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Acta metallurgica Sinica(English Letters) 2004年第4期17卷 560-568页

作者： j.m.Gong y.jiang S.T.Tu Nanjing University of Technology Nanjing 210009 ChinaNanjing University of Technology Nanjing 210009 ChinaNanjing University of Technology Nanjing 210009 China East China University of Science and Technology Shanghai 200237 China

In this paper, the effect of carbon migration on creep properties of Cr5mo dissimilar welded joints with Ni-based (Inconel 182) and Cr23Nil3 (A302) austenitic weld metal was investigated. Carbon migration near the weld metal/ferritic steel interface of Cr5mo dissimilar welded joints was analyzed by aging method. Local creep deformations of the dissimilar welded joints were measured by a long-term local creep deformation measuring technique. The creep rupture testing was performed for Cr5mo dissimilar welded joints with Inconel 182 and A302 weld metal. The research results show that the maximum creep strain rate occurs in the decarburized zone located on heat affect zone (HAZ) of Cr5mo ferritic steel. The creep rupture life of Cr5mo dissimilar welded joints with A 302 weld metal decreases due to carbon migration and is about 50% of that welded with Inconel 182 weld metal.

关键词： dissimilar welded joint carbon migration creep rupture localized deformation

Electromagnetoelastic behaviors of functionally graded piezoelectric solid cylinder and sphere

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Acta mechanica Sinica 2007年第1期23卷 55-63页

作者： H. L. Dai y.m. Fu j.H. yang Department of Engineering mechanics Hunan University Changsha 410082 China

Analytical studies on electromagnetoelastic behaviors are presented for the functionally graded piezoelectric material （FGPm） solid cylinder and sphere placed in a uniform magnetic field and subjected to the external pressure and electric loading. When the mechanical, electric and magnetic properties of the material obey an identical power law in the radial direction, the exact displacements, stresses, electric potentials and perturbations of magnetic field vector in the FGPm solid cylinder and sphere are obtained by using the infinitesimal theory of electromagnetoelasticity. Numerical examples also show the significant influence of material inhomogeneity. It is interesting to note that selecting a specific value of inhomogeneity parameter β can optimize the electromagnetoelastic responses, which will be of particular importance in modern engineering designs.

关键词： Functionally graded piezoelectric material (FGPm) Electromagnetoelastic Solid cylinder Solid sphere Perturbation of magnetic field vector

Rotational and translational domains of beta precipitate in aged binary mg-Ce alloys

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journal of magnesium and Alloys 2021年第3期9卷 1039-1056页

作者： B.Z.Sun H.X.Zhang y.Dong j.X.Ren y.Tian G.m.Xie j.Tan y.H.Sun Na Xiao School of materials Science and Engineering Northeastern UniversityShenyang 110819China State Key Lab Rolling&Automat Northeastern UniversityShenyang 110819China Key Laboratory for Anisotropy and Texture of materials Ministry of EducationNortheastern UniversityShenyang 110819China Analytical and Testing Center Northeastern UniversityShenyang 110819China

The structural evolution fromβ_(1)(mg_(3)Ce)toβ(mg_(12)Ce)precipitates,which takes place at the over-aged stage of binary mg-Ce alloys,are investigated by high-angle annular dark-field scanning transmission electron *** structural transformation mainly occurs in the{111}_(β1)crystallographic planes,where the newly formedβlattices exhibit two categories of domain structures,namely rotational and translational *** rotational domain is composed of threeβdomains(β_(RA),β_(RB)andβ_(RC)),which are related by a 120°rotation with respect to each other around the 111_(β1)axis of theirβ_(1)parent ***{111}_(β1)crystallographic planes can provide four sets of sublattices with the same orientation for an initial nucleation ofβ*** leads to the formation of four translationalβdomains(β_(TA),β_(TB),β_(TC)andβ_(TD)),among which any two differ by a vector of 1/6112_(β1).We deduce theoretically that there exist twenty-fourβdomains during this ***,considering the interfacial misfit,only one-third of domains can grow up and eventually formsβ***,a majority ofβribbons overlap partiallyβ_(1)plate,which is beneficial to relax interfacial strain amongβ,β_(1)andα-mg matrix(α/β/β_(1)).The configuration of multipleβdomains can effectively regulate interfacial misfit ofα/βandβ/β_(1),which are responsible for enhancing the hardness and strength of mg-Ce ***,this study aims to provide some clues to improve the over-aged performance of magnesium alloys by constructingβdomains and optimizing theα/β/β_(1)interface.

关键词： magnesium alloys HAADF-STEm Rotational domain Translational domain Phase transition Interfacial misfit

Effect of coating material and lubricant on forming force and surface defects in wire drawing process

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Transactions of Nonferrous metals Society of China 2011年第A01期21卷 104-110页

作者： S.m.ByON S.j.LEE D.W.LEE y.H.LEE y.LEE Department of mechanical Engineering Dong-A University Department of mechanical Engineering Chung-Ang University Wire Rod Research Group POSCO Technical Research Laboratories

A pilot wire drawing machine as well as wire end-pointing roller was developed. Using these machines, a wire drawing test for four different coating materials and two different lubricants was performed as the reduction ratio increased from 10% to 30%. materials used for a substrate in this study are plain carbon steel （AIS11045） and ultra low carbon bainite steel. To compute the friction coefficient between the coating layer of wire and the surface of die lbr a specific lubricant, a series of finite element analyses were carried out. SEm observations were also conducted to investigate the surface defects of wire deformed. Results show that the behavior of drawing force varies with the lubricant-type at the initial stage of drawing. The powder-typed lubricant with a large particle causes the retardation of lull lubrication on the entire contact surface and the local delamination of coating layer on the wire surface. As the flow stress of a substrate increases, the delamination becomes severe.

关键词： coating lubricant wire drawing delamination

SyNTHESIS OF NANO-ZnO PARTICLES FOR ALUmINUm mETALLURGy AS INERT ANODE mATERIAL

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Acta metallurgica Sinica(English Letters) 2004年第1期17卷 97-106页

作者： A.A.A.Saleh y.Fu X.j.Zhai y.C.Zhai m.m.Elomella A.L.Zhang School of materials and metallurgy Northeastern University Shenyang 110006 China

Nano-ZnO particle was produced by evaporating zinc powders in air at air flow-rate from 0.2 to 0.6m3/h. Nano-ZnO particles was formed by the oxidation of the evaporated zinc vapor. X-ray diffraction shows the powders to be ZnO with lattice parameters of a=0.3249nm and c=0.5205nm. The particle size is dependent upon the transit time from the source to the collection area. The size of particles was ranged between 81 to 103nm. The average density resulted was 4.865g/cm3. Normal ZnO and nano-ZnO were investigated to use them in aluminum metallurgy as an inert anode material. A certain amount of both oxides were molded subsequently inserted to the molten cryolite-aluminum oxide to investigate the corrosive behavior of both oxides. When the sintering temperature increased up to 1300℃, the weight loss ratio rose to 5.01%-7.33% and up to 7.67%-10.18% for nano-ZnO and normal ZnO, respectively. However, when the samples in the molten cryolite aluminum oxide were put for long time, the corrosive rate was found to be higher. It was found that the corrosive loss weight ratio of nano-ZnO anode was much lower than the normal one made from ordinary-ZnO providing that the nano-ZnO is more possible to be use inert anode material.

关键词： reactive evaporation method nano-ZnO normal ZnO XRD SEm molten electrolysis inert anode

Optical and thermal performance analysis of aerogel glazing technology in a commercial building of Hong Kong

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Energy and Built Environment 2020年第2期1卷 215-223页

作者： C.K.Leung L.Lu y.Liu H.S.Cheng jeff H.tse Department of Building Services Engineering The Hong Kong Polytechnic UniversityZS850Block ZHung HomKowloonHong KongChina College of Civil Engineering Hunan UniversityChangshaHunan 410082China Electrical and mechanical Services Department HKSARHong KongChina

Improving the thermal insulation of glazing units is a common strategy of reducing building energy use for spacing *** paper newly examined the application of aerogel glazing technology in Hong Kong by the means of laboratory testing and *** prototypes of granular aerogel glazing were selected to examine their optical properties,and the measured optical properties of aerogel were used to calculate the total window thermal performance indices.A typical 40-story commercial office building was chosen for energy simulation to compare the thermal performance of aerogel glazing with different glazing technologies in Hong *** results showed that aerogel glazing could achieve the promising reduction of window heat gain up to 57%and cooling energy up to 8.5%compared with double *** heat insulation performance of aerogel glazing is even better than the double glazing with low-E coating in Hong ***,aerogel glazing can be a good alternative of glazing to comply with the existing local Overall Thermal Transfer Value(OTTV)requirement and to reduce the building energy use for space cooling in Hong Kong and other regions.

关键词： Glazing technology Aerogel glazing Building energy saving

Exploring the uncertainties in theoretical predictions of nuclear β-decay half-lives

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Chinese Physics C 2021年第4期45卷 273-278页

作者： m.Shi j.y.Fang Z.m.Niu School of mathematics and Physics Anhui Jianzhu UniversityHefei 230601China Key Laboratory of Architectural Acoustic Environment of Anhui Higher Education Institutes Hefei 230601China Key Laboratory of Advanced Electronic materials and Devices Anhui Jianzhu UniversityHefei230601China School of Physics and materials Science Anhui UniversityHefei 230601China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China

Nuclear β-decay half-lives are predicted based on an empirical formula and the mass predictions from various nuclear *** is found that the empirical formula can reproduce the nuclearβ-decay half-lives well,especially for short-lived nuclei with T_(1/2)mβ-decay energies and the parameters of the empirical formula are further *** is found that the uncertainties of the half-lives are relatively large for heavy nuclei and nuclei near the neutron-drip *** nuclei on the r-process path,the uncertainties for those with N=126 are about one order of magnitude,which are much larger than the uncertainties for those with N=50 and ***,theoretical uncertainties from the parameters of the empirical formula are relatively small for the nuclei on the r-process path,which indicates that the empirical formula is very suitable for predicting theβ-decay half-lives in r-process simulations.

关键词： βdecay nuclear mass r process

Study of neutron response for two hybrid RPC setups using the GEANT4 mC simulation approach

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Chinese Physics C 2009年第10期33卷 887-891页

作者： m. jamil j. T. Rhee y. j. jeon Institute for Advanced Physics Konkuk University Liquid Crystal Research Center Konkuk University

The present article describes a detailed neutron simulation study in the energy range 10^-10 meV to 1.0 GeV for two different RPC configurations. The simulation studies were taken by using the GEANT4 mC code. Aluminum was utilized on the GND and readout strips for the （a） Bakelite-based and （b） glass-based RPCs. For the former type of RPC setup the neutron sensitivity for the isotropic source was Sn = 2.702 × 10^-2 at En = 1.0 GeV, while for the latter type of RPC, the neutron sensitivity for the same source was evaluated as Sn = 4.049 × 10^-2 at En = 1.0 GeV. These results were further compared with the previous RPC configuration in which copper was used for ground and pickup pads. Additionally A1 was employed at （GND＋strips） of the phosphate glass RPC setup and compared with the copper-based phosphate glass RPC. Good agreement with sensitivity values was obtained with the current and previous simulation results.

关键词： resistive plate chambers neutron sensitivity GEANT4 monte Carlo simulation

Superplasticity of Ti2448 Alloy with Nanostructured Grains

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journal of materials Science & Technology 2011年第12期27卷 1099-1104页

作者： m.j. Xiao y.X. Tian G. W. mao S.j. Li y.L. Hao R. yang School of Astronautics Northwestern Polytecllnic University Xi＇an 710072 China - Shenyang National Laboratory for materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Ti-24Nb-4Zr-8Sn, abbreviated as Ti2448 from its chemical composition in weight percent, is a multifunctional /3 type titanium alloy with body centered cubic （bcc） crystal structure, and its highly localized plastic deformation behavior contributes significantly to grain refinement during conventional cold processing. In the paper, the nanostructured （NS） alloy with grain size less than 50 nm produced by cold rolling has been used to investigate its superplastic deformation behavior by uniaxial tensile tests at initial strain rates of 1.5 ×10-2, 1.5×10^-3 and 1.6×10-4 s-1 and temperatures of 600,650 and 700℃. The results show that, in comparison with the coarse-grained alloy with size of 50 μm, the NS alloy has better superplasticity with elongation up to ～275% and ultimate strength of 50-100 mPa. Strain rate sensitivity （m） of the NS alloy is 0.21, 0.30 and 0.29 for 600,650 and 700℃, respectively. These results demonstrate that grain refinement is a valid way to enhance the superplasticity of Ti2448 alloy.

关键词： Titanium alloy bcc crystal Superplasticity Nanostructured grain

Photoluminescence characteristics of soft PZT 53/47 ceramic doped at A and/or B sites

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journal of Advanced Ceramics 2018年第2期7卷 109-116页

作者： m.D.DURRUTHy-RODRíGUEZ j.j.GERVACIO-ARCINIEGA m.HERNáNDEZ-GARCíA j.m.y.nEZ-LImóN Universidad Nacional Evangélica Departamento de Física Aplicada Instituto de CibernéticaMatemáticay FísicaCITMA Catedrático CONACyT-Facultad de Ciencias Físico matemáticas Benemérita Universidad Autónoma de Puebla CINVESTAV-Unidad Querétaro del IPN Libramiento Norponiente 2000Fracc.Real de Juriquilla

This study presents the photoluminescence characteristics of the PZT 53/47 system doped at A and/or B sites, with Nb(PZTN), La(PLZT), and Nb–La(PLZTN) in the concentration range from 0.2 to 1.0 molar fraction. The intensity of the emission bands of the system PZTN is two orders higher than the intensity of the emission bands of the systems PLZT and PLZTN, and these emission bands are located at 1.73 eV(718 nm), 2.56 eV(485 nm), and 2.93 eV(424 nm). The origin of the luminescence in these systems is associated with lead and oxygen vacancies produced during the sintering process. The results from X-ray diffraction(XRD) show a mixture of rhombohedral and tetragonal phases. The system PZTN shows a higher tetragonal phase concentration, while PLZT and PLZTN systems show a higher rhombohedral phase concentration. The cell volume shows an increase with dopant concentration only in the case of the PLZTN system. The band gap energy shows a small variation in the PZTN and PLZTN cases around 3.0 eV, a close value to the band gap energy of the pure PZT 53/47 sample. The system PLZT shows an increasing behavior until 4.41 eV for the higher dopant concentration.

关键词： photoluminescence PZT ceramics band structure X-ray diffraction(XRD)