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Morphology and orientation evolution of cu_(6)Sn_(5)grains on(001)cu and(011)cu single crystal substrates under temperature gradient

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Journal of materials Science & Technology 2021年第36期95卷 29-39页

作者： Yuanyuan Qiao Xiaoying Liu Ning Zhao Lawrence c M Wu chunying Liu Haitao ma School of materials Science and Engineering Dalian University of TechnologyDalian 116024China Department of materials Science and Engineering City University of Hong KongHong Kong Special Administrative RegionChina

The morphology and orientation evolution of cu_(6)Sn_(5)grains formed on(001)cu and(011)cu single crystal substrates under temperature gradient(TG)were *** initial orientated prism-type cu_(6)Sn_(5)grains transformed to non-orientated scallop-type after isothermal ***,the cu_(6)Sn_(5)grains with strong texture were revealed on cold end single crystal cu substrates by imposing *** cu_(6)Sn_(5)grains on(001)cu grew along their c-axis parallel to the substrate and finally merged into one grain to form a fully IMc joint,while those on(011)cu presented a strong texture and merged into a few dominant cu_(6)Sn_(5)grains showing about 30°angle with the *** merging between neighboring cu_(6)Sn_(5)grain pair was attributed to the rapid grain growth and grain boundary ***,a model was put forward to describe the merging *** different morphology and orientation evolutions of the cu_(6)Sn_(5)grains on single crystal and polycrystal cu substrates were revealed based on crystallographic relationship and cu *** method for controlling the morphology and orientation of cu_(6)Sn_(5)grains is really benefitial to solve the reliability problems caused by anisotropy in 3 D packaging.

关键词： 3D packaging Single crystal cu Temperature gradient Orientation Disregistry Grain boundary migration

characterization of high-pressure die-cast hypereutectic Al-Si alloys based on microstructural distribution and fracture morphology

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Journal of materials Science & Technology 2019年第6期35卷 1099-1107页

作者： X.Y. Jiao J. Wang c.f. Liu Z.P. Guo G.D. Tong S.L. ma Y. Bi Y.f. Zhang S.M. Xiong School of materials Science and Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Automobile Safety and Energy Tsinghua University Beijing China china fAW foundry co. Ltd. Changchun 130011. China

The fracture behavior of high-pressure die-cast hypereutectic(HPDc) Al-Si alloys was investigated using a high-resolution laboratory cT and synchrotron X-ray tomography with a particular focus on the influence of HPDc microstructure. Results showed that microstructure of the alloy was mainly comprised of primary silicon particles(PSPs), Al dendrites, cu-rich phases and pores. Most of the coarse PSPs, cu-rich phases and pores were located in the center of the specimen. The rapid solidification of HPDc led to a heterogeneous microstructural feature. Elemental cu was enriched in the frontiers of solid-liquid interface, causing the formation of large size dendritic arms. The pores were formed in the interdendrites which endured high stress intensity under high applied stress. Microcracks were originated from pores and further connected cu-rich phases causing intergranular fracture. PSPs worked as obstacles causing piling-up dislocations in the phase interface. In the regions where large size of PSPs enriched in, PSPs ruptured rather than debonded from matrix, indicating transgranular fractures of PSPs. Microcracks originated around pores and PSPs tended to converge on the main cracks to decrease the energy required for crack propagation.

关键词： Hypereutectic Al-Si alloy Primary silicon particles Porosity fracture morphology High pressure die casting

Stereoscopic PIV Measurements of the flow field in a Turbine cascade

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Journal of Thermal Science 2017年第1期26卷 89-95页

作者： TIAN Yangtao ma Hongwei ma Rong National Key Laboratory of Science and Technology on Aero-Engines Collaborative Innovation Center of AdvancedAero-Engine School of Energy & Power Engineering Beihang University Beijing I00191 China

This paper presents experimental measurements of the flow field in a Low-speed Turbine cascade using a stereoscopic particle-image velocimetry(SPIV). During the measurements, a pair of frame-straddling-based ccD cameras were configured at different sides of the laser light sheet, and appropriate tracing particles(DEHS) were employed. The measurements were conducted at the incidence angle of 0 degree and exit Reynolds number of 1.7 × 105 with the tip clearance 1.18% of blade chord. The tip flow features, such as the evolution and breakdown of tip leakage vortex, the horseshoe vortex, turbulence characteristics of tip leakage flow, were studied for the flow field analysis. The results showed that the tip leakage flow/vortex mainly dominate flow fields in the tip region. The tip leakage vortex performs as a concentrated vortex before its breaking down and splitting into small vortices. The highest turbulence intensity mainly occurs in the tip region along with the trajectory of tip leakage vortex, and when the vortex breaks down, the turbulence intensity reduces rapidly. Additionally, the SPIV with this configuration also shows an advantage in investigating the flow structures and mechanism inside the turbine cascade.

关键词： Stereoscopic PIV, turbine cascade, tip leakage vortex, horseshoe vortex

DATA DRIVEN MODELING fOR POWER TRANSfORMER LIfESPAN EVALUATION

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Journal of Systems Science and Systems Engineering 2014年第1期23卷 80-93页

作者： charles V.TRAPPEY Amy J.c.TRAPPEY Lin ma Wan-Ting TSAO Department of management Science National Chiao Tung University Department of Industrial Engineering and Engineering management National Tsing Hua University School of chemistry Physics and Mechanical EngineeringQueensland University of Technology

Large sized power transformers are important parts of the power supply chain. These very critical networks of engineering assets are an essential base of a nation＇s energy resource infrastructure. This research identifies the key factors influencing transformer normal operating conditions and predicts the asset management lifespan. Engineering asset research has developed few lifespan forecasting methods combining real-time monitoring solutions for transformer maintenance and replacement. Utilizing the rich data source from a remote terminal unit （RTU） system for sensor-data driven analysis, this research develops an innovative real-time lifespan forecasting approach applying logistic regression based on the Weibull distribution. The methodology and the implementation prototype are verified using a data series from 161 kV transformers to evaluate the efficiency and accuracy for energy sector applications. The asset stakeholders and suppliers significantly benefit from the real-time power transformer lifespan evaluation for maintenance and replacement decision support.

关键词： condition based maintenance (cBM) prognostics and health management (PHM) logisticregression remaining life prediction sustainable engineering asset management

Experimental and Numerical Investigations of Ship Parametric Rolling in Regular Head Waves

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china Ocean Engineering 2018年第4期32卷 431-442页

作者： ma Shan GE Wen-peng R.c.Ertekin HE Qiang DUAN Wen-yang college of Shipbuilding Engineering Harbin Engineering University

Parametric rolling is one of five types of the ship stability failure modes as proposed by IMO. The periodic change of the metacentric height is often considered as the internal cause of this phenomenon. Parametric rolling is a complex nonlinear hydrodynamic problem, often accompanied by large amplitude vertical motions of ships. In recent years,the Reynolds-averaged Navier–Stokes(RANS) equation simulations for viscous flows have made great progress in the field of ship seakeeping. In this paper, the parametric rolling for the c11 containership in regular waves is studied both experimentally and numerically. In the experiments, parametric rolling amplitudes at different drafts, forward speeds and wave steepnesses are analyzed. The differences in the steady amplitudes of parametric rolling are observed for two drafts. The effect of the incident wave steepness(or wave amplitude) is also studied, and this supports previous results obtained on limits of the stability for parametric rolling. In numerical simulations, the ship motions of parametric rolling are analyzed by use of the potential-flow and viscous-flow methods. In the viscousflow method, the Reynolds-averaged Navier–Stokes equations are solved using the overset grid method. The numerical accuracies of the two methods at different wave steepnesses are also discussed.

关键词： parametric rolling nonlinear strip theory cfD method overset grid method

Reprogrammed mouse astrocytes retain a“memory”of tissue origin and possess more tendencies for neuronal differentiation than reprogrammed mouse embryonic fibroblasts

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Protein & cell 2011年第2期2卷 128-140页

作者： changhai Tian Yongxiang Wang Lijun Sun Kangmu ma Jialin c.Zheng Laboratory of Neuroimmunology and Regenerative Therapy University of Nebraska Medical CenterOmahaNE 68198-5930USA Departments of Pharmacology/Experimental Neuroscience University of Nebraska Medical CenterOmahaNE 68198-5930USA Departments of Pathology/Microbiology University of Nebraska Medical CenterOmahaNE 68198-5930USA

Direct reprogramming of a variety of somatic cells with the transcription factors Oct4(also called Pou5f1),Sox2 with either Klf4 and Myc or Lin28 and Nanog generates the induced pluripotent stem cells(iPScs)with marker similarity to embryonic stem ***,the difference between iPScs derived from different origins is *** this study,we hypothesized that reprogrammed cells retain a“memory”of their origins and possess additional potential of related tissue *** reprogrammed primary mouse astrocytes via ectopic retroviral expression of OcT3/4,Sox2,Klf4 and Myc and found the iPScs from mouse astrocytes expressed stem cell markers and formed teratomas in ScID mice containing derivatives of all three germ layers similar to mouse embryonic stem cells besides semblable *** test our hypothesis,we compared embryonic bodies(EBs)formation and neuronal differentiation between iPScs from mouse embryonic fibroblasts(MEfsiPScs)and iPScs from mouse astrocytes(masiPScs).We found that masiPScs grew slower and possessed more potential for neuronal differentiation compared to *** results suggest that masiPScs retain a“memory”of the central nervous system,which confers additional potential upon neuronal differentiation.

关键词： mouse astrocytes induced pluripotent stem cells neural progenitor cells neuronal differentiation

Microstructure and mechanical properties of double-side friction stir welded 6082Al ultra-thick plates

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Journal of materials Science & Technology 2020年第6期41卷 105-116页

作者： c.Yang J.f.Zhang G.N.ma L.H.Wu X.M.Zhang G.Z.He P.Xue D.R.Ni B.L.Xiao K.S.Wang Z.Y.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China cRRc changchun Railway Vehicles co. Ltd.Changchun 130062China School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China

In the present work,80 mm thick 6082Al alloy plates were successfully double-side welded by friction stir welding(fSW).The relationship between the microstructures and mechanical properties was built for the double-side fSW butt joint with more attention paid to the local characteristic *** was shown that a phenomenon of microstructural inhomogeneity existed in the nugget zone(NZ)through the thickness *** grain size presented an obvious gradient distribution from the top to the bottom for each single-pass weld,and the microhardness values decreased from both surfaces to the middle of the *** lowest hardness zone(LHZ)exhibited a"hyperbolical"-shaped distribution extending to the middle of the *** tensile properties were obtained in the three sliced specimens of the fSW joint,and the joint coefficient reached about 70%which achieved the same level as the conventional fSW Al alloy *** element modeling proved that the"hyperbolical"-shaped heat affected zone(HAZ)was beneficial to resisting the strain concentration in the middle layer specimen which helped to increase the tensile *** on the analysis of the hardness contour map,tensile property and microstructural evolution of the joints,an Isothermal Softening Layer(ISL)model was proposed and established,which may have a helpful guidance for the optimization on the fSW of ultra-thick Al alloy plates.

关键词： Ultra-thick aluminum alloy plates Double-side friction stir welding finite element model Microstructural inhomogeneity Mechanical properties

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

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chinese Physics c 2024年第12期48卷 1-10页

作者： M.Ablikim M.N.Achasov P.Adlarson O.Afedulidis X.c.Ai R.Aliberti A.Amoroso Q.An Y.Bai O.Bakina I.Balossino Y.Ban H.-R.Bao V.Batozskaya K.Begzsuren N.Berger M.Berlowski M.Bertani D.Bettoni f.Bianchi E.Bianco A.Bortone I.Boyko R.A.Briere A.Brueggemann H.cai X.cai A.calcaterra G.f.cao N.cao S.A.cetin J.f.chang G.R.che G.chelkov c.chen c.H.chen chao chen G.chen H.S.chen H.Y.chen M.L.chen S.J.chen S.L.chen S.M.chen T.chen X.R.chen X.T.chen Y.B.chen Y.Q.chen Z.J.chen Z.Y.chen S.K.choi G.cibinetto f.cossio J.J.cui H.L.Dai J.P.Dai A.Dbeyssi R.E.de Boer D.Dedovich c.Q.Deng Z.Y.Deng A.Denig I.Denysenko M.Destefanis f.De Mori B.Ding X.X.Ding Y.Ding Y.Ding J.Dong L.Y.Dong M.Y.Dong X.Dong M.c.Du S.X.Du Y.Y.Duan Z.H.Duan P.Egorov Y.H.fan J.fang J.fang S.S.fang W.X.fang Y.fang Y.Q.fang R.farinelli L.fava f.feldbauer G.felici c.Q.feng J.H.feng Y.T.feng M.fritsch c.D.fu J.L.fu Y.W.fu H.Gao X.B.Gao Y.N.Gao Yang Gao S.Garbolino I.Garzia L.Ge P.T.Ge Z.W.Ge c.Geng E.M.Gersabeck A.Gilman K.Goetzen L.Gong W.X.Gong W.Gradl S.Gramigna M.Greco M.H.Gu Y.T.Gu c.Y.Guan A.Q.Guo L.B.Guo M.J.Guo R.P.Guo Y.P.Guo A.Guskov J.Gutierrez K.L.Han T.T.Han f.Hanisch X.Q.Hao f.A.Harris K.K.He K.L.He f.H.Heinsius c.H.Heinz Y.K.Heng c.Herold T.Holtmann P.c.Hong G.Y.Hou X.T.Hou Y.R.Hou Z.L.Hou B.Y.Hu H.M.Hu J.f.Hu S.L.Hu T.Hu Y.Hu G.S.Huang K.X.Huang L.Q.Huang X.T.Huang Y.P.Huang Y.S.Huang T.Hussain f.Hölzken N.Hüsken N.in der Wiesche J.Jackson S.Janchiv J.H.Jeong Q.Ji Q.P.Ji W.Ji X.B.Ji X.L.Ji Y.Y.Ji X.Q.Jia Z.K.Jia D.Jiang H.B.Jiang P.c.Jiang S.S.Jiang T.J.Jiang X.S.Jiang Y.Jiang J.B.Jiao J.K.Jiao Z.Jiao S.Jin Y.Jin M.Q.Jing X.M.Jing T.Johansson S.Kabana N.Kalantar-Nayestanaki X.L.Kang X.S.Kang M.Kavatsyuk B.c.Ke V.Khachatryan A.Khoukaz R.Kiuchi O.B.Kolcu B.Kopf M.Kuessner X.Kui N.Kumar A.Kupsc W.Kühn J.J.Lane L.Lavezzi T.T.Lei Z.H.Lei M.Lellmann T.Lenz c.Li c.Li c.H.Li cheng Li D.M.Li f.Li G.Li H.B.Li H.J.Li H.N.Li Hui Li J.R.Li J.S.Li K.Li L.J.Li L.K.Li Lei Li M.H.Li P.R.Li Q.M.Li Q.X.Li R.Li S.X.Li T.Li W.D.Li W.G.Li X.Li X.H.Li X.L.Li X.Y.Li X.Z.Li Y.G Institute of High Energy Physics Beijing 18049China Beihang University Beijing 18191China Bochum Ruhr-University D-44780 BochumGermany Budker Institute of Nuclear Physics SB RAS(BINP) Novosibirsk 630090Russia carnegie Mellon University PittsburghPennsylvania 15213USA central china Normal University Wuhan 430079China central South University Changsha 41883China china center of Advanced Science and Technology Beijing 18190China china University of Geosciences Wuhan 430074China chung-Ang University Seoul06974Republic of Korea cOMSATS University Islamabad Lahore CampusDefence RoadOff Raiwind Road54000 LahorePakistan fudan University Shanghai 200433China GSI Helmholtzcentre for Heavy Ion Research GmbH D-64291 DarmstadtGermany Guangxi Normal University Guilin 54184China Guangxi University Nanning 530004China Hangzhou Normal University Hangzhou 31836China Hebei University Baoding 07182China Helmholtz Institute mainz Staudinger Weg 18D-55099 MainzGermany Henan Normal University Xinxiang 453007China Henan University Kaifeng 475004China Henan University of Science and Technology Luoyang 47183China Henan University of Technology Zhengzhou 450001China Huangshan college Huangshan 245000China Hunan Normal University Changsha 41881China Hunan University Changsha 41882China Indian Institute of Technology madras Chennai 600036India Indiana University BloomingtonIndiana 47405USA INfN Laboratori Nazionali di frascati INFN Laboratori Nazionali di FrascatiI-00044FrascatiItaly INfN Laboratori Nazionali di frascati INFN Sezione di PerugiaI-0618PerugiaItaly INfN Laboratori Nazionali di frascati University of PerugiaI-0618PerugiaItaly INfN Sezione di ferrara INFN Sezione di FerraraI-44122FerraraItaly INfN Sezione di ferrara University of FerraraI-44122FerraraItaly Inner Mongolia University Hohhot 01821China Institute of Modern Physics Lanzhou 730000China Institute of Physics and Technology Peace Avenue 54BUlaanbaatar 13330Mongolia Instituto de Alta Investigación Universidad de Tarapacá

We present a measurement of the integrated luminosity of e^(+)e^(-)collision data collected by the BESIII detector at the BEPcII collider at a center-of-mass energy of Ecm=3.773 *** integrated luminosities of the datasets taken from December 2021 to June 2022,from November 2022 to June 2023,and from October 2023 to february 2024 were determined to be 4.995±0.019 fb^(-1),8.157±0.031 fb^(-1),and 4.191±0.016 fb^(-1),respectively,by analyzing large angle Bhabha scattering *** uncertainties are dominated by systematic effects,and the statistical uncertainties are *** results provide essential input for future analyses and precision measurements.

关键词： Bhabha scattering events integrated luminosity cross-section

Measurement of Monochromatic Emissivity of cement clinker with Various fe_2O_3 content at High Temperature

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Journal of Thermal Science 1996年第2期5卷 128-131页

作者： Z.J. Ye c.f. ma S.Y. Huang(Beijing Polytechnic University, Beijing 100022, china) Beijing Polytechnic University Beijing China

An application of the optical pyrometer is studied for measuring monochromatic emissivities of cement clinker with various fe2O3 *** idea of using “brightness temperature”is introduced into the emissivity measurement. In this method, there is no need for measuring an actual temperature of sample surfaces, only with determining both brightness temperatures of a sample and a blackbody can the required emissivity be evaluated according to Wien’s radiation law. In practice, the cement clinker is regarded as a greybody, the monochromatic emissivity is approximately equal to the total emissivity, so a single-colour optical pyrometer is applied for this purpose. Test measurements are carried out on 10 kinds of cement clinkers. Experimental data are treated by the least square method. As a result, the emissivity variation with temperature at a certain fe2O3 content is quite well represented by εn=α+bT. furthermore, this work first reported that the emissivities of cement clinker change considerably with fe2O3 contents. In multiple cement production this conclusion is very important.

关键词： monochromatic emissivity brightness temperature cement clinker blackbody radiation