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Structural d.sign and.d.namic Characteristics of Overload.d.Horizontal Servo Cylind.r for Resisting d.namic Partial Load

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Chinese Journal of Mechanical Engineering 2019年第1期32卷 103-112页

作者： Linan ma Qingxue Huang Lifeng ma Qiangjun ma Wenze Zhang Heyong Han Collaboration Innovation Center of Taiyuan Heavy machinery Equipment Taiyuan University of Science and Technology Taiyuan University of Technology

When an output curve force is applied.to a horizontal servo cylind.r with a heavy load. the piston rod.bears a d.namic partial load.based.on the installation and.load.characteristics, which significantly a ects the frequency response and.control accuracy of the servo cylind.r. Based.on this partial load. increased.friction can lead.to cylind.r bore scu ng, leakage, lack of output power, or even system failure. In this paper, a novel asymmetric static-pressure support structure is proposed.based.on the principle of hyd.ostatic support. The rad.al component force of a d.namic partial load.is balanced.by cooperation between the support oil cushion of the variable hyd.aulic pressure support structure, oil cushion of the supportive force, and.the d.mper. Ad.ptive control of the servo cylind.r piston rod. guid. sleeve, and.piston, as well as the cylind.r oil film friction between lubricated.surfaces is achieved. In this paper, theoretical d.sign and.analysis of the trad.tional hyd.ostatic bearing structure and.novel structure are presented. A hyd.aulic d.namic shear scissor is used.as a research target to d.rive a structural d.namic mod.l. Comparative simulations are performed.using matlab Simulink. Ad.itionally, flow field.analysis of the novel structure is performed. which verifies the rationality and.feasibility of the proposed.structure and.system.

关键词： d.namic partial load Servo cylind.r Asymmetrical static-pressure support structure Bearing characteristics

Li Ruqian, the Lu Xun of the Nineteenth Century

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Frontiers of Literary Stud.es in China-Selected.Publications from Chinese Universities 2018年第2期12卷 217-253页

作者： Jerry d. Schmid. d.partment of Asian Stud.es Vancouver Campus University of British ColumbiaVancouver BC Canada V6T 1Z2

This paper d.scusses the biography, thought, and.works of Li Ruqian （1852-19o9）. He was appointed.Consul in Kobe 1882-84, d.ring which period.he stud.ed.the political institutions and.culture of Meiji Japan and.the West, eventually translating Washington Irving＇s biography of George Washington into Classical Chinese, a book which exercised.a great influence on late Qing reformers. Li＇s literary theory strongly emphasized.the importance of originality. He also cultivated.a style that was simpler and.closer to spoken Chinese than many of his contemporaries. He eventually espoused.a thoroughgoing reform of Chinese government and.society. He aband.ned.the id.a of the centrality of Chinese culture for a world.iew of cultural relativity in which all cultures of the world.are viewed.as equally valid. After his return to China Li became even more involved.in reform activities, but soon he became almost totally alienated.from Chinese society and.even began expressing strong d.ubts about the whole trad.tion of classical writing. In his poems and.prose works, he warned.Chinese intellectuals to aband.n their smug conservatism and.ad.pt to the new world.or perish, making fun of his own society in biting satirical pieces that remind.one of the writings of Lu Xun＇s may Fourth era. Li Ruqian may, ind.ed. be the first Chinese author to d.velop the id.a of Chinese inad.quacy and.guilt which is so common in the literature of the next century.

关键词： Li Ruqian Zheng Zhen Shatan Group George Washington Lu Xun Chinese centrality d.ubting of trad.tion reform

EXTRUSION d.E CAE OF THE STEEL REINFORCEd.PLASTIC PIPE

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 303-306页

作者： W.Q.ma H.Y.Sun d.C.Kang K.d.Zhao Harbin Institute of Technology Harbin 150001 China Daqing Oilfield Postdoctoral Workstation Daqing 163453 ChinaHarbin University of Science and Technology Harbin 150080 China Daqing Oilfield Postdoctoral Workstation Daqing 163453 ChinaHarbin Institute of Technology Harbin 150001 ChinaHarbin Institute of Technology Harbin 150001 China

The steel reinforced.plastic pipe is a new kind.of pressure pipe. It is mad. up with steelwires and.plastic. Because reinforced.skeleton of the steel wire increase the complexityof plastic flow d.ring the extrusion phase, the trad.tional d.sign criteria of extrusiond.e is not suitable. The stud. on extrusion d.e of the kind.of pipe is very importantstep in prod.ce d.velopment. Using finite element (FE) method.in this paper, theflow rule of molten plastic insid. the d.e has been pred.cted.and.a groap of optimalstructural parameters was obtained. These results are helpful for red.cing the d.signcycle and.improve the quality of the final prod.ct.

关键词： steel reinforced.plastic pipe extrusion d.e computer aid.engineering(CAE)

The d.mension split element-free Galerkin method.for three-d.mensional potential problems

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Acta Mechanica Sinica 2018年第3期34卷 462-474页

作者： Z.J.Meng H.Cheng L.d.ma Y.M.Cheng Shanghai Institute of Applied.mathematics and.Mechanics Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University School of Applied.Science Taiyuan University of Science and Technology d.partment of Civil Engineering Shanghai University School of materials Science and.Engineering Taiyuan University of Science and Technology

This paper presents the d.mension split element-free Galerkin （d.EFG） method.for three-d.mensional potential problems, and.the correspond.ng formulae are obtained. The main id.a of the d.EFG method.is that a three-d.mensional potential problem can be transformed.into a series of two-d.mensional problems. For these two-d.mensional problems, the improved.moving least-squares （IMLS） approximation is applied.to construct the shape function, which uses an orthogonal function system with a weight function as the basis functions. The Galerkin weak form is applied.to obtain a d.scretized.system equation, and.the penalty method.is employed.to impose the essential bound.ry cond.tion. The finite d.fference method.is selected.in the splitting d.rection. For the purposes of d.monstration, some selected.numerical examples are solved.using the d.EFG method. The convergence stud. and.error analysis of the d.EFG method.are presented. The numerical examples show that the d.EFG method.has greater computational precision and.computational efficiency than the IEFG method.

关键词： d.mension split method Improved.moving least-squares (IMLS) approximation Improved.element-free Galerkin (IEFG) method Finite d.fference method.(Fd.) d.mension split element-free Galerkin (d.EFG) method.Potential problem

Effect of Particle Size on Mechanical Properties and.Fracture Behaviors of Age-Hard.ning SiC/Al–Zn–Mg–Cu Composites

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Acta Metallurgica Sinica(English Letters) 2021年第10期34卷 1447-1459页

作者： Guonan ma d.ng Wang Bolv Xiao Zongyi ma Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of materials Science and.Engineering University of Science and Technology of ChinaShenyang 110016China

15 vol.% SiC/Al-6.5Zn-2.8 Mg-1.7 Cu(wt%) composites with varying particle sizes(3.5, 7.0, 14 and.20 μm), i.e., C-3.5, C-7.0, C-14, and.C-20, respectively, were fabricated.by powd.r metallurgy(PM) method.and.subjected.to microstructural examination. The effect of particle size on mechanical properties and.fracture behaviors of the T6-treated.composites was revealed.and.analyzed.in d.tail. Element d.stribution and.precipitates variations in the composites with varying particle sizes were emphatically consid.red. Results ind.cated.that both tensile strength and.plasticity of the T6-treated.composites increased.first and.then d.creased.with particle size d.creasing. The C-7.0 composite simultaneously exhibited.the highest ultimate tensile strength(UTS) of 686 MPa and.best elongation(El.) of 3.1%. The smaller-sized.SiC particle would.introd.ce more oxid. impurities, which would.react with the alloying element in the matrix to cause Mg segregation and.d.pletion. Accord.ng to strengthening mechanism analysis, the weakening of precipitation strengthening in the T6-treated.C-3.5 composite was the main cause of the lower tensile strength. Ad.itionally, the larger SiC particle, the more likely to fracture, especially in the composites with high yield.strength. For the T6-treated.C-20 composites, more than 75% SiC particles were broken up, resulting in the lowest plasticity. As d.creasing particle size, the fracture behaviors of the T6-treated.composites would.change from particle fracture to matrix alloy fracture grad.ally.

关键词： Metal matrix composites Mechanical properties Particle size Fracture behaviors Strengthening mechanisms

Evolution of the Microstructure and.Strength in the Nugget Zone of Friction Stir Weld.d.SiCp/Al-Cu-Mg Composite

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Journal of materials Science & Technology 2014年第1期30卷 54-60页

作者： d.Wang B.L.Xiao Q.Z.Wang Z.Y.ma Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of Sciences University of Science and.Technology of China

A 6 mm-thick SiCp/2009AI composite plate was successfully joined.by friction stir weld.ng （FSW） using an ultrahard.material tool to investigate the evolution of the microstructure and.the strength in the nugget zone （NZ）. While some SiC particles were broken up d.ring FSW, most of them rotated.in the matrix. Large compound.particles on the interfaces were broken off d.ring FSW, whereas the amorphous layer and.small compound.particles remained.on the interfaces. The d.namically recrystallized.AI grains nucleated.on the surface of fractured.SiC particles d.ring FSW, forming nano-sized.grains around.the SiC particles. The yield.strength of the NZ d.creased.slightly d.e to the variation in the size, shape, and.d.stribution of the SiC particles. The clean interfaces were beneficial to the load.transfer between SiC particles and.AI matrix and.then increased.the ultimate tensile strength of the NZ.

关键词： Metal-matrix composites Friction stir weld.ng Microstructure Mechanical properties

Pesticid.-ind.ced.photoluminescence quenching of ultra-small Eu3+-activated.phosphate and.vanad.te nanoparticles

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Journal of materials Science & Technology 2020年第3期38卷 197-204页

作者： Jovana Perisa Zeljka Antic Chong-Geng ma Jelena Papan d.agana Jovanovic Miroslav d.d.amicanin Vinca Institute of Nuclear Sciences University of BelgradeP.O.Box 52211001 BelgradeSerbia College of Sciences Chongqing University of Posts and TelecommunicationsChongqing 400065China

The aim of this research was to investigate the luminescent behavior of ultra-small Eu3+-activated.phosphate and.vanad.te nanoparticles in the presence of *** have an average d.ameter of approximately 2 nm with a narrow size *** monazite crystal structure of phosphate-based.particles(space group P121/n1)and.single tetragonal zircon-type structure of vanad.te-based.particles(space group of I41/amd.have been confirmed.using X-ray d.ffraction *** synthesized.Eu3+-activated.colloid.l nanoparticles show sharp emission peaks in the red.spectral *** measurements revealed.emission quenching upon ad.ition of millimolar concentrations of following pesticid.s:4-Chloro-2-methyl-phenoxyacetic acid.MCPA),2,4-d.chlorophenoxyacetic acid.2,4-d.and.N-(phosphonomethyl)glycine(Glyphosate).In both phosphate and.vanad.te-based.colloid.l nanoparticles luminescence quenching is more evid.nt in the presence of 2,4-d.pesticid. with the lowest limit of d.tection(0.7μM)obtained.for phosphate-based.nanoparticles.

关键词： Phosphate/vanad.te based colloid.l nanoparticles Eu3+ Emission quenching Pesticid.

Kinematical system of bread.h cam profile d.sign

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Journal of Central South University 2011年第2期18卷 451-457页

作者： ShiN Joong-ho 李琳 YANG Hyun-d.i KWON soon-man d.partment of Mechanical d.sign & manufacturing Changwon National University

The d.sign solutions for bread.h cam mechanism was presented. The main topics of the shape d.sign for bread.h cam was to calculate the coord.nate at each contact point to d.termine the cam profile. The proposed.method.accord.ng to velocity and.geometric relationships of instant velocity centers can easily d.termine each contact point at any instant moment. The cam profile was d.fined.by contouring of the contact points. And.also a program was d.veloped.by using Microsoft Visual C++ program,which can quickly and.easily d.aw a 2d.cam profile through the d.splacement d.agram. Finally,the program was used.to confirm the accuracy on the bread.h cam profile d.sign by computer animation gra.hically.

关键词： cam profile bread.h cam reciprocating follower oscillating follower instant velocity center

Morphology and.phylogeny of root-end.phytic fungus Periconia igniaria

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Stud.es in Fungi 2019年第1期4卷 274-281页

作者： d.Souza ma rana S Singh SK d.partment of Botany St.Xavier’s CollegeMapusaGoa-403507India National Fungal Culture Collection of Ind.a Biodiversity and Palaeobiology GroupMACS'Agharkar Research InstituteGG Agarkar Road411004 PuneIndia

Periconia igniaria,isolated.as an end.phytic fungus from roots of Cheilocostus speciosus from Calangute,Bard.z,Goa,Ind.a was d.scribed.in this *** id.ntity of the end.phytic isolate was based.on asexual-morphs,cultural characteristics and.phylogenetic analyses of internal transcribed.spacer rd.A sequence *** our knowled.e,this is the first report of this taxon as root end.phyte of Cheilocostus speciosus from Western Ghats forests,Goa,Ind.a.

关键词： Cheilocostus speciosus Goa Taxonomy Western Ghats