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Laser powder b e d fusion of copper matrix iron particle reinforced nanocomposite with high strength and high conductivity

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Journal of Materials Science & Technology 2023年第3期134卷 50-59页

作者： Yingang Liu Jingqi zhang Qiang Sun Meng Li ming Yan b xing Cheng Miaoquan Li ming-xing zhang School of Mechanical and Mining Engineering The University of QueenslandSt.LuciaQLD 4072Australia Department of Materials Science and Engineering and Shenzhen Key Laboratory for Additive Manufacturing of High-performance Materials Southern University of Science and TechnologyShenzhen 518055China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China

Liquid-liquid phase separation,and the resulted solute segregation,during conventional solidification have been a long-term challenge to produce copper(Cu)-iron(Fe)immiscible composites with high strength and high *** present work reports an effective solution to this issue through laser powder bed fusion(L-PBF)in-situ alloying of Cu-8 wt.%*** observation showed that the fast cooling within micron-scale melt pools fully eliminated the Fe segregation and therefore the L-PBF fabricated nanocomposite achieved the homogeneous microstructure,which featured equiaxed fine grains around 1μm in *** of the nanocomposite at 600℃for 1 h enabled precipitation of two types of *** is coarser Fe nanoprecipitates with body-centered cubic(BCC)structure and diam-eter of 100-300 nm,mainly distributing along grain *** other is smaller Fe nanoprecipitates with face-centered cubic(FCC)structure and diameter of 10-35 nm,being observed within the grains and having coherent interfaces with the Cu *** a result,the aged Cu-Fe nanocomposite achieved tensile strength of 462.9±6.6 MPa with 30.4%±1.7%elongation to failure and 74.5%IACS(International Annealed Copper Standard)electrical *** formation mechanisms of the nanoprecipitates and the strengthening mechanisms of the nanocomposite are discussed.

关键词： Immiscible alloy Copper Laser powder bed fusion Ageing Nanocomposite

Effect of processing parameters on the densification of an additively manufactured 2024 Al alloy

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Journal of Materials Science & Technology 2020年第23期58卷 34-45页

作者： Qiyang Tan Yingang Liu Zhiqi Fan Jingqi zhang Yu Yin ming-xing zhang School of Mechanical and Mining Engineering The University of QueenslandSt.LuciaQLD 4072Australia

Understanding the densification behaviours and formation mechanisms of defects are essential to fabricate high quality and high strength aluminium components using selective laser melting(SLM) technology. In this work, the effects of laser power and scanning speed on the densification, defects evolution and their formation mechanisms in a SLMed 2024 aluminium(Al) alloy were investigated in consideration of the corresponding laser energy input, melting mode transition and microstructural evolution. The results showed that optimizing the processing parameters effectively reduced the porosity level below1% by avoiding the lack of fusion and keyhole melting mode, and minimizing the gas pores. However,optimization of the processing parameters could not eliminate the columnar structure associated with the SLMed 2024 Al alloy, which contributed to the hot-tearing cracks in the SLMed parts. It was found that the dependence of porosity formation on SLM processing parameters was contrary to the crack density. Hence, to further improve the SLM-processability of the 2024 Al alloy it is necessary to develop SLM methods in order avoid the hot-cracking within the optimized processing parameter window associated with the minimum porosity formation.

关键词： Powder Bed Fusion Aluminum alloys Metallography Defects SEM

Spheroidization behaviour of a Fe-enriched eutectic high-entropy alloy

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Journal of Materials Science & Technology 2020年第16期47卷 173-179页

作者： Yu Yin Damon Kent Qiyang Tan Michael Bermingham ming-xing zhang School of Mechanical and Mining Engineering the University of QueenslandSt LuciaQLD 4072Australia School of Science and Engineering University of the Sunshine CoastSippy DownsQLD 4556Australia

A cost-effective Fe-enriched eutectic high-entropy alloy(EHEA),Fe35Ni25Cr25Mo15,was designed and prepared to avoid the use of expensive Co that is commonly used in ***,the as-cast Feenriched EHEA was associated with *** present work aims to evaluate the possibility and feasibility of spheroidization of the lamellar structure of the EH EA in order to improve the *** to the high cooling rate of arc-melting,the as-melted Fe35Ni25Cr25Mo15 EHEA was found to be a pseudo eutectic alloy comprised of alternantσphase(Cr(0.22)Mo0.18Fe0.6-type intermetallic)and face centred cubic(FCC)*** lamellar structure in the Fe-enriched EHEA remained stable up to 800Κ.The instability of the lamellar structure occurred at temperatures over 800℃,which was resulted from migration of high-density faults(*** termination and ledges in the lamellae).However,the Fe35Ni25Cr25Mo15EHEA still exhibited brittleness even after spheroidization at 1100℃for 168 h due to the formation of the hard and brittleσmatrix in the pseudo Fe35Ni25Cr25Mo15 EHEA as a result of decomposition of the lamellar ***,in contrast to the softening of traditional eutectic alloys,spheroidization treatment was considered as invalid to improve the ductility of pseudo-eutectic HEA with high fraction of intermetallic *** present work provides a valuable re ference for those who aim to improve the ductility of brittle EHEA through spheroidization.

关键词： Eutectic high-entropy alloys Instability Lamellar structure Spheroidization Mechanical properties

Boundary Reducible Handle Additions on Simple 3-Manifolds

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Acta Mathematica Sinica,English Series 2009年第2期25卷 235-244页

作者： Yan Nan LI Rui Feng QIU ming xing zhang Department of Applied Mathematics Dalian University of Technology Dalian 116023 P. R. China

Let M be a simple manifold, and F be a component of δM of genus two. For a slope γ on F, we denote by M（γ） the manifold obtained by attaching a 2-handle to M along a regular neighborhood of γon F. In this paper,... 详细信息

关键词： δ-reducible Scharlemann cycle simple manifold

Critical review in adsorption kinetic models

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第5期10卷 716-724页

作者： Hui QIU Lu LV Bing-cai PAN Qing-jian zhang Wei-ming zhang Quan-xing zhang State Key Laboratory of Pollution Control and Resource Reuse Department of Environmental Engineering School of the Environment Nanjing University Nanjing 210093 China

Adsorption is one of the most widely applied techniques for environmental remediation. Its kinetics are of great significance to evaluate the performance of a given adsorbent and gain insight into the underlying mechanisms. There are lots of references available concerning adsorption kinetics, and several mathematic models have been developed to describe adsorption reaction and diffusion processes. However, these models were frequently employed to fit the kinetic data in an unsuitable or improper manner. This is mainly because the boundary conditions of the associated models were, to a considerable extent, ignored for data modeling. Here we reviewed several widely-used adsorption kinetic models and paid more attention to their boundary conditions. We believe that the review is of certain significance and improvement for adsorption kinetic modeling.

关键词： Adsorption kinetics Reaction models Diffusion models Film diffusion Intraparticle diffusion

Effect of Ce on solute redistribution in liquid ahead of solid–liquid interface during solidification of Fe–4 wt.%Si alloy

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Journal of Iron and Steel Research International 2021年第10期28卷 1251-1258页

作者： Yun-ping Ji ming-xing zhang Yuan Hou Tong-xin Zhao Yi-ming Li Hui-ping Ren School of Material and Metallurgy Inner Mongolia University of Science and TechnologyBaotou014010Inner MongoliaChina Inner Mongolia Autonomous Region Key Laboratory of Advanced Metal Materials Baotou014010Inner MongoliaChina School of Mechanical and Mining Engineering The University of QueenslandBrisbaneQLD4072Australia Testing Center Inner Mongolia University of Science and TechnologyBaotou014010Inner MongoliaChina Analytical Applications Center SHIMADZU(China)Co. Ltd.Shanghai200233China

The high efficiency of Ce addition in grain refinement ofδ-ferrite in a cast Fe–4 wt.%Si alloy was *** order to further understand the solute effect of Ce on the grain refinement of δ-ferrite,the conventional directional solidification technique,which enabled to freeze the solid–liquid interface to room temperature,was used to investigate the interfacial morphology and solute redistribution in the liquid at the front of the interface,together with thermodynamic calculation of the equilibrium partition coefficients of Ce and Si in Fe–4 wt.%Si–Ce system using the Equilib module and the FsStel database in FactSage software *** examination using a laser scanning confocal microscope showed a transition of the solid–liquid interface from planar to cellular in the Fe–4 wt.%Si alloy after adding 0.0260 wt.%Ce during the directional solidification ***,electron probe microanalysis revealed an enhanced segregation of Si solute in the liquid at the front of the solid–liquid interface due to the Ce *** solute segregation is considered as the cause of planar to cellular interface transition,which resulted from the creation of constitutional supercooling *** calculation indicated that Ce also segregated at the solid–liquid interface and the Ce addition had negligible effect on the equilibrium partition coefficient of *** is reasonable to consider that the contribution of Ce to the grain refinement ofδ-ferrite in the cast Fe–4 wt.%Si alloy as a solute was marginal.

关键词： Ce Fe-4 wt.%Si alloy Solute redistribution Directional solidification Electron probe microanalysis Thermodynamic calculation

Light-and Heat-Controlled Formation of Osmanaphthalenes and Osmanaphthalynes

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Chinese Journal of Chemistry 2022年第24期40卷 2853-2860页

作者： ming-xing zhang Xiaofei Yang Zhiqiang Xu Jun Yin Sheng Hua Liu Key Laboratory of Pesticide and Chemical Biology Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhanHubei430079 China Hubei Key Laboratory of Purification and Application of Plant Anti-cancer Active Ingredients College of Chemistry and Life ScienceHubei University of EducationWuhanHubei430205 China Key Laboratory for Green Chemical Process of Ministry of Education School of Chemical Engineering and PharmacyWuhan Institute of TechnologyWuhanHubei430205 China

mple and efficient synthesis of metalla-aromatics with tailored distinctive optical,magnetic,redox,and light-emitting properties is attractive yet *** have now successfully synthesized three paramagnetic osmanaphthalenes bearing different electron-donating groups as well as the first osmabenzo[b]carbazole containing an osmanaphthalene unit with four fused rings in good yields by subjecting suitable osmium carbyne precursors to a visible-light-induced *** contrast,the four corresponding diamagnetic cyclic metal carbynes containing an osmanaphthalyne unit were obtained from the same osmium carbyne precursors by a heating *** lowest-energy absorptions of the paramagnetic osmanaphthalenes are red-shifted compared to the corresponding ***,experimental observations including X-ray analysis as well as nucleus-independent chemical shift(NICS),anisotropy of the current-induced density(AICD)calculations revealed these novel osmapolycycles bearing phosphonium substituents to be of aromatic character.

关键词： Metallacycles Aromaticity Osmanaphthalyne Osmanaphthalene Photolysis

Rapid detection of intestinal pathogens in fecal samples by an improved reverse dot blot method

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World Journal of Gastroenterology 2009年第20期15卷 2537-2542页

作者： Jian-ming xing Su zhang Ying Du Dan Bi Li-Hui Yao Huzhou Maternity and Child Care Hospital Huzhou 313000 Zheiiang Province China

AIM:To develop a new, rapid and accurate reverse dot blot(RDB) method for the detection of intestinal pathogens in fecal ***:The 12 intestinal pathogens tested were Salmonella spp., Brucella spp., Escherichia coli O157:H7, Clostridium botulinum , Bacillus cereus , Clostridium perfringens , Vibrio parahaemolyticus , Shigella spp., Yersinia enterocolitica, Vibrio cholerae, Listeria monocytogenes and Staphylococcus *** two universal primers were designed to amplify two variable regions of bacterial 16S and 23S rDNA genes from all of the 12 bacterial species *** hundred and forty fecal samples from the diarrhea patients were detected using the improved RDB ***:The methods could identify the 12 intestinal pathogens specifi cally, and the detection limit was as low as 103 *** consistent detection rate of the improved RDB assay compared with the traditional culture method was up to 88.75%.CONCLUSION:The hybridization results indicated that the improved RDB assay developed was a reliable method for the detection of intestinal pathogen in fecal samples.

关键词： Immunoblotting Intestinal pathogens Feces

Synthesis and bioactivity of novel coumarin derivatives containing(E)-methyl 2-(methoxyimino)-2-phenylacetates

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Chinese Chemical Letters 2011年第6期22卷 663-666页

作者： Ai Ying Guan Chang Ling Liu Zhi Nian Li ming xing zhang State Key Laboratory of the Discovery and Development of Novel Pesticide Shenyang Research Institute of Chemical Industry Co.Ltd. Shenyang 110021China

Ten coumarin derivatives containing（E）-methyl 2-（methoxyimino）-2-phenylacetate were synthesized and *** compounds were identified by IR,~1H NMR and elemental *** test results indicated that compound 5j（R^1 is methyl and R^2 is n-C_6H_（13）） was the optimal structure in this paper with good fungicidal activity against CDM（85%） at 6.25 mg/L concentration.

关键词： Coumarins Methoxyacrylates Intermediate derivatization method Fungicides