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Effects of fibers on expansive shotcrete mixtures consisting of calcium sulfoaluminate cement,ordinary Portland cement,and calcium sulfate

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 212-221页

作者： H.Yu l.wu W.V.liu Y.Pourrahimian School of Mining and Petroleum Engineering Department of Civil and Environmental Engineering University of Alberta

The mining industry often uses shotcrete for ground stabilization. However, cracking within shotcrete is commonly observed, which delays production schedules and increases maintenance costs. A possible crack reduction method is using expansive shotcrete mixture consisting of calcium sulfoaluminate cement(CSA), ordinary Portland cement(OPC), and calcium sulfate(CS) to reduce shrinkage. Furthermore, fibers can be added to the mixture to restrain expansion and impede cracking. The objective of this paper is to study the effects of nylon fiber, glass fiber, and steel fiber on an expansive shotcrete mixture that can better resist cracking. In this study, parameters such as density, water absorption, volume of permeable voids, unconfined compressive strength(UCS), splitting tensile strength(STS), and volume change of fiber-added expansive mixtures were determined at different time periods(i.e. the strengths on the 28 th day, and the volume changes on the 1 st, 7 th, 14 th, 21 st, and 28 th days). The results show that addition of fibers can improve mixture durability, in the form of decreased water absorption and reduced permeable pore space content. Moreover, the expansion of the CSA-OPC-CS mixture was restrained up to50% by glass fiber, up to 43% by nylon fiber, and up to 28% by steel fiber. The results show that the STS was improved by 57% with glass fiber addition, 43% with steel fiber addition, and 38% with nylon fiber addition. The UCS was also increased by 31% after steel fiber addition, 26% after nylon fiber addition, and16% after glass fiber addition. These results suggest that fiber additions to the expansive shotcrete mixtures can improve durability and strengths while controlling expansion.

关键词： Shotcrete Restrained expansion Fibers Calcium sulfoaluminate cement(CSA) Ordinary Portland cement(OPC) Calcium sulfate(CS)

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MICROSTRUCTURAl STUDIES OF FRICTION STIR WElDED AZ31 MAGNESIUM AllOY

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Acta Metallurgica Sinica(English letters) 2004年第5期17卷 747-753页

作者： H.Zhang S.B.lin l.wu J.C.Feng StateKeylab.ofAdvancedWeldingProductionTechnology HarbinInstituteofTechnologyHarbin150001China

Friction stir welding achieves the weld in solid phase by locally introducing frictional heating and plastic flow arising from rotation of the welding tool, which results in changes in the local microstructure of magnesium alloy. The purpose in the paper is to study the microstructures of friction stir welded AZ31 magnesium alloy. Residual microstructures, including dynamic re-crystallization zone and nugget structures have been systematically investigated utilizing optical microscopy (OM), scanning electric microscopy (SEM), transmission electron microscopy (TEM) with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and micro-hardness. AZ31 magnesium alloy has been successfully friction stir welded and exhibits the variations of microstructure including dynamically recrystallized, equaxied grains in the weld nugget. Residual hardness in the nugget was found slightly lower than the parent but not too obvious.

关键词： friction stir welding AZ31magnesium alloy weld nugget thermo- mechanically affected zone microstructure

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Probing for Conditioned Hallucinations Through Neural Activation in a Ketamine Mouse Model of Schizophrenia

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Neuroscience Bulletin 2020年第8期36卷 937-941页

作者： Jenny l.wu Rebecca P.Haberman Michela Gallagher Ming Teng Koh Department of Psychological and Brain Sciences Johns Hopkins UniversityBaltimoreMD 21218USA

Dear Editor,When two stimuli such as a tone and a visual stimulus are repeatedly presented together,individuals diagnosed with hallucinations tend to report hearing the tone subsequently in response to the visual stimulus alone [1].Such conditioned hallucinations involved evoked sensory representations as evidenced by increased neural activation in tone-responsive brain regions during the conditioned *** and other observations underscore the importance of prior associative experiences in driving hallucinatory perception,and reflect new efforts to conceptualize and understand psychosis from a cognitive perspective.

关键词： neural individual associative

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Bioinspired Ultra-low Adhesive Energy Interface for Continuous 3D Printing: Reducing Curing Induced Adhesion

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Research 2018年第1期2018卷 194-200页

作者： l.wu ZDong H.Du Cli N.X.Fang Y.Song Key laboratory of Green Printing Institute of ChemistryChinese Academy of SciencesZhongguancun North First Street 2100190 BeijingChina CAS Key laboratory of Bio-inspired Materials and Interfacial Sciences Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMA 02139USA

Additive manufacturing based on liquid resin curing is one of the most promising methods to construct delicate ***,precision and speed are limited by the vertical adhesion of in situ cured resin at the curing *** overcome the unavoidable adhesion and to develop a general curing interface,we propose a slippery surface taking inspiration of the peristome surface of the pitcher *** surface shows ultra-low adhesive energy at the curing interface due to the inhibition of the direct contact between the cured resin and the solid surface,which also increases the reflling speed of liquid *** ultra-low adhesive energy interface is efective for continuous 3D printing and provides insights into the physical mechanisms in reducing vertical solid-solid interfacial adhesion.

关键词： curing resin interface

Stereodynamics study of reactions N（2D）＋HD→NH＋D and ND＋H

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Chinese Physics B 2010年第4期19卷 223-228页

The product polarizations of the title reactions are investigated by employing the quasi-classical trajectory （QCT） method. The four generalized polarization-dependent differential cross-sections （PDDCSs）（2π/σ）（dσ00/dωt）, （2π/σ）（dσ20/dωt）, （2π/σ）（dσ22＋/dωt）, and （2π/σ）（dσ21-/dωt） are calculated in the centre-of-mass frame. The distribution of the angle between κ and j＇, P（θr）, the distribution of the dihedral angle denoting κ-κ＇-j＇ correlation, P（Фr）, as well as the angular distribution of product rotational vectors in the form of polar plots P（θr, Фr） are calculated. The isotope effect is also revealed and primarily attributed to the difference in mass factor between the two title reactions.

关键词： stereodynamics quasi-classical trajectory method vector correlation polarization-dependent differential cross-section isotope effect

Extraordinary tensile strengthening of graded structure IF steel

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Extraordinary tensile strengthening of graded structure IF s...

layer thickness dependent tensile deformation mechanisms in sub-10 nm multilayer nanowires

第十二届全国物理力学学术会议

作者： P.Jiang X.-l.wu The State Key laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences

A surface mechanical attrition treatment(SMAT) method has been applied to bulk specimens of IF steel,where the structures gradually change from the surface to the interior. Uniaxial tensile tests at room temperature show that grain refinement down to the nanometer range in the surface layer has the potential to significantly improve the mechanical *** thicker the nanocrystalhne layer,the higher the yield ***,it is unknown how the graded structure affects the mechanical *** yield strength gradually reduced and the ultimate tensile stress and uniform elongation basically unchanged as the annealing temperature increases after ***,at 550℃and 650℃,the enhancement of both yield strength and ultimate tensile strength appears compared to other annealed bulk IF *** may be due to that high dislocation densities rearrange and annihilate through a recovery *** an increase in the yield stress is needed in order to activate new dislocation *** relationship between the graded structure and mechanical property was discussed in detail.

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Layer thickness dependent tensile deformation mechanisms in ...

支架置入联合腔内射频消融和肝动脉灌注化疗治疗晚期胆管癌伴胆道梗阻的多中心回顾性对照研究

第十二届全国物理力学学术会议

作者： F.-P.Yuan X.-l.wu State Key laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Science

Using molecular dynamics simulations,the tensile deformation behavior for two types of sub-10 nm multilayer nanowires(NWs) have been *** the structure with interfaces perpendicular to the wire axis,the deformation mechanism is changed from interface crossing by dislocations to interface rotation as the layer thickness is decreasing,causing a significantly reduction in yield ***,the deformation mechanisms are all accommodated through interface crossing by dislocations regardless of layer thickness for the structure with interfaces parallel to the wire ***,the yield strengths in the second structure are found to be controlled by two competing mechanisms:the interface strengthening by increased repulsive force and interface softening by increased dislocation source *** sudden stress drop after yielding point in NWs could be explained by the dislocation source-limited hardening mechanism:the more atomic fraction of newly formed stacking faults(SF) after stress drop,the larger normalized stress drop and the larger uniform tensile *** the second structure,the larger total tensile elongation for larger layer thickness could be related to the twinning induced plasticity at the necking *** findings should have implications for designing functionalized structures and devices in nanoelectromechanical systems.

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国际医学放射学杂志 2021年第5期 614-615页

作者： Q.Gou l.wu W.Cui Z.Mo D.Zeng l.Gan 陈小倩

摘要目的评价支架置入联合腔内射频消融(intra-RFA)和肝动脉灌注化疗(HAIC)治疗晚期胆管癌(Ad-BTC)合并胆道梗阻(BO)的疗效和安全性。方法回顾性分析2013

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基于深度学习的CT成骨性转移瘤和骨岛诊断：一项多中心诊断研究

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国际医学放射学杂志 2023年第6期 748-749页

作者： Y.C.Xiong W.Guo Z.P.liang l.wu G.X.Ye Y.Y.liang 周彤

摘要目的开发并验证基于CT的骨岛和成骨性转移瘤的深度学习（Dl）模型。方法回顾性分析3家医院的硬化性骨病变（SBl）病人。来自医院1的影像被随机分配用于开发

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