简介：沿试验段侧壁发展的附面层是影响飞行器半模型实验数据精准度的主要因素之一．利用数值模拟方法验证了涡流发生器减小附面层影响的可行性，重点分析了安装角度、结构尺寸、安装位置及个数等设计参数对附面层内速度分布的影响规律，对涡流发生器尾涡强度以及沿流向的发展规律进行了初步探讨．结果表明，涡流发生器产生的尾涡能够有效改善附面层内的速度分布，进而减小附面层厚度，降低附面层影响；涡流发生器的后缘应略高于当地附面层厚度，安装角度、位置、个数等参数必须合理设计以减小涡流发生器对试验段主气流的影响．基于计算结果初步设计了可用于2．4m跨声速风洞半模试验段的涡流发生器，在亚声速范围内能够减小模型区侧壁附面层厚度66％左右，对核心流Mach数影响小于0．003，为涡流发生器的实际应用提供了依据．

简介：基于各向异性非结构网格生成技术，开发了面向复杂几何和复杂湍流燃烧问题的自适应求解算法，并进行了程序代码的可靠性验证工作，展示了各向异性网格自适应算法在降低问题求解规模、提高火焰面和流场计算精度等方面的优势．应用该自适应求解技术准确捕捉到了一维预混层流火焰、二维对冲火焰和三维本生灯湍流火焰的流场信息，火焰面附近的温度、速度、组分等物理量与实验值吻合很好．对一款富油-快速混合-贫油（rich—bum，quick-mix，lean-burn，RQL）低排放发动机燃烧室进行了计算分析，发现了燃烧室内的热声不稳定现象．

简介：Thereisaneedtostandardizemethodsassociatedwiththedispersionofnanomaterialsinnano（eco）toxicologicalinvestigations.Thefirststeptowardthisgoalistounderstandthedegreeofvariabilitythatexistsinnanomaterialdispersionspreparedbyusingdifferentprotocols.Usingtwocasestudies,thedegreeofvariabilityinTiO2nanomaterialdispersionswasassessedbydifferentialcentrifugalsedimentation（DCS）methods.Casestudy1addressesthevariabilitythatarisesfromvariationswithinoneprotocol,investigatingtheeffectsofdispersionaging,sonicationexposuretime,sonicationinthepresence/absenceofanicebath,materialsubsampling,particleconcentrationandhavingapre-wettingstep.Casestudy2addressesthevariabilitybetweenfourdifferentprotocolsdevelopedthroughpastresearchactivitiesandprojects.Theresultsindicatethatthereisalargedegreeofvariability（relativestandarddeviation（RSD）ofmeanparticlediameter=26%）inthedispersionofTiO2nanomaterialsbetweenthefourdifferentprotocolsstudiedandthatseveralstepsinadispersionprotocolarepotentialsourcesofvariation,withfinalparticleconcentrationbeingthemostsignificant.Theimplicationofthisstudyisclear:forthepurposeofdatacomparability,thereisaneedtoprovidetheexactdetailsofallstepsinvolvedinadispersionprotocol.

简介：为nanostructuredSnO2的先锋在不同条件下面经由一个帮助微波的热水的方法被综合，用SnCl2吗？

简介：Laminatedcompositematerialsarewidelyimplementedinseveralengineeringconstructions.Foritsrelativelightweight,thesematerialsaresuitableforaerospace,military,marine,andautomotivestructuralapplications.Toobtainsafeandeconomicalstructures,themodellinganalysisaccuracyishighlyrelevant.Sincemeshlessmethodsintherecentyearsachievedaremarkableprogressincomputationalmechanics,thepresentworkusesoneofthemostflexibleandstableinterpolationmeshlesstechniqueavailableintheliterature—theRadialPointInterpolationMethod(RPIM).Here,a2Dapproachisconsideredtonumericallyanalysecompositelaminatedbeams.Boththemeshlessformulationandtheequilibriumequationsrulingthestudiedphysicalphenomenonarepresentedwithdetail.Severalbenchmarkbeamexamplesarestudiedandtheresultsarecomparedwithexactsolutionsavailableintheliteratureandtheresultsobtainedfromacommercialfiniteelementsoftware.Theresultsshowtheefficiencyandaccuracyoftheproposednumerictechnique.

简介：在组成的部件之间的有瑕疵的结合能极大地影响合成结构的性质。处于2Dfibrereinforced的问题产生的有瑕疵的接口的不同类型的asymptotic分析合成材料被建议。执行学习基于管理biharmonic问题的asymptotic减小进二个泛音问题。所有答案在一种关上的分析形式被获得。获得的结果能被用于撤退和pushout测试的计算，以及为合成材料的破裂的调查。

简介：ThecaptureoforthophosphatesandtotalphosphorusfromthePudongCanalriverinthePudongDistrictofShanghaibyTiO2nanoparticlesisstudiedusingarotatingphotoreactorandthenano-TiO2photocatalystDegussaP25.TheeffectsofUVirradiationintensityinarangeof20-74mW/cm2.theloadingoftheTiO2nanoparticlesinarangeof0.05-0.1g/L,irradiationtimeupto4h,andpHvaluesinarangeof2-10.5onthecaptureefficiencyareinvestigated.TheresultsshowthatthecaptureoforthophosphatesandtotalParesignificantlyenhancedbyUVirradiation;ataloadingof0.1g/Landanirradiationintensityabove36mW/cm2,orthophosphatesandtotalphosphorusarerapidlycapturedbyTiO2nanoparticles,causinganobservedreductionfrom0.4mg/Ldownto0.02mg/L.pHvaluesinarangeof2-10.5havelittleeffectonthecaptureefficiencyoforthophosphatesandtotalphosphorus.

简介：Hierarchicalsea-urchin-shapedmanganeseoxidemicrospheresweresynthesizedviaatacilemetnoabasedonthereactionbetweenKMnO4andMnSO4inHNO3solutionat50C.Theaveragediameterofthemicrospheresis850nm.Themicrospheresconsistofacoreofdiameterof800nmandnanorodsofwidth50nm.Thenanorodsexistattheedgeofthecore.TheBrunauer-Emmett-Tellersurfaceareaofthesea-urchin-shapedmicrospheresis259.4m2/g.Apossibleformationmechanismofthehierarchicalsea-urchin-shapedmicrospheresisproposed.Thetemperaturefor90%conversionofbenzene(T90%)onthehierarchicalurchin-shapedMnO2microspheresisabout218℃.

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简介：ZrO2nanopowdersbasedstearicacidphasechangematerials(PCMs)werepreparedbyhigh-energymilling.Theconceptofheatcapacityfactor(HCF)wasusedtoanalyzethethermalpropertiesofthematerials.TheheatstoragepropertyofPCMs,containingthesamecontentofstearicacid(23%bymass)inthestartingmaterialsbutsynthesizedbydifferenttechnicalprocesses,wasinvestigatedbyusingHCF.Itwasfoundthattherewerevastinfluencesofdifferentdispersantsontheheatcapacity.Thesamplespreparedwithchloroformprovidedthebestheatstorageabilityinallsamplestested.

简介：Anewmicromechanicsconstitutivemodelforpuredilatanttransformationplasticityofstructureceramicsisproposedinthispaper.Basedonthethermodynamics,micromechanicsandmicroscalet→mtrans-formationmechanismanalysisoftheTZPandPSZZrO2-containingceramics,ananalyticexpressionsoftheHelmholtzandcomplementaryfreeenergyoftheconstitutiveelementforthecaseofpuredilatanttransforma-tionisderivedforthefirsttimeinaself-consistentmanner.Bytheanalysisofenergydissipationinthefor-wardandreversetransformations,themieromechanicsconstitutivelawisderivedintheframeworkofHill-Rice’sinternalvariableconstitutivetheory.

简介：Afacilemethodforthesynthesisofsilver-silica（Ag-SiO2）Janusparticleswithfunctionalitiessuitablefortextileapplicationsisreported.SilicananoparticlespreparedbytheStobermethodwerefunctionalizedwithepoxy,amine,andthiolgroups,whichwereconfirmedbyFouriertransforminfraredanalysis.ThefunctionalizedsilicananoparticleswereusedtoproducePickeringemulsions,andtheexposedsurfacewasusedfortheattachmentofsilvernanoparticles（AgNPs）viathelow-temperaturechemicalreductionmethod.ThemorphologyandstructureoftheAg-SiO2Janusparticleswerecharacterizedbyscanningelectronmicroscopy,scanningtransmissionelectronmicroscopy,high-resolutiontransmissionelectronmicroscopy,energy-dispersiveX-rayanalysis,andUV-visspectroscopy.Becauseoftheirspecificfunctionalities,theseAg-SiO2Janusparticlesareproposedforapplicationsontextilesubstrates,astheycanovercomeseveraldrawbacksofdirectapplicationofAgNPsontextiles,suchasleaching,agglomeration,andinstabilityduringstorage.

简介：Thispaperpresentsanovelmechanicalattachment,i.e.,nonlinearenergysink(NES),forsuppressingthelimitcycleoscillation(LCO)ofanairfoil.Thedynamicresponsesofatwo-degree-of-freedom(2-DOF)airfoilcoupledwithanNESarestudiedwiththeharmonicbalancemethod.DiferentstructureparametersoftheNES,i.e.,massratiobetweentheNESandairfoil,NESofset,NESdamping,andnonlinearstifnessintheNES,arechosenforstudyingtheefectoftheLCOsuppressiononanaeroelasticsystemwithasupercriticalHopfbifurcationorsubcriticalHopfbifurcation,respectively.TheresultsshowthatthestructuralparametersoftheNEShavediferentinfluenceonthesupercriticalHopfbifurcationsystemandthesubcriticalHopfbifurcationsystem.

简介：为它的高氧化抵抗，钇硅酸盐是为在在1600°C上面的温度的carbon-fiber-reinforcedcomposites的保护的涂层的一个重要候选人。一个新奇方法，由一起沉淀组成，弄干水花，热处理和plasma-densification，被开发准备Y2SiO5粉末为热喷洒。作文，形态学和综合Y2SiO5粉末的流动能力被XRD，SEM和霍尔流量计分别地调查。结果证明综合Y2SiO5粉末与高纯净是将近球形的。分别地，Y2SiO5粉末的明显的密度和流动能力是1.87g/cm3和37s/50g它为大气的血浆喷洒导致多达80%的高免职效率。

简介：Aunifiedperturbationtheoryisdevelopedhereforcalculatingsolitarywavesofallheightsbyseriesexpansionofbaseflowvariablesinpowersofasmallbaseparametertoeighteenthorderfortheone-parameterfamilyofsolutionsinexactform,withallthecoefficientsdeterminedinrationalnumbers.Comparativestudiesarepursuedtoinvestigatetheeffectsduetochangesofbaseparameterson(i)theaccuracyofthetheoreticallypredictedwavepropertiesand(ii)therateofconvergenceofperturbationexpansion.Twoimportantresultsarefoundbycomparisonsbetweenthetheoreticalpredictionsbasedonasetofparametersseparatelyadoptedforexpansioninturn.First,theaccuracyandtheconvergenceoftheperturbationexpansions,appraisedversustheexactsolutionprovidedbyanearlierpaper[1]asthestandardreference,arefoundtodepend,quitesensitively,onchangesinbaseparameter.Theresultingvariationsinthesolutionarephysicallydisplayedinvariouswavepropertieswithdifferencesfounddependentonwhichproperty(e.g.thewaveamplitude,speed,itsprofile,excessmass,momentum,andenergy),onwhatrangeinvalueofthebase,andontherankoftheordernintheexpansionbeingaddressed.Secondly,regardingconvergence,thepresentperturbationseriesisfounddefinitelyasymptoticinnature,withtherelativeerrorδ(n)(therelativemean-squaredifferencebetweensuccessiveordersnofwaveelevations)reachingaminimum,δm,ataspecificorder,n=nm,bothdependingonthebaseadopted,e.g.n=11-12basedonparameterα(waveamplitude),nm,β=15onβ(amplitude-speedsquareratio),andnm.∈=17on∈(wavenumbersquared).Theasymptoticrangeisbroughttocompletionbythehighestorderofn=18reachedinthiswork.

简介：Nano-sizedhexagonalmagnesiumhydroxide（Mg（OH）2）withgooddispersibilitywassynthesizedbyadoubleinjection-hydrothermalmethod,utilizingpolyvinylpyrrolidone（PVP）asanadditiveandwithoptimizedprocessingparameters.SEMandBETanalysisshowedthatthemeanparticlesizeandspecificsurfaceareaoftheMg（OH）2particleswere174nmand50.77m2/g,respectively.TheFT-IRspectraandtheXRDpatternsshowedthatPVPwasadsorbedonthesurfaceoftheMg（OH）2crystal,thuseffectivelylimitingparticleagglomerationandhinderingcrystalgrowthalongthe（101）plane.TGAshowedadecreaseinthedecompositiontemperatureandanincreaseintheweightlossoftheMg（OH）2particlesduetoadditionofPVP.

简介：从理论上推导了声学超表面对平面声波的作用模型,该理论模型计及声波高阶衍射模态,从而能够计及超表面微结构之间的声学干扰.通过与数值结果对比,该模型预测的反射频率精度得到了一定程度的提高,并能够分辨出相邻孔声场之间的耦合模态.讨论了声学超表面吸声特性与阻抗特性对高超声速边界层内Mack第2模态的抑制机理,研究发现通过设计超表面阻抗特性,使得入射声波与反射声波在壁面处相位相反,同样可以抑制Mack第2模态.基于理论模型,分别优化设计得到最优的微结构几何尺寸,并通过对Mach6平板边界层流动进行稳定性分析,验证了超表面不同声学特性的抑制效果.

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简介：采用三维CFD黏性模拟考察涡发生器对高超声速轴对称进气道外部流动的影响.针对前缘钝化半径0.8mm和3.2mm的轴对称进气道外部流场,以涡发生器高度与当地位移边界层厚度比值为影响参数,考察流场结构与性能参数的影响规律.结果表明,涡发生器产生的干扰波系使得前缘激波向外偏移,下游近壁面流动与主流区出现明显的交换,下游流动出现明显的展向非均匀性.涡发生器对流动的影响沿流向逐渐减弱.在气流压缩性能方面,涡发生器下游压比、动压比沿流向开始增大,随后逐渐恢复到无涡发生器工况;Mach数、总压恢复系数开始降低,随后逐渐向无涡发生器工况趋近.涡发生器高度与当地位移边界层厚度的比值h可作为衡量其影响的重要参数.当h≤1.5时,进气道流场结构、性能参数的变化几乎可忽略,h≤3.0时进气道入口处性能参数几乎能够恢复到无涡发生器工况.

简介：W，N共同做TiO2nanoparticles被一个solgel方法综合。准备样品被X光检查衍射(XRD)描绘，域排放扫描电子显微镜学(FE-SEM)，传播电子显微镜学(TEM)，Fourier变换红外线的光谱学(英尺红外)，X光检查光电子光谱学(XPS)和弥漫的反射spectrophotometry(医生)。结果证明共同做的光催化剂是有22.5nm的最小的粒子尺寸的实质上一致的球形的粒子。比作未做的TiO2，N-TiO2和P-25，W的吸收边，N共同做转移到更长的波长的TiO2和它为在Xe灯(350W)下面的甲基橘子(瞬间)的降级的photocatalytic活动更高。