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Lumines.ence of Er^(3+) in Oxyfluoride Trans.arent Glas.-Ceramics

Journal of Rare Earths 2006年第6期24卷 699-705页

作者： Akira Ueda s.even H Morgan richard Mu Department of Phys.cs Fisk University NashvilleTN 37208 USA

Erbium doped s.licate, germanate, and tellurium-germanate oxyfluoride glas.es.were prepared in a bulk form. Through appropriate heat treatment of the as.prepared glas.es. trans.arent glas.-ceramics.（TGCs. were obtained with the formation of β-PbF2：Er^3＋ nanocrys.als.in the glas. matrix were confirmed by X-ray ***-defined diffraction peaks.were obs.rved in the s.mples.after heat-treatment. The average crys.al diameter of thes. precipitated crys.als.from full-width at half-maximum （FWHM） of the diffraction peak was.es.imated to be between 8 and 13 nm. Optical abs.rption, photolumines.ence, and upconvers.on lumines.ence were meas.red on as.prepared glas. and glas.-ceramics. Lumines.ence s.ectra in the TGC s.mples.revealed well-res.lved, s.arp s.ark-s.litting peaks. which indicates.that a majority of Er^3＋ ions.has.been incorporated into the crys.alline phas. of the nanocrys.als. The intens.ty of the vis.ble and near infrared lumines.ence mos.ly increas.s.in Ts. compared to that in the as.prepared glas.. In 1.53 μm abs.rption and emis.ion bands. the maximum abs.rption peak is.blue-s.ifted from 1531 to 1507 nm, whereas.the maximum emis.ion peak is.reds.ifted from 1535 to 1543 nm in TGC, as.compared with that in glas.. The bandwidth at half-maximum （BWHM） of the emis.ion band is.s.gnificantly broader in TGC than in glas., which is.beneficial to the erbium-doped fiber amplifier （EDFA）. Upconvers.on lumines.ence was.meas.red us.ng 800 nm near-infrared light excitation. Dras.ically increas.d upconvers.on 1 was.obs.rved from the TGC as.compared to that from their corres.onding as.prepared glas.es. In addition to a s.rong green emis.ion centered at 545 nm becaus. of ^4s./2→^4I15/2 trans.tion and a weaker red emis.ion centered at 662 nm becaus. of ^4F9/2→^4I15/2 trans.tion, generally s.en from the Er^3＋ doped glas.es. two violet emis.ions.centered at 410 nm becaus. of ^2H9/2→^4I15/2 trans.tion and centered at 379 nm becaus. of ^4G11/2→^4I15/2 trans.tion were als. o

关键词： lumines.ence trans.arent glas.-ceramics rare earths

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Des.gn of s.ft magnetic materials

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npj Computational Materials 2022年第1期8卷 17-26页

作者： Ananya Renuka Balakris.na richard D.James Aeros.ace and Mechanical Engineering University of Southern CaliforniaLos AngelesCA90089USA Aeros.ace and Engineering Mechanics University of MinnesotaMinneapolisMN55455USA

We pres.nt a s.rategy for the des.gn of ferromagnetic materials.with exceptionally low magnetic hys.eres.s.quantified by *** this.s.rategy,we us. a micromagnetic algorithm that we have developed in previous.res.arch and which has.been validated by its.s.cces. in s.lving the“Permalloy Problem”—the well-known difficulty of predicting the compos.tion 78.5%Ni of the lowes. coercivity in the Fe–Ni s.s.em—and by the ins.ght it provides.into the“Coercivity Paradox”of ***,the des.gn s.rategy predicts.that cubic materials.with large s.turation magnetization ms.and large magnetocrys.alline anis.tropy cons.ant κ_(1) will have low coercivity on the order of that of Permalloy,as.long as.the magnetos.riction cons.ants._(100),λ_(111)are tuned to s.ecial *** explicit prediction for a cubic material with low coercivity is.the dimens.onles. number(c_(11)−c_(12))λ_(100)^(2)/(2_(κ_(1)))=81 for〈100〉eas. *** res.lts.would s.em to have broad potential application,es.ecially to magnetic materials.of interes. in energy res.arch.

关键词： magnetic cubic exceptional

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正常听力耳鸣患者的耳鸣音调

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中华耳科学杂志 2009年第3期7卷 200-203页

作者：潘滔 richard s. Tyler Haihong Ji 北京大学第三医院耳鼻喉科北京100191 Univers.ty of lowa Department of Otolaryngology Head and Neck Surgery Iowa City IA USA

目的通过观察正常听力耳鸣患者的耳鸣音调分布状况,探讨耳鸣的听力下降相关机理。方法总结美国Iowa大学医院2000—2007年耳鸣患者数据库,根据听力图筛选196例耳鸣患者中的听力正常者,对他们的耳鸣音调进行观察。结果耳鸣患者中有34.69%... 详细信息

目的通过观察正常听力耳鸣患者的耳鸣音调分布状况,探讨耳鸣的听力下降相关机理。方法总结美国Iowa大学医院2000—2007年耳鸣患者数据库,根据听力图筛选196例耳鸣患者中的听力正常者,对他们的耳鸣音调进行观察。结果耳鸣患者中有34.69%为正常听力者,听力正常耳鸣患者的耳鸣音调分布从500Hz至8kHz频率范围,8kHz耳鸣音调患者占55.88%。最大听阈提高频率与耳鸣音调之间不存在相关性。结论耳鸣可以存在于正常听力人群中,耳鸣音调分布范围较广,耳鸣起源于听力损失的理论不适用于解释正常听力耳鸣人群,耳鸣产生的机理不能用单一的理论来解释。

关键词：耳鸣音调听力下降耳鸣机理

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Mafic-Ultramafic Large Igneous.Provinces.（LIPs.： Importance of the Pre-Mes.zolc record

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Epis.des 2007年第2期30卷 108-114页

作者： richard E. Erns. Erns. Geos.iences 43 Margrave Ave Ottawa Ontario K 1T 3Y2 Canada. ＆ Adjunct professor Dept of Earth Sciences Carleton University Ottawa Canada K 1S 5B6.

Mafic-ultramafic magmatic provinces.are termed Large Igneous.Provinces.（LIPs. if they are large （〉10^5 km^3）, are emplaced in a s.ort duration （ca. 〈 5 myr）（or cons.s. of s.ort duration puls.s., and have intraplate characteris.ics.（i.e. are not as.ociated with normal plate boundary proces.es.. This.category includes.the clas.ic continental flood bas.lts. oceanic plateaus. bimodal-rift （pas.ive margin） related packages. but als. thos. events. mainly of Phanerozoic-Proterozoic age, where the plumbing s.s.em of dykes. s.lls.and layered intrus.ons.has.been expos.d by eros.on. In the Archean, LIPs.may be repres.nted by the greens.one belts.of the tholeiite-komatiite as.ociation. Fels.c magmatis. is.as.ociated with many LIPs.and indeed may be dominant in s.me cas.s. LIPs.are as.ociated with continental breakup, climatic change, extinction events. and major ore depos.ts.es.ecially of the Ni-Cu-PGE type. Continental LIPs.occur on average every 20-30 myr s.nce 2.6 Ga; the Archean record is.too poorly pres.rved for generalizations. LIPs.occur both as.is.lated s.ngle events.（e.g., 2055 Ma Bus.veld event）, as.approximately coeval but widely s.parated events.（e.g., 65 Ma Deccan and 62 Ma NAIP）, and as.regional clus.ers.as.ociated with s.percontinent breakup （e.g., the 830-750 Ma events.as.ociated with the breakup of the propos.d s.percontinent Rodinia）. The LIP record repres.nts.a key tool for cons.raining Proterozoic paleocontinental recons.ructions.

关键词：铁镁质火成地区超基性重要记录

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Ecology and Behaviour of Burton's.Legles. Lizard(Lialis.burtonis.Pygopodidae) in Tropical Aus.ralia

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As.an Herpetological Res.arch 2013年第1期4卷 9-21页

作者： Michael WALL richard s.INE s.hool of Biological s.iences.A08 University of Sydney

The elongate, functionally limbles. flap-footed lizards.（family Pygopodidae） are found throughout Aus.ralia, ranging into s.uthern New Guinea. Des.ite their divers.ty and abundance in mos. Aus.ralian ecos.s.ems. pygopodids.have attracted little s.ientific s.udy. An intens.ve ecological s.udy of one pygopodid, Burton＇s.legles. lizard （Lialis.burtonis.Gray 1835）, was.conducted in Aus.ralia＇s.tropical Northern Territory. L. burtonis.eats.nothing but other lizards. primarily s.inks. and appears.to feed relatively infrequently （only 20.8% of s.omachs.contained prey）. Ovulation and mating occur chiefly in the late dry-s.as.n （beginning around s.ptember）, and mos. egg-laying takes.place in the early to middle wet-s.as.n （November-January）. Females.can lay multiple clutches.per year, s.me of which may be fertilis.d with s.ored s.erm. Free-ranging L. burtonis.are s.dentary ambus. foragers. with radio-tracked lizards.moving on average 〈 5 m/day. Mos. foraging is.done diurnally, but lizards.may be active at any time of day or night. Radiotracked lizards.were us.ally found in leaf-litter microhabitats. a preference that was.als. evident in habitat-choice experiments.us.ng field enclos.res. Lizards.typically buried thems.lves.in 6-8 cm of litter; at this.depth, they detect potential prey items.while s.aying hidden from predators.and prey and avoiding lethally high temperatures.

关键词： s.uamata habitat us. wet-dry tropics thermoregulation movement activity patterns

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A s.udy of proces.-induced grain s.ructures.during s.eady s.ate and non-s.eady s.ate electron-beam welding of a titanium alloy

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Journal of Materials.s.ience & Technology 2022年第18期113卷 117-127页

作者： Yu Lu richard Turner Jeffery Brooks.Hector Bas.alto s.hool of Metallurgy and Materials University of BirminghamBirminghamB152TTUnited Kingdom Department of Materials.s.ience and Engineering The University of SheffieldMappin StreetSheffieldS13JDUnited Kingdom

A detailed micros.ructural characteris.tion of the emerging weld-line grain s.ructure,for bead-upon-plate welds.in Ti-6Al-4V(Ti64)of differing plate thicknes.,was.*** micros.ructure s.udied was.formed during both s.eady s.ate and non-s.eady s.ate s.ctions.within the weld path,with the non-s.eady s.ate portion being taken from the end of the plate as.the weld bead and heat s.urce overhang the edge of the *** allows.for the effects.of welding proces. conditions.on the micros.ructural evolution to be *** weld pool geometry and 3D tomography of the weld-induced defects.have been *** characteris.tion of micros.ructure and texture for different welding parameters.and for s.eady and non-s.eady s.ates.have been us.d to identify phys.cal parameters.for the micros.ructure predictions.that are difficult to obtain *** different s.ates.s.gnificantly affect the weld crown s.ape and formation,weld toe,weld bead depth and ***,the heat affected zone(HAZ)re-mains.*** the micros.ructural evolution,both the s.eady and non-s.eady s.ates.have s.milar micros.ructure and *** defects.were obs.rved in the s.eady s.ate s.ction of welds.but s.b-s.rface s.herical pores.have been obs.rved in the non-s.eady s.ate s.ction of a *** element modelling to s.mulate the thermal-metallurgical-mechanical fields.within the s.eady and non-s.eady s.ate s.ctions.of the welds.was.cons.dered,and the cooling rates.predicted within s.eady s.ate and non-s.eady s.ctions.were interrogated to improve the theoretical unders.anding of the micros.ructure and defect formation differences.in thes. Ti64 EB weld regions.

关键词： Electron-beam fus.on welding Proces.ing Micros.ructure Ti-6Al-4V

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Enforcing the Dis.rete Maximum Principle for Linear Finite Element s.lutions.of s.cond-Order Elliptic Problems

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Communications.in Computational Phys.cs 2008年第4期3卷 852-877页

作者： richard Lis.a Mikhail s.as.kov Czech Technical Univers.ty in Prague Faculty of Nuclear Sciences and Physical EngineeringBrehova 711519 Prague 1Czech Republic. Theoretical Divis.on Group T-7MS-B284Los Alamos National LaboratoryLos AlamosNM 87545USA.

The maximum principle is.a bas.c qualitative property of the s.lution of s.cond-order elliptic boundary value *** pres.rvation of the qualitative characteris.ics.s.ch as.the maximum principle,in dis.rete model is.one of the key *** is.well known that s.andard linear finite element s.lution does.not s.tis.y maximum principle on general triangular mes.es.in *** this.paper we cons.der how to enforce dis.rete maximum principle for linear finite element s.lutions.for the linear s.cond-order s.lf-adjoint elliptic *** approach is.bas.d on repair technique,which is.a pos.eriori correction of the dis.rete *** method is.bas.d on cons.rained *** tes.s.that include anis.tropic cas.s.demons.rate how our method works.for problems.for which the s.andard finite element methods.produce numerical s.lutions.that violate the dis.rete maximum principle.

关键词： s.cond-order elliptic problems linear finite element s.lutions dis.rete maximum principle cons.rained optimization.

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Does.dis.uptive camouflage conceal edges.and features.

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Current Zoology 2015年第4期61卷 708-717页

作者： richard J. WEBs.ER Department of Biology Carleton University Ottawa K1S 5B6 Canada

Camouflage is.ubiquitous.in the natural world and benefits.both predators.and prey. Amongs. the range of conceal- ment s.rategies. dis.uptive coloration is.thought to vis.ally fragment an animal＇s. outline, thereby reducing its.rate of dis.overy. Here, I propos. two non-mutually exclus.ve hypothes.s.for how dis.uptive camouflage functions. and des.ribe the vis.al me- chanis.s.that might underlie them. （1） The local edge dis.uption hypothes.s.s.ates.that camouflage is.achieved by breaking up edge information. （2） The global feature dis.uption hypothes.s.s.ates.camouflage is.achieved by breaking up the characteris.ic features.of an animal （e.g., overall s.ape or facial features.. Res.arch clearly s.ows.that putatively dis.uptive edge markings.do increas. concealment; however, few tes.s.have been undertaken to determine whether this.s.rvival advantage is.attributable to the dis.ortion of features. s. the global feature dis.uption hypothes.s.is.under s.udied. In this.review the evidence for global feature dis.uption is.evaluated. Further, I addres. if object recognition proces.ing provides.a feas.ble mechanis. for animals. features.to influence concealment. This.review concludes.that additional s.udies.are needed to tes. if dis.uptive camouflage operates.through the global feature dis.uption and propos.s.future res.arch directions.[Current Zoology 61 （4）： 708-717, 2015].

关键词： Antipredator Background matching Contour Cryps.s Camouflage Dis.uptive coloration Edge detection Objectrecognition

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Unders.anding s.ience Through the Computational Lens

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Journal of Computer s.ience & Technology 2011年第4期26卷 569-577页

作者： richard M.Karp Department of Electrical Engineering and Computer s.iences University of California

This.article explores.the changing nature of the interaction between computer s.ience and the natural and s.cial s.iences. After briefly tracing the his.ory of s.ientific computation, the article pres.nts.the concept of computational lens. a metaphor for a new relations.ip that is.emerging between the world of computation and the world of the s.iences. Our main thes.s.is.that, in many s.ientific fields. the proces.es.being s.udied can be viewed as.computational in nature, in the s.ns. that the proces.es.perform dynamic trans.ormations.on information repres.nted as.digital data. Viewing natural or engineered s.s.ems.through the lens.of their computational requirements.or capabilities.provides.new ins.ghts.and ways.of thinking. A number of examples.are dis.us.ed in s.pport of this.thes.s. The examples.are from various.fields. including quantum computing, s.atis.ical phys.cs. the World Wide Web and the Internet, mathematics. and computational molecular biology.

关键词： computational proces. computer s.ience and other s.iences computational lens

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Emis.ion-Bas.d s.atter Correction in s.ECT Imaging

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Ts.nghua s.ience and Technology 2010年第1期15卷 1-10页

作者： Hetal Babla richard Conwell Digirad Corporation PowayCA 92064USA

s.atter correction in s.ngle photon emis.ion computed tomography （s.ECT） has.been focus.d on either us.ng multiple-window acquis.tion technique or the s.atter modeling technique in iterative image recons.ruction. We propos. a technique that us.s.：only the emis.ion data for s.atter correction in s.ECT. We as.ume that the s.atter data can be approximated by convolving the primary data with a s.atter kernel followed by the normalization us.ng the s.atter-to-primary ratio （s.R）, s.nce the emis.ion data is.the s.perpos.tion of the primary data and the s.atter data, the convolution normalization proces. approximately res.lts.in the s.m of the s.atter data and a convolved vers.on of s.atter data with the kernel. By applying a proper s.aling factor, we can make the es.imation approximately equal to or les. than the s.atter data anywhere in the projection domain. Phantom and patient cardiac s.ECT s.udies.s.ow that us.ng the propos.d emis.ion-bas.d s.atter es.imation can effectively reduce the s.atter-introduced background in the recons.ructed images. And additionally, the computational time for s.atter correction is.negligible as.compared to no s.atter correction in iterative image recons.ruction.

关键词： s.ECT emis.ion-bas.d s.atter correction iterative image recons.ruction

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