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Grain refinement of Mg-alloys by native MgO particles: An overview

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Journal of Magnesium and Alloys 2022年第11期10卷 2919-2945页

作者： Z.Fan F.Gao Y.wang s.h.wang J.B.Patel Brunel Centre for Advanced solidification Technology(BCAsT) Brunel University LondonUxbridgeUB83PHUK

A fine and equiaxed solidification process delivers multidimensional benefits to Mg-alloys, such as improved castability, reduced casting defects, enhanced mechanical properties, increased corrosion resistance and potential for increased recycled contents. Despite extensive research on grain refinement of Mg-alloys in the last few decades, currently, there is no effective grain refiner available for refining Mg-Al alloys, and our current understanding of grain refining mechanisms is not adequate to facilitate the development of effective grain *** the EPsRC(UK) Li ME hub’s research program, substantial advances have been made in understanding the early stages of solidification covering prenucleation, heterogeneous nucleation, grain initiation and grain refinement. In this paper, we provide a comprehensive overview of grain refinement of Mg-alloys by native MgO particles. We show that native MgO particles can be made available for effective grain refinement of Mg-alloys by intensive melt shearing regardless of the alloy compositions. More importantly, we demonstrate that(1) the addition of more potent exogenous particles will not be more effective than native MgO;and(2) MgO particles are difficult to be made more impotent for grain refinement through promoting explosive grain initiation. We suggest that the most effective approach to grain refinement of Mg-alloys is to make more native MgO particles available for grain refinement through dispersion, such as by intensive melt shearing.

关键词： Mg-alloys Grain refinement Magnesia(MgO) Nucleation Grain initiation

CORROsION REsIsTANCE OF hOT DIP GALVANIZED sTEEL PRETREATED WITh BIs-FUNCTIONAL sILANEs MODIFIED WITh NANOALUMINA

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Acta Metallurgica sinica(English Letters) 2008年第4期21卷 245-252页

作者： F.J. shan C.s. Liu s.h. wang G.C. Qi Key Laboratory for Anisotropy and Texture of Materials Ministry of Education Northeastern University Shenyang 110004 China Material ＆ Chemical Engineering College Liaoning University of Technology Jinzhou 121001 China

The corrosion behavior of hot dip galvanized steel pretrvated with bis-[triethoxysilylpropyl] tetrasulfide （BTEsPT） modified with alumina particles was studied. The corrosion resistance of the passiving films was evaluated by Tafel polarization curve and electrochemical impedance spectroscopy. The films formed on the galvanized steel substrate were characterized by Fourier transform infrared spectroscopy and energy dispersive X-ray spectrometry. The surface morphology of the treated hot dip galvanized steel samples was observed by Field Emission scanning Electron Microscope. The results show that the pretrvatments on the basis of silane films modified with nanoalumina particles have reduced both anodic and cathodic current densities, and increased total impedance in the measured frequency, consequently, improving corrosion protection for hot dip galvanized steel during immersion in NaCl solutions compared to chromate films and silane films.

关键词： Bis-sulfur silane Nanoalumina Corrosion protection Characterization hot dip galvanised steel

AMINO-TRIs-(METhYLENEPhOsPhONIC ACID)LAYERs ADsORPTION ON AA6061 ALUMINUM ALLOY

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Acta Metallurgica sinica(English Letters) 2008年第5期21卷 355-361页

作者： s.h. wang C.s. Liu F.J. shan G.C. Qi Key Laboratory for Anisotropy and Texture of Materials Ministry of Education Northeastern University Shenyang 110004 China Material＆ Chemical Engineering College Liaoning University of Technology Jinzhou 121001 China

The amino-tri-（methylenephosphonic acid） layers were adsorbed on the surface of AA6061 aluminum alloy for improving the lacquer adhesion and corrosion inhibition as a substitute for chromate coatings. The surface structure and characteristic of the amino-tri-（methylenephosphonic acid） layers on AA6061 aluminum alloy were investigated by means of XPs and ATR-FTIR analysis. The analyzed results showed that the amino-tri-（methylenephosphonic acid） adsorption layers adsorb on the surface of aluminium alloy via acid-base interaction in a bi-dentate conformation. After the amino-tri-（methylenephosphonic acid） layers were coated with epoxy resin, the layers showed good adhesive strength and favorable corrosion resistance in contrast to chromate coatings.

关键词： Amino-tri-(methylenephosphonic acid) layer Organophosphonate Aluminum alloy Corrosion resistance

Novel insight into dry sliding behavior of Cu-Pb-sn in-situ composite with secondary phase in different morphology

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Journal of Materials science & Technology 2020年第5期40卷 158-167页

作者： B.W.Dong s.h.wang Z.Z.Dong J.C.Jie T.M.wang T.J.Li school of Material science and Engineering Dalian University of TechnologyDalian 116024China

The Cu-24 Pb-x sn(wt%)(x=0,2,4,6)alloys with Pb-rich second-phase particles(sPPs)in different shapes show obviously differently mechanical and self-lubricating *** influence of the sPPs’shape difference on the alloys’mechanical and self-lubricating properties was ***-24 Pb alloy with continuously netty sPPs shows much more intensive stick-slip phenomenon during dry sliding than the other three alloys with independently rodlike *** is mainly due to insufficient lubrication resulted by the netty sPPs’splitting *** the sPPs transforming from netty to rodlike shape under the addition of sn,the stick-slip phenomenon was notably weakened,which was proven to be related to the higher self-lubricating property of alloys with rodlike ***,the simultaneous increase of ductility and tensile strength was observed in the Cu-24 Pb-x sn alloys with increasing sn content,which is because the netty sPPs’splitting behavior will be weakened with them replaced by the rodlike sPPs.

关键词： second-phase particles Netty shape Rodlike shape stick-slip Mechanical property self-lubricating property

OXIDATION BEhAVIOR OF Ni_3Al AND NiAl ALLOYs CONTAINING Fe ADDITIONs

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Acta Metallurgica sinica(English Letters) 1996年第6期9卷 641-645页

作者： J.T.Guo s.h. wang h. Li W.h. Lai and M.h.Tan(Institute of Metal Research, Chinese Academy of sciences, shenyang 110015, ) Inst of Metal Research Chinese Acad of Sciences Shenyang China

The isothermal oxidation behavior of Ni_3Al containtng 15 at.% Fe and NiAl containing 30 at.% Fe was studied for 100 h at 850, 950, 1050 and 1150℃, respectively. The results show that the oxidation kinetics of the two alloys obey a parabolic law at various temperatures and every parabolic curve possesses two oxidation rate constants. The morphology, microstructure and the chemical composition of the oxide scales were examined using optical metallography, X-ray diffraction analysis, scanning electron microscopy and electron probe microanalysis. The oxide scale of Ni_3Al containing 15 at.% Fe consists mainly of NiO, NiFe_2O_4, and FeAl_2O_4, and that of NiAl containing 30 at.% Fe consists of Fe_2O_3 and (Fe,Ni)Fe_2O_4, contrasting sharply to the oxide scales of pure Ni_3Al and NiAl which consist of Al_2O_3. The oxide scales on the surfaces of Ni_3Al and NiAl containing Fe are not too dense and not too cohesive to the matrix,so their oxidation resistance is not too good.

关键词： oxidation kinetics Ni_3Al-Fe,NiAl-Fe

INFLUENCE OF OPERATION UNDER EPIDURAL ANEsThEsIA ON PERIPhERAL T LYMPhOCYTE sUBsETs

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中华医学杂志(英文版) 1991年第3期104卷 194-197页

作者： J E Chen Z X Zheng s h wang Q h Chen Department of Anesthesiology Union Hospital Fujian Medical College Fuzhou.

This paper reports the variation of peripheral T lymphocyte subsets in patients before and after operation under epidural anesthesia using OKT monoclonal antibodies (McAb). The results show that Th and Ts after anesthesia and during surgery were lower than before anesthesia and in normal controls (Phe ratio of Th/Ts after anesthesia and during operation were lower than before anesthesia (Phere was no significant difference with normal controls (P>0.05). Therefore, we consider that the decrease in Th cells was one of the reasons for decrease in patient immune function during anesthesia and surgery. Five to seven days after surgery, patient Th cell levels tended to normalize. This showed that this abnormality was transient and reversible. The results also indicated that emphasising prevention of infection in post-operational case. should be done during the first 5-7 days after surgery.

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A mild, configurable, flexible CoNi-LDh（v）/Zn battery based on h-vacancy-induced reversible Zn2+ intercalation

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Journal of Energy Chemistry 2025年第1期100卷 498-508页

作者： Xinyue Cheng Dingsheng Wu hao Gao Qingqing wang Pengfei Lv sam s.Yoon Qufu Wei Key Laboratory of Eco-textiles Ministry of Education Jiangnan University school of Mechanical Engineering Korea University

Flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage ***,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered double hydroxide （CoNi-LDh） as the cathode material is hampered by their poor cycling stability and the corrosiveness of alkaline ***,CoNi-LDh nanosheets enriched with h vacancies (CoNi-LDh（v）) were constructed on a flexible carbon cloth （CC） substrate via electrochemical deposition and *** Zn-based battery comprising CoNi-LDh（v）@CC as the cathode exhibited highly reversible conversion reactions and stable operation in 3 M ZnsO4electrolyte （ph=4）.The battery delivered an excellent specific capacity (225 mA h g-1,0.26 mA h cm-2),acceptable cycling stability（53.9%,900 cycles）,and high discharging *** abundant h vacancies served as active sites for the reversible intercalation of Zn2+and the extravasation of NO3-generated channels and space for Zn2+transport and storage,together enabling an excellent Zn2+storage ***,a sandwich-structured solid-state CoNi-LDh（v）@CC//Zn@CC battery was fabricated and was found to exhibit a noteworthy electrochemical performance and mechanical *** a proof of concept,the unencapsulated battery powered a digital watch under various deformation conditions and operated stably for 80 ***,the flexible battery displayed outstanding customizability,maintaining an open-circuit voltage of 1.42 V even after being cut *** proposed engineering strategy contributes to the realization of textiles with truly wearable energy-storage devices.

关键词： CoNi/Zn battery h vacancies Mild aqueous electrolyte Tailorable battery Wearable energy storage device

Phase Evolution and Magnetic studies of La and Refractory Metals Co-substituted α-Fe/R_2Fe_(14)B-type Nanocomposites

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Journal of Materials science & Technology 2000年第2期16卷 102-106页

作者： W. C. Changt, s.h. wang, s.J. Chang and M. Y. Tsai (Department of Physics, Chung Cheng University, Ming-hsiung, Chia-Yi, 621, Taiwan-China Q.Chen) (Rhodia Inc., Rare Earths and Gallium, CN 7500, Cranbury, New Jersey 08512, U.s.A.) Department of Physics Chung Cheng University Ming-Hsiung Chia-Yi 621 Taiwan Rhodia Inc. Rare Earths and Gallium CN 7500 Cranbury NJ 08512 United States

Phase evolution and magnetic properties of (Nd_o.95La_0.05)9.5-11Febal.M_2B10.5. where M=Cr, Ti, Nb, V, Mo, Zr, hf, Ta, Mn or W, melt spun ribbons have been investigated. Almost all the alloy ribbons. except for(Nd_0.95La_0.05)_9.5Fe_78M_2B_10.5(M=Mo and Mn),consist merely two magnetic phases, namely α-Fe and R_2Fe_14B, which display a better combination of _ih_c and magnetic energy product. Remanence (Br) and coercivity (i_h_c) values in the range of 8.0 to 9.1 kG and 9.5 to 18.9 kOe. respectively, can be achieved. Among compositions studied, the Ti and W-substitutions were found to be most effective in increasing the Br and i_h_c, respectively. For a fixed refractory metal substitution, namely, M=C_r, Ti or Nb, an increase in the total rare earth concentration resulted in nanocomposites of small grain sizes and a high volume fraction of the R_2Fe_14B phase, leading to an increase in the magnetic properties.

关键词： Fe/R2Fe B-type Nanocomposites Phase Evolution and Magnetic studies of La and Refractory Metals Co-substituted type La

The symplectic schemes On Regular Lattice

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The Symplectic Schemes On Regular Lattice