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thermodynamic Aspects of Nanostructured CoAl Intermetallic Compound during Mechanical Alloying

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Journal of Materials Science & technology 2011年第7期27卷 601-606页

作者： S.N. Hosseini t. Mousavi F. Karimzadeh M.H. Enayati department of Materials Engineering Nanotechnology and Advanced Materials Institute Isfahan University of Technology84156-83111 Iran

the nanostructured CoAl intermetallic compound was produced by mechanical alloying （MA） of the Co50Al50 elemental powder mixture in a planetary high energy ball mill. the ordered B2-CoAl structure with the grain size of about 6 nm was formed via a gradual reaction after 10 h of MA. A thermodynamic analysis of the process was also done. the results showed that the intermetallic compound of CoAl had the minimum gibbs free energy compared to solid solution and amorphous states indicating the initial MA product was the most stable phase in the Co-Al system which was changed to a partially disordered structure with a steady long-range order of 0.82 at further milling. this amount of disordering caused the enthalpy of final product to show an increase of about 5.1 kJ·mol-1. Calculation of enthalpy related to the triple defect formation revealed that the enthalpy required for Al anti-sites formation was about 3 times greater than that for Co anti-sites formation.

关键词： Intermetallics CoAl Nanostructured materials Mechanical alloying thermodynamics

Effect of Pulsed Current t.g Welding Parameters on Pitting Corrosion Behaviour of AA6061 Aluminium Alloy

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Journal of Materials Science & technology 2007年第2期23卷 223-229页

作者： t.Senthil Kumar V.Balasubramanian M.Y.Sanavullah S.Babu department of Automobile technology Bharathidasan UniversityTiruchirappalli 620 024India department of Manufacturing Engineering Annamalai UniversityAnnamalainagar 608 002India Principal V.M.K.V.Engineering CollegeSalem 636 308India

Medium strength aluminium alloy （Al-Mg-Si alloy） has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to weight ratio, such as transportable bridge girders, military vehicles, road tankers and railway transport systems. the preferred welding process for aluminium alloy is frequently t.g （tungsten inert.gas） welding due to its comparatively easier applicability and better *** the case of single pass t.g welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advant.ges over the conventional continuous current process. the use of pulsed current parameters has been found to improve the mechanical properties of the welds compared to those of continuous current welds of this alloy due to grain refinement occurring in the fusion zone. A mathematical model has been developed to predict pitting corrosion potential of pulsed current t.g welded AA6061 aluminium *** experimental design has been used to optimize the experimental conditions. Analysis of variance technique has been used to find out the significant pulsed current parameters. Regression analysis has been used to develop the model. Using the developed model pitting corrosion potential values have been estimated for different combinations of pulsed current parameters and the results are analyzed in detail.

关键词： Pulsed current tungsten inert.gas welding Medium strength aluminium alloy Pitting corrosion design of experiments Analysis of variance

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冻结肩病理——一种杜普依特伦样疾病

中华骨科杂志 1997年第3期17卷 212-216页

作者：徐瑾 Consultant Orthopaedic Surgeon Princess Elizzbeth Orthopaefic Hospital 英国 University of Exeter 英国

连续９３５例肩痛病人中，有５０例符合原发性冻结肩的标准。在保守和手法治疗后，其中１２例病人未见改善而行喙肱韧带及关节囊的旋肌间隔切除术。标本用特殊的胶原染色进行组织学检查。以单克隆抗体抗白细胞共同抗原（ＬＣＡ，ＣＤ４... 详细信息

连续９３５例肩痛病人中，有５０例符合原发性冻结肩的标准。在保守和手法治疗后，其中１２例病人未见改善而行喙肱韧带及关节囊的旋肌间隔切除术。标本用特殊的胶原染色进行组织学检查。以单克隆抗体抗白细胞共同抗原（ＬＣＡ，ＣＤ４５）和巨噬细胞／滑膜抗原（ＰＧＭＩ，ＣＤ６８）来测定其炎性成分；以波形蛋白（ｖｉｍｅｎｔｉｎ）和平滑肌肌动蛋白（ＡＳＭＡ）评价纤维母细胞和肌纤维母细胞等进行免疫细胞化学检查。组织学和免疫细胞化学结果表明其病理过程是伴有一些向平滑肌表型转变的活跃的纤维母细胞增殖（肌纤维母细胞）。这些纤维母细胞产生一种粗结节带状或肥厚团块状的胶原。病理表现与既非炎症又无滑膜受累的手Ｄｕｐｕｙｔｒｅｎ’ｓ病非常相似。挛缩充当了一根牵制缰绳来拮抗外旋，导致主动与被动运动均丧失。

关键词：冻结肩病理学

Corrosion Resistance of transmission Pipeline Steel Coated with Five types of Enamels

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Acta Metallurgica Sinica(English Letters) 2017年第4期30卷 390-398页

作者： Liang Fan Fujian tang Signo t. Reis genda Chen Michael L. Koenigstein department of Civil Architectural and EnvironmentalEngineering Missouri University of Science andTechnology Rolla MO 65409-0030 USA Pro-Perma Engineered Coatings Roesch Inc. Belleville IL62226 USA

Corrosion is one of the main causes of incidents occurred in hazardous liquid and gas transmission pipelines in the USA, resulting in a loss of over $12 billion per year. In this study, the corrosion resistance of pipeline steel coated with five types of enamel was invest.gated in 3.5 wt% NaCl solution with linear polarization resistance and electrochemical impedance spectroscopy tests. Steel coupons were cut from API 5L X65 pipeline steel and coated with five types of enamels using the wet process. the microstructures of all enamel samples were examined by scanning electron microscopy. Experimental results indicate that all enamel coatings increase the corrosion resistance of pipeline steel, and pure enamel PE2, mixed enamels ME1 and ME2 have higher corrosion resistances than pure enamel PE1 and mixed enamel ME3.

关键词： Steel pipe Enamel coating Scanning electron microscopy (SEM) Electrochemical impedance spectroscopy (EIS)

Unusual switchable peroxidase-mimicking nanozyme for the determination of proteolytic biomarker

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Nano Research 2019年第3期12卷 509-516页

作者： Claire McVey Natasha Logan Nguyen t. K. thanh Christopher Elliott Cuong Cao Institute for global Food Security School of Biological Sciences Queens University Belfast 18-30 Malone Road Belfast BT9 5BN UK Biophysics group Department of Physics and Astronomy University College London London WC1E 6BT UK UCL Healthcare Biomagnetic and Nanomaterials Laboratories 21 Albemarle Street London W1S 4BS UK Material and Advanced technologies for Healthcare Queens University Belfast 18-30 Malone Road Belfast BT9 5BN UK

detection of enzyme biomarkers originating from either bio-fluids or contaminating microorganisms is of utmost importance in clinical diagnostics and food safety. Herein, we present a simple, low-cost and easy-to-use sensing approach based on the switchable peroxidase-mimicking activity of plasmonic gold nanoparticles (AuNPs) that can catalyse for the oxidation of 3,3’,5’5-tetramethylbenzidine (tMB) for the determination of protease enzyme. the AuNP surface is modified with casein, showing dual functionalities. the first function of the coating molecule is to suppress the intrinsic peroxidase-mimicking activity of AuNPs by up to 77.1%, due to surface shielding effects. Secondly, casein also functions as recognition sites for the enzyme biomarker. In the presence of protease, the enzyme binds to and catalyses the degradation of the coating layer on the AuNP surface, resulting in the recovery of peroxidase-mimicking activity. this is shown visually in the development of a blue colored product (oxidised tMB) or spectroscopically as an increase in absorbance at 370 and 650 nm. this mechanism allows for the detection of protease at 44 ng·mL^-1 in 90 min. the nanosensor circumvents issues associated with current methods of detection in terms of ease of use, compatibility with point-of-care testing, low-cost production and short analysis time. the sensing approach has also been applied for the detection of protease spiked in ultra-heat treated (UHt) milk and synthetic human urine samples at a limit of detection of 490 and 176 ng·mL^-1, respectively, showing great potential in clinical diagnostics, food safety and quality control.

关键词： gold nano particles peroxidase-mimicking nanozyme enzyme detection biomarkers

Role of CARd15,dLg5 and OCtN genes polymorphisms in children with inflammatory bowel diseases

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World Journal of gastroenterology 2007年第8期13卷 1221-1229页

作者： S Cucchiara A Latiano O Palmieri AM Staiano R d'Incà g guariso g Vieni V Rut.gliano O Borrelli MR Valvano V Annese Clinica Pediatrica Università "La Sapienza" Roma Italy U.O. gastroenterologia IRCCS "Casa Sollievo della Sofferenza" San Giovanni Rotondo Italy Clinica Pediatrica Università di Napoli Università di Padova Italy Cattedra di gastroenterologia Università di Padova Italy Clinica Pediatrica Università di Padova Italy Clinica Pediatrica Università di Messina Italy Clinica Pediatrica Università di Bari Italy

AIM: to invest.gate the contribution of variants of CARd15, OCtN1/2 and dLg5 genes in disease predispo- sition and phenotypes in a large Italian cohort of pediatric patients with inflammatory bowel diseases (IBd). MEtHOdS: two hundred patients with Crohn’s disease (Cd), 186 ulcerative colitis (UC) patients, 434 par- ents (217 trios), and 347 healthy controls (HC) were studied. Polymorphisms of the three major variants of CARd15, 1672C/t and -207g/C SNPs for OCtN genes, IgR2096a_1 and IgR2198a_1 SNPs for the IBd5 locus, and 113g/A variant of the dLg5 gene were evaluated. Potential correlations with clinical sub-phenotypes were invest.gated. RESULtS: Polymorphisms of CARd15 were significantly associated with Cd, and at least one variant was found in 38% of patients (15% in HC, OR = 2.7, P gosis for both OCtN1/2 variants was more com- mon in Cd patients (1672tt 24%, -207CC 29%) than in HC (16% and 21%, respectively; P = 0.03), with an in- creased frequency of the tC haplotype (44.8% vs 38.3% in HC, P = 0.04). No association with the dLg5 variant was found. Cd carriers of OCtN1/2 and dLg5 variants more frequently had penetrating disease (P = 0.04 and P = 0.01), while carriers of CARd15 more frequently had ileal localization (P = 0.03). No gene-gene interaction was found. In UC patients, the tC haplotype was morefrequent (45.4%, P = 0.03), but no genotype/phenotype correlation was observed. CONCLUSION: Polymorphisms of CARd15 and OCtN genes, but not dLg5 are associated with pediatric on- set of Cd. Polymorphisms of CARd15, OCtN, and dLg5 genes exert a weak influence on Cd phenotype.

关键词：儿童炎症性肠病 CARd15基因 dLg5基因 OCtN基因基因多态性

CONtINUOUS StIFFNESS MOdE NANOINdENtAtION RESPONSE OF POLY(MEtHYL MEtHACRYLAtE) SURFACES

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Chinese Journal of Polymer Science 2013年第8期31卷 1096-1107页

作者： t. Iqbal B.J. Briscoe S. Yasin P.F. Luckham Chemical Engineering department University of Engineering & Technology Chemical Engineering department Imperial College

Indentation is a comparatively simple and virtually nondestructive method of determining mechanical properties of material surfaces by means of an indenter inducing a localized deformation. the paper present experimental results of the load-displacement curves, the hardness and the elastic modulus data, and associated analysis for poly（methyl methacrylate）（PMMA） surfaces as a function of contact displacement. the experimental results include continuous stiffness indentations performed using constant loading rate and constant displacement rate experiments. the continuous stiffness indentation involves continuous calculation of a material stiffness, and hence hardness and elastic modulus of surfaces, during discrete loading-unloading cycles, as in a conventional indentation routine, and in a comparatively smaller time constant, the dependence of the compliance curves, the hardness, the elastic modulus and the plasticity index upon the imposed penetration depth, the applied normal load and the deformation rate are described. tip area and load frame calibrations for the continuous stiffness indentation are also reported. the paper includes practical considerations encountered during indentation of polymers specifically at low penetration depths. the experimental results show a peculiarly harder response of PMMA surfaces at the submicron （near to surface） layers.

关键词： Nanoindentation PMMA Hardness Modulus Continuous stiffness.

Microstructure and properties of ti-6Al-4V fabricated by low-power pulsed laser directed energy deposition

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Journal of Materials Science & technology 2019年第9期35卷 2027-2037页

作者： Hua tan Mengle guo Adam t. Clare Xin Lin Jing Chen Weidong Huang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an710072China Key Laboratory of Metal High Petformance Additive Manufacturing and Innovative design MIIT ChinaNorthwestern Polytechnical UniversityXi'an 710072China Institute for Advanced Manufacturing Faculty of EngineeringUniversity Of NottinghamNG7 2RDUK department of Mechanical Materials and Manufacturing EngineeringFaculty of Science and EngineeringUniversity o f Nottingham China199 Taikang East RoadUniversity ParkNingbo315100China

thin-wall structures of ti-6A1-4V were fabricated by low-power pulsed laser directed energy deposition. during deposition, consistent with prior reports, columnar grains were observed which grew from the bottom toward the top of melt pool tail. this resulted in a microstructure mainly composed of long and thin prior epitaxial β columnar grains (average width ^200μm). A periodic pattern in epitaxial growth of grains was observed, which was shown to depend upon laser traverse direction. Utilizing this, a novel means was proposed to determine accurately the fusion boundary of each deposited layer by inspection of the periodic wave patterns. As a result it was applied to invest.gate the influence of thermal cycling on microstructure evolution. Results showed that acicular martensite,α' phase, and a small amount of Widmanstatten, a laths, gradually converted to elongated acicular a and a large fraction of Widmanstatten a laths under layer-wise thermal cycling. tensile tests showed that the yield strength, ultimate tensile strength and elongation of ti-6Al-4V thin wall in the build direction were 9.1 %, 17.3% and 42% higher respectively than those typically observed in forged solids of the same alloy. It also showed the yield strength and ultimate tensile strength of the transverse tensile samples both were 13.3% higher than those from the build direction due to the strengthening effect of a large number of vertical β grain boundaries, but the elongation was 69.7% lower than that of the build direction due to the uneven grain deformation of β grains.

关键词： directed energy deposition ti-6Al-4V Microstructure thermal cycle history Mechanical properties

An essential role for tAK1 in the contact hypersensitivity response

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Cellular & Molecular Immunology 2011年第4期8卷 315-324页

作者： Yan g Zhao Yunqi Wang Weidong Hao Yisong Y Wan department of toxicology School of Public HealthPeking UniversityBeijingChina department of Microbiology and Immunology Lineberger Comprehensive Cancer CenterUniversity of North Carolina at Chapel HillNCUSA

Contact hypersensitivity(CHS)is a delayed-type hypersensitivity that can be induced by haptens,such as 2,4-dinitrofluorobenzene(dNFB).Innate and adaptive immunities are both important for the development of *** treat CHS-related diseases,such as allergic contact dermatitis,a disease prevalent in industrialized countries,ways of interfering with improper immune function during CHS responses need to be *** growth factor-b-activated kinase-1(tAK1),a member of mit.gen-activated protein kinase kinase kinase family,is important for both innate and adaptive *** thus hypothesized that the CHS response could be inhibited by interfering with tAK1 *** a mouse model in which tAK1 deletion can be locally induced,we observed that tAK deficiency led to an impaired CHS response and was associated with defective t-cell expansion,activation and interferon(IFN)-c *** addition,we invest.gated the effect of deleting tAK1 specifically in dendritic cells(dC)on the CHS *** found that when tAK1 is deficient in dC,the CHS response was abolished and hapten-elicited t-cell responses were ***,this study demonstrates an essential role of tAK1 in the induction of CHS and suggests that targeting tAK1 could be a viable approach to treat CHS.

关键词： CHS dC 2,4-dinitrofluorobenzene(dNFB) tAK1