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Influence of Processing Parameters on Microstructural Evolution and Tensile Properties for 7075 Al Alloy Prepared by an ECAP-Based SIMA Process

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Acta Metallurgica Sinica(English Letters) 2018年第4期31卷 337-350页

作者： jin-long fu Hong-Jun Jiang Kai-Kun Wang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China Wuxi Turbine Blade Co. LtdWuxi 214174JiangsuChina

A modified strain-induced melt activation（SIMA）process consisting of homogenization,equal-channel angular pressing（ECAP）and subsequent heating to the semisolid temperatures was introduced to prepare the 7075 aluminum alloy with superior thixotropic *** effects of both the homogenization and the number of ECAP passes,as well as the isothermal temperatures on the microstructural evolution,were *** results indicate that ideal microstructure wherein fine and globular solid grains surrounded by uniform liquid films can be achieved through ECAP deformation-recrystallization *** the number of ECAP passes accelerates the recrystallization of strained grains,thus reducing the average grain size and improving the grain ***,higher holding temperatures and prolonged soaking time can improve the growth of the solid *** main coarsening mechanisms,*** and Ostwald ripening,contribute to the growth of the solid grains simultaneously and *** tensile strength of the 7075 alloys after four-pass ECAP-based SIMA and T6 heat treatment is relatively lower than the as-received billet,while the elongation of SIMA processed samples is much higher than that of as-received *** the number of ECAP passes improves the tensile strength for alloys with and without T6 treatment due to the fine grain strengthening mechanism.

关键词： Semisolid Aluminum Equal-channel angular pressing Mierostructural evolution Tensileproperty

Microstructure evolution and thixoforming behavior of 7075 aluminum alloy in the semi-solid state prepared by RAP method

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International Journal of Minerals,Metallurgy and Materials 2016年第12期23卷 1404-1415页

作者： jin-long fu Kai-kun Wang Xiao-wei Li Hai-kuan Zhang School of Materials Science and Engineering University of Science and Technology Beijing Tianjin Zhonglian Precision Casting Co. Ltd.

The effects of isothermal treatments on the microstructural evolution and coarsening rate of semi-solid 7075 aluminum alloy produced via the recrystallization and partial remelting （RAP） process were investigated. Samples of 7075 aluminum alloy were subjected to cold extrusion, and semi-solid treatment was carried out for 5-30 min at temperatures ranging from 580 to 605℃. A backward-extrusion experiment was conducted to investigate liquid segregation during the thixoforming process. The results revealed that obvious grain coarsening and spheroidization occurred during prolonged isothermal treatments. In addition, higher soaking temperatures promoted the spheroidization and coarsening process because of the increased liquid fraction and the melting of second phases. Segregation of the liquid phase caused by the difference in fluidity between the liquid and the solid phases was observed in different regions of the thixoformed specimens.

关键词： aluminum alloys microstructural evolution thixoforming grain coarsening segregation

Study of removal effect on Mesocyclops leukarti with oxidants

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第3期7卷 171-179页

作者： ZUO jin-long CUI fu-yi LIN Tao School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

Cyclops of zooplankton propagates prolifically in eutrophic waterbody and it cannot be exterminated by conventional disinfection process. The mutagenicity of Mesocyclops leukarti and its extermination with oxidants in a drinking waterworks in China were studied. Among five oxidants for use in bench-scale, chlorine dioxide is the most effective and the potassium per-manganate is the weakest against Mesocyclops leukarti under the same conditions. full-scale results showed that Mesocyclops leukarti could be effectively removed from water by 1.0 mg/L chlorine dioxide preoxidation combined with conventional removal physical process. After filtration, chlorite, a by-product of prechlorine dioxide, is stable at 0.45 mg/L, which is lower than the critical value of the USEPA. GC-MS examination and Ames test further showed that the quantity of organic substance and the mutagenicity in water treated by chlorine dioxide preoxidation are obviously less than those of prechlorination.

关键词： Oxidants Chlorine Chlorine dioxide Mesocyclops leukarti Preoxidation Water safety Oxidants, Chlorine, Chlorine dioxide, Mesocyclops leukarti, Preoxidation, Water safety

Numerical simulation of 3D-microstructures in solidification processes based on the CAFE method

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International Journal of Minerals,Metallurgy and Materials 2009年第6期16卷 640-645页

作者： jin-long Wang fu-ming Wang Yan-yu Zhao Jiong-ming Zhang Wei Ren School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

It was analyzed that the finite element-cellular automaton （CAFE） method was used to simulate 3D-microstructures in solidification processes. Based on this method, the 3D-microstructure of 9SMn28 free-cutting steel was simulated in solidification processes and the simulation results are consistent with the experimental ones. In addition, the effects of Gaussian distribution parameters were also studied. The simulation results show that the higher the mean undercooling, the larger the columnar dendrite zones, and the larger the maximum nucleation density, the smaller the size of grains. The larger the standard deviation, the less the number of minimum grains is. However, the uniformity degree decreases first, and then increases gradually.

关键词： finite element-cellular automaton model numerical simulation solidification 3D-microstructure Gaussian distribution parameters

Obtaining Ultra-High Strength and Ductility in a Mg–Gd–Er–Zn–Zr Alloy via Extrusion,Pre-deformation and Two-Stage Aging

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Acta Metallurgica Sinica(English Letters) 2021年第1期34卷 39-44页

作者： Lin-Yue Jia Wen-Bo Du jin-long fu Zhao-Hui Wang Ke Liu Shu-Bo Li Xian Du College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China

The Mg–12Gd–1Er–1Zn–0.9 Zr(wt%)alloy with ultra-high strength and ductility was developed via hot extrusion combined with pre-deformation and two-stage aging *** age-hardening behavior and microstructure evolution were ***-deformation introduced a large number of dislocations,resulting in strain hardening and higher precipitation strengthening in the subsequent two-stage *** a result,the alloy showed a superior strength–ductility balance with a yield strength of 506 MPa,an ultimate tensile strength of 549 MPa and an elongation of 8.2%at room *** finer and denserβ’precipitates significantly enhanced the strength,and the bimodal structure,smallβ-Mg5RE phase as well as denseγ’precipitates ensured the good ductility of the *** is suggested that the combination of pre-deformation and two-stage aging treatment is an eff ective method to further improve the mechanical properties of wrought Mg alloys.

关键词： Magnesium alloys Pre-deformation Two-stage aging Precipitation strengthening Mechanical properties

Decreased IgA+ plasma cells and IgA expression in acute liver necrosis mice

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World Journal of Gastroenterology 2010年第30期16卷 3827-3833页

作者： jin-long fu, Zhao-Han Wang, Guo-Zhen Li, Yu-Rong Wang, Pei Liu, Department of Infectious Diseases, The First Aff iliated Hospital, China Medical University, Shenyang 110001, Liaoning Province, China Department of Infectious Diseases The First Affiliated Hospital China Medical University No. 155 Nanjing Street Shenyang 110001 Liaoning Province China. syliupei2003@***

AIM: To investigate the number of intestinal immunoglobulin A (IgA+) plasma cells and expression of intestinal IgA in mice with acute liver necrosis. METHODS: A model of acute liver necrosis was established by intraperitoneal injection of galactosamine (GalN) and lipopolysaccharide (LPS). Sixty mice were randomly divided into one of 4 equal groups: normal control, acute liver necrosis, LPS, or GalN. Hematoxylin and eosin staining, immunohistochemistry, and an enzyme-linked immunosorbent assay were employed to assess liver and intestinal injury, count intestinal IgA+ plasma cells, and measure the expression level of IgA and interferon γ (IFN-γ) in the small intestinal mucosa of mice. RESULTS: Injured intestinal mucosa was observed in the acute liver necrosis group but not in the normal, LPS or GalN groups. Compared with the normal group,intestinal IgA+ plasma cells were slightly decreased in the LPS and GalN groups [429 ± 20 per high power f ield (HPF), 406 ± 18/HPF, respectively], whereas they were markedly decreased in the acute liver necrosis group (282 ± 17/HPF vs 495 ± 26/HPF in normal group, P 0.05). CONCLUSION: Intestinal IgA+ plasma cells and IgA expression levels indicating that mucosal immune barrier dysfunction, does exist in acute liver necrosis.

关键词： Acute liver necrosis Intestinal mucosa Immunity Immunoglobulin A

Tumor necrosis factor alpha increases intestinal permeability in mice with fulminant hepatic failure

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World Journal of Gastroenterology 2012年第36期18卷 5042-5050页

作者： Guo-Zhen Li Zhao-Han Wang Wei Cui jin-long fu Yu-Rong Wang Pei Liu Department of Infectious Diseases the First Affiliated HospitalChina Medical UniversityShenyang 110001Liaoning ProvinceChina

AIM:To determine the effect of tumor necrosis factor alpha(TNF-α) on intestinal permeability(IP) in mice with fulminant hepatic failure(FHF),and the expression of tight junction ***:We selected D-lactate as an index of IP,induced FHF using D-galactosamine/lipopolysaccharide and D-galactosamine/TNF-α,assessed the results using an enzymatic-spectrophotometric method,transmission electron microscopy,immunohistochemistry,Western blotting and real-time quantitative polymerase chain *** effect of the administration of antiTNF-α immunoglobulin G(IgG) antibody,before the administration of D-galactosamine/lipopolysaccharide,on TNF-α was also ***:IP was significantly increased in the mouse model of FHF 6 h after injection(13.57 ± 1.70 mg/L,13.02 ± 1.97 mg/L vs 3.76 ± 0.67 mg/L,P = 0.001).Electron microscopic analysis revealed tight junction(TJ) disruptions,epithelial cell swelling,and atrophy of intestinal *** of occludin and claudin-1 mRNA was significantly decreased in both FHF models(occludin:0.57 ± 0.159 fold vs baseline,P = 0.000;claudin-1:0.3067 ± 0.1291 fold vs baseline,P = 0.003),as were the distribution density of proteins in the intestinal mucosa and the levels of occludin and claudin-1 protein(occludin:0.61 ± 0.0473 fold vs baseline,P = 0.000;claudin-1:0.6633 ± 0.0328 fold vs baseline,P = 0.000).Prophylactic treatment with antiTNF-α IgG antibody prevented changes in IP(4.50 ± 0.97 mg/L vs 3.76 ± 0.67 mg/L,P = 0.791),intestinal tissue ultrastructure,and the mRNA levels of occludin and claudin-1 expression(occludin:0.8865 ± 0.0274 fold vs baseline,P = 0.505;claudin-1:0.85 ± 0.1437 fold vs baseline,P = 0.1),and in the protein levels(occludin:0.9467 ± 0.0285 fold vs baseline,P > 0.05;claudin-1:0.9533 ± 0.0186 fold vs baseline,P = 0.148).CONCLUSION:Increased in IP stemmed from the downregulation of the TJ proteins occludin and claudin-1,and destruction of the TJ in the colon,which were induced by TNF-α in FHF mice.

关键词： Tumor necrosis factor alpha fulminant he-patic failure Intestinal permeability Occludin Claudin-1

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SC结构、功能及其临床研究进展

世界华人消化杂志 2009年第3期17卷 293-298页

作者：付金龙刘沛中国医科大学附属第一医院传染科辽宁省沈阳市110001

分泌型免疫球蛋白A(SIgA)被认为是免疫防御中的第一道防线在黏膜免疫中发挥至关重要的作用,由2个单体IgA、1分子J链和1分子分泌成分(SC)组成.SC是多聚免疫球蛋白受体(pIgR)的胞外段部分,作为SIgA的重要组成部分,不仅在SIgA的转运、形成... 详细信息

分泌型免疫球蛋白A(SIgA)被认为是免疫防御中的第一道防线在黏膜免疫中发挥至关重要的作用,由2个单体IgA、1分子J链和1分子分泌成分(SC)组成.SC是多聚免疫球蛋白受体(pIgR)的胞外段部分,作为SIgA的重要组成部分,不仅在SIgA的转运、形成中发挥重要作用,而且可以保护SIgA的铰链区及增强其抗感染活性.因此关于SC的研究日益受到学者们的青睐,近年来有关SC的结构、功能及其在临床中的研究已经取得较大进展.

关键词：多聚免疫球蛋白受体分泌型免疫球蛋白A 分泌成分

Mechanical properties and corrosion behaviors of Mg-4Zn-0.2Mn-0.2Ca alloy after long term in vitro degradation

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Transactions of Nonferrous Metals Society of China 2020年第2期30卷 363-372页

作者： Yuan-fen CHENG Wen-bo DU Ke LIU Jun-jian fu Zhao-hui WANG Shu-bo LI jin-long fu College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China

An extruded Mg-4Zn-0.2Mn-0.2Ca alloy was developed as potential biodegradable bone-plate due to its excellent *** term in vitro immersion in Hank’s solution and bending test were used to evaluate the degradability and the mechanical integrity of the *** results revealed that the degradation rate of the bone-plate increased in the first 7 days and then decreased with the prolonged immersion time before it finally reached a steady stage(about 0.84 mm/a)after immersion for 90 *** bending strength after immersion for 60 days was 67.6 MPa,indicating that the bone-plate could support certain mechanical load after long term *** formation of corrosion pits after degradation stemmed from the separation of the continuously distributed second phases from Mg matrix under the action of micro-galvanic *** a result,the mechanical performance of Mg-4Zn-0.2Mn-0.2Ca alloy was aggravated owing to the corrosion holes on its surface.

关键词： magnesium alloys bending strength corrosion behaviors in vitro degradation bone-plate