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Acta Metallurgica Sinica(English letters) 2005年第5期18卷 620-626页

作者： A.l. Fan W.H. Tian q. Suns B.S. wang Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China Taiyuan University of Science and Technology Taiyuan 030024 China 210 Institute The Chinese Ordnance Industry Institute Beijing 100081 China

The microstructures of electroformed copper liners of shaped charges that had undergone high-strain-rate deformation were observed by optical microscopy （OM） and scanning electron microscopy （SEM）. Meanwhile, the orientation distribution of the grains in the recovered jet was examined by electron backscattering Kikuchi pattern （EBSP） technique. EBSP analysis reveals that the fibrous texture observed in the as-electroformed copper liners disappeared after explosive detonation deformation. OM observation shows that the microstructure evolves system- atically from the jet center to its perimeter during cooling from high temperatures after explosive detonation deformation. This microstructural characteristic is similar to that of solidification, i.e. there exist equiaxed grains in the center of the jet and significant columnar grains around the equiaxed grains. The result reveals that there is melting-related phenomenon in the jet center. Corresponding microhardness variations from the jet center to its perimeter is also determined. All the phenomena can be explained by a strong gradient of temperature across the section of the jet during plastic deformation at high-strain-rate.

关键词： jetting electroformation microstructure hardness,ultra-high strain rate deformation

Design and Pilot Programs of Marine Exposure Station of A Sea-crossing Bridge

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武汉理工大学学报 2010年第17期32卷 131-136页

作者： qIN M q wang C J TU l q ZHANG G Z SUN T X Wuhan Harbour Engineering Design and Research Co. ltd. Wuhan 430071China Key lab of large-span Bridge Construction Technology Ministry of CommunicationsWuhan 430071China Zhejiang Province Zhoushan Island linking Construction Commanding Department Zhoushan 316032China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

This paper presents the location,the structural design as well as the anti-corrosion and the pilot programs of the marine exposure station of Zhoushan Archipelago seas sea-crossing bridges. Subjected to the marine environment,the concrete structures in serve with different mixing proportions,cover thickness,additional anti-corrosion measures such as rust-preventing agent,coating,penetration crystalline waterproof material,silicone and permeable fabric were studied. Those results obtained provide important information for the maintenance of marine concrete and the structural design of sea-crossing bridges in the above sea area.

关键词： exposure station sea-crossing bridge marine concrete durability design

Effect of Silver Content on Microstructure and Properties of Brass/steel Induction Brazing Joint Using Ag-Cu-Zn-Sn Filler Metal

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Journal of Materials Science & Technology 2011年第4期27卷 377-381页

作者： J. Cao l.X. Zhang H.q. wang l.Z. Wu J.C. Feng State Keylab of AdvanCed Welding Production Technology Harbin Instituteof Technology Harbin 150001 China Center for Composite Materials and Structures Harbin Institute of Technology Harbin 150001 China

The induction brazing of brass to steel using Ag-Cu-Zn-Sn filler metal was investigated in this study. The influence of A8 content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag- Cu-Zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and Cu-based solid solution. The increase of A8 content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25CuZnSn filler metal reached 445 MPa. All fractures using Ag-Cu-Zn-Sn filler metal presented ductile characteristic.

关键词： Induction brazing Brass Steel Microstructure Tensile strength

Constitutive equation and model validation for a 31 vol.% B_4Cp/6061Al composite during hot compression

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Journal of Materials Science & Technology 2018年第10期34卷 1730-1738页

作者： l. Zhou C. Cui q.Z. wang C. li B.l. Xiao Z.Y. Ma Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China School of Electromechanical and Vehicle Engineering Yantai University Yantai 264005 China School of Mechanical Engineering Shenyang Ligong University Shenyang 110159 China Nuclear and Radiation Safety Center Ministry of Environmental Protection Beijing 100082 China

An accurate constitutive equation is essential to understanding the flow behavior of B4C/A1 compos-ites during the hot deformation. However, the constitutive equations developed previously in literature are generally for low strain rate deformation. In the present work, we modified the general consti-tutive equation and take the high strain rate correction into account. The constitutive equation for a 31 vol.% B4Cp/6061AI composite was constructed based on the flow stresses measured during isothermal hot compression at temperatures ranging from 375 to 525 ℃ and strain rates from 0.01 to 10 s^-1. The experimental flow stresses were corrected by considering temperature-dependent Arrhenius factor. The modified equation was then verified by using DEFORM-3D finite element analysis to simulate the exper-imental hot compression process. The results show that the modified equation successfully predicts flow stress, load-displacement, and the temperature rise. This helps to optimize the hot deformation process, and to obtain desirable properties, such as reduced porosity and homogenous particle distribution in B4C/AI composites.

关键词： Composites B4C/AI Constitutive equation Hot compression Finite element simulation

INVESTIGATION ON THE FORMATION MECHANISM OF TITANIUM CARBIDE PREPARED BY IN SITU REACTION IN MOlTEN AlUMINUM

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Acta Metallurgica Sinica(English letters) 1997年第6期10卷 485-488页

作者： Yang, B. wang, Y.q Zhang, J. Zhou, B.l. Inst of Metal Research Chinese Acad of Sciences Shenyang China

A novel technique in which TiC particulate are prepared by an in situ reaction in molten aluminum was introduced for producing TiC/Al composite. In order to reveal the characteristics of the technique, the formation mechanism of TiC particulate prepared by this method was studied. Both theoretical and experimental results show that the TiC particulate is formed by a diffusion mechanism when the molar fraction of aluminum in the preforms is higher than 20.02%. On the contrary, the TiC particulate is formed by a solution-precipitation mechanism when the fraction of aluminum in the preforms is lower than 20.02%.

关键词： Aluminum metallurgy In situ processing Metallic matrix composites Titanium carbide

Microstructure and mechanical properties of Mg-to-Al dissimilar welded joints with an Ag interlayer using ultrasonic spot welding

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Journal of Magnesium and Alloys 2020年第2期8卷 552-563页

作者： H.Peng D.l.Chen X.F.Bai P.q.wang D.Y.li X.q.Jiang College of Engineering and Technology Southwest UniversityTiansheng Road 2Beibei DistrictChongqing 400715China Department of Mechanical and Industrial Engineering Ryerson University350 Victoria StreetTorontoOntario M5B 2K3Canada School of Materials and Energy Southwest UniversityTiansheng Road 2Beibei DistrictChongqing 400715China Department of Chemical and Materials Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada

lightweight ZEK100-0 Mg alloy and A16022-T43 Al alloy with an Ag interlayer were joined via ultrasonic spot welding(USW),focusing on the microstructural change and tensile lap shear strength of the welded joints in relation to welding ***/Al interface was superseded by Mg/Ag and Al/Ag interfaces,and unfavorable Mg门A-intermetallic compound was *** foil was observed to be intact in the nugget center,while it was broken or dissolved at the nugget edge at high welding energy *** diffusion layer at the Mg/Ag interface consisted of two distinctive sub-layers:Mg3Ag intermetallic compound adjoining Ag foil,and Mg3Ag-l-Mg eutectic structure adjacent to *** a thin diffusion layer consisting mainly of Ag3Al occurred al lhe Al/Ag *** tensile lap shear strength first increased,reached its peak value,and then decreased with increasing welding *** shear strength achieved in the present study was〜31%higher than that of the joint without *** failure occurred at all energy levels,with Ag foil particles or fragments being stuck on both Mg and Al sides due to its intense interaction with Mg and Al via accelerated diffusion during *** results obtained pave the way for the challenging dissimilar welding between Mg and Al alloys.

关键词： Magnesium alloy Aluminum alloy Ultrasonic spot welding Ag interlayer Microstructure Tensile lap shear strength

A Special Kind of Interplanetary Coronal Mass Ejection

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Research in Astronomy and Astrophysics 2024年第12期24卷 185-193页

作者： H.q.Feng Y.Zhao G.q.Zhao H.B.li l.Xiang J.M.wang Institute of Space Physics Luoyang Normal University Henan Key laboratory of Electromagnetic Transformation and Detection Luoyang Normal University

It is generally believed that coronal mass ejections(CMEs) have magnetic flux rope structures because of their helical shapes. However, only about 30%–40% of interplanetary CMEs(ICMEs) have a local magnetic flux rope structure. The usual explanations are that the spacecraft only crossed the flank of the ropes and failed to detect the complete magnetic flux rope structure or that some processes destroyed these magnetic flux rope structures. Several studies suggest that some ICMEs inherently possess disordered magnetic fields and consequently exhibit no magnetic flux-rope structures. We introduce a special kind of ICME which has a low magnetic field magnitude and stable magnetic field direction, relatively fast expansion speed, and lower proton temperature and density. All three of the measured magnetic field components are relatively stable. We want to know whether these ICMEs also have magnetic flux rope structures or not. We identified 20 special ICMEs and analyzed their evolution based on their observed characteristics. We took a special ICME as an example, which had an apparent rope configuration at 1 au but evolved to a special ICME at 5.4 au, to illustrate that this kind of ICME could come from magnetic clouds(MCs) whose rope structure had been being stretched due to expansion. We inferred that the missing obvious flux rope structure may be due to the expansion of MCs, not the flank crossing effect. However, more than 50% of the events were associated with the dominant x-component of the magnetic field, which indicates a leg ***, the detection of part of these special ICMEs may also be the result of the leg-crossing effect.

关键词： (Sun:) solar wind interplanetary medium Sun: coronal mass ejections (CMEs)

Embedding laser-generated CdTe nanocrystals into ultrathin ZnIn_(2)S_(4) nanosheets with sulfur vacancies for boosted photocatalytic H_(2) evolution

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Journal of Materials Science & Technology 2023年第35期166卷 113-122页

作者： Z.G.Tai G.T.Sun X.H.Zhang X.B.Yang T.wang Z.Y.Fang q.Ye l.C.Jia H.q.wang State Key laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China School of Materials Science and Engineering Shaanxi Normal UniversityXi’an 710119China

To suppress the inner charge recombination and inject vast electrons,CdTe nanocrystals are embedded into ultrathin ZnIn_(2)S_(4) nanosheets to construct ZnIn_(2)S_(4)/CdTe heterostructures,where the nanocrystals are generated by a laser irradiation *** optimal ZnIn_(2)S_(4)/CdTe heterojunction exhibits an excellent catalytic activity of 24.3 mmol/h/g,which is relatively high among the ZnIn_(2)S_(4)-based photocatalysts with-out noble *** enhancement is ascribed to a win-win mechanism of nanoscale heterojunctions and sulfur *** strong electron coupling effect,which is verified by density functional the-ory(DFT)calculations,impels the photo-generated electrons transfer from CdTe to ZnIn_(2)S_(4),boosting the charge ***,the sulfur vacancies existing in ZnIn_(2)S_(4) can capture photoelectrons and act as active sites,facilitating the H_(2) generation *** addition,the ZnIn_(2)S_(4) base and the ZnIn_(2)S_(4)/CdTe heterojunction also possess an evident photothermal effect and renewable cycle phenomena,enhancing the photocatalytic *** research provides new insights into the regulation of charge transfer through embedding nanocrystals.

关键词： Photocatalysis Hydrogen evolution laser irradiation Heterostructure Sulfur vacancies

Structural Effects of l16q, S20G, and l16q-S20G Mutations on hlAPP： A Comparative Molecular Dynamics Study

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Chinese Journal of Chemistry 2012年第2期30卷 241-248页

作者： wang,Mian Yang,Jipeng wang,Jianyi wang,Xiaojuan School of Chemistry and Chemical Engineering Guangxi UniversityNanningGuangxi 53004China Jiyuan Vocational and Technical College JiyuanHenan 459000China

The conformation change picture of human islet amyloid polypeptide （hlAPP） is outlined using molecular dynamics simulation, and the structural influences of l16q, S20G, and l16q-S20G mutations on the conformation of hlAPP are analyzed. Particularly, the conformational changes of the amyloidogenic-related regions of residues 15-- 17 and 20--29 are emphasized. Our studies find that, for WT hlAPP, residues 15--17 always maintain a stable a-helix structure, residues 20--25 structurally fluctuate between turn and 5-helix, and residues 26--29 mainly adopt coil and bend structures. The hydrogen bonds between the polar groups of hlAPP, long-rang van der Waals forces between the residues, and hydrophobic interactions between the residues of hlAPP are important driving forces to maintain the secondary structure of hlAPP. The replacement of leucine 16 by glutamine stabilizes the helix structure of residues 15--17 and 20--23 of hlAPP monomer, and the structure of residues 24--29 fluctuates be- tween helix and turn. The relatively stable helix structures of residues 15--17 and 20--29 are supposed to be beneficial for l16q hlAPP to resist the aggregation as observed in the experiment. The substitution of serine20 by glycinc drives residues 15--17 and 20--29 of hlAPP to transform from helix structure to β-strands or coil structures with higher extension and flexibility, which may promote the aggregation of hlAPP as the experiments reported. These results are significant to understand the aggregation mechanism of hlAPP monomer into the dimer, trimer, oligomers and fibrils associated with the type 2 diabetes at the atomic level.

关键词： hIAPP wild type mutant molecular dynamics simulation

FEM SIMUlATION FOR lASER FORMING PROCESSING

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Acta Metallurgica Sinica(English letters) 2004年第3期17卷 317-322页

作者： l.q.li Y.B.Chen X.Y wang S.Y lin State Key laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Harbin Research Institute of Welding Harbin 150001 ChinaState Key Laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China Harbin Research Institute of Welding Harbin 150001 ChinaHarbin Research Institute of Welding Harbin 150001 ChinaHarbin Research Institute of Welding Harbin 150001 China

laser forming involves heating sheet metal workpiece along a certain path with adefocused laser beam directed irradiate to the surface. During laser forming, a tran-sient temperature fields is caused by the irradiation and travelling of a laser beam.Consequently, thermal expansion and contraction take place, and allows the thermal-mechanical forming of complex shapes. This is a new manufacturing technique thatforming metal sheet only by thermal stress. Therefore, the analysis of temperaturefields and stress fields are very useful for studying the forming mechanism and con-trolling the accuracy of laser forming. The non--liner finite element solver, MARC, isemployed to solve the thermal--mechanical analysis. Using this model, the stress andstrain distribution of pure aluminum plate with different thickness are analyzed. Theinfluence of scanning speed on temperature fields and plastic strain of metal sheet un-der the condition of constant line energy are also presented. Numerical results agreewell with the experimental results.

关键词： laser forming FEM simulation temperature fields stress distributton