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21 个结果
  • 简介:在这研究,为热带以外的气旋的修改鉴定和追踪的算法被开发。这个鉴定计划基于技术与一个连接部件的标记方法相结合以便检测外部边界和单个气旋的空间领域特征的三角形网孔的contouring。允许的一个新追踪方法气旋合并并且切开事件的鉴定,以及短命暴风,被开发在追踪热带以外的气旋减少无常。我也证明这个方法排除将不必要地用常规NCP方法被检测的开的系统的轨道。气旋频率的分发的climatological特征在与在以前的研究看见的那些相比的传统的暴风雨轨道区域上是实质地更大的。有趣地,在北极的气旋密度的重要增加发生在所有四个季节期间(多达19%在夏天)与与纬度经度gridded网孔分析看那相比。我基于气旋的领域开发二个新地区性的紧张索引(深度和涡度)更好确定在北极区域的气旋的活动,并且发现在这二个索引的interannual可变性是高度一致的。这分析的结果可以经由从这个cyclonic-domain-based算法导出的最新检测的2D气旋地图集使高纬度的气旋的行为研究清楚些。

  • 标签: 温带气旋 跟踪算法 识别 气候特征 北极地区 三角形网格
  • 简介:Aliquidmodifiedphotoniccrystalfiber(PCF)integratedwithanembeddeddirectionalcouplerandmulti-modeinterferometerisfabricatedbyinfiltratingthreeadjacentairholesoftheinnermostlayerwithstandard1.48refractiveindexliquids.Therefractiveindexofthefilledliquidishigherthanthatofbackgroundsilica,whichcannotonlysupportthetransmittingrodmodesbutalsothe'liquidmodifiedcore'modespropagatingbetweenthePCFcoreandtheliquidrods.Hence,thelightpropagatingintheliquidmodifiedcorecanbeefficientlycoupledintothesatellitewaveguidesunderthephase-matchingconditions,resultinginadramaticdecreaseoftheresonantwavelengthintensity.Furthermore,thereisamulti-modeinterferenceproducedbymodifiedcoremodesandrodmodes.Suchacompact(~0.91cm)deviceintegratedwithanembeddedcouplerandinterferometerisdemonstratedforhigh-sensitivitysimultaneoustemperature(~14.72nm∕℃)andstrain(~13.01pm∕με)measurement.

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  • 简介:Theeffectofnanoparticleaggregationonthethermalconductivityofnanocompositesornanofluidsistypicallynonnegligible.Auniversalmodel(Maxwellmodel)includingnanoparticleaggregationismodifiedinordertopredictthethermalconductivityofnanocompositesmoreaccurately.Thepredictedthermalconductivitiesofsilicaandtitaniananoparticlepowdersarecomparedfirstwiththatmeasuredbyahot-wiremethodandthenwiththoseinpreviousexperimentalworks.Theresultsshowthatthereisgoodagreementbetweenourmodelandexperiments,andthatnanoparticleaggregationinananocompositeenhancesthethermalconductivitygreatlyandshouldnotbeignored.Becauseitconsiderstheeffectofaggregation,ourmodelisexpectedtoyieldprecisepredictionsofthethermalconductivityofcomposites.

  • 标签: 纳米复合材料 通用模型 聚集作用 热导率 复合纳米粒子 二氧化钛纳米粉
  • 简介:Amodifiedsuctioncaisson(MSC),whichwasreportedbytheauthorsofthispaperpreviously,comprisesanexternalshort-skirtedstructurethatisaddedtoaregularsuctioncaisson(RSC).IthasbeenprovedthatMSCscanimprovethelateralbearingcapacityandlimitthedeflectionofthecaissoncomparedwithRSCs.AseriesofmodeltestswereconductedtoinvestigateresponsesofMSCssubjecttoupliftloadinginsaturatedsand.TheeffectsofexternalskirtdimensionsontheupliftbearingcapacityofMSCswereconsidered.Inaddition,theinfluencesofthesealedtoplidoftheskirtedstructureontheupliftbearingcapacityandtheresultingpassivesuctionofMSCswerealsostudied.ItwasfoundthattheupliftbearingcapacitiesofMSCsare1.4-1.7timesthatofRSCs.Moreover,testresultsinserviceableconditionsshowthatthesealedexternalskirtedstructureofperspex-madesuctioncaissonssignificantlycontributedtotheupliftbearingcapacityasaresultofpassivesuction.

  • 标签: OFFSHORE wind turbine MODIFIED SUCTION CAISSON
  • 简介:Biocharisapotentialcarrierfornutrientsduetoitsporousnatureandabundantfunctionalgroups.However,rawbiocharhasalimitedorevennegativecapacitytoadsorbphosphate.Toenhancephosphateremovalandreducephosphatereleases,acidic,alkaline,andsurfactantpretreatments,followedbygranulationandferricoxideloading,wereappliedtorawbiocharpowder(Bp).Thealkalinepretreatmentprovedtobethemosteffectivemethodandexhibitedsignificantporeexpansionandsurfaceoxidation.Bg-OH-FOshowedthehighestphosphateremovalefficiencyat99.2%(initialphosphateconcentrationof20mg/L)aftergranulationandferricoxideloading.StaticadsorptionresultsindicatedthatapHvalueof4wasthemostsuitableforphosphateadsorptionbecauseofthesurfacepropertiesofBg-OH-FOandthedistributionofP(V)inwater.Highertemperaturesandalargerinitialphosphateconcentrationledtobetteradsorption;theadsorptioncapacityofBg-OH-FOwas1.91mg/gat313Kwithaninitialphosphateconcentrationof50mg/L.TheBg-OH-FOadsorptionprocesswasendothermicinnature.TheFreundlichmodelseemedtobetheoptimumisothermmodelforBg-OH-FO.Undercontinuousadsorption,theflowrateandbeddepthwerechangedtooptimizetheoperationconditions.Theresultsindicatethataslowflowrateandhighbeddepthhelpedincreasetheremovalefficiency(g)ofthefixedbed.ThebreakthroughcurvesfittedwellwiththeYoonNelsonmodel.

  • 标签: BIOCHAR PHOSPHATE Modification Ferric oxide STATIC
  • 简介:Inearthquakeproneareas,understandingoftheseismicpassiveearthresistanceisveryimportantforthedesignofdifferentgeotechnicalearthretainingstructures.Inthisstudy,thelimitequilibriummethodisusedforestimationofcriticalseismicpassiveearthresistanceforaninclinedwallsupportinghorizontalcohesionlessbackfill.Acompositefailuresurfaceisconsideredinthepresentanalysis.Seismicforcesarecomputedassumingthebackfillsoilasaviscoelasticmaterialoverlyingarigidstratumandtherigidstratumissubjectedtoaharmonicshaking.Thepresentmethodsatisfiestheboundaryconditions.Theamplificationofaccelerationdependsonthepropertiesofthebackfillsoilandonthecharacteristicsoftheinputmotion.Theaccelerationdistributionalongthedepthofthebackfillisfoundtobenonlinearinnature.Thepresentstudyshowsthatthehorizontalandverticalaccelerationdistributioninthebackfillsoilisnotalwaysin-phaseforthecriticalvalueoftheseismicpassiveearthpressurecoefficient.Theeffectofdifferentparametersontheseismicpassiveearthpressureisstudiedindetail.Acomparisonofthepresentmethodwithothertheoriesisalsopresented,whichshowsthemeritsofthepresentstudy.

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  • 简介:Byusingthebimodalmesoporoussilica(BMMS)asthecarrierandbutyltitanateasthetitaniumsource,theTiO2/BMMScatalystwasprepared.ThesampleswerecharacterizedbyXRD,XRF,N2adsorptionanddesorption,FTIR,UVvis,SEM,EDS,andTEMtechniques.ThetestresultsshowedthatTiO2wasamorphous,theTiO2/BMMScatalysthadanorderedbimodalmesoporousstructure,andthechemicalinteractionexistedbetweenBMMSandTiO2.SincetheTiO2/BMMShadalowerbandgap,itsphotocatalyticactivitywasbetterthanTiO2.UnderUVirradiationaone-potPODSsystemwassetup,usingTiO2/BMMSasthecatalyst,H2O2astheoxidant,andmethanolasthesolvent.TheTiO2/BMMScatalystshowedbetterphotocatalyticactivitythanthemono-modalmesoporousTiO2/SBA-15catalyst,andthedesulfurizationrateofdibenzothiophene(DBT)overTiO2/BMMScatalystcouldreach99.2%.TheTiO2/BMMScatalystalsohadsogoodstabilitythatthedesulfurizationrateofDBTdidnotdropapparentlyafter8cyclesofreusing,andcouldstillbecloseto90%.

  • 标签: BIMODAL MESOPOROUS silica amorphous TIO2 PHOTOCATALYTIC
  • 简介:在现代数据中心,网络消费的电源是全部的精力预算并且这样的看得见的部分改进数据中心网络(DCN)的精力效率真正有关系。为这精力效率的一个有效方法是由流动巩固与交通要求一起使DCN的尺寸有弹性,关掉减少电源消费的不必要的网络部件并且安排的带宽,即。同时,为数据中心管理有本能支持,软件定义联网(SDN)提供一个范例有弹性地控制DCN的资源。完成如此的电源积蓄,大多数优先的努力就采用简单贪婪对还原剂启发式计算复杂性。由于贪婪算法的固有的问题,然而,好足够的优化不能总是被保证。处理这个问题,一个修改混合基因算法(MHGA)被采用改善答案精确性,和SDN的有细密纹理的路由功能充分被利用。模拟结果证明更有效的电源管理能比以前的研究被完成,由增加大约5%网络精力积蓄。

  • 标签: 数据中心网络 精力效率 软件定义联网 有弹性的拓扑学 基因算法
  • 简介:Flyashfloatingbead(FAFB)wasmodifiedbythenonionicsurfactantpolyethyleneglycol(PEG)undervariousconcentrationstoimproveitshydrophobility,andthenPEGmodifiedFAFBcompositedwithpolyaniline(FAFB-PEG/PAn)byemulsionpolymerizationmethodusingdifferentfeedratiosofFAFBPEG.Thechemicalstructure,phasestructure,microstructure,conductivity,anddielectricpropertieswerestudiedbyFT-IR,XRD,SEM,four-probetechnique,andLCRdigitalbridge,respectively.ItwasdemonstratedthattheoptimalconcentrationofPEGwas1mol/Landthecorrespondinggraftingratiowas1.42%.ThephasestructureofFAFBwasnotdestroyedaftermodificationbyPEG,whilethesurfacebecamesmootherandcouldbecoatedbyPAnsuccessfullyaccordingtoSEMtechnique.ComparedtothatofdodecylbenzenesulfonicaciddopedPAn(PAn-DBSA),theconductivityofFAFB-PEG/PAnwasdecreasedby10-100timesafterintroductionofvariousamountsofFAFB-PEG,especiallythevaluecouldbedecreasedto0.01Scm~(-1)if50wt%ofFAFBPEGwasprovided.Additionally,thedielectricconstantandlossfactorofFAFB-PEG/PAncompositesgraduallydecreasedwithincreasingamountofFAFB-PEGinthefrequencyrangeof100KHz-2MHz,namely,thedielectricconstantcouldbestillkeptat500andcorrespondinglythelossfactordecreasedto4.7at100KHzif50wt%ofFAFB-PEGwasprovided.TheleakingcurrentphenomenonderivedfromPAn-DBSAcouldalsobeweakenedbyFAFB-PEG.

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  • 简介:在这研究,老化和很多橡胶材料和橡胶轴承的海洋的腐蚀测试被执行了。为橡胶的组成的Mooney-Rivlin模型参数孤立适用被决定了。由把最少平方的方法用于试验性的数据,在有在为适用的橡胶的组成的模型的常数的变老的时间和海洋的腐蚀时间之间的关系被导出。下次,Mooney-Rivlin模型因此被修改了。进一步,使用修改Mooney-Rivlin模型和Abaqus软件,橡胶的性能孤立轴承被模仿了。模拟结果与试验性的结果相比以便验证修改模型的精确性。比较证明为垂直、水平的僵硬的最大的错误分别地是16.8%和0.49%。因为这些错误被认为可接受,修改组成的模型的精确性能被认为验证。这研究的结果能提供理论支持因为橡胶上的表演学习在复杂海洋环境和桥和其它的生命周期表演评估下面孤立轴承近海结构。

  • 标签: 孤立的橡胶适用 海洋的腐蚀 老化 Mooney-Rivlin 模型 有限元素分析
  • 简介:Carbondioxide(CO2)captureusingmagnesiumoxide(MgO)-basedadsorbentsatintermediatetemperatureshasbeenregardedasaveryprospectivetechnologyfortheirrelativelyhighadsorptioncapacity,lowcost,andwideavailability.Duringthepastfewyears,greatefforthasbeendevotedtothefabricationofmoltensalts-modifiedMgO-basedadsorbents.TheextraordinaryprogressachievedbycoatingwithmoltensaltsgreatlypromotestheCO2capturecapacityofMgO-basedadsorbents.Therefore,wefeelitnecessarytodeliveratimelyreviewonthistypeofCO2capturingmaterials,whichwillbenefittheresearchersworkinginbothacademicandindustrialareas.Inthiswork,weclassifiedthemoltensaltsmodifiedMgOadsorbentsintofourcategories:(1)homogenousmoltensalt-modifiedMgOadsorbents,(2)moltensalt-modifieddoublesalts-basedMgOadsorbents,(3)mixedmoltensalts-modifiedMgOadsorbents,and(4)moltensalts-modifiedMgO-basedmixedoxidesadsorbents.Thiscontributioncriticallyreviewstherecentdevelopmentsinthesyntheticmethod,adsorptioncapacity,reactionkinetics,promotionmechanism,operationalconditionsandregenerabilityofthemoltensalts-modifiedMgOCO2adsorbents.Thechallengesandprospectsinthispromisingfieldofmoltensalts-modifiedMgOCO2adsorbentsinrealapplicationsarealsobrieflymentioned.

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  • 简介:提高的不一致的合理B花键(NURBS)放大了边界在有修改精确集成方法的联合的有限元素方法在这份报纸为短暂的热传导问题被建议。放大边界有限元素方法是一种半分析的技术,它削弱管理沿着环绕的方向的微分方程并且在光线的方向解决那些经分解。在这个方法,仅仅边界是在没有要求的基本答案在一个导致空间尺寸的减小的有限元素意义的discretized。但在复杂几何学的情况下,元素的一个巨大的数字通常被要求适当地接近,领域和弄歪的网孔的准确形状在常规有限元素途径经常是不可避免的,它导致精确性的巨大的计算努力和损失。NURBS由于它的灵活性是在CAD工业的最流行的数学工具适合任何自由形态的形状。在建议方法论,问题领域的任意的弄弯的边界确切与NURBS基础函数被代表,当边界的直部分是由常规Lagrange形状函数的discretized时。两isogeometric分析和放大边界的概念有限元素方法被联合形成短暂的热传导分析的管理方程,答案用修改精确集成方法被获得。僵硬矩阵从一个标准二次的特征值问题被获得,集体矩阵从低频率的扩大是坚定的。最后,管理方程成为一阶的平常的微分方程的一个系统,时间域反应被修改精确集成方法数字地解决。建议方法的精确性和稳定性被数字例子表明处理短暂的热传导问题。

  • 标签: 短暂的热传导分析 放大边界有限元素方法 NURBS Isogeometric 分析 修改精确集成方法
  • 简介:Theefficiencyofphoto-electrocatalytic(PECa)devicesfortheproductionofsolarfuelsdependsonseverallimitingfactorssuchaslightharvesting,chargerecombinationandmasstransportdiffusion.WeanalyseherehowtheyinfluencetheperformancesinPECacellshavingaphoto-anodebasedonAu-modifiedTiO2nanotube(TNT)arrays,withtheaimofdevelopingdesigncriteriatooptimizethephoto-anodeandthePECacellconfigurationforwaterphoto-electrolysis(splitting)andethanolphoto-reformingprocesses.TheTNTsampleswerepreparedbycontrolledanodicoxidationofTifoilsandthendecoratedwithgoldnanoparticlesusingdifferenttechniquestoenhancethevisiblelightresponsethroughheterojunctionandplasmoniceffects.Theactivitytestsweremadeinagas-phasereactor,aswellasinaPECacellwithoutappliedbias.Resultswereanalysedintermsofphoto-generatedcurrent,H2productionrateandphotoconversionefficiency.Particularly,asolar-to-hydrogenefficiencyof0.83%andaFaradaicefficiencyof91%wereobtainedwithoutaddingsacrificialreagents.

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  • 简介:MonophasicCe~(3+)andPr~(3+)co-dopedyttriumaluminumgarnet(YAG:Ce~(3+),Pr~(3+))nanoparticleswithgooddispersityanduniformgrainsizesintherangeof50–80nmwerepreparedbyatwo-steproute,whichconsistedofamodifiedco-precipitationpreparationofmixedmetalhydroxidehydrateintermediatesatlowtemperatureofabout40oCandasubsequentcalcinationconversionofthesynthesizedintermediatestocrystallinenanoparticleproductsatabout1000oC.Theinfluencesofboththelanthanideion(Ce~(3+)andPr~(3+))dopingconcentrationanddifferentdoping(Ce~(3+)/Pr~(3+))ratioonthephotoluminescenceintensityweresystematicallyinvestigated.Thesynthesized(Ce_(0.6)Pr_(0.4))_(0.04)Y_(2.96)Al_5O_(12)nanoparticleswerenearsphericalnanoclusterswithgooddispersityanduniformsizesintherangeof50–80nmforabout85%oftheparticles.Thestrongestphotoluminescenceintensitywasobservedforthe(Ce_(0.6)Pr_(0.4))_(0.04)Y_(2.96)Al_5O_(12)nanoparticleproducts.

  • 标签: 纳米颗粒 发光特性 共沉淀法 YAG 合成 荧光粉