct heterogeneous Interfaces for Corrosion Prevention and Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第1期17卷 507-527页

作者： Zhiqiang Guo Di Lan Zirui Jia Zhenguo Gao Xuetao shi Mukun he Hua Guo Guanglei Wu Pengfei Yin College of science Sichuan Agricultural UniversityYa’an 625014People’s Republic of China school of Materials science and Engineering Hubei University of Automotive TechnologyShiyan 442002People’s Republic of China Institute of Materials for Energy and Environment State Key Laboratory of Bio‑Fibers and Eco‑TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071People’s Republic of China shaanxi Key Laboratory of Macromolecular science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’anShaanxi 710072People’s Republic of China

Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly ***-component interface engineering is considered an effective means to achieve high-efficiency EMW ***,interface modulation engineering has not been fully discussed and has great potential in the field of EMW *** this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal *** utilizing the different properties of different substances,rich heterogeneous interfaces are *** effectively promotes charge transfer and enhances interfacial polarization and conduction *** prepared sns/sns_(2)/snO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy *** minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 ***,sns/sns_(2)/snO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on q235 steel ***,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.

关键词： Electrostatic spinning Component regulation heterogeneous interfaces Electromagnetic wave absorption Corrosion protection