简介:TenfractionatedsamplesofChineselacquerpolysaccharideinaqueous0.1MNaC1solutionwerestudiedbyaqueous-phasegelpermeationchromatography(GPC).Theuniversalcalibration,broadMWDcalibrationandcorrectedcolumndispersionwereadoptedtotheanalysisofGPCchromatogramsofthepolysaccharide.ThemolecularweightsM_w,M_nandpolydispersityindexM_w/M_nobtainedfromGPCareingoodagreementwiththeresultsoflightscatteringandmembraneosmometry.Itisverifiedthattheuniversalcalibrationconceptisapplicabletothelacquerpolysaccharidehavinganumberofsidechains.
简介:Thebucklingofthingelfilmhasattractedmuchattentionduetoitsapplicationsinthedesignofthreedimensionalstructurefromtwo-dimensionaltemplate.Wehaveestablishedananalyticalmodeltostudytheswelling-inducedbucklingofathingelstripwithoneedgeclampecdandtheothersfree.Theclosed-formsolutionsfortheamplitudeandwavelengthofthebuckledshapeareobtainedbyenergyminimizationofthetotalpotentialenergy.Theanalyticalresultsagreewellwithfiniteelementanalysisbasedontheinhomogeneousgeltheorywithoutanyparameterfitting.Themodelprovidesaroutetostudycomplexpostbucklingbehaviorsofthingelfilmsandguidelinestodesignthebuckledconfigurationquantitativelybycontrollingtheswellingratio.
简介:BeOnanoparticlesweresynthesizedbypolyacrylamidegelroute.TheeffectsoftheprocessingparametersonthemorphologyandsizeofthesynthesizedBeOnanoparticleswereinvestigated.Thecalcinationtemperatureofthegelprecursorcontainingberylliumsulfatewasdeterminedbythermogravimetryanddifferentialscanningcalorimetry(TG-DSC),whichisaround690Cand160Clowerthanthegeneraltemperature.Xraydiffractometry(XRD),transmissionelectronmicroscopy(TEM),andspecificsurfaceareameasurements(BET)showedthatthesynthesizednanoparticlesunder700Cwerepure,globularandabout~5-20nmwithnarrowdistribution.Interestingly,thenanograinscoalescedandgrewunderhighercalcinationtemperaturesandlongercalcinationtime.Theinfluenceofcalcinationtemperatureonthemorphologyandgrowthbehaviorisgreaterthanthatofitsduration.Theactivationenergyforgraingrowthwasestimatedtobe24.53kJ/mol,andthedominantgrowthmechanismwasmostlikelytoberelatedtothevaportransportinporecontrolmodeandgrain-rotation-inducedgraincoalescence(GRIGC)mechanism.
简介:Asoxidematerials,continuousmullitefiberhassuperiorpropertiesinhightemperatureresis-tancewhenexposedinair,Presentworkshowstheproductionofoxidesolutioandthespinningofthenullitefiber,Thestablespinninglastedover10hours,Thestrengthofthemullite-basedfiberis1900MPawithadiameterof10μmafterabout1000℃treatment,Whenthetreatmenttemperatureexceeds1300℃thegrainsoffiberbecomecolumncrystalsandresultsinreductionoffiberstrength.
简介:钕做了金轧镓氧化物(Nd:GGG)当燃料被报导,nanopowders用丙氨酸由微波胶化燃烧综合了。有丙氨酸燃料的金属硝酸盐答案是在微波的combusted给先锋。微波先锋粉末从800~1100°C在不同温度被锻烧。分阶段执行纯Nd:GGG形成在由X光检查衍射(XRD)和Fourier变换观察了的800~1100°C发生了红外线(FTIR)光谱学。然而,粒子尺寸在1100°C在800°C从25nm与锻烧温度增加了到200nm。Nd:在不同锻烧温度获得的GGGnanopowder被压缩并且在为在空中的3h的1550°C的sintered。最使增加密度陶器从Nd被获得:在1100°C锻烧的GGGnanopowder。从扫描电子显微镜学(SEM)观察了的微观结构证明大多数使增加密度陶器,从在更高的锻烧温度锻烧的nanopowder获得了,有更一致的谷物尺寸分布,更少毛孔和更大的densification。sintered样品的XRD显示出阶段纯净的保留。
简介:一个新奇高产量的系统,为分离和反应(4SR)叫了叠的片胶化系统,为DNA/RNA和蛋白质/肽的分析被开发。系统提供利用叠的片胶化的性质的一条新奇三维的胶化电气泳动途径。它同时允许多重样品反应以及被分开,出现一二维(mxn)样品装载系统。为这个目的,包含井(在这篇论文的100口井)的可变数字的高产量的多微的容器(MMV)被使用了,它用25公里做的是方形尺寸的polyacrylamide胶化。在electrophoretic分离以后,而且,包含一件需要的样品的片胶化能容易被移开并且继续到下一步。不同生物反应以及产品的连续分离有效地被执行处理DNA/RNA和蛋白质/肽。它证明这个系统有多种潜力被发展。
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简介:Sphericalcrosslinkedpolystyrene-isocyanuricacidresinwassynthesizedbyreactionofchloromethylatedpolystryenewithisocyanuricacid.Thesorptionisothermsofphenolfromaqueoussolutionandcyclohexanesolutionontotheresinweremeasured.Itisofinteresttonoticethattheresinsorbedphenolefficientlythoughitsspecificsurfaceareawas0anddidnotswellinwater,andthesorptioncapactityfromaqueoussolutionwasclosetothatofphenolontoXAD-4atthesameequilibriumconcentration.SorptionenthalpiescalculatedfromtheisothermsaccordingtotheClausius-Clapeyronequationwere-21-25kJ/moland-39-41kJ/molrespectively.Thesevaluesimpledthatthesorptionprocesseswerebasedonhydrogenbonding.Inaddition.thedetailsofthehydrogenbondingbetweentheactivesitesoftheresinandphenolweresuggested.
简介:Aneworganic-inorganichybridmaterial,whichshowsphoto-inducedreductionofrefractiveindexaswellasvolumecontraction,ispreparedusingasol-gelmethod.ThismaterialiscoatedonaSisubstratebyspin-coatingtomanufacturefilm.Afterirradiatedbyultraviolet(UV)lightwithadeuteriumlampfor5h,thethicknessoffilmdecreaseslargelyby55%,andtherefractiveindexoffilmchangesfrom1.484to1.445at550nm.Thefilm'sopticalthicknessexhibitsanexponentialchangewiththeincreasingirradiationtime.Futhermore.thephoto-patternningoftheorganic-inorganichybridfilmwithoutanyfurtherprocess(wetetchingandthermalcuring)isperformedutilizingthevolumecontractiononUV-lightirradiation.Thisfilmhaspotentialapplicationsforfabricationofpatternedfilterarrayandapodizingfilterbydirectlightwriting,andalsodemonstratesgoodtemperaturestabilityandimmunitytovisiblelightexposure.
简介:SnO2preparedwiththesol-geltechniqueatdifferenttemperatureswasusedasananodematerialofthelithium-ionbattery.Weobtainedthequalititaverelationshipbetweentheelectrochemicalperformanceoftinoxideanodematerialandeachofitscarboncomponent,particlesize,structureandsurfacemorphologyindetail.ItwasfoundthatthebestelectrochemicalperformancecanbereachedbycontrollingthephysicalcharacteristicsofSnO2,whichwasaffectedgreatlybythetreatmenttemperature.TheSnO2obtainedat600℃waspure.Whenitwasusedastheanodematerialofthelithium-ionbattery,itdemonstratedahighinitialspecificcapacityof770mA·h/g.