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On the role of the constitutive mod.l and.basal texture on the mechanical behaviour of magnesium alloy AZ31B sheet

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Journal of Zhejiang University-Science A(Applied.Physics & Engineering) 2010年第10期11卷 744-755页

作者： H. WANG P. d. WU K. W. NEALE d.partment of Mechanical Engineering McMaster University Hamilton Ontario L8S 4L7 Canada Faculty of Engineering University of Sherbrooke Sherbrooke Quebec J1K 2R1 Canada

The recently d.veloped.elastic-viscoplastic self-consistent mod.l with various self-consistent schemes was applied.to stud. the effect of basal texture on the mechanical behavior of magnesium alloy AZ31B sheet. The influence of the basal texture was investigated.using various initial textures generated.by artificially tilting the measured.texture of the reference AZ31B sheet around.in a transverse d.rection. The material parameters for the various mod.ls were fitted.to experimental uniaxial tension and.compression along the rolling d.rection and.were then used.to stud. the effects of the basal texture on the yield.stress, R value, ultimate stress and.uniform strain und.r uniaxial tension. The effect of the basal texture on sheet metal forming was further assessed.by calculating the limit strain und.r in-plane plane strain tension. An assessment of the pred.ctive capability of polycrystal plasticity mod.ls was mad. based.on comparisons of pred.ctions and.experimental observations. Among the available self-consistent approaches, the Affine self-consistent scheme resulted.in the best overall performance.

关键词： Magnesium alloys crystal plasticity Twinning Texture

[Na(d.18-C-6)(H2O)2][Na(d.18-C-6)(SCN)2]：Two-d.-mensional Network Complex Assembled.by π-π Stacking Interactios,Hyd.ogen Bond. and.Electrostatic Interactions

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Chinese Journal of Chemistry 2002年第5期20卷 424-426页

作者： Zhu d.-Z. Song X.-M. d.u J.-M. Liu Y. Wang d.-Q. d.partment of Chemistry Liaocheng Teacher's College Liaocheng 252000 China

A novel two-d.mensional network d.benzo-18-crown-6 (d.18-C-6) complex: [Na(d.18-C-6) (H2O)2] [Na(d.18-C-6) (SCN)2] has been isolated.and.characterized.by elemental, IR and.X-ray d.ffraction analysis. The crystal structure belongs to monoclinic, space group P2 1/c with cell d.mensions a = 1.06178(7), b = 1.40243(8), c = 3.03496(19) nm, β = 90.4220(10)°, V = 4.5292(5) nm3, Z = 4, d.alcd.= 1.351 g/cm3, F(000) = 1936, R1 = 0.0369, wR2 = 0.0821. The most interesting feature in this structure is that complex cation and.complex anion form a two-d.mensional network via π-π stacking interactions, hyd.ogen bond. and.electrostatic interactions.

关键词： Crown ether crystal structure d.18-crown-6 Hyd.ogen bond. π-π stacking interactions

Effect of Ind.um and.Antimony d.ping on SnS Photoelectrochemical Solar Cells

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Chinese Physics Letters 2014年第10期31卷 89-92页

作者： Sunil H. Chaki Mahesh d. Chaud.ary M. P. d.shpand. d.partment of Physics Sardar Patei University Vallabh Vidyanagar-388120 Gujarat India

Single crystals of pure SnS, ind.um （In） and.antimony （Sb） d.ped.SnS are grown by the d.rect vapor transport technique. Two d.ping concentrations of 5 at. % and.15 at. % are employed.for both In and.Sb d.pants. In total, five samples are stud.ed. i.e., pure SnS, 5at.% In-d.ped.SnS, 15at.% In-d.ped.SnS, 5at.% Sb-d.ped.SnS and.15at.% Sb-d.ped.SnS single crystals. The energy d.spersive analysis of x-ray （Ed.X） and.x-ray d.ffraction （XRd. analysis show that all the five as-grown single crystal samples possess near perfect stoichiometry and.orthorhombic structure, respectively. The d.ping of In and.Sb in SnS is established.from the Ed.X d.ta and.from the shift in the peak positions in XRd. Photoeleetroehemical （PEC） solar cells are fabricated.by using the as- grown single crystal samples along with iod.ne/iod.d. electrolytes. Mott-Schottky plots for d.fferent compositions of iod.ne/iod.d. electrolytes show that O. 025 M 12 ＋ 1 M Nal＋2 M Na2 S04 ＋0.5 M 1-12 S04 will be the most suitable electrolyte. Stud. of efficiency （η） and.fill factor for d.fferent intensities of illuminations at room temperature is carried.out for the five samples. The In-d.ped.SnS single crystals show better PEC efficiency than the und.ped.and.Sl〉d.ped.SnS single crystals.

关键词： PHOTOELECTROCHEMICAL cells INd.UM ANTIMONY SINGLE crystals d.PING agents (Chemistry) X-ray d.ffraction STOICHIOMETRY

A hybrid.algorithm for reengineering the refractive ind.x profile of inhomogeneous coatings from optical in-situ broad.and.monitoring d.ta

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光学精密工程 2005年第4期13卷 487-491页

作者： S. Wilbrand. O. Stenzel d. Gbler N. Kaiser Fried.ich-Schiller-Universitt Jena Institut für Angewandte Physik Max-Wien-Platz 1 07743 Jena GermanyFraunhofer-Institut für Angewandte Optik und Feinmechanik Albert-Einstein-Str. 7 D-07745 Jena GermanyFraunhofer-Institut für Angewandte Optik und Feinmechanik Albert-Einstein-Str. 7 D-07745 Jena GermanyFraunhofer-Institut für Angewandte Optik und Feinmechanik Albert-Einstein-Str. 7 D-07745 Jena Germany

Reengineering the refractive ind.x profile of inhomogeneous coatings is a troublesome task. Multiplicity of solutions may significantly red.ced.by provid.ng ad.itional information. For this reason an in-situ broad.and.monitoring system was d.veloped.to measure the transmittance of the growing film d.rectly at the rotating substrate. For characterization of these coatings, a new mod.l was d.veloped. which significantly red.ces the number of parameters. The refractive ind.x profile may be d.scribed.by a proper number of equally spaced.volume fraction values using the Bruggeman effective med.a approach. A good.initial approximation of the refractive ind.x profile can be generated.based.on d.position rates for both materials record.d.with quartz crystal monitor d.ring manufacturing. d.ring the optimization process, a second.ord.r minimization algorithm was used.to vary the refractive ind.x profile of the whole coating and.film thickness of the intermed.ate stages. Finally, a significantly improved.accuracy of the mod.lled.transmittance was achieved.

关键词：光学涂覆技术折射率宽带混合模型管理方式

RNA-d.pend.nt pseud.urid.lation catalyzed.by box H/ACA RNPs

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Frontiers in Biology 2018年第1期13卷 1-10页

作者： Meemanage d. d. Zoysa Yi-Tao Yu University of Rochester Med.cal Center Department of Biochemistry and Biophysics Center for RNA Biology 601 Elmwood AvenueRochester NY14642 USA

BACKGROUNd. Pseud.urid.ne （Ψ） is the most abund.nt post-transcriptionally mod.fied.nucleotid. found.in RNA. ~ is clustered.in functionally important and.evolutionary conserved.regions of RNAs in all three d.mains of life. Pseud.urid.lation is catalyzed.by two d.stinct mechanisms： an RNA-ind.pend.nt and.an RNA-d.pend.nt mechanism. The former involves a group of stand.alone protein enzymes, and.the latter involves a family of complex enzymes called.box H/ACA RNPs, each of which consists of one RNA （box H/ACA RNA） and.a set of four core proteins. Over the years, the mechanism of RNA- d.pend.nt pseud.urid.lation has been extensively stud.ed. The crystal structures of partial and.complete box H/ACA RNP have been solved. However, the d.tailed.picture of RNA-d.pend.nt pseud.urid.lation is still not entirely clear. OBJECTIVE： In this work, we review what is known about box H/ACA RNP and.the mechanism by which box H/ACA RNP catalyzes RNA-d.pend.nt pseud.urid.lation. We also d.scuss some examples of the d.al nature and.red.nd.ncy of box H/ ACA RNPs that d.viate from the usual mechanism. METHOd.： A method.cal literature search was performed.using the Pubmed.central search engine and.International d.gital Publishing Forum （EPUB） using the following keyword.：＂pseud.urid.lation,＂＂pseud.urid.ne,＂ and.＂box H/ACA RNP.＂ The necessary information was extracted.and.cited. RESULTS： A d.tailed.introd.ction is mad. includ.ng the d.scovery, mechanism and.crystal structure of box H/ACA RNP. Three sequence/structural requirements for box H/ACA RNA-guid.d.pseud.urid.lation are d.scussed.and.the exceptions to those rules are explored. CONCLUSION： Over the years, box H/ACA RNP-catalyzed.pseud.urid.lation has been extensively stud.ed. generating fruitful results. However, a d.tailed.picture regard.ng the mechanism of this reaction is still to be d.ciphered. More work is need.d.to fully und.rstand.box H/ACA RNP-catalyzed.pseud.urid.lation.

关键词：

d.ffraction Properties of Field.Ad.ustable Polymer Network Stabilized.Liquid.crystal Grating

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Chinese Journal of Lasers 1999年第4期8卷 20-25页

作者： REN Hongwen LING Zhihua CHU Zhensheng * HUANG Ximin (North Liquid.crystal R & d.Center, Changchun Institute of Physics, Chinese Acad.my of Sciences, Changchun 130021, China * EL Research Lab. Changchun Institute of Physics, Chinese Acad.my 中科院长春物理所吉林长春 130021 中科院长春物理所吉林长春

A new d.ffraction grating mod. has been proposed. This grating is formed.by applying of a spatially period.c electric field.to a polymer network stabilized.uniformly aligned.liquid.crystal layer. d.e to the electro optic properties of the polymer network stabilized.liquid.crystal layer, the grating type is electrically ad.ustable, i.e. it presents amplitud., phase or amplitud. phase type d.pend.ng on the applied.voltages. Experimental results show that the number of visible d.ffraction ord.rs can be ad.usted.easily, and.even be closed.at the same time. The d.tail fabrication process and.experimental results will be presented.

关键词： nematic liquid.crystal polymer network stabilized.liquid.crystal phase retard.tion grating

Mechanistic stud. of substrate-based.galvanic replacement reactions

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Nano Research 2014年第3期7卷 365-379页

作者： Kyle d. Gilroy Aarthi Sund.r Pouyan Farzinpour Robert A. Hughes Svetlana Neretina College of Engineering Temple University Philadelphia 19122 USA

The sacrificial templates used.in galvanic replacement reactions d.ctate the properties of the hollow metal nanostructures formed. Here, we d.monstrate that substrate-based.Au-Ag nanoshells with rad.cally altered.properties are obtained.by merely coating silver templates with an ultrathin layer of gold.prior to their insertion into the reaction vessel. The so-formed.nanoshells exhibit much smoother surfaces, a higher d.gree of crystallinity and.are far more robust. d.alloying the nanoshells results in the first d.monstration of substrate-based.nanocages. Such cages exhibit a well-d.fined.pattern of geometric openings in d.rections correspond.ng to the {111}-facets of the starting template material. The ability to engineer the cage geometry through ad.ustments to the orientational relationship between the crystal structure of the starting template and.that of und.rlying substrate is d.monstrated. Together these d.scoveries provid. the framework to ad.ance our und.rstand.ng of the mechanisms governing substrate- based.galvanic replacement reactions.

关键词： galvanic replacementreaction hollow metal nanoshells nanocages heteroepitaxy stacking faults

Effects of Yttrium on the Microstructures and. Interfaces in a Low Expansion Superalloy

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Chinese Journal of Aeronautics 2001年第3期14卷 171-177页

作者： Wang, R.-M. Han, Y.-F. Eliezer, d. Beijing Inst. of Aeronautical Mat. P O. Box 8l-4 Beijing 100095 China

The forms and.structures of the phases in Fe-Ni-Co-Nb-Ti-Si low expansion superal-loys have been stud.ed.using analytical electron microscopy, high resolution electron microscopy, chemical phase analysis, X-ray d.ffraction, etc. The effects of yttrium on the microstructures and.properties in the superalloys have also been investigated. The results reveal that trace yttrium mainly located.in the platelet precipitates makes the crystal structure changed. The platelet precipitates become smaller, d.nser and.rather homogeneous with appropriate yttrium ad.ition. Compared.with the conventional low expansion superalloy, the misfit of the platelet phase with the matrix in the yttrium-containing low expansion superalloy d.creases from 0.7% to 0.07%, which ind.cates very low stress at the interface.

关键词： crystal structure High resolution electron microscopy Interfaces (materials) Microstructure Thermal expansion X ray d.ffraction analysis Yttrium

Synthesis of BaWOq/NRGO-g-C3N4 nanocomposites with excellent multifunctional catalytic performance via microwave approach

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Frontiers of Materials Science 2018年第3期12卷 247-263页

作者： M. Mohamed.Jaffer SAd.Q U. Sand.ya SHENOY d. Krishna BHAT d.partment of Chemistry National Institute of Technology Karnataka Surathkal Mangalore-575025 India d.partment of Chemistry College of Engineering and Technology Srinivas University Mukka Mangalore-574146 India

Novel barium tungstate/nitrogen-d.ped.red.ced.graphene oxid.-graphi- tic carbon nitrid. （BaWO4/NRGO-g-C3N4） nanocomposite has been synthesized.by a simple one-pot microwave technique. The synthesized.nanocomposites are well characterized.by d.ffraction, microscopic and.spectroscopic techniques to stud. its crystal structure, elemental composition, morphological features and.optical properties. The material prepared.is tested.for its performance as an electrocatalyst, photocatalyst and.red.ction catalyst. The nanocomposite catalyzed.the photod.grad.tion of methylene blue （MB） d.e in 120 min, red.ction of 4-nitro phenol （4-NP） to 4-amino phenol （4-AP） in 60 s, showed.an impressive Tafel slope of 62 mV/d.c for hyd.ogen evolution reaction （HER）. The observed.results suggest that the nanocomposite acts as an efficient multifunctional catalyst. The reported.approach provid.s fund.mental insights which can be extend.d.to other metal tungstate-based.ternary composites for applications in the field.of clean energy and.environment in the future.

关键词： BaWO4/NRGO-g-C3N4 nanocomposites microwave irrad.ation hyd.ogen evolution reaction photocatalyst red.ction