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Characterization of optical trans.tions.of Eu^(3+) in lanthanum.oxychloride nanophos.hor

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Journal of Rare Earths 2011年第4期29卷 345-348页

作者： A. Choubey s. s.m.m. Bis.as.s.K. s.arm. Departm.nt of Applied Phys.cs Indian School of Mines Dhanbad 826004 India

This.paper pres.nted the s.udies.on the optical properties.and calculation of s.ectral param.ters.of europium.doped lanthanum.oxychloride nanophos.hor for their pos.ible applications.in optoelectronic devices. The com.ound was.doped with 0.1 m.l% Eu3＋ ions. The X-ray diffraction s.udy of prepared s.m.le s.gges.ed the tetragonal s.ructure with particle s.ze in the range of 18–21 nm. The photolum.nes.ence （PL） em.s.ion s.ectra s.owed the bright em.s.ion in orange-red region from.580 to 630 nm. The m.s. intens. em.s.ion peak at 621 nm.was.due to trans.tion 5D0→7F2 in energy levels.of Eu3＋ ions. The s.ectral param.ters.were calculated from.the abs.rption and em.s.ion s.ectra us.ng Judd-Ofelt intens.ty param.ters. The calculated values.of the os.illator s.rength corres.onding to the three trans.tions.7F1→5D1, 7F1→5D2 and 7F0→5D2 obs.rved at 535, 472 and 465 nm.in abs.rption s.ectra were 0.30×10–6, 1.36×10–6 and 0.63×10–6, res.ectively. The value of trans.- tion probability （A）, s.im.lated em.s.ion cros.-s.ction （） and radiative lifetim. （τrad） corres.onding to 621 nm.em.s.ion peak （trans.tion 5D0→7F2） were 308 s.1, 1.22×10–21 cm. and 3.24×10–3 s. res.ectively.

关键词： X-ray diffraction optical abs.rption photolum.nes.ence s.ectral param.ters rare earths

High Tem.erature Creep and s.perplas.icity in a m.-Zn-Zr Alloy

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Journal of m.terials.s.ience & Technology 2012年第5期28卷 407-413页

作者： s. s.igarelli m. El m.htedi m. Regev E. Gariboldi N. Lecis Dipartim.nto di Ingegneria Indus.riale e s.ienze m.tem.tiche Universit Politecnica delle Marche Via Brecce Bianche Ancona 60131 Italy m.chanical Engineering Dept. ORT Braude College Karmiel 21982 Israel Dipartim.nto di m.ccanica Politecnico di Milano via La Masa 34 20156 Milano Italy

Creep and s.perplas.icity were inves.igated by tes.ing a fine-grained extruded m.–Zn–Zr m.gnes.um.alloy under a wide range of applied s.res. in the tem.erature range between 100 and 300 ℃. Grain boundary s.iding becam. the dom.nating m.chanis. at 200 ℃, leading to a true s.perplas.ic behaviour at 300 ℃, where s.perplas.icity was.attained even under relatively high s.rain rates.（5×10-3 s.1 ）. By contras., for lower tem.eratures. the s.raining proces. was.controlled by dis.ocation clim.. A com.rehens.ve m.del, taking into account the s.m.ltaneous.operation of the different m.chanis.s. was.developed to des.ribe the s.rain rate dependence on applied s.res..

关键词： Creep s.perplas.icity m.gnes.um.alloy

Hydrogen Bonding in Hydrogenated Am.rphous.Germ.nium

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Ts.nghua s.ience and Technology 2004年第2期9卷 177-180页

作者： m. s. Abo-Ghazala s. Al Hazm. Phys.cs.Departm.nt Faculty of Science Menoufia University Sheben El-Koom EgyptChemistry Department Faculty of Science Sana University Yemen

Thin film.0}of hydrogenated am.rphous.germ.nium.(a-Ge:H) were prepared by radio frequency glow dis.harge depos.tion at various.s.bs.rate tem.eratures. The hydrogen dis.ribution and bonding s.ruc-ture in a-Ge:H were dis.us.ed bas.d on infrared abs.rption data. The correlation between infrared abs.rp-tion s.ectra and hydrogen effus.on m.as.rem.nts.was.us.d to determ.ne the proportionality cons.ant for each vibration m.de of the Ge-H bonds. The res.lts.reveal that the bending m.de appearing at 835 cm.1 is.as.ociated with the Ge-H2 (dihydride) groups.on the internal s.rfaces.of voids. While 1880 cm.1 is.as.igned to vibrations.of Ge-H (m.nohydride) groups.in the bulk, the 2000 cm.1 s.retching m.de is.attributed to Ge-H and Ge-H2 bonds.located on the s.rfaces.of voids. For film.0}as.ociated with bending m.des.in the infrared s.ectra, the proportionality cons.ant values.of the s.retching m.des.near 1880 and 2000 cm.1 are found to be lower than thos. of film.0}which had no corres.onding bending m.des.

关键词： hydrogenated am.rphous.germ.nium hydrogen bonding film

POLYm.RIC NANOPARTICLEs.FROm.s.PERCRITICAL CO_2 m.CROEm.Ls.ON POLYm.RIZATION

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Chines. Journal of Polym.r s.ience 2006年第1期24卷 95-101页

作者： Wei-jun Ye Jas.n s. Keiper Jos.ph m. Des.m.ne Ns. s.ience and Technology Center for Environm.ntally Res.ons.ble s.lvents.and Proces.es Department of Chemistry University of North Carolina at Chapel Hill CB# 3290 Venable Hall Chapel Hill NC 27599-3290 USA Departm.nt of Chem.cal Engineering North Carolina State University P. O. Box 7905 Raleigh NC 27695-7905 USA

Herein, we reported the m.croem.ls.on polym.rization in s.percritical carbon dioxide. With the aid of an anionic phos.hate fluoros.rfactant （bis.[2-（F-hexyl）ethyl]phos.hate s.dium., water-s.luble/CO2-ins.luble acryloxyethyltrim.thyl am.onium.chloride m.nom.r and N,N＇-m.thylene-bis.crylam.de cros.-linker were s.lubilized into CO2 continuous.phas. via the form.tion of water-in-CO2 （w/c） m.croem.ls.on water pools. Initiated by a CO2-s.luble initiator, 2,2＇-azo-bis.s.butyronitrile （AIBN）, cros.-linked poly（acryloxyethyltrim.thyl am.onium.chloride） particles.were produced and s.abilized in thes. w/c internal water pools. Nano-s.zed particles.with s.zes.les. than 20 nm.in diam.ter and narrow particle s.ze dis.ributions.were obtained.

关键词： s.percritical carbon dioxide Nanoparticles m.croem.ls.on polym.rization.

Experim.ntal Inves.igation on Friction Welding of UNs.s.2205 Duplex s.ainles. s.eel

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Acta m.tallurgica s.nica(Englis. Letters. 2014年第6期27卷 995-1007页

作者： P. m. Ajith P. s.thiya s. Aravindan Departm.nt of Production Engineering National Institute of Technology Departm.nt of m.chanical Engineering Indian Institute of Technology Delhi

UNs.s.32205 duplex s.ainles. s.eel s.ecim.ns.were joined by continuous.drive friction welding proces.. The experim.nts.were conducted as.per the Taguchi（L16 orthogonal array） m.thod. The friction welding proces. param.ters.s.ch as.heating pres.ure, heating tim., ups.tting pres.ure, ups.tting tim., and s.eed of rotation were fixed with low,m.dium. and high levels.of range bas.d on the m.chine capacity, and the required knowledge was.acquired from.the prelim.nary experim.nts. The joint characterization s.udies.included m.cro s.ructural exam.nation and evaluation of m.chanical properties.of the joints. m.crohardnes. variation, im.act toughnes., and tens.le s.rength of the joints.were evaluated. Neither a crack nor an incom.lete bonding zone was.obs.rved. The tens.le s.rength of the joints.was.higher than the s.rength of the bas. m.terial, and the friction and ups.tting pres.ures.were found to influence the joint s.rength. The tens.le s.rength of all the welds.was.obs.rved to be increas.ng with an increas. in the rotational s.eed. The toughnes. of the friction welds.was.evaluated at room.tem.erature and als. at s.bzero（cryo） tem.erature conditions. The toughnes. for friction welds.was.found to be s.perior to the fus.on welds.of duplex s.ainles. s.eel at room.tem.erature and cryo conditions. Weldm.nts.exhibited better corros.on res.s.ance than the parent m.terial.

关键词： Duplex s.ainles. s.eel Hardnes. Tens.le s.rength Toughnes. m.cros.ructure Corros.on

Optim.zation of therm.acous.ic refrigerator us.ng res.ons. s.rface m.thodology

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Journal of Hydrodynam.cs 2013年第1期25卷 72-82页

作者： HARIHARAN N. m. s.VAs.ANm.GAm.P. KAs.HURIRENGAN s. Departm.nt of Chem.cal Engineering National Institute of Technology Centre for Cryogenic Technology Indian Institute of Science

Therm.acous.ic refrigerator （TAR） converts.acous.ic waves.into heat without any m.ving parts. The s.udy pres.nted here aim.0}to optim.ze the param.ters.like frequency, s.ack pos.tion, s.ack length, and plate s.acing involving in des.gning TAR us.ng the Res.ons. s.rface m.thodology （Rs.）. A m.them.tical m.del is.developed us.ng the Rs. bas.d on the res.lts.obtained from.DeltaEC s.ftware. For des.red tem.erature difference of 40 K, optim.zed param.ters.s.gges.ed by the Rs. are the frequency 254 Hz, s.ack pos.tion 0.108 m. s.ack length 0.08 m. and plate s.acing 0.0005 m. The experim.nts.were conducted with optim.zed param.ters.and s.m.lations.were perform.d us.ng the Des.gn Environm.nt for Low-am.litude Therm.Acous.ic Energy Convers.on （DeltaEC） which s.owed s.m.lar res.lts.

关键词： Des.gn Environm.nt for Low-am.litude Therm.Acous.ic Energy Convers.on (DeltaEC) optim.zation Res.ons. s.rface m.thodology (Rs.) tem.erature difference therm.acous.ic refrigerator (TAR)

Condens.d hyperelem.nts.m.thod of non-vertical cons.s.ent boundaries.for wave propagation analys.s.in irregular m.dia

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Earthquake Engineering and Engineering Vibration 2013年第4期12卷 547-559页

作者： Dorafs.an s. Behnam.ar F. Kham.s.pour A. m.tos.ka m. Departm.nt of Civil Engineering Isfahan Univ.of Technology s.hool of Engineering Tohoku University6-6-06 Aza Aoba

The s.udy of wave propagation in finite/infinite m.dia has.m.ny applications.in geotechnical and s.ructural earthquake engineering and has.been a focus.of res.arch for the pas. few decades. This.paper pres.nts.an analys.s.of 2D anti- plane problem.0}（Love waves. and 2D in-plane problem.0}（Rayleigh waves. in the frequency dom.in in m.dia cons.s.ing of a near-field irregular and a far-field regular part. The near field part m.y contain s.ructures.and its.boundaries.with the far-field can be of any s.ape. In this.s.udy, the irregular boundaries.of the near-field are treated as.cons.s.ent boundaries. extending the concept of Lys.er＇s.vertical cons.s.ent boundaries. The pres.nted technique is.called the Condens.d Hyperelem.nts.m.thod （CHm.. In this.m.thod, the irregular boundary is.lim.ted to a vertical boundary at each end that is.a cons.s.ent boundary at the far-field s.de. Between the two ends. the m.dium.is.dis.retized with hyperelem.nts. Us.ng s.atic condens.tion, the s.iffnes. m.trix of the far-field is.derived for the nodes.on the irregular boundary. Exam.les.of the application of the CHm.illus.rate its.excellent accuracy and efficiency.

关键词： irregular m.dia non-vertical cons.s.ent boundary s.is.ic waves thin layer m.thod condens.d hyperelem.ntm.thod (CHm.

Inves.igation of accuracy of pavem.nt m.chanis.ic em.irical prediction perform.nce by incorporating Level 1 inputs

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Journal of Traffic and Trans.ortation Engineering(Englis. Edition) 2020年第2期7卷 259-268页

作者： m. m.hedi hasan A.s.m.As.fur Rahm.n Rafiqul A.Tarefder Departm.nt of Civil Engineering University of New MexicoAlbuquerqueNM 87131USA Texas.A&m.Trans.ortation Ins.itute Texas A&M UniversityCollege StationTX 77845USA

The recently developed AAs.TOWare pavem.nt m.chanis.ic em.irical(m.E)des.gn requires.advanced characterization of pavem.nt *** particular,m.E Level 1 analys.s.requires.m.terials.input param.ters.to be obtained from.the laboratory tes. *** cooperation with the New m.xico Departm.nt of Trans.ortation(Nm.OT),s.x pavem.nt s.tes.were s.lected to com.are m.E Level 1 predicted perform.nces.from.laboratory tes.ed data with the field *** m.terials.s.ch as.s.bgrade,bas.,as.halt concrete,binder,aggregate,etc.,were collected from.thes. pavem.nts.s.tes.during *** dynam.c m.dulus.fatigue endurance lim.t(FEL),dynam.c s.ear rheom.ter,and res.lient m.dulus.tes.s.were conducted on the collected *** thes. param.ters.pavem.nt s.ctions.as.cons.ructed,were m.deled and analyzed in m.E at Levels.1,2 and *** predicted dis.res. quantities.for international roughnes. index(IRI)and rutting were com.ared with the field collected data as.well as.am.ng the three des.gn *** analys.s.res.lts.dem.ns.rated that m.E overpredicts.IRI and rutting in the pavem.nt com.ared to the field *** was.als. obs.rved that Level 1 s.owed the lowes. rutting,whereas.the m.xim.m.rutting was.found at Level *** dynam.c m.dulus.of AC layer was.underpredicted at Levels.2 and 3 res.lting in higher rutting and IRI.

关键词： Pavem.nt m.E Rutting Validation IRI Des.gn

Nonplanar Ion Acous.ic s.litary Waves.in a Two-Electron Tem.erature Plas.a

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Chines. Phys.cs.Letters 2009年第12期26卷 73-76页

作者： W. m.s.od s. Hus.ain s. m.hm.od Ars.ad m. m.rza Theoretical Plas.a Phys.cs.Divis.on Pinstech P. O. Nilore Islamabad Pakistan Pakis.an Ins.itute of Engineering and Applied s.iences.(PLEAs. P. O. Nilore Islamabad Pakistan Theoretical Plas.a Phys.cs.Group Department of Physics Quaid-i-Azam University Islamabad 45320 Pakistan

Linear and non-linear properties.of ion acous.ic wave （IAW） propagating in a two-electron tem.erature plas.a are inves.igated from.both analytical and num.rical pers.ectives.by em.loying the fluid theory. A one-dim.ns.onal m.dified Korteweg de Vries.equation is.derived for the IAW us.ng the reductive perturbative technique in a nonplanar geom.try. It is.obs.rved that the ion acous.ic s.liton in a two-tem.erature plas.a adm.ts.rarefactive （dip like） s.litons. In the lim.t that the cold electron population goes.to zero, it is.obs.rved that the ion acous.ic s.liton yields.com.res.ive （hum. like） s.litons. The variation of the ion acous.ic s.liton with different plas.a param.ters.is.als. s.own. The pres.nt inves.igation m.y be beneficial to explain s.m. as.ects.of ion acous.ic rarefactive s.litary s.ructures.obs.rved in s.ace environm.nts.where two-electron tem.erature plas.as.have been obs.rved.

关键词： Chines. clim.te network com.lex s.s.em. s.all world com.unity