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此文是一篇竹子论文范文,竹子方面论文范文参考文献,与gocheck文检测试题相关毕业论文开题报告。适合不知如何写竹子及工业工程及建筑材料方面的写论文专业大学硕士和本科毕业论文以及竹子类开题报告范文和职称论文的作为写作参考文献资料下载。

*E-Material

*MetalAlloy

*Organic&,Polymer

*CompositeMaterials

*PracticalApplication

*TechNews&,NewTech

MCanxixunInformationandNewsService

Contents

TechNews&,NewTech(技术前沿)3

Researchersdevelopsimpleproceduretoobtainnanosizedgraphene3

研究人员开发简单程序获得纳米字素3

Simple,lowcostlasertechniqueimprovesnanomaterials4

简单的低酿成激光技术改善纳米材料6

MetalAlloy(金属合金)7

Chinatoshutoutdatedcopper,steel,ferroalloycapacitybyendSep:MIIT7

中国将在九月末之前停止不合时宜的铜,钢,铁合金产能7

Discoveryiskeytometalwearinslidingparts8

金属在滑动部位磨损的关键发现10

CompositeMaterials(复合材料)11

AudiAnnouncesCompositeSpringsToSaveWeight,EnteringProductionLaterThisYear11

奥迪宣布使用复合弹簧以减轻车重,今年下半年将投产12

AOC'sR058DesignedforCarbonReinforcedComposites13

AOCR058开发出碳增强型复合材料13

DymaxLaunchLight-CurableColouredAdhesives14

制造商可使用Dymax胶粘剂公司的新"包含"技术,可轻松进行硫化以及硫化后粘结层检查.14

PracticalApplication(实际应用)15

"Nanopixels"promisethin,flexiblehigh-resdisplays15

"纳米像素"有望实现轻薄,灵活的高分辨率显示器16

Buildingupbamboo17

建造竹子机构19

Chemistdevelopsx-rayvisionforqualityassurance20

化学家开发X射线透视保证产品质量22

Organic&,Polymer(有机高分子材料)24

Companyconvertscoconuthuskfibersintomaterialsforcarsandhomes24

公司将椰壳纤维转化为制造汽车和房屋的材料26

HemlockSemiconductorsalesrecoveronimprovingpolysiliconshipments27

HemlockSemiconductor销售复苏27

Solarenergy:Acarbon-basedmaterialgivessolarsteam-poweraboost28

太阳能:碳基材料推动太阳能蒸汽动力的发展29

E-Material(电子材料)30

GadgetWatch:PadFonenovelasphone-tablethybrid30

作为手机-平板混合体的PadFone31

Futureelectronicsmaydependonlasers,notquartz32

未来的电子产品可能会依赖于激光,而不是石英33

Towardultimatelightefficiencyonthecheap34

便宜的极致光效率35

RECSilicon'ssalesincreasefollowinghigherQ2demandandASPs36

RECSilicon销售增长37

TechNews&,NewTech(技术前沿)

Researchersdevelopsimpleproceduretoobtainnanosizedgraphene

ThejournalAngewandteChemiehasrecentlypublishedaworkbyCiQUSresearchers(UniversityofSantiagodeCompostela,Spain)incollaborationwithIBMResearch-Zurich(Switzerland),whichdescribesanextremelysimplemethodtoobtainhighqualitynanographenesfromeasilyavailableanicpounds.

Grapheneisconsideredanuniquematerial,whichisleadingtotheemergenceofapletelynewtechnology.Oneofthebiggestchallengesinthisnewfieldisthedevelopmentofmethodologiesforthepreparationofthismaterialwithnanometricsizeandhighquality:iftheresearchersgetaperfectcontrolovertheirsizeandgeometry,theycouldexplorenewapplicationsforhigh-performanceelectronicdevices.ThemethoddiscoveredbyCiQUSresearchersallowstoobtainwell-definednanographenesinone-potfromperylene,averymonanicpound.

Thismethodisbasedonthereactivityofagroupofmoleculesnamedarynes,whichcanactas"molecularglue"topastegraphenefragmentstogether.Theclover-shapednanographenesobtainedinthisresearchweredepositedonultrathininsulatingfilms,andimagedwithatomicresolutionbyatomicforcemicroscopy(AFM).Thepreparationofthesematerialswithdifferentsizeandshapescouldbecrucialtobuildgraphene-basedelectroniccircuits,molecularmachineryand/orsinglemoleculeelectronicdevices.

Theresearchwork,ledbyProf.DiegoPea,isacontributionoftheresearchgroupCOMMO,partofCiQUS,andincludestheparticipationofProf.EnriqueGuitián,Prof.DoloresPérezandthePhDstudentSaraCollazos.ThisCOMMOgroupispioneeronthesynthesisofnanosizedgraphenesfollowingbottom-upapproachesthroughchemicalmethodsinsolution.TheIBMGroupisaspecialistintheuseofAFMwithatomicresolutionandinthisworkDr.LeoGross,Dr.GerhardMeyerandPhDstudentBrunoSchulerwereinvolved.

BothgroupshavealreadycollaboratedandpublishedpreviousresultsinchemistryscientificjournalsasScience(2016),andcurrentlytheytakepartoftheLargeEuropeanProjectPAMS(PlanarAtomicandMolecularScaleDevices),withatotalbudgetover9millionEuros.PAMSmainobjectiveistodevelopelectronicdevicesofnanometric-scalesize,inordertogettheextrememiniaturizationoftheequipmentusedininformationtechnologyandmunication.

Source:CiQUS

研究人员开发简单程序获得纳米字素

苏黎世(瑞士),它描述了一个非常简单的方法,从容易获得的有机化合物获得高质量的纳米石墨烯.应用化学杂志》最近发表了CiQUS研究员(圣地亚哥德孔波斯特拉大学,西班牙)与IBM研究中心合作的研究成果.

石墨烯被认为是一种独特的材料,这是导致一个完全新的技术的出现.其中一个在这个新领域的最大挑战是这种材料具有纳米尺寸和高品质的制剂的发展:如果研究人员得到一个完美的控制自己的尺寸和几何形状,他们可以探索高性能电子新应用设备.CiQUS研究人员发现的方法将允许从一种很常见的有机化合物,二萘嵌苯用一步法获得定义明确的纳米石墨烯.

此方法是基于一组命名arynes的分子,它可以充当"分子胶水"来将石墨烯片段粘贴在一起.在本研究中得到的三叶草形的纳米石墨烯沉积在超薄绝缘膜上,并且在原子力显微镜(AFM)的原子级的分辨率成像.这些材料的不同的大小和形状的制备可能对建立基于石墨烯的电子电路,分子机械和/或单分子的电子设备是至关重要的,.

这项研究工作是由迭戈尼亚教授领导的,是CiQUS的一部分,研究小组COMMO的贡献,包括教授恩里克归田,多洛雷斯佩雷斯教授和博士生SaraCollazos的参与.COMMO小组是自下而上方法通过在溶液中的化学方法合成纳米石墨烯的先驱.IBM集团是在利用原子力显微镜与原子分辨率发热的专家,在此工作中,LeoGross博士,格哈德迈耶博士和博士研究生布鲁诺舒勒参与其中.

这两个集团已经合作,并将结果发表在化学科学期刊《科学》(2016)上,目前他们采取的大欧洲计划PAMS(平面原子与分子尺度器件),总预算超过900万欧元的一部分.PAMS主要目标是开发的纳米级大小的电子设备,以获得在信息技术和通信所使用的设备的极端小型化.

资料来源:CiQUS

Simple,lowcostlasertechniqueimprovesnanomaterials

Mesoporoussiliconnanowireswerescannedbyafocusedlaserbeamintwodifferentpatterns,imagedbybright-fieldopticalmicroscope,asdepictedby(a)and(c),aswellasfluorescencemicroscopy,asdepictedby(b)and(d).Evidently,theimageshiddeninboxesshownin(a)and(c)areclearlyrevealedunderfluorescencemicroscopy.Image:NationalUniversityofSingapore

Thechallengesfacedbyresearchersinmodifyingpropertiesofnanomaterialsforapplicationindevicesmaybeaddressedbyasimpletechnique,thankstorecentinnovativestudiesconductedbyscientistsfromtheNationalUniversityofSingapore(NUS).

Throughtheuseofasimple,efficientandlowcosttechniqueinvolvingafocusedlaserbeam,twoNUSresearchteams,ledbyProf.SowChorngHaurfromtheDepartmentofPhysicsattheNUSFacultyofScience,demonstratedthatthepropertiesoftwodifferenttypesofmaterialscanbecontrolledandmodified,andconsequently,theirfunctionalitiescanbeenhanced.

SaidSow:"Inourchildhood,mostofusarelikelytohavetheexperienceofbringingamagnifyingglassoutdoorsonasunnydayandtriedtofocussunlightontoapieceofpapertoburnthepaper.Suchasimpleapproachturnsouttobeaveryversatiletoolinresearch.Insteadoffocusingsunlight,wecanfocuslaserbeamontoawidevarietyofnanomaterialsandstudyeffectsofthefocusedlaserbeamhasonthesematerials."

Micropatterns"drawn"onMoS2filmscouldenhanceelectricalconductivityandphotoconductivity

Molybdenumdisulfide(MoS2),aclassoftransitionmetaldichalcogenidepound,hasattractedgreatattentionasanemergingtwo-dimensional(2-D)materialduetowiderecognitionofitspotentialinandoptoelectronics.Oneofthemanyfascinatingpropertiesof2-DMoS2filmisthatitspropertiesdependonthethicknessofthefilm.Inaddition,itspropertiescanbemodifiedoncethefilmismodifiedchemically.HenceoneofthechallengesinthisfieldistheabilitytocreatemicrodevicesoutoftheMoS2filmprisingponentswithdifferentthicknessorchemicalnature.


怎样撰写竹子本科论文
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Toaddressthistechnologicalchallenge,Sow,DrLuJunpeng,apostdoctoralcandidatefromtheDepartmentofPhysicsattheNUSFacultyofScience,andtheirteammembers,utilisedanopticalmicroscope-focusedlaserbeamsetupto'draw'micropatternsdirectlyontolargeareaMoS2filmsaswellastothinthefilms.

Withthissimpleandlowcostapproach,thescientistswereabletousethefocusedlaserbeamtoselectively"draw"patternsontoanyregionofthefilmtomodifypropertiesofthedesiredarea,unlikeothercurrentmethodswheretheentirefilmismodified.

Interestingly,theyalsofoundthattheelectricalconductivityandphotoconductivityofthemodifiedmaterialhadincreasedbymorethan10timesandaboutfivetimesrespectively.TheresearchteamfabricatedaphotodetectorusinglasermodifiedMoS2filmanddemonstratedthesuperiorperformanceofMoS2forsuchapplication.

ThisinnovationwasfirstpublishedonlineinthejournalACSNano("ImprovedPhotoelectricalPropertiesofMoS2FilmsafterLaserMicromachining")on24May2016.

Hiddenimages"drawn"byfocusedlaserbeamonsiliconnanowirescouldimproveopticalfunctionalities

InarelatedstudypublishedinthejournalScientificReports("Laser-inducedGreenish-BluePhotoluminescenceofMesoporousSiliconNanowires")on13May2016,SowledanotherteamofresearchersfromtheNUSFacultyofScience,incollaborationwithscientistsfromHongKongBaptistUniversity,toinvestigatehow'drawing'micropatternsonmesoporoussiliconnanowirescouldchangethepropertiesofnanowiresandadvancetheirapplications.

Theteamscannedafocusedlaserbeamrapidlyontoanarrayofmesoporoussiliconnanowires,whicharecloselypackedlikethetightlywoventhreadsofacarpet.Theyfoundthatthefocusedlaserbeamcouldmodifytheopticalpropertiesofthenanowires,causingthemtoemitgreenish-bluefluorescencelight.Thisisthefirstobservationofsuchalaser-modifiedbehaviourfromthemesoporoussiliconnanowirestobereported.

Theresearcherssystematicallystudiedthelaser-inducedmodificationtogaininsightsintoestablishingcontrolovertheopticalpropertiesofthemesoporoussiliconnanowires.Theirunderstandingenabledthemto'draw'awidevarietyofmicropatternswithdifferentopticalfunctionalitiesusingthefocusedlaserbeam.

Toputtheirfindingstothetest,theresearchersengineeredthefunctionalponentsofthenanowireswithinterestingapplications.Theresearchteamdemonstratedthatthemicropatternscreatedatalowlaserpowerareinvisibleunderbright-fieldopticalmicroscope,butbeeapparentunderfluorescencemicroscope,indicatingthefeasibilityofhiddenimages.

Furtherresearch

Thefastgrowingfieldofelectronicsandoptoelectronicsdemandsprecisematerialdepositionwithapplication-specificoptical,electrical,chemical,andmechanicalproperties.

Todevelopmaterialswithpropertiesthatcancatertotheindustry'sdemands,Sow,togetherwithhisteamofresearchers,willextendtheversatilefocusedlaserbeamtechniquetomorenanomaterials.Inaddition,theywilllookintofurtherimprovingthepropertiesofMoS2andmesoporoussiliconwithdifferenttechniques.

Source:NationalUniversityofSingapore

简单的低酿成激光技术改善纳米材料

介孔硅纳米线在两个不同的模式中通过聚集的激光束进行了扫描,通过明视野光学显微镜成像,正如(a)和(c)所描述的,以及荧光显微镜,正如(b)和(d)所描述的.显然,在(a)和(c)中显示的框架中隐藏的图像在荧光显微镜下被清晰地显现出来了.图片:新加坡国立大学.

研究人员在为器件的应用修改纳米材料的性能时所面对的挑战也许可以通过一个简单的技术来解决,这要归功于由新加坡国立大学(NUS)的科学家们最近所进行的创新研究.

通过使用包含了聚集激光束的一个简单,高效,低成本的技术,由新加坡国立大学科学学院物理系教授孙崇豪领导的两个NUS研究小组证明了两种不同类型的材料的属性能够得到控制和修改,并且因此,它们的功能也可以得到增强.

孙表示:"在我们的童年,我们大多数人有可能都有这样一次经历,即在一个阳光明媚的日子里将放大镜带到户外,试图将太阳光聚集到一张纸上来燃烧这张纸.这样一个简单的办法原来是研究中一个非常灵活的工具.不同于聚集阳光,我们可以将激光束聚集到各种各样的纳米材料上,然后研究聚集激光束对这些材料的影响."

对二硫化钼薄膜"绘制"的微图案能够提高导电性和光导

由于对其的潜力和光电子学的广泛认可,二硫化钼(MoS2)这种过渡金属二硫属化物化合物作为一个新兴的二维(2-D)材料已经引起了高度地重视.在二维二硫化钼薄膜的许多特性中,有一个非常有趣的特性是它的性能取决于薄膜的厚度.此外,一旦该薄膜得到了化学修饰,那么它的属性也可以得到修改.因此,在这一领域所面临的一个挑战就是运用由不同厚度或化学性质的组件组成的MoS2薄膜创建微型器件的能力.

为了解决这一技术难题,孙,新加坡国立大学科学学院物理系的博士后候选人陆军鹏博士以及他们的团队成员利用光学显微镜聚集的激光束的安装来直接对大面积的二硫化钼薄膜"绘制"微图案以及使薄膜变薄.

运用这个简单,低成本的方法,科学家们能够利用聚集激光束有选择性地对薄膜的任何区域"绘制"图像,从而修改所需区域的属性,而不像现在的方法会改变整个薄膜的属性.

有趣的是,他们还发现,修改后的材料的电导率和光电导性分别增加了十倍以上以及大约五倍.该研究小组采用激光修改的MoS2薄膜制造了一个光电探测器,并且证明了MoS2在这种应用方面的卓越性能.

这一创新首先发表于2016年5月24日《ACS纳米》杂志的网络版本中(《MoS2薄膜在激光微加工后改进的光电性能》).

聚集激光束对硅纳米线"绘制"的隐藏影像能够提高光学功能

在2016年5月13日刊登于《科学报告》杂志的一项相关研究(《介孔硅纳米线激光诱导的绿蓝光致发光》中,孙领导的另一组来自新加坡国立大学理学院的研究人员小组与香港浸会大学的科学家们一同合作,研究了对介孔硅纳米线"绘制的"微图案是如何改变纳米线的属性以及推动其应用的.

该小组迅速将聚集激光束扫描到介孔硅纳米线上,这种纳米线紧密排列,就像是地毯上紧密编织的线一样.他们发现,聚集激光束能够修改纳米线的光学性质,使它们发出蓝绿色的荧光.这是第一个对介孔硅纳米线的这种激光改性行为进行报告的观察资料.

研究人员系统地研究了激光诱导修改,从而对介孔硅纳米线的光学特性建立控制有了更深入地了解.他们的了解使得他们能够利用聚集激光束"绘制出"具有不同光学功能的各种微图案.

为了对他们的发现进行测试,研究人员运用有趣的应用设计了纳米的功能组件.该研究小组证实,以低功率激光产生的微图案在明视野光学显微镜下是看不见的,但是在荧光显微镜下就会变得很明显,这表明了隐藏图像的可行性.

进一步研究

电子和光电子快速发展的领域需要具有特定应用光学,电学,化学和机械性能的精密材料的沉积.

为了开发出具有可满足业界需求的性能的材料,孙,与他的研究小组一同,将向更多的纳米材料扩张该多功能的聚集激光束技术.此外,他们将考虑运用不同的技术进一步提高二硫化钼和介孔硅的性能.

资料来源:新加坡国立大学

MetalAlloy(金属合金)

Chinatoshutoutdatedcopper,steel,ferroalloycapacitybyendSep:MIIT

Chinawillshut725,600mt/yearofoutdatedcoppersmeltingcapacity,includingrecycledcoppercapacity,beforetheendofSeptember,thecountry'sMinistryofIndustryandInformationTechnologysaidonitswebsiteFriday.

Atotalof43coppersmelterswillberequiredtoshut,MIITsaid.

Inaddition,30steelproducerswithabinedsteelmakingcapacityof22.595millionmt/yearand164ferroalloyproducerswithabinedcapacityofaround2millionmt/yearcapacitywillbeaskedtoshutbeforeendSeptember,MIITsaid.

WhilethepanieswillhavetostopproductionbytheendofSeptember,theywillhaveuntiltheendofthisyeartoensurethatalltheirproductionfacilitiesaredismantled.Companieswillnotbeallowedtomovetheirequipmentelsewhere.

Theshutdownorderisinlinewiththecentralgovernment'saimtoloweremissionsandsaveenergyinits12thFive-YearPlanperiodover2016-2016.

中国将在九月末之前停止不合时宜的铜,钢,铁合金产能

中国在九月底之前将封锁725600吨/年的过时铜冶炼能力,包括铜再生能力,中国工业和信息化部星期五在其网站上表示称.

共有43座铜冶炼厂将要关闭,工信部说.

此外,结合2259.5万吨/年的炼钢能力和164家铁合金生产商约200万吨/年的总生产能力,钢铁生产商将要求在9月30日前关闭,工信部表示.

同时公司将在九月底停止生产,他们将在今年年底前确保所有生产设施都被拆除.公司将不被允许他们将设备搬到其他任何地方.

停止顺序与 政府在2016-2016间第十二个五年计划期间内降低排放并节约能源的目标一致.

Discoveryiskeytometalwearinslidingparts

Thissequenceofimagesrevealssurprisingfluid-likebehaviorinasolidpieceofmetalslidingoveranother,formingdefectsleadingtowearinmetalparts.(Top)Twoimageframesofthematerialflowshowinghowthesedefectsarespawnedinthewakeofthecontact.(Bottom)Scanningelectronmicroscopepicturesofthecorrespondingwearsurfacesshowingatearandacrack.Wearparticlesareformedwhenthetearsandcracksdetachfromthesurfaces.Images:PurdueUniv.SchoolofIndustrialEngineeringimage/AnirbanMahato

Researchershavediscoveredapreviouslyunknownmechanismforwearinmetals:aswirling,fluid-likemicroscopicbehaviorinasolidpieceofmetalslidingoveranother.

Thefindingscouldbeusedtoimprovethedurabilityofmetalpartsinnumerousapplications.

"Wearisamajorcauseoffailureinengineeringapplications,"saidSrinivasanChandrasekar,aPurdueUniv.professorofindustrialengineeringandmaterialsengineering."However,ourfindingshaveimplicationsbeyondwearitself,extendingtomanufacturingandmaterialsprocessing."

ThefindingsaretheresultofacollaborationofresearchersfromPurdue,theIndianInstituteofScienceinBangalore,India,andM4Sciences,apanyinWestLafayette,Ind.

"Usinghigh-resolutionimagingofslidingcontactsinmetals,wehavedemonstratedanewwaybywhichwearparticlesandsurfacedefectscanform,"saidPurduepostdoctoralresearchassociateAnirbanMahato,whoisworkingwithChandrasekar,NarayanSundaram,anassistantprofessorattheIndianInstituteofScience,andYangGuo,aresearchscientistatM4Sciences.

FindingsaredetailedinaresearchpaperappearinginProceedingsoftheRoyalSociety.

Theresearchers,usingamicroscope,high-speedcameraandothertools,hadpreviouslyrevealedtheformationofbumps,foldsandvortex-likefeaturesonslidingmetalsurfaces.Thenewfindingsbuildonthepreviouspaper,publishedin2016inPhysicalReviewLetters,toshowhowthebehaviorleadstocracksandwearparticles.

Thefindingswerecounter-intuitivebecausetheexperimentwasconductedatroomtemperature,andtheslidingconditionsdidnotgenerateenoughheattosoftenthemetal.Yet,theswirlingflowismorelikebehaviorseeninfluidsthaninsolids,Chandrasekarsaid.

Theteamobservedwhathappenswhenawedge-shapedpieceofsteelslidesoveraflatpieceofaluminumorcopper.Themetalsaremonlyusedtomodelthemechanicalbehaviorofmetals.

"Wespeculatedintheearlierpaperthattheswirlyfluid-likesurfaceflowdiscoveredonslidingmetalsurfacesislikelytoimpactwearinslidingmetalsystems,"hesaid."Nowweareconfirmingthisspeculationbydirectobservations."

Theobservationsshowhowtinybumpsforminfrontofthewedge,followedbytheswirlingmovement.Whenthewedgeangleisshallow,theflowislaminar,orsmooth.However,itchangestoaswirlyflowwhentheangleisadjustedtoaless-shallowangle,mimickingwhathappensinactualslidingmetalparts.Asthewedgeslidesacrossthemetalspecimen,foldsformbetweenthebumps,andthenthefoldstransformintotearsandcracksinthewakeofthewedge,eventuallyfallingoffaswearparticles.

"Asingleslidingpassissufficienttodamagethesurface,andsubsequentpassesresultinthegenerationofplatelet-likewearparticles,"Chandrasekarsaid.

Thebehaviorwascapturedinmoviesthatshowtheflowincolor-codedlayersjustbelowthesurfacesofthecopperandaluminumspecimens.

Thedefectsrangeinsizefrom5to25micronsandaresimilartothosefoundinslidingponentssuchaspartsinautomotiveengines,pressorsandnumeroustypesofequipmentandmachinery.

"Inthepastweonlysawthesefeaturesaftertheyhadformed,andweattributedthemtovariouspossiblemechanisms,"hesaid."Here,weshowamechanismforhowtheyareformed.Thedefectfeaturesobservedalsooccurinsurfacescreatedbymanufacturingprocesseslikegrinding,polishing,burnishing,peening,drawing,extrusion,rolling,andsoon,whichareallmonlyusedinmakingstructuralandmechanicalponentsinthegroundtransportation,aerospace,sheet-andwire-metalsprocessing,andenergysystemssectors."

Ongoingresearchwillexplorepotentialroutestoreduceweararisingfromthistypeofmechanism.Metalsaremadeofgroupsofcrystalscalledgrains.Futureworkwillstudyhowamaterial'sgrainsizeandductilityinfluencethistypeofwear,howthesetypesofsurfacedefectsinmanufacturingprocessescanbeeliminatedthroughthemodifieddesignoftoolsanddies,improvedmodelsforslidingwearandwear-controlstrategies.

"Wewanttolookatthismechanisminmaterialsthathavesmallercrystals—inthe5to30micronrange,"Chandrasekarsaid."Wewanttoshowthatthemechanismismoregeneralandextendsdowntoevenfiner-grainedmetals."

Source:PurdueUniv.

金属在滑动部位磨损的关键发现

图像的序列揭示了在一个固体金属片没过另一个固体金属处时出现的令人惊讶的流体状行为,这形成了最终导致金属零件磨损的缺陷.(上)显示出这些缺陷是如何在接触之后出现的两个材料流动的图像帧.(下)呈现出撕裂和裂缝的相应磨损表面的扫描电镜照片.磨损颗粒是在撕裂和裂纹从表面分离时形成的.图片:普渡大学工业工程学院图像/艾米班马哈头

研究人员已经为金属的磨损发现了一种以前未知的机制:在一个固体金属片滑过另一个固体金属片时其内部存在的一个漩涡流体状的微观行为.

该研究结果可以被用来提高在众多应用中的金属部件的耐久性.

"磨损是工程应用失败的一个主要原因,"普渡大学工业工程和材料工程学教授斯里尼瓦桑钱德拉塞卡尔表示."然而,我们的研究结果具有超越磨损本身的影响,延伸到了制造和材料的加工."

这一发现是普渡大学的研究人员与印度班加罗尔的印度科学研究所以及印第安纳州拉斐特西部的M4科学公司一同协作的结果.

"使用金属中滑动触点的高分辨率成像,我们已经展示了一种新的方式,磨损颗粒和表面缺陷能够通过这种方式形成,"与钱德拉塞卡尔一同工作的普渡大学博士后研究助理艾米班马哈头,印度科学研究所的助理教授纳拉扬孙达拉姆,以及M4科学公司的一名研究科学家郭扬表示.

研究论文中的详细结果发表于《英国皇家学会论文集》.

使用显微镜,高速摄像机等工具的研究人员在此前曾透露出滑动金属表面颠簸,折叠和旋涡状特点的形成.新的研究结果建立在之前的论文之上,于2016年发表于《物理评论快报》,其显示出该行为是如何形成裂纹和磨损颗粒的.

该研究结果是与正觉相反的,因为实验是在室温下进行的,并且滑动条件并没有产生足够的热量来软化金属.然而,旋流更像是出现在液体中的行为,而不是出现在固体中的行为,钱德拉塞卡尔表示.

该研究小组观察了当楔形钢块没过一个平坦的铝或铜块时会发生什么.这些金属通常被用来模拟金属的机械性能.

"我们在早期的论文中猜测,在滑动金属表面发现的旋涡流体状表面流动很可能会影响滑动金属系统中的磨损,"他表示."现在,我们通过直接观察证实了这种猜测."

该观察结果表明了微小的颠簸是如何涡旋运动之后在楔前方形成的.当楔角是浅的时,该流动就是层流的或光滑的.然而,当该角度调整为一个较低的小角度时,它就成为了一个旋涡状流动,从而模拟了实际滑动的金属部件中会发生的事情.由于整个金属试样的楔滑动,折叠在凸块之间形成了,并且之后折叠在楔形之后转化为撕裂和裂缝,最终像磨粒一样脱落.

"一个单一的滑动通过足以破坏表面,并且后续的通过会导致片状磨损颗粒的产生,"钱德拉塞卡尔表示.

该行为是在铜和铝试样表面下方的颜色编码层流中显示出流动的影片中被捕获的.

缺陷的尺寸范围从5至25微米,并且类似于那些在滑动部件中发现的缺陷,例如汽车发动机,压缩机和多种类型的设备和机械部件中所发现的缺陷.

"在过去,我们只有在它们形成之后才看到这些特点,并且我们将其归因于各种可能的机制,"他表示."现在,我们为它们是如何形成的展示了一种机制.所观察到的缺陷特征同样也发生在制造过程创造的表面之上,例如研磨,抛光,打磨,喷丸,拉丝,挤出,压延等等,这些通常都用于制造地面交通,航空航天,板材和线金属加工以及能源系统领域的结构和机械部件."

正在进行的研究将探索潜在的途径来减少这类机制所产生的磨损.金属是由称为粒的晶体组制成的.今年的工作将研究材质的晶粒尺寸和塑性是如何影响这种类型的磨损的,在生产过程中出现的这些表面缺陷的类型是如何通过为滑动磨损和损耗控制策略进行的工具和模具修改后的设计以及改善的模型来得到消除的.

"我们想要在具有更小晶体的研究这种机制——接近5-30微米的范围,"钱德拉塞卡尔表示."我们希望表明,这种机制更加普遍地向下延伸至更细粒度的金属."

资料来源:普渡大学

CompositeMaterials(复合材料)

AudiAnnouncesCompositeSpringsToSaveWeight,EnteringProductionLaterThisYear

Youmightnotoftenthinkaboutthem,butthespringsinyourcar'ssuspensionareakeypieceoftechnology—andonethathasbeenlargelyunchangedfordecades.Thesimplesteelcoilspringhasservedineffectiveanonymity—butitsdaysmaybenumbered.Audiisplanningtoputalightweightpositespringintoproductionbyfall2016.

Theglassfiber-reinforcedpolymer,orGFRP,springswillsaveabout40percentoftheweightofsteelsprings,cuttingabout2.5poundsperspringforalargermid-sizecar.Thatamountstoasavingsof9.7poundstotal,halfofwhichisunsprungmass.

Unsprungmassrelatesdirectlytoacar'shandlingandridequality,andreducingitcanyieldevenlargerdividendsthanasimilarweightreductionfromthecar'ssprungmass(i.e.,fromthecar'sbody).Fordhasshownalightweightconceptcarusingsimilarpositespringtechnology,buthasn'tannouncedanyplansforproduction.

TheGFRPspringssaveweightatacruciallocationinthechassissystem.Wearethereforemakingdrivingmorepreciseandenhancingvibrationalfort,"saidDr.UlrichHackenberg,MemberoftheBoardofManagementforTechnicalDevelopmentatAUDIAG.

ButhowdurablearetheseGFRPspringsCantheytakethesamestressesassteelAudithinkstheycan.Inadditiontobeinglargerinoveralldiameterandsportingasmallernumberofcoils,theGFRPspringsareposedoflongglassfiberstwistedtogetherthenimpregnatedwithepoxyresin.Thisglass-resinstructureisthenwrappedwithmoreglassfibersatcounter-poised45-degreeangles.Themulti-plystructureisdesignedtosupportandabsorbthestressesthespringundergoesduringdriving.Onceformed,thespringiscuredatmorethan100degreesCelsius(212degreesFahrenheit).

TheGFRPspringsareposedofresinandglassfiber,andthereforecannotcorrode,andisimpervioustoawiderangeofchemicals,includingharshwheelcleaners.Audialsonotesthattheproductionprocessconsumesfarlessenergythantheproductionofsteelcoilsprings.

Audi'sglassfiber-reinforcedpolymer(GFRP)springswillsaveweightparedtosteelsprings

奥迪宣布使用复合弹簧以减轻车重,今年下半年将投产

你可能并不太关注你汽车悬挂装置上的弹簧,但是它们却是一个很关健的技术――并且这项技术已经数十年没有大的变动了.这个简单的钢制圆簧有效而无声的工作着――但是它的时代可能快要结束了.奥迪正计划在2016年的秋季将一种轻质的复合弹簧投入生产.

玻璃纤维强化聚合物(简称GFRP)制造的弹簧与钢制弹簧相比,将减重40%左右.对于一辆中型车而言,每个弹簧将减重2.5磅,整体将减重9.7磅,其中一半是簧下重量.

簧下重量直接关系到一个汽车的操作性和驾驶质量,因此,与减轻同等的簧上重量(例如,减轻车身重量)相比,减轻它的重量能够获得更明显的效果.福特已经展示了一款使用类似复合弹簧技术的轻质概念车,但是并未宣布任何的投产计划.

"GFRP弹簧在底盘系统的关健部位进行了减重.因此,我们可以获得更精确的驾驶性能并增强减震舒适性,"奥迪技术开发部的管理董事成员UlrichHackenberg说.

但是GFRP弹簧的耐久性如何它们能够承受和钢制弹簧一样的压力吗奥迪公司认为它们可以.除了整体直径的增大以及圆簧数量的减少之外,GFRPP弹簧首先是将长玻璃纤维拧到一起,然后在环氧树脂中浸泡.之后这种玻璃-树脂结构由更多的成反向平衡45度角的玻璃纤维所包裹.这种多层结构被设计成可以支撑和吸收弹簧在驾驶过程中所承受的压力.一旦成型,这种弹簧需要在高于100°C(212°F)的温度下才能进行加工.

GFRP弹簧由树脂和玻璃纤维组成,因此它不能被腐蚀,而且不受很多化学物质的影响,包括严酷的车轮清洗剂.奥迪公司还注意到该生产过程与钢制圆簧相比,消耗的能源更少.

奥迪的玻璃纤维强化聚合物(GFRP)弹簧与钢制弹簧相比会减重.

AOC'sR058DesignedforCarbonReinforcedComposites

AOCstatesithasdevelopedalineofresinsdesignedspecificallyforcarbonfibrereinforcements.

ThepanyexplainstheR058seriesofepoxyvinylesterresinscreateslightweightpositepartswithexceptionalstrength-to-weightratios.

AccordingtoAOC,theR058seriesbinestheperformanceofepoxyresinswiththeprocessingspeedofunsaturatedpolyesterresins.Theresinsaredesignedforvacuuminfusionandresintransfermoulding(RTM).Theresinserieshasaroomtemperaturecureandchemicalresistanceoverabroadrangeoftemperatures.

"TheR058seriesisanexcellentchoiceforapplicationsrequiringlightweightandhigh-performancelaminate,"saysMikeDettre,AOC'sBusinessManager."Theydon'trequirepost-curingorautoclaving,whichmakesthemfastertoprocessthanmostpureepoxyresins.Andthat'scriticalforhigh-volumeapplications."

PhotoprovidedbyAOCResins

AOCR058开发出碳增强型复合材料

AOC声明已经开发出一种针对碳纤维增强加固的专门树脂.

该公司解释称,该环氧乙烯基酯树脂的R058系列可创建具有特殊强度-重量比的轻质复合部件.

根据AOC公司,R058系列结合了环氧树脂的性能与不饱和聚酯树脂的处理速度.树脂是用于真空灌注和树脂传递模塑(RTM).树脂系列室温固化和化学抵抗了范围广泛的温度.

"R058系列是需要轻量级和高性能层压板的一个优秀的选择,"AOC的业务经理MikeDettre说,."他们不需要辅助硬化或高压灭菌法,这使他们比大多数纯环氧树脂的处理更快.这是高容量应用的关键."

照片由AOC树脂提供

DymaxLaunchLight-CurableColouredAdhesives

DymaxAdhesivesnew"Enpass"technologyallowsmanufacturerseasycureconfirmationandpost-curebond-lineinspection.

AccordingtoDymax,adhesivesformulatedwithnew"Enpass"technologyincorporatethepany'spatentedSee-Curecolour-changeandUltra-Redfluorescingtechnologiesintoonelight-curableproduct.

Thepanyexplainsinanuncuredstate,anadhesiveformulatedwithSee-Curetechnologyisblueincolourforeasyverificationofplacement.AstheproductcureswithsufficientexposuretoUVlight,itsbluecolourtransitionstocolourlessandprovidesobviousvisualconfirmationthattheadhesiveisfullycuredandthebondsitesecure.

DymaxstatesproductsformulatedwithUltra-Redtechnologyfluorescebrightredunderlow-intensityblacklight(365nm),contrastingextremelywellonplasticsthatnaturallyfluoresceblueincolour(likePVC).Thisallowsmanufacturerstoincorporateautomatedormanualqualityinspectiontoverifypleteandaccurateplacementoftheadhesiveaftercure.Dymaxiscurrentlyofferingseveralmedical-gradeadhesivesthatareformulatedwiththenewEnpasstechnology.

制造商可使用Dymax胶粘剂公司的新"包含"技术,可轻松进行硫化以及硫化后粘结层检查.

根据Dymax,粘合剂的配方中加入了新的"包含"技术,并将公司的专利See-Curecolour-change和红外荧光技术,融合为了一种可光-硫化(light-curable)产品.

公司解释说,在未硫化的状态下,为了确认定位,加入了See-Cure技术的胶粘剂的配方是蓝色的.随着产品过度暴露于紫外线进行硫化,其会从蓝色过渡到无色,并提供明显的视觉确认,胶已经完全固化,并且粘合地点安全.

Dymax声明,使用红外光(Ultra-Red)技术的产品,在低强度下黑色光(365nm)发出荧光明亮的红色,在塑料上对比非常明显,发出自然荧光蓝的颜色(如PVC).这允许制造商将自动或手工质量检验来验证胶固化的完整,准确位置.Dymax目前的产品供应加入了包含新技术的多种医用粘合剂的配方.

PracticalApplication(实际应用)

"Nanopixels"promisethin,flexiblehigh-resdisplays

Stillimagesdrawnwiththetechnology:ataround70micrometersacrosseachimageissmallerthanthewidthofahumanhair.

Anewdiscoverywillmakeitpossibletocreatepixelsjustafewhundrednanometresacrossthatcouldpavethewayforextremelyhigh-resolutionandlow-energythin,flexibledisplaysforapplicationssuchas"smart"glasses,syntheticretinas,andfoldablescreens.

AteamledbyOxfordUniv.scientistsexploredthelinkbetweentheelectricalandopticalpropertiesofphasechangematerials(materialsthatcanchangefromanamorphoustoacrystallinestate).Theyfoundthatbysandwichinga7-nmthicklayerofaphasechangematerial(GST)betweentwolayersofatransparentelectrodetheycoulduseatinycurrentto'draw'imageswithinthesandwich"stack".

Initiallystillimageswerecreatedusinganatomicforcemicroscopebuttheteamwentontodemonstratethatsuchtiny'stacks'canbeturnedintoprototypepixel-likedevices.These"nano-pixels"—just300by300nminsize—canbeelectricallyswitched'onandoff'atwill,creatingthecoloureddotsthatwouldformthebuildingblocksofanextremelyhigh-resolutiondisplaytechnology.

Areportoftheresearchispublishedinthisweek'sNature.

Whilsttheworkisstillinitsearlystages,realizingitspotential,theOxfordteamhasfiledapatentonthediscoverywiththehelpofIsisInnovation,OxfordUniversity'stechnologymercialisationpany.Isisisnowdiscussingthedisplayswithpanieswhoareinterestedinassessingthetechnology,andwithinvestors.

"Wedidn'tsetouttoinventanewkindofdisplay,"saidProfessorHarishBhaskaranofOxfordUniversity'sDepartmentofMaterials,wholedtheresearch.'WewereexploringtherelationshipbetweentheelectricalandopticalpropertiesofphasechangematerialsandthenhadtheideaofcreatingthisGST"sandwich"madeupoflayersjustafewnanometersthick.Wefoundthatnotonlywereweabletocreateimagesinthestackbut,tooursurprise,thinnerlayersofGSTactuallygaveusbettercontrast.Wealsodiscoveredthatalteringthesizeofthebottomelectrodelayerenabledustochangethecolouroftheimage.'

ThelayersoftheGSTsandwicharecreatedusingasputteringtechniquewhereatargetisbombardedwithhighenergyparticlessothatatomsfromthetargetaredepositedontoanothermaterialasathinfilm.

"Becausethelayersthatmakeupourdevicescanbedepositedasthinfilmstheycanbeincorporatedintoverythinflexiblematerials—wehavealreadydemonstratedthatthetechniqueworksonflexibleMylarsheetsaround200nmthick,"saidProfessorBhaskaran."Thismakesthempotentiallyusefulfor'smart'glasses,foldablescreens,windshielddisplays,andevensyntheticretinasthatmimictheabilitiesofphotoreceptorcellsinthehumaneye."

PeimanHosseiniofOxfordUniversity'sDepartmentofMaterials,firstauthorofthepaper,said:"Ourmodelsaresogoodatpredictingtheexperimentthatwecantuneourprototype'pixels'tocreateanycolourwewant—includingtheprimarycoloursneededforadisplay.Oneoftheadvantagesofourdesignisthat,unlikemostconventionalLCDscreens,therewouldbenoneedtoconstantlyrefreshallpixels,youwouldonlyhavetorefreshthosepixelsthatactuallychange(staticpixelsremainastheywere).Thismeansthatanydisplaybasedonthistechnologywouldhaveextremelylowenergyconsumption."

Theresearchsuggeststhatflexiblepaper-thindisplaysbasedonthetechnologycouldhavethecapacitytoswitchbetweenapower-saving"colore-readermode",andabacklitdisplaycapableofshowingvideo.Suchdisplayscouldbecreatedusingcheapmaterialsand,becausetheywouldbesolid-state,promisetobereliableandeasytomanufacture.Thetiny'nano-pixels'makeitidealforapplications,suchassmartglasses,whereanimagewouldbeprojectedatalargersizeas,evenenlarged,theywouldofferveryhigh-resolution.


该文 :http://www.svfree.net/xie/0704968.html

ProfessorDavidWrightoftheDepartmentofEngineeringattheUniversityofExeter,co-authorofthepaper,said:"AlongwithmanyotherresearchersaroundtheworldwehavebeenlookingintotheuseoftheseGSTmaterialsformemoryapplicationsformanyyears,butnoonebeforethoughtofbiningtheirelectricalandopticalfunctionalitytoprovideentirelynewkindsofnon-volatile,high-resolution,electroniccolourdisplays—soourworkisarealbreakthrough."

ProfessorBhaskaransaidthatthediscoverywouldnothavebeenpossiblewithoutthesupportoftheUK'sEngineeringandPhysicalSciencesResearchCouncil(EPSRC):"EPSRChavebeenfundingourfundamentalresearchandthischancediscoveryshowsjustwheresupportforso-called'blueskies'researchcanlead."

ThephasechangematerialusedwasthealloyGe2Sb2Te5(germanium-antimony-telluriumorGST)sandwichedbetweenelectrodelayersmadeofindiumtinoxide(ITO).

Source:OxfordUniv.

"纳米像素"有望实现轻薄,灵活的高分辨率显示器

(图为)利用该技术绘制的静止图:每个图像仅70微米,小于人类头发的宽度.

新发现将有可能创造只有几百纳米的像素,我们可能因此制造出超高分辨率,极薄的显示屏,并应用于"智能"眼镜,合成视网膜柔性显示器以及可折叠屏幕等.

牛津大学科学家领导的团队研究了相变材料电学和光学性质之间的联系(即可以从非晶态转变为晶态材料).他们发现,通过将一层7纳米厚的相变材料(GST)夹在两层透明电极夹中间,他们可以用微小的电流在此三明治"堆栈"中进行图像"绘制".

最初的静止图像是使用原子力显微镜获得的,但科研团队进一步证明了这样微小的"堆栈"可以变成原型类像素装置.这些"纳米像素"只有300乘300纳米大小,可以任意接通和关闭,并产生色点进而形成一个超高分辨率显示的堆.

该研究报告发表于本周的《自然》杂志.

虽然工作仍处于实现其潜力的早期阶段,但牛津队已经向伊西斯创新-牛津大学商业技术公司提交专利.伊希斯现在正在与对评估技术感兴趣的公司及投资者讨论显示器的问题.

"我们并不打算发明一种新的显示器,"牛津大学材料系哈里什巴斯卡兰教授,研究领导人这样说."我们探讨了相变材料电学和光学特性之间的关系,然后就做了这个几纳米厚的GST"三明治"层.我们发现,我们不仅能在堆栈中创建图像,而且让我们更惊讶的是,薄层GST实际上能给我们更好的对比.我们还发现,改变底层电极的大小能使图像的颜色改变."

GST夹心层使用了溅射技术,其中一个靶子会让高能量粒子轰击,这样靶心的原子就会沉积到另一种材料上形成薄膜.

"因为这使我们的设备层可沉积为薄膜,从而可以被变为非常薄的柔性材料——我们已经证明这一技术可以用在约200nm厚的柔性聚酯薄膜片上,"巴斯卡兰教授说."这使得它们在"智能"眼镜,可折叠屏幕,挡风玻璃,甚至是模仿人眼感光细胞的人造视网膜能力中发挥作用."

论文第一作者,牛津大学材料系的PeimanHosseini说:"我们的模型都是很好的预测实验,我们可以调整原型"像素"以创造我们想要的任何颜色,包括显示器所需的原色.我们设计的一个优点是,它不像传统的LCD屏幕,没有必要不断刷新所有像素,而你只需要更新那些真正需要改变的像素(保持那些静态像素).这意味着,基于这种技术,任何显示器会有极低的能源消耗."

研究表明,基于该技术的柔性超薄显示器可以在彩色电子阅读器"省电"模式之间切换,并且能够进行视频背光显示.这种显示器可以使用廉价材料,并且因为他们是固态,那么是可靠的并且易于制造.微小纳米像素让它成为理想的应用,如智能眼镜,其图像将会放到更大的尺寸,甚至是扩大,并且会提供非常高的分辨率.

论文合着者,埃克塞特大学工程系的DavidWright教授说:"我们和世界各地的研究人员一起,一直在寻找多年来这些GST材料的记忆性应用,但之前结合电气和光学功能的人都没能完全提供非易失性,高分辨率,电子彩色显示的新类型,因此我们的研究工作是一个真正的突破."

巴斯卡兰教授说,如果没有英国工程与物理科学研究理事会(EPSRC)的支持,该发现是不可能的:"EPSRC一直资助我们的基础研究,而这次偶然发现表明,所谓的"蓝天"研究是可行的."

(研究)使用的相变材料是合金Ge2Sb2Te5(锗锑碲或GST),它夹在铟锡氧化物(ITO)电极层之间.

来源:牛津大学

Buildingupbamboo

Bambooconstructionhastraditionallybeenratherstraightforward:Entirestalksareusedtocreatelatticededifices,orwoveninstripstoformwall-sizedscreens.Theeffectcanbestunning,andalsopracticalinpartsoftheworldwherebamboothrives.

Buttherearelimitationstobuildingwithbamboo.Thehardygrassisvulnerabletoinsects,andbuildingwithstalks—essentiallyhollowcylinders—limitstheshapeofindividualbuildingponents,aswellasthedurabilityofthebuildingitself.

MassachusettsInstituteofTechnology(MIT)scientists,alongwitharchitectsandwoodprocessorsfromEnglandandCanada,arelookingforwaystoturnbamboointoaconstructionmaterialmoreakintowoodposites,likeplywood.Theideaisthatastalk,orculm,canbeslicedintosmallerpieces,whichcanthenbebondedtogethertoformsturdyblocks—muchlikeconventionalwoodposites.Astructuralproductofthissortcouldbeusedtoconstructmoreresilientbuildings—particularlyinplaceslikeChina,IndiaandBrazil,wherebambooisabundant.

Suchbambooproductsarecurrentlybeingdevelopedbyseveralpanies.TheMITprojectintendstogainabetterunderstandingofthesematerials,sothatbamboocanbemoreeffectivelyusedstructurally.Tothatend,MITresearchershavenowanalyzedthemicrostructureofbambooandfoundthattheplantisstrongeranddenserthanNorthAmericansoftwoodslikepine,firandspruce,makingthegrassapromisingresourceforpositematerials.

Bamboogrowsextensivelyinregionswheretherearerapidlydevelopingeconomies,soit'sanalternativebuildingmaterialtoconcreteandsteel,"saysLornaGibson,theMatoulaS.SalapatasProfessorofMaterialsScienceandEngineeringatMIT."Youprobablywouldn'tmakeaskyscraperoutofbamboo,butcertainlysmallerstructureslikehousesandlow-risebuildings."

Gibsonandhercolleaguesanalyzedsectionsofbamboofromtheinsideout,measuringthestiffnessofeachsectionatthemicroscale.Asitturnsout,bambooisdensestnearitsouterwalls.Theresearchersusedtheirdatatodevelopamodelthatpredictsthestrengthofagivensectionofbamboo.

Themodelmayhelpwoodprocessorsdeterminehowtoassembleaparticularbambooproduct.AsGibsonexplainsit,onesectionofbamboomaybemoresuitableforagivenproductthananother:"Ifyouwantedabamboobeamthatbends,maybeyou'dwanttoputthedensermaterialatthetopandbottomandthelessdensebitstowardthemiddle,asthestressesinthebeamarelargeratthetopandbottomandsmallerinthemiddle.We'relookingathowwemightoptimizetheselectionofbamboomaterialsinthestructurethatyoumake."

GibsonandhercolleagueshavepublishedtheirresultsintheJournaloftheRoyalSociety:Interface.

Alookatbamboo,fromtheinsideout

Fortheirexperiments,theresearchersanalyzedspecimensofmoso,themainspeciesofbamboousedinChina.Likemosttypesofbamboo,mosogrowsashollow,cylindricalstalks,orculms,segmentedbynodesalongthelengthofastalk.Bamboocanreachheightsof20m—astallasasix-storybuilding—injustafewmonths.Thestalksthentakeanotherfewyearstomature—butstillmuchfasterthanapinetree'sstatelier,decades-longgrowth.

Oneoftheimpressivethingsishowfastbamboogrows,"Gibsonnotes."Ifyouplantedapineforestversusabambooforest,youwouldfindyoucangrowfarmorebamboo,andfaster."

Researchersusedelectronmicroscopytoobtainimagesofthebamboomicrostructureandcreateplete,microscalecross-sectionsoftheentireculmwallatdifferentheightsalongthestalk.

Theresultingimagesshoweddensitygradientsofvascularbundles—hollowvessels—thatcarryfluidupanddownthestalk,surroundedbysolidfibrouscells.Thedensityofthesebundlesincreasesradiallyoutward—agradientthatseemstogrowmorepronouncedathigherpositionsalongastalk.

Theresearcherscutsectionsofbamboofromtheinsideout,notingeachsample'sradialandlongitudinalpositionalongaculm,thengaugedthestiffnessandstrengthofthesamplesbyperformingbendingandpressiontests.Inparticular,theyperformednanoindentation,whichusesatinymechanicaltiptopushdownonasample,togainanunderstandingofbamboo'smaterialpropertiesatafinerscale.Fromtheresultsofthesemechanicaltests,Gibsonandhercolleaguesfoundthatingeneral,bambooisstifferandstrongerthanmostNorthAmericansoftwoodsmonlyusedinconstruction,andalsodenser.

Theresearchersthenusedthestiffnessanddensitydatatocreateamodelthataccuratelypredictsthemechanicalpropertiesofbambooasafunctionofpositioninthestalk.GibsonsayswoodprocessorsthatsheworkswithinCanadamayusethemodelasaguidetoassembledurablebambooblocksofvariousshapesandsizes.

Goingforward,theprocessors,inturn,willsendtheMITteampositesamplesofbambootocharacterize.Forexample,aproductmaybeprocessedtocontainbambooalongwithothermaterialstoreducethedensityoftheproductandmakeitresistanttoinsects.Suchpositematerials,Gibsonsays,willhavetobeunderstoodatthemicroscale.

Wewanttolookattheoriginalmechanicalpropertiesofthebambooculm,aswellashowprocessingaffectstheproduct,"Gibsonsays."Maybethere'sawaytominimizeanyeffects,andusebambooinamoreversatileway."

Source:MassachusettsInstituteofTechnology

建造竹子机构

竹构建筑在传统上是非常简单的:整个秸秆被用来创建网格状的大厦,或纺织成条以形成墙壁大小的屏风.其效果是令人惊叹的,并且在竹子蓬勃发展的世界各地也是非常实际的.

但是运用竹子来进行建造也是具有局限性的.耐寒的草容易招至昆虫,并且用茎来建造——实质上是中空圆柱体——限制了单个建筑构件的形状以及建筑物本身的耐久性.

麻省理工学院(MIT)的科学家们与来自英国和加拿大的建筑师和木材加工商正在寻找方法能够将竹子变成更像是木质复合材料的建筑材料,例如胶合板.其想法是,一个杆或秆可以被切成小块,然后能够结合在一起形成坚固的块——就像是传统的木质复合材料.这种类型的结构性产品可以用于建造更具弹性的建筑物——尤其是在像中国,印度和巴西这样竹子丰富的地方.

这样的竹制品目前得到了几家公司的开发.MIT的项目计划旨在对这些材料获得更好地了解,从而使竹子能够在结构上得到更有效地使用.为了达到这一目的,麻省理工学院的研究人员已经分析了竹子的微观结果,并且他们发现,该植物比松树,冷杉和云杉这样的北美软木更加强壮,而且密度也更大,从而使得该植物成为了复合材料的一个良好的前景资源.

"竹子广泛生长在快速发展经济的区域里,因此它是混凝土和钢材的一个替代的建筑材料,"麻省理工学院材料科学家与工程专业的教授马图拉S萨拉帕塔斯表示."你可能不会用竹子建造一个摩天大楼,但是肯定会建造较小的结构,例如房子和低层建筑."

吉布森和她的同事们由内而外地分析了竹子的部分,并且在微尺度上测量了每个部分的刚度.事实证明,竹子接近外壁的地方是最密集的.研究人员利用他们的数据建立了一个预测竹子给定部分强度的模型.

该模型可能有助于木材加工者确定如何组装一个特定的竹制品.正如吉布森对其解释的,竹子的一个部位可能比另一个部位更适合于某一特定的产品:"如果你想要一个弯的竹染,可能你会希望把密度较大的材料放在顶部和底部,而密度较小的部位放在中间,因为梁顶部和底部的压力较大,而中间的压力较小.我们正在研究我们能够如何在你所建造的结构中优化竹子材料的选择."

吉布森和她的同事们将他们的研究结果发表于《皇家学会:接口》杂志上.

对竹子的研究,由内而外

对于他们的实验,研究人员分析了毛竹的标本,这种竹子是中国所使用的竹子的主要品种.与大多类型的竹子一样,毛竹长得是中空的,圆柱形的茎或秆,根据茎长度的节点出现分段.竹子能够在短短几个月的时间内就生长到20米的高度——与一个六层的大楼一样高.然后,秸秆再用几年的时间才能成熟——但是仍然比松树雄伟的,长达数十年的增长要快得多.

"一个令人印象深刻的事情是竹子生长的速度有多快,"吉布森指出."如果你种植和一片松树林和一片竹林,你会发现,你能够种植更多的竹子,并且其生长速度更快."

研究人员用电子显微镜获得了竹子微观结构的图像,并且创建了在茎的不同高度上整个茎壁完整的,微尺度的横截面.

所得到的图像显示出了维管束——空间的管道——的密度梯度,维管束在从上到下的茎体中携带着流体,并且是由固体纤维细胞所包围的.这些束的密度向外以放射状增加——这是一种似乎在茎的较高位置增长地更为明显的渐变.

研究人员由内而外地将竹子砍成几部分,指出每个样品的径向和沿茎秆的纵向位置,然后通过执行弯曲和压缩试验来衡量样本的刚度和强度.特别是他们进行了纳米压痕,该方法是使用一个微波的机械尖端在样品上向下推,从而对更加精细尺度上的竹子材料的特性有了了解.从这些机械测试的结果中,吉布森和她的同事发现,在一般情况下,竹子比大多数通常用于建筑的北美软木要更加强壮,并且也更加密集.

然后,研究人员使用刚度和密度的数据创建了一个能够精确地预测作为茎的位置函数的竹子机械性能的模型.吉布森表示,她在加拿大合作的木材加工商能够使用该模型作为指导来组装各种形状和尺寸的耐用竹块.

展望未来,加工商反过来将向MIT的研究小组发送合成样品来进行特征的描述.例如,产品可以被加工成含有竹子以及其他材料,从而减少产品的密度并且使其对昆虫具有抗性.这样的复合材料,吉布森表示,将不得不在微尺度上得到了解.

"我们想要研究竹秆原有的机械性能,以及处理是如何影响到该产品的,"吉布森表示."也许会有一种方法能够尽量减少任何类型的影响,并且以一种更通用的方式来使用竹子."

资料来源:麻省理工学院

Chemistdevelopsx-rayvisionforqualityassurance

ATechnicalUniv.ofDenmarkresearcherhasdevelopedamethodthatusesx-raysfortherapididentificationofsubstancespresentinanindeterminatepowder.Thenewtechniquehasthecapacitytorecognizeadvancedbiologicalmoleculessuchasproteins.Themethodthereforehasenormouspotentialinbothfoodproductionandthepharmaceuticalindustry,whereitopensupnewopportunitiesforthequalityassuranceofprotein-basedmedicines,forexample.

Itisseldomsufficienttoreadthedeclarationofcontentsifyouneedtoknowpreciselywhatsubstancesaproductcontains.Infact,todothisyouneedtobeahighlyskilledchemistortohavegenuinex-rayvisionsothatyoucanlookdirectlyintothemolecularstructureofthevarioussubstances.ChristianGrundahlFrankr,aPostdocatDTUChemicalEngineering,isalmostboth,ashehasdevelopedamethodthatallowshimtousex-raystolookdeepintobiologicalsamples.

The"fingerprints'"ofasubstance

Thetechniqueiscalled"powderdiffraction"andinvolvessubjectingasampletoanintensebeamofx-rays.Whenthebeamhitsthesample,itdisseminatesinthesamewayaslightdoeswhenreflectedbyadiscoball.Thisgeneratesapatternthatreflectsthestructureofthematerial.Eachindividualsubstancehasitsownuniquepattern—akindof'fingerprint'—whichmakesitreadilyidentifiablewhentheresultsarerunthroughadatabase.

Twodifferentcrystalformsoftheproteininsulin.Theillustrationtotherightshowstwodifferentcrystalformsofinsulinusingsinglecrystaldiffraction,whilethegraphstotheleftpresenttwodifferentinsulin'fingerprints'takenusingpowderdiffraction.

Powderdiffractioniscurrentlyusedtoidentifysimplesubstancessuchassugar,saltsandminerals,buttheideaofusingthesametechniquetocharacterizeadvancedbiologicalmoleculessuchasproteinsistrulyinnovative.Itisforthisreasonthatthemethodhasenormouspotentialinbothfoodproductionandthepharmaceuticalindustry,wheremoreandmoreattentionisbeingdevotedtoprotein-basedmedicines.

Ihavetesteddifferenttypesofinfantmilkformula,proteinpowdersanddetergents.Bytakingasmallsampleofpowderandbombardingitwithx-rays,Icandeterminewhatsubstancesthepowdercontains—andinwhatconcentrations—withintenminutes.Inaddition,theanalysiswilltypicallyrevealsomeinformationabouthowtheproductwasmade,"relatesFrankr.Themethodisthereforeidealforqualityassuranceofnewproductsonthemarket.

Crystalformsdetermineproperties

Proteinsarelargemoleculeswithplex3-Dstructures.Theshapeofaprotein—oritscrystalstructure—cansignificantlyalteritsproperties.Aproteinsuchasinsulinmayhavemanydifferentcrystalforms,andtheformthesubstanceappearsinmayaffectitssolubilityorlevelofactivity.This,inturn,maybeofsignificancetohowtheproteinwillreactwhenitentersthehumanbody.Forthisreason,itmakesalotofsensetoanalysethecrystalformsofdifferentproteinsbothduringproductionandinthequalityassuranceofprotein-basedmedicines,butthishassimplynotbeenpracticalnorfinanciallyviableuntilnow.Frankrexplains:

Wehavenowdemonstratedthatpowderdiffractioncanactuallybeusedonbiologicalsubstancessuchasproteins.Theresultsarenotasdetailedasinsinglecrystaldiffraction,whichmakesitpossibletodecodetheentirestructureoftheprotein,buttheydoallowusto'liftfingerprints'quicklyandeasilysothatwecanidentifytheproteinanditscrystalstructure.Thisisvaluableknowledgewhenyouareworkingwiththeproductionofproteins."

Quickanswer

Thenewmethodmakesitpossibletoestablishveryquicklywhatsubstances—proteinsandothers—aproductinpowderformcontains.Forexample,aquickanalysisofawashingpowderdevelopedfortheDanishmarketrevealedahighlevelofzeolitematerial,whichisusedtobindlimestonefromthehardwaterthatissoprevalentinDenmark,whileasamplefromMoroccocontainednoneofthismaterial.Analysisofanotherwashingpowderrevealedthat'activeoxygen'issimplythepoundsodiumpercarbonate,i.e.bondedhydrogenperoxide.Image:IbenJulieSchmidt

Themethodhasgreatpotentialinthecontextofoptimizingbothqualityandproductionprocessesinallproductionset-upsthatinvolvesolidsubstances.Applyingthenewmethodwillmakeitpossibletocheckcontinuouslyforchangesin—ortransformationsof—differentsubstancesusedintheproductionprocess.

Theadvantageofourmethodisthatitallowsyoutotakesamplesdirectlyfromaproductionline.Youthenhavetheresultswithin15minutesandcantellpreciselywhatcrystallinematerialisinvolved.Inaddition,thex-raybeamsweusecaneasilybegeneratedusingstandardlaboratoryequipment,"saysFrankr.

Theencouragingresultsareonlythebeginning:

Whatwewanttodonowistotesthowfarwecanpushthemethod.Wehavealreadyestablishedthatitworksonproteins,butwillitalsoworkonotherplexproductsAndwhathappensifwetakethesamplestothesynchrotroninGrenoble,wherethex-raybeamisamilliontimesmorepowerfulthantheonewehaveinourlaboratory"asksFrankr.

Source:TechnicalUniv.ofDenmark

化学家开发X射线透视保证产品质量

丹麦技术大学研究者已经开发出一种使用X射线对不确定粉末物质快速识别的新方法.新技术已经具备识别如蛋白质等大生物分子的能力.该方法具有巨大的食品生产和医药行业潜力,它也开辟了基于蛋白质等药品质保的新机遇.

我们很少充分去阅读,而你又需要精确知道,物质产品中是否含有它所宣称的内容.事实上,这样做你需要是高度熟练的化学家或有真正的X光视力,你可以直接看到各种物质的分子结构.DTU的化工博士后ChristianGrundahlFrankr,几乎同时开发出一种方法,以允许他使用X射线深入到生物样品内部.

物质"指纹"

这种技术被称作"粉末衍射",并能向样品射进一束X射线.当光束击中样品时,被迪斯科球反射后它传播的光具有相同的方式.这会产生一个反映该材料结构的模式.每一种物质都有自己独特的模式"指纹"——这使得它通过数据库易于识别.

胰岛素蛋白有两种不同的晶体形式.右边插图显示了单晶衍射胰岛素的两种不同晶体形式,而左侧呈现了两种不同胰岛素使用粉末衍射图采取的"指纹".

粉末衍射目前用于识别简单的物质,如糖,盐和矿物质,但使用相同技术来表征如蛋白质等大生物分子的想法是真正的创新.正是因为这一原因,该方法具有巨大的食品生产和医药行业的潜力,而其越来越多的关注正集中于以蛋白质为基础的药物上.

"我已经测试了不同类型的婴儿配方奶粉,蛋白粉和洗涤剂.向一个小样本粉末上用X射线轰击,我可以在十分钟内确定粉中含有什么浓度的什么物质.此外,分析还将揭示一些关于产品是如何形成的问题,"Frankr说.因此,该方法是市场上新产品最为理想的质量保证.

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有关论文范文主题研究: 关于竹子的论文范文集 大学生适用: 在职论文、学士学位论文
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确定晶体形式

蛋白质具有复杂的大分子三维结构.蛋白或其晶体结构形状可以显着改变其性质.如胰岛素等蛋白可能有许多不同的晶体形式,以何种形式出现可能会影响其溶解性或活动水平.反过来,这可能对蛋白质进入人体后如何反应具有重要意义.因为这个原因,分析以蛋白质为基础的药物可能是很有意义的分析,因为能保证不同的蛋白质晶体形式,但到目前为止这还根本不现实也不经济.Frankr解释道:

"我们现在已经证明,粉末衍射实际上可以用于如蛋白质等生物物质.结果不单是晶体衍射,还可以让它解码整个蛋白质的结构,但它们确实可以迅速且轻松地"识别指纹",从而让我们能够识别蛋白及其晶体结构.当你从事蛋白质生产工作时,那这就是有价值的知识."

快速的回答

新方法可以很快识别产品含有粉末形式的什么蛋白质.例如,丹麦市场开发出了对洗衣粉的快速分析方法,采用的是高水平的沸石分子筛材料,它可以从硬水中结合石灰石,在丹麦很普遍,但摩洛哥样品中没有这种材料.另一种洗衣粉显示,"活性氧"分析是简单的过碳酸钠化合物,即结合过氧化氢.图片提供:IbenJulieSchmidt

该方法在涉及固体物质的各生产过程的优化中具有很大的潜力.应用新方法将能够检查在生产过程中使用的,连续变化或不同物质转换.

"我们方法的优点是,它允许你直接从生产线上把样品拿下了.然后你在15分钟内有涉及晶体材料的结果.此外,我们使用的X射线束可以很容易地使用标准实验室设备产生,"Frankr说.

令人鼓舞的结果仅仅是一个开始:

"我们现在要做的是把测试推广到尽可能的远.我们已经确立了蛋白质,但也对其他复杂产品也适用么如果我们把样品推广到格勒诺布尔,那那里的X射线束会比我们已经在我们实验室获得的强大一百万倍么"Frankr问道.

来源:丹麦技术大学

Organic&,Polymer(有机高分子材料)

Companyconvertscoconuthuskfibersintomaterialsforcarsandhomes

WhenElisaTeipel,andhercollaboratorsbegantheirresearchseveralyearsago,theirgoalwastotakeanagriculturalwasteproductoflittlevalue—inthiscase,fibersextractedfromcoconuthusks—andturnitintoanenvironmentally-friendly,valuablemodity.

Equallyimportant,Teipel,alongwithcolleaguesRyanVano,husbandBlakeTeipel,andMattKirbywantedtheprojecttohelpthelocaleconomieswheretheyobtainedtherawmaterials.

Todaytheirnewpany,theCollegeStation,Texas-basedEssentiumMaterials,isturningoutautomotivetrunkliners,loadfloors(batterypackcoversinelectriccars),andlivingwallplanters,amongotherthings,withtechnologytheydevelopedthatproducesapositematerialmadeofcoconuthusksbinedwithrecycledplastics.

Theresultisgreenerandcostneutral,aswellasstrongerandstiffer,thanthetraditionalall-syntheticplasticfibers,andwithnaturalanti-microbialpropertiesduetoahighlignincontent.

"Thecoolestpar

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tisseeingsomethingthatwasoncejustwastebeeanewresource,"Teipelsays."Also,itisbenefittingboththeenvironmentandthemunitiesindevelopingnationswherethecoconutsaregrown."

Theresearchersestimatethatreplacingsyntheticpolyesterfiberswithcoconuthuskfibers,knownascoir,willreducepetroleumconsumptionby2-4millionbarrelsandcarbondioxideemissionsby450,000tonsannually.

Also,theimprovedperformanceandlowerweightofthesematerialswillleadtocostsavingsthroughincreasedfueleconomy,savingupto3milliongallonsofgasolineperyearintheUnitedStates,accordingtoTeipel.

Niy-fivepercentofthe50billioncoconutsgrownworldwideareownedby10millioncoconutfarmerswhoseaverageineislessthan$2aday,shesays.Moreover,about85percentofthecoconuthuskscurrentlycreatepollutionwhentheyaretreatedliketrash."ThesuccessfuladoptionofthesenewpositematerialswithinNorthAmericanmarketswouldinmanycasesdoubletheannualineforthesefarmers,"shesays.

Essentium'sworkissupportedbya$1,018,475grantfromtheNationalScienceFoundation(NSF)throughitssmallbusinessinnovationresearchprogram(SBIR)inthedirectorateforengineering.

"Projectsthatusewastematerialsasafeedstocktocreatevalue-addedproductsareaperfectfitforNSFSBIRbecausewelooktosupportentrepreneurswhocan'dogoodbydoingwell,"'saysBenSchrag,theproject'sprogramdirectoratNSF."Webelievethatsmallbusinesseswithinnovativetechnologyholdthekeytosolvingmanyofthebroadersocietalandenvironmentalproblemsfacedbythecountryandtheworld.

"Newmaterialconceptsthatincorporatewastematerialsarealsobeingincreasinglyattractivetomanyconsumersandbusinesses,"headds."Thisiscreatingsignificantopportunitiesforshrewdanddedicatedtechnologistsandentrepreneurs."

TheideatousecoconuthuskmaterialoriginatedaboutsevenyearsagowhenTeipelwasingraduateschool.

"Wewerereallyinterestedinseeinghowwecouldhelppeopleinotherpartsoftheworldwitheconomicdevelopmentwork,"shesays."Initially,wewerelookinginPapuaNewGuinea.Aformerprofessorofmine,WalterBradley,whohassinceretiredfromBaylorUniversity,suggestedwelookatavailablematerialsandwhatwecoulddowiththem,initiallytoproduceelectricity.

"Coconutwasoneofthemostreadilyavailablematerialsthatfarmersandpeopleinthemunityhadaccessto,"sheadds."Sowetookalookandwonderedwhethercoconutwasaviableengineeringmaterial,andwhatwecoulddowithit."

Atthetime,farmersharvestedcoconutsonlytoproducecoconutmilkandcoconutoil,whilethehusksandfiberwereconsideredwaste.Yetthestudentsbelievedtheycouldtakethefibersandconvertthemintoausableproductwhile"elevatingboththedignityofthepeopleandthedignityoftheresources,"shesays.

Itwasaprocessoftrialanderrortodevelopthematerialinthelab,thentryitinaproductionsetting."Theinitialphaseoftheresearchwastotrytounderstandtheinh

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