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Effect of Ni Content on Mechanical Properties and Corrosion Behavior of Al/Sn－9Zn－xNi/Cu Joints

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Journal of Materials Science & Technology 2012年第9期28卷 844-852页

作者： M.l.Huang N.kang Q.Zhou y.Z.Huang key laboratory of liaoning Advanced Welding and Joining Technology School of Materials Science&EngineeringDMian University of TechnologyDalian 116024China

The effects of Ni content on the microstructure and the wetting behavior of Sn-9Zn-xNi solders on Al and Cu substrates, as well as the mechanical properties and electrochemical corrosion behavior of Al/Sn-9Zn-xNi/Cu solder joints, were investigated. The microstructure of Sn-gZn-xNi revealed that tiny Zn and coarsened Ni5Zn21 phases dispersed in theβ-Sn matrix. The wettability of Sn-9Zn-xNi solders on Al substrate was much better than that on Cu substrate. With increasing Ni content, the wettability on Cu substrate was slightly improved but became worse on Al substrate. In the Al/Sn-9Zn-xNi/Cu joints, an Al4.2Cu3.2Zn0.7 intermetallic compound （IMC） layer formed at the Sn-gZn-xNi/Cu interfaces, while an Al-Zn-Sn solid solution layer formed at the Sn-9Zn-xNi/Al interface. The mixed compounds of Ni3Sna and Al3Ni dispersed in the solder matrix and coarsened with increasing Ni content, thus leading to a reduction in shear strength of the Al/Sn-9Zn- xNi/Cu joints. Al particles were segregated at both interfaces in the solder joints. The corrosion potentials of Sn-9Zn-xNi solders continuously increased with increasing Ni content. The Al/Sn-9Zn-0.25Ni/Cu joint was found to have the best electrochemical corrosion resistance in 5% NaCl solution.

关键词： Al-Cu disslmilar-metal solder joint Sn-9Zn-xNi Microstructure Mechanicalproperties Electrochemical corrosion Corrosion potential

Effect of void nucleation on microstructure and stress state in aluminum alloy tailor-welded blank

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Progress in Natural Science:Materials International 2021年第1期31卷 77-85页

作者： l.Xing M.Zhan P.F.Gao M.li y.D.Dong T.y.Wang State key laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University Shaanxi key laboratory of High-Performance Precision Forming Technology and Equipment key laboratory of High Performance Manufacturing for Aero Engine (Northwestern Polytechnical university) Ministry of Industry and Information Technology

The microscopic damage initiation characteristic in welded joint greatly determines the subsequent damage evolution and fracture behavior of aluminum alloy tailor-welded blank(TWB) during plastic forming. In this study, the interactive dependence of void nucleation on microstructure and stress state in the welded joint of a2219 aluminum alloy TWB was quantitatively explored by in-situ SEM testing. Moreover, a micromechanical model based on actual microstructure was adopted to reveal the underlying mechanisms from the perspective of microscopic heterogeneous deformation. The results showed that three void nucleation mechanisms, including particle-cracking, interface-debonding and matrix-cracking, coexisted in the deformation at different microstructure regions and stress states. The nucleation strain of each mechanism mainly depended on the particle volume fraction, grain size and stress triaxiality. Besides, the proportions of particle-cracking and interfacedebonding greatly varied with the grain size and particle volume fraction, and the variation law changed with the stress state. The proportion of matrix-cracking had a weak dependence on the microstructure, while increased with the stress triaxiality decreasing. It made the damage initiation in aluminum alloy welded joint transit from particle-cracking dominance to matrix-cracking dominance with the stress triaxiality *** micromechanical modeling results suggested that the changes of evolutions and distributions of Mises stress in particle, hydrostatic stress at interface and plastic strain in matrix with microstructure and stress state were responsible for the above effects.

关键词： Aluminum alloy Welded joint Void nucleation Microstructure Stress state Micromechanical model

Overcoming the strength-ductility trade-off by tailoring grain-boundary metastable Si-containing phase in β-type titanium alloy

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Journal of Materials Science & Technology 2021年第9期68卷 112-123页

作者： X.luo l.H.liu C.yang H.Z lu H.W.Ma Z.Wang D.D.li l.C.Zhang y.y.li National Engineering Research Center of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou510640China State key laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan430074China key laboratory of Automobile Materials of MOE Department of Materials ScienceJilin UniversityChangchun130012China School of Engineering Edith Cowan University270Joondalup DriveJoondalupPerthWA 6027Australia

It is well accepted that grain-boundary phases in metallic alloys greatly deteriorate the mechanical *** our work,we report on a novel strategy to prepare high strength-ductility β-type(Ti69.71 Nb23.72Zr4.83Ta1.74)97Si3(at.%)(TNZTS) alloys by tailoring grain-boundary metastable Si-containing ***,the thin shell-shaped metastable S1 phase surrounding the columnar β-Ti grain was intercepted successfully via nonequilibrium rapid solidification achieved by selective laser melting(SlM).Subsequently,the thin shell-shaped metastable(Ti,Nb,Zr)5 Si3(called S1) phase was transformed into globular(Ti,Nb,Zr)2 Si(called S2) phase by the solution heat ***,the globular S2 phases reinforced TNZTS alloy exhibits ultrahigh yield strength of 978 MPa,ultimate strength of 1010 MPa and large elongation of 10.4 %,overcoming the strength-ductility trade-off of TNZTS alloys by various ***,the reported yield strength herein is 55 % higher than that of conventionally forged TNZT *** analysis indicates the globularization process of the metastable S1 phase is controlled by the model of termination *** quantitative analysis on strengthening mechanism demonstrates that the increase in yield strength of the heat-treated alloys is mainly ascribed to the strengthening of the precipitated silicide and the dislocations induced by high cooling *** obtained results provide some basis guidelines for designing and fabricating β-titanium alloys with excellent mechanical properties,and pave the way for biomedical application of TNZTS alloy by SlM.

关键词： Selective laser melting βtitanium alloys Heat treatment

Resolution Enhancement of Optical Surface Plasmon Resonance Sensor using Metamaterial

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Photonic Sensors 2015年第4期5卷 330-338页

作者： Sarika PAl y. k. PRAJAPATI J. P. SAINI V. SINGH Sarika Pal Department of Electronics & Communication Engineering KIET Ghaziabad (U.P.) India yogendra kumar Prajapati Department of Electronics & Communication Engineering MNNIT Allahabad-211004 (U.P.) India jai Prakash Saini Department of Electronics & Communication Engineering BIET Jhansi-284128 (U.P.) India Vivek Singh Department of Physics Faculty of Science Banaras Hindu University Varanasi (U.P.) India

In this paper, we present and discuss a an optical surface plasmon resonance （SPR） path to extend the enhancement of the resolution of sensor. Basically, our approach is to combine bi-metamaterial layers to design the SPR sensor. The calculation shows that the proposed SPR sensor structure has a preference over the conventional SPR sensors and bimetallic SPR sensors since it gives a much sharper reflectance dip and can achieve considerable sensitivity improvement when compared to the recently reported investigations. The effects of the metamaterial permittivity, permeability, and thickness on the reflectance curve are studied. It is also seen that metamaterial layers improve the field of the proposed SPR structure, which may provide a novel tool to significantly enhance the sensitivity and resolution of the sensors.

关键词： Surface plasmon resonance sensor metamaterials Fresnel equations reflectance

Trends and risk factors for opioid administration for non-emergent lower back pain

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World Journal of Orthopedics 2021年第9期12卷 700-709页

作者： Chukwuweike u Gwam Ahmed k Emara Noor Chughtai Sameer Javed T David luo kevin y Wang Morad Chughtai Tadhg O'Gara Johannes F Plate Department of Orthopedic Surgery Wake Forest School of MedicineWinston-SalemNC 27157United States Department of Orthopedic Surgery Cleveland Clinic FoundationClevelandOH 44195United States Department of Orthopaedic Surgery University of Pittsburgh5200 Centre AvenueSuite 415PittsburghPA 15232USA

BACkGROuND Non-emergent low-back pain(lBP)is one of the most prevalent presenting complaints to the emergency department(ED)and has been shown to contribute to overcrowding in the ED as well as diverting attention away from more serious *** has been an increasing focus in current literature regarding ED admission and opioid prescriptions for general complaints of pain,however,there is limited data concerning the trends over the last decade in ED admissions for non-emergent lBP as well as any subsequent opioid prescriptions by the ED for this *** To determine trends in non-emergent ED visits for back pain;annual trends in opioid administration for patients presenting to the ED for back pain;and factors associated with receiving an opioid-based medication for non-emergent lBP in the ED METHODS Patients presenting to the ED for non-emergent lBP from 2010 to 2017 were retrospectively identified from the National Hospital Ambulatory Medical Care Survey ***“year”variable was transformed to two-year intervals,and a weighted survey analysis was conducted utilizing the weighted variables to generate incidence *** statistics were used to assess differences in count data,and logistic regression was performed to identify factors associated with patients being discharged from the ED with *** significance was set to a P value of *** Out of a total of 41658475 total ED visits,3.8%(7726)met our inclusion and exclusion *** was a decrease in the rates of non-emergent back pain to the ED from 4.05%of all cases during 2010 and 2011 to 3.56%during 2016 and *** most common opioids prescribed over the period included hydrocodone-based medications(49.1%)and tramadol-based medications(16.9),with the combination of all other opioid types contributing to 35.7%of total opioids *** significantly associated with being prescribed narcotics included age over 43.84-years-old,higher income,priva

关键词： Opioids low back pain Emergency Department Spine Complications Trends

Static spheroidization and its effect on superplasticity of fine lamellae in nugget of a friction stir welded Ti-6Al-4V joint

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Journal of Materials Science & Technology 2022年第24期119卷 1-10页

作者： C.l.Jia l.H.Wu P.Xue H.Zhang D.R.Ni B.l.Xiao Z.y.Ma Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China key laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The spheroidization of the lamellar structure can greatly contribute to the superplasticity of the nugget zone(NZ)of Ti alloy welds,which is the key to achieve the integral superplastic forming of welds for the fabrication of large-scale complex ***,the spheroidization process is complex and costly since it cannot be obtained generally,unless the lamellae suffers from a large *** this study,the static spheroidization was achieved for the fine lamellae structure in the nugget of a friction stir welded(FSW)Ti-6Al-4V joint,particularly by the annealing without any *** specialα/βinterface obeying a Burgers orientation relationship(BOR)after FSW was first time directly observed,whose effect on the spheroidization was discussed.A new static spheroidization mechanism with the gradual coalescence of the adjacent lamellae was discovered,which we named as“termination coalescence”.There was a slower coarsening rate in the lamellar structure than in the classical equiaxed one,due to the BOR in the lamellae,although both of them exhibited a volume diffusion character during ***,the similar superplasticity can be achieved for the base material and NZ after *** study can provide a new way to the spheroidization and a theoretical basis for the integral superplastic forming of welds during production.

关键词： Friction stir welding Titanium alloys Spheroidization mechanism Coalescence Superplasticity Static annealing

Role of Baicalein in the regulation of proliferation and apoptosis in human myeloma RPMI8226 cells

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Chinese Medical Journal 2006年第11期119卷 948-952页

作者： lI Qiu-bai y0u yong CHEN Zhi-chao lü Jian SHA0 Jing Z0u Ping Institute of Hematology Union Hospital Tongji Medical CollegeHuazhong University of Science and Technology Wuhan 430022China

Multiple myeloma （MM） is a uniformly fatal disease characterized by a clonal proliferation of neoplastic plasma cells in the bone marrow and is the second most commol hematological malignancy.1 At present, a cure for multiple myeloma has not been achieved with chemotherapeutic regimen, and many patients die of drug-resistant disease. Thus, the development of new effective anticancer agents to treat both early and advanced MM seems to be an attractive perspective.

关键词： Baicalein 12-lipoxygenase proliferation apoptosis

Plasma production and preliminary results From the ADITyA upgrade tokamak

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Plasma Science and Technology 2018年第7期20卷 7-14页

作者： R l TANNA J GHOSH Harshita RAJ Rohit kuMAR Suman AICH Vaibhav RANJAN k A JADEJA k M PATEl S B BHATT k SATHyANARAyANA P k CHATTOPADHyAy M N MAkWANA k S SHAH C N GuPTA V k PANCHAl Praveenlal EDAPPAlA Bharat ARAMBHADIyA Minsha SHAH Vismay RAulJI M B CHOWDHuRI S BANERJEE R MANCHANDA D RAJu P k ATREy umesh NAGORA J RAVAl y S JOISA k TAHIlIANI S k JHA S k JHA M V GOPAlkRISHANA Institute for Plasma Research BhatGandhinagar 382 428India HBNI Training School complexAnushakti NagarMumbai 400085India

The Ohmically heated circular limiter tokamak ADITyA （R0 = 75 cm, a = 25 cm） has been upgraded to a tokamak named the ADITyA upgrade （ADITyA-u） with an open divertor configuration with divertor plates. The main goal of ADITyA-u is to carry out dedicated experiments relevant for bigger fusion machines including ITER, such as the generation and control of runaway electrons, disruption prediction, and mitigation studies, along with an improvement in confinement with shaped plasma. The ADITyA tokamak was dismantled and the assembly of ADITyA-u was completed in March 2016. Integration of subsystems like data acquisition and remote operation along with plasma production and preliminary plasma characterization of ADITyA-u plasmas are presented in this paper.

关键词： ADITyA-u tokamak Phase I plasma operation toroidal limiter enhanced parameters

Targeting growth hormone function: strategies and therapeutic applications

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Signal Transduction and Targeted Therapy 2019年第1期4卷 614-624页

作者： Man lu Jack u.Flanagan Ries J.langley Michael P.Hay Jo k.Perry liggins Institute University of AucklandAucklandNew Zealand Auckland Cancer Society Research Centre School of Medical SciencesUniversity of AucklandAucklandNew Zealand Maurice Wilkins Centre for Molecular Biodiscovery AucklandNew Zealand Department of Molecular Medicine and Pathology School of Medical SciencesUniversity of AucklandAucklandNew Zealand

Human growth hormone(GH)is a classical pituitary endocrine hormone that is essential for normal postnatal growth and has pleiotropic effects across multiple physiological *** is also expressed in extrapituitary tissues and has localized autocrine/paracrine effects at these *** adults,hypersecretion of GH causes acromegaly,and strategies that block the release of GH or that inhibit GH receptor(GHR)activation are the primary forms of medical therapy for this *** of GH has also been linked to cancer and the microvascular complications that are associated with ***,studies to investigate the therapeutic potential of GHR antagonism in these diseases have been limited,most likely due to difficulty in accessing therapeutic tools to study the pharmacology of the receptor in *** review will discuss current and emerging strategies for antagonizing GH function and the potential disease indications.

关键词： therapeutic pituitary diseases