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500 个结果
  • 简介:Crackopeningdisplacement(COD)wasappliedtocharacterizethefractureinitiationofthetoughhighdensitypolyethylene.Normalsinglesidenotchedthree-pointbendspecimensandsilicarubberreplicatechniqueswereusedtostudythecharacteristicCODofhigh-densitypolyethylenepipeanditsbutt-fusionjointsincludingtheweldfusionzoneandheataffectedzoneatdifferenttemperaturefrom-78℃to20℃.TestingresultsshowthatthecharacteristicCODappearstodependonthestructuralfeaturesthataredeterminedbyweldingprocessandthetestingtemperature.Asthetemperatureislowered,thecharacteristicCODofallzonesstudieddecreases.Becausetheweldingprocesssignificantlychangessomestructuralfeatureofthematerial,characteristicCODoftheweldfusionzoneisthesmallestoneamongthoseofthethreezones.TheresultscanbeusedfortheengineeringdesignandfailureanalysisofHDPEpipe.

  • 标签: 熔焊 高密度聚乙烯管 断裂 裂纹张开位移 COD HDPE
  • 简介:Waveguidesuperlattices,aspecialtypeofwaveguidearrays,canbedesignedtoachieveverylowcrosstalkatsubmicrometer/subwavelengthpitches.Thetheoreticalframeworkanddesignrationalesforsuchwaveguidesuperlatticeswillbepresentedindepth.Waveguidesidewallroughnesscanhelptodeterthecoherentcouplingbetweenidenticalwaveguidesinnearbysupercells,butitalsoinducesrandomfluctuationoftransmission.Statisticalbehaviorofthetransmissionduetoroughnessinawaveguidesuperlatticeissystematicallytreated.Complextransmissioncharacteristicsduetospectraloscillationandrandomroughnesswillbepresented,andtheirevolutionwiththesuperlatticelengthwillbeanalyzed.

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  • 简介:Ahigh-density,high-fluxcirculatingfluidizedbed(CFB)riser(100mminIDand10.614minheight)wasappliedinawiderangeofoperatingconditions(withsolidfluxesupto400kg/m2sandsuperficialgasvelocitiesupto12m/s)toexamineitsradialnon-uniformitydynamics.Thesolidsholdupwasdeterminedthroughtheuseofafiber-opticprobeat11axiallevels.Theresultsindicatedthatunderalloperatingconditions,thehighsuperficialgasvelocityandlowsolidfluxesmaintainedalowradialnon-uniformityindex(RNI).Thehigh-density/fluxCFBriserhadseveraluniquecharacteristics,sothatthepeakoftheradialsolidsholdupprofileoccurredatapositionwithr/R=0.8.TheRNIandsolidsholdupatthecross-sectionalpositionhadagoodlogarithmicrelationshipatthelow-densitycondition(withameansolidsholdupof<0.2),andtheRNIdecreasedwhenthemeansolidsholdupexceeded0.2.InvestigationofthedynamicsofstratifiedinjectionrevealedthatthefeedratiohadanimportanteffectonGsandonsolidsholdupdistribution.Anovel"<"shapedaxialsolidsholdupprofilewasfound.Gsdecreasedsharplywhentheup-flowfeedratioexceeded0.5,andRNIwaslowestwhentheup-flowfeedratiowas1.

  • 标签: 气固循环流化床 高密度 高通量 均匀性指标 径向 颗粒浓度分布
  • 简介:BackgroundThisstudytestedthehypothesisthatmoderatealcoholintakeexertsitscardioprotectiveeffectmainlythroughanincreaseintheserumlevelofhigh-densitylipoproteincholesterol.MethodsandResultsIntheCohortofNorway(CONOR)study,149729adultparticipants,recruitedfrom1994to2003,werefollowedbylinkagetotheCauseofDeathRegistryuntil2006.Atrecruitment,questionnairedataonalcoholintakewerecollected,andtheconcentrationofhigh-densitylipoproteincholesterolinserumwasmeasured.UsingCoxregression,wefoundthattheadjustedhazardratioformenfordyingfromcoronaryheartdiseasewas0.52(95%confidenceinterval,0.39-0.69)whenconsumingalcoholmorethanonceaweekcomparedwithneverorrarely.Theratiochangedonlyslightly,to0.55(0.41-0.73),aftertheregressionmodelincludedtheserumlevelofhigh-densitycholesterol.Forwomen,thecorrespondinghazardratioswere0.62(0.32-1.23)and0.68(0.34-1.34),respectively.ConclusionsAlcoholintakeisrelatedtoareducedriskofdeathfromcoronaryheartdiseaseinthefollow-upofalarge,population-basedNorwegiancohortstudywithextensivecontrolforconfoundingfactors.Ourfindingssuggestthattheserumlevelofhigh-densitycholesterolisnotanimportantintermediatevariableinthepossiblecausalpathwaybetweenmoderatealcoholintakeandcoronaryheartdisease.

  • 标签: 高密度脂蛋白胆固醇 冠心病 控制 酒精 幅度 胆固醇水平
  • 简介:ThephotoluminescencepropertiesofBiTaO4∶Pr3+andBiTaO4atroomtemperaturewerestudied,andtheinfraredtransmissionanddiffusionreflectionspectraofBiTaO4weremeasured.ThephotoluminescencespectrumofBiTaO4peaksatabout420,440and465nm.Therehasanobviousexcitationbandfrom330to370nm.ThephotoluminescencespectrumofBiTaO4∶Pr3+consistsofthecharacteristicemissionofPr3+,anditsmainpeakisat606nmfrom3P0→3H6transitionofPr3+.Itsexcitationspectrumconsistsofthewidebandwithmaximumat325nm,thewidebandintherangeof375~430nm,andthecharacteristicexcitationofPr3+.Thebandsat325nmand375~430nmmaybefromtheabsorptionofthechargetransfertransitionofthetantalategroupanddefectenergylevelsinitsforbiddenband,respectively.ThereisenergytransferfromhosttoPr3+.BecauseboththehostdensityandphotoluminescencepeakintensityofBiTaO4∶Pr3+aresuperiortoPbWO4,BiTaO4∶Pr3+maybeapotentialheavyscintillator.

  • 标签: BiTaO4 稀土 掺杂 发光材料 发光性能
  • 简介:锌(Zn)缺乏是限制米饭庄稼生长和产量的主要土壤限制,然而,忍耐机制的基因控制仍然糟糕被理解。这里,我们介绍了有希望的loci和候选人基因交谈忍耐给Zn缺乏并且通过协会分析识别了用一365?在多样的aus(半野的类型米饭)的K单个核苷酸多型性(SNP)标记数组面板。容忍的就职与相对稀罕的压力症状展出了更高的生长率。染色体上的二loci7和9强烈在一个山峰压力阶段在Zn缺乏下面与植物活力被联系。从一样的试验性的阴谋基于以前的microarray数据,我们加亮其表达式被重要遗传型或环境效果在Zn下面伴随的四候选人基因缺乏。网络基因本体论支持了已知的忍耐机制,例如维生素酸小径,并且也建议了光合作用基因的重要性克服Zn缺乏症状。

  • 标签: 锌缺乏 水稻 植物学 种植技术
  • 简介:TheAtomicWeaponsEstablishment(AWE)istaskedwithsupportingContinuousAtSeaDeterrence(CASD)bycertifyingtheperformanceandsafetyofthenationaldeterrentintheComprehensiveTestBanTreaty(CTBT)era.Thismeansthatrecoursetofurtherundergroundtestingisnotpossible,andcertificationmustbeachievedbysupplementingthehistoricaldatawiththeuseofcomputercalculation.Inordertofacilitatethis,AWEoperatessomeofthelargestsupercomputersintheUK.Tovalidatethecomputercodes,andindeedthedesignerswhoareusingthem,itisnecessarytocarryoutfurtherexperimentsintherightregimes.Anexcellentwaytomeetmanyoftherequirementsformaterialpropertydataandtoprovideconfidenceinthevalidityofthealgorithmsisthroughexperimentscarriedoutonhighpowerlaserfacilities.

  • 标签: HIGH energy density PHYSICS HEDP HIGH
  • 简介:Recentresearchactivitiesrelevanttohighenergydensityphysics(HEDP)drivenbytheheavyionbeamattheInstituteofModernPhysics,ChineseAcademyofSciencesarepresented.RadiographyofstaticobjectswiththefastextractedhighenergycarbonionbeamfromtheCoolingStorageRingisdiscussed.Investigationofthelowenergyheavyionbeamandplasmainteractionisreported.WithHEDPresearchasoneofthemaingoals,theprojectHIAF(HighIntensityheavy-ionAcceleratorFacility),proposedbytheInstituteofModernPhysicsasthe12thfive-year-planofChina,isintroduced.

  • 标签: heavy ION BEAM high energy density
  • 简介:高密度聚乙烯(HDPE)的薄墙样品经由注射塑造,不同注射速度从100mm/s到1200mm/s被准备。在张力的力量和幼仔模量的重要减少与增加注射速度被观察。为了在这后面调查机制,减少,取向,分子的重量,分子的重量分发,融化流动率,crystallinity和水晶HDPE的形态学用二维的宽角度的X光检查衍射(2D-WAXD)被描绘,胶化浸透层析(GPC),毛状的电流测定和微分扫描热量测定(DSC)分别地。这被表明取向,分子的重量,分子的重量分发,融化流动率和crystallinity没与增加有明显的变化注射速度。不过,扩大的链晶体的内容或大合拢的链晶体被发现与增加注射速度减少。因此,在张力的性质的减少被扩大的链晶体或大合拢的链晶体的减少的内容主要贡献,这被结束。这研究为高速度注射塑造的申请向工业提供珍贵信息。

  • 标签: 高密度聚乙烯 注射速度 注塑成型 拉伸性能 分子量分布 熔体流动速率
  • 简介:AnewtypeofSiO_2-MgO-CaO(SMC)whiskerwasusedtomodifyhighdensitypolyethylene(HDPE).Themeltingbehaviorandcrystallinitywereinvestigatedbydifferentialscanningcalorimetry(DSC).ThedispersionofwhiskersandinterfacialadhesioninthepreparedHDPE/SMCwhiskercompositeswereinvestigatedbyscanningelectronmicroscopy(SEM).Themechanicalpropertieswereevaluatedbymechanicaltestsanddynamicmechanicalanalysis(DMA).DSCdataindicatedthatthemeltingtemperatureandthecrystall...

  • 标签: SMC WHISKER POLYETHYLENE MECHANICAL properties.
  • 简介:Adetailedstudywasperformedonthecrystalstructuresofpan-milledhigh-densitypolyethylene(HDPE)usingdifferentialscanningcalorimetry(DSC)andX-raydiffraction.ThecrystallinityofHDPEfirstdecreasedslightly,followedbyagradualincreasewithincreasingmillingtimes.Monocliniccrystalsappearedafter4cyclesofmilling.Withincreasingtimesofmilling,theproportionofmonocliniccrystalsincreasedsignificantlywhiletheproportionoforthorhombiccrystalsdecreasedgradually.Withincreasingtimesofmilling,thecrystallitesizeoforthorhombicformdecreasedgreatly,whilethesizeofmonocliniccrystalliteskeptalmostconstantduringmilling.

  • 标签: HIGH-DENSITY POLYETHYLENE PAN-MILLING CRYSTAL structure
  • 简介:“开火的复合真空”和熄灭的水技术在LiFePO4的合成被介绍阴极粉末。样品被加热在真空石英试管封上的预先分解的先锋混合物准备,走水路在sintering温度熄灭跟随。结果显示使用“快熄灭”的处理能成功控制最后的产品的谷物尺寸的增生并且改进它活跃材料的利用比率。样品由这种技术综合了有高可逆的分泌物特定的能力和好周期的电气化学的性能。

  • 标签: 锂电池 阴极材料 淬火 LIFEPO4
  • 简介:Anenergyapproachisproposedtodescribetheelectromigrationinducedgrainrotationunderhighcurrentdensity.Thedrivingforceisassumedtoarisefromthegrain-boundaryenergyreductionandincreaseoftheinnerenergyfromthejouleheating.Energydissipatesbythegrainboundarydiffusionunderelectromigrationandviscousboundaryslidingisconsidered.Basedontheconservationofenergyproductionanddissipation,anequilibriumequationisdevelopedtopredictthegrainrotationrateanalytically.Itisrecognizedthatthegrainrotateswiththereducingofelectricalresistivityandinverselyproportionaltothegrainlength.Thetheoreticalpredictioniscomparedwiththeexperimentaldata,whichshowsgoodaccuracyontherotationtrendandthespecificrotationrate.

  • 标签: ELECTROMIGRATION GRAIN ROTATION ENERGY ANALYTICAL model
  • 简介:LatticeBoltzmannmethodisoneofthewidelyusedinmultiphasefluidflow.However,thetwomaindisadvantagesofthismethodaretheinstabilityofnumericalcalculationsduetothelargedensityratiooftwophasesandimpossibilityofthetemperaturedistributiontobefedbackintothevelocitydistributionfunctionwhenthetemperatureissimulated.BasedonthecombinationprescribedbyInamuro,thelargedensityratiotwo-phaseflowmodelandthermalmodelmakesthedensityratioofthemodelsimulationtobeincreasedto2778:1byoptimizingtheinterfacedistributionfunctionoftwo-phasewhichimprovestheaccuracyofdifferentialformat.Thephasetransitiontermisaddedassourcetermintothedistributionfunctioncontrollingtwophaseorderparameterstodescribethetemperatureeffectonthegas-liquidphasetransition.Thelatentheatgeneratedfromthephasechangeisalsoaddedasasourcetermintothetemperaturedistributionfunctionwhichsimulatesthemovementoftheflowunderthecommoncouplingofdensity,velocity,pressureandtemperature.Thedensityandthetemperaturedistributionofsinglebubblearesimulated.Comparisonofthesimulationresultswithexperimentalresultsindicatesagoodagreementpointingouttheeffectivenessoftheimprovedmodel.

  • 标签: LATTICE BOLTZMANN model Density RATIO Composite
  • 简介:Flowbatterieswithhighenergydensityandlongcyclelifehavebeenpursuedtoadvancetheprogressofenergystorageandgridapplication.Non-aqueousbatterieswithwidevoltagewindowsrepresentapromisingtechnologywithoutthelimitationofwaterelectrolysis,buttheysufferfromlowelectrolyteconcentrationandunsatisfactorybatteryperformance.Here,anon-aqueouslithiumbrominerechargeablebatteryisproposed,whichisbasedonBr2/Br-andLi+/Liasactiveredoxpairs,withfastredoxkineticsandgoodstability.TheLi/Brbatterycombinestheadvantagesofhighoutputvoltage(3.1V),electrolyteconcentration(3.0mol/L),maximumpowerdensity(29.1mW/cm2)andpracticalenergydensity(232.6Wh/kg).Additionally,thebatterydisplaysacolumbicefficiency(CE)of90.0%,avoltageefficiency(VE)of88.0%andanenergyefficiency(EE)of80.0%at1.0mA/cm2aftercontinuouslyrunningformorethan1000cycles,whichisbyfarthelongestcyclelifereportedfornon-aqueousflowbatteries.

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  • 简介:AnalgorithmforcomputationofcloudmotionwindshasbeendevelopedattheNationalSatelliteMeteorologicalCenterinChina.Since1997,ithasbeenappliedtocalculatethecloudmotionwindsfora1.25lat.×1.25long.meshoverthenorthwestPacificregionwiththesatellitedatafromGMS-5.Thedevelopmentofthetropicalcyclonesisstudied.Itshowsthatthetropicalcycloneisusuallyintriguedbythewesterlyjetstreamsattheupperlevelsofthetroposphere,whichmaybecausedbymid-latitudetroughswellextendingintothetropics.Duringtheprimeseasonofsummer,thewesterlyflowingequatorwardoftheTUTTmayalsobeacauseforthegenerationoftyphoons.

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  • 简介:Inthispaperwereviewthedesignanddevelopmentofa100J,10Hznanosecondpulsedlaser,codenamedDiPOLE100X,beingbuiltattheCentralLaserFacility(CLF).This1kWaveragepowerdiode-pumpedsolid-statelaser(DPSSL)isbasedonamasteroscillatorpoweramplifier(MOPA)design,whichincludestwocryogenicgascooledamplifierstagesbasedonDiPOLEmulti-slabceramicYb:YAGamplifiertechnologydevelopedattheCLF.Thelaserwillproducepulsesbetween2and15nsindurationwithprecise,arbitrarilyselectableshapes,atpulserepetitionratesupto10Hz,allowingreal-timeshapeoptimizationforcompressionexperiments.Oncecompleted,thelaserwillbedeliveredtotheEuropeanX-rayFreeElectronLaser(XFEL)facilityinGermanyasaUK-fundedcontributioninkind,whereitwillbeusedtostudyextremestatesofmatterattheHighEnergyDensity(HED)instrument.

  • 标签: cryogenic LASERS DIODE-PUMPED solid-state LASER high