简介:Theheattransferfromanelectricallyheatedcylinder(wire)offinitelengthtothesurroundingfluidcanbedividedintoheatradiation,conductionandconvection.Atechnicalapplicationofthesecylinderswithtypicaldimensionsof1-2mmlengthandafewmicrometersdiameteristheHot-Wire-Anemometry.Thissystematicstudyshouldclarifytheinfluenceoffreeconvectiontothreedimensionalheattransferofcylinders.forthisaimitisplannedtoinvestigateReynoldsnumbersbelowRe=1(creepingflow).Forthisreasonmeasurementsshouldbedoneunder1gintheearthlaboratoryandalsoundermicrogravity(μg)conditions.Comparisonsofthesemeasurementsunderotherwisesameconditionsallowstodistinguishbetweenthepureconvectionheattransferandthecontributionsduetoconductionandothereffects.FormeasurementsunderμgtheDropTowerBremencanbeusedasresearchfacility.DuetothefastresponseofconvectiontochangesinthegravityconditionstheDropTowerisanidealandcostefficientexperimentaltool.Theexperimentalsetupisbuildtooperateatvelocityrangeof0-1m/swhichincludesthewholerangeofconvectionfrompurefreeconvectionat0m/sovermixedconvectionuptopureforcedconvectionatvelocitiesaboveabout0.15m/s.ThisvelocityregioncorrespondstoarangeoftheReynoldsnumberofRe=0-0.18foracylinderof5μmdiameteratTf=140℃inairatanambienttemperatureofabout21℃.
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简介:Thedynamiccharacteristicsofthelargescalecoherentstructuresinaforcedfreeshearlayerareexperi-mentallystudiedbymeansofflowvisualization.ThequantitativemeasurementsareacquiredbytheuseofaLDV.Itisshownthatthedevelopmentofthecoherentstructurescanbegreatlyinfluencedbyupstreamartificialperturbationsandasaresultthemixinginthelayercanbecontrolled.Likevortexmerging,vortexsplittingisalsoacommonevolu-tionpatterninthedevelopmentofthecoherentstructures.
简介:没有羡慕的定价问题能作为发现每个消费者在被分配的一个定价和分配计划在定价下面最大化其用途的一套项目被说。目标是最大化卖主收入。我们与作为在项目上定义的一个独立系统被给的一般供应限制学习这个问题。例如,限制能是很多线性限制或matroids。这捕获项目不在资源的限制下面在项目的消费者估价的思考先存在,但是被生产的状况。这份报纸集中于单位要求消费者的盒子。在背景,有n消费者和m项目;每个项目可以在多重拷贝被生产。每消费者i[n]在他/她感兴趣的集合S对i在条款j上有估价vij。他/她必须被分配(如果任何)给最大值的一个项目(非否定)用途。假定我们为发现最大的重量独立人士为给定的独立系统设定被给近似神谕(或稍微更强壮的神谕);为很多自然、有趣的供应限制,经常的近似算法是可得到的。我们获得下列结果。1)O(木头n)为一般盒子的近似。2)O(k)近似每个消费者什么时候至多对感兴趣k项目的不同类型。3)O(f)近似条款的每种类型什么时候至多对有趣f消费者。笔记期末考试甚至没有独立系统限制,二结果以前是未知的。
简介:AccordingtoXinhuaNet,startingfrom2011,InnerMongoliaAutonomousRegionwillprovidefreeeducationandtextbookstoallthestudentsstudyingingeneralMongoliansecondaryschoolsandsecondaryvocationalschools,andfinanciallydisadvantagedstudentswhoarelearningingeneralChinesesecondaryschools.By2013,thepracticeswillcoverallsecondaryschoolstudentsinalldistricts,sofreeeducationfor
简介:Fluorineinmoldpowderisknownasharmfultohumanhealthandtheenvironment.Beingtheadvocateofgreenproduction,Baosteeldevelopedanenvironmentallyfriendlymoldpowderwithoutfluorine.Themainproblemoffluorine-freefluxfilmissmallheatresistanceandthustheheattransferintensityofthemoldistoolarge,whichtosomeextenthinderstheincreaseofthecastingspeed.Withtheheatflowsimulationequipment,controllingprecipitationofcrystalinfluxandsolidificationtemperatureproperly,fluorine-freemoldpowderforlowcarbonsteel,whichsubstitutesFwithB2O3,wassuccessfullydevelopedandappliedinindustrialproduction.Theproductionresultsshowthat,byusingboronicfluorine-freemoldpowder,theboronincrementinmoltensteelislessthan1.3ppmforconventionalaluminiumkilledlowcarbonsteel.
简介:ThispaperprovidesareviewonsampleinjectorswhichareprovidedatSPring-8AngstromCompactfreeelectronLAser(SACLA)forconductingserialmeasurementina‘diffract-before-destroy'schemeusinganx-rayfreeelectronlaser(XFEL).VersatileexperimentalplatformsatSACLAareabletoacceptvarioustypesofinjectors,amongwhichliquidjet,dropletandviscouscarrierinjectorsarefrequentlyutilized.Theseinjectorsproducedifferentformsoffluidtargetssuchasaliquidfilamentwithadiameterintheorderofmicrometer,micro-dropletsynchronizedtoXFELpulses,andslowlyflowingcolumnofhighlyviscousfluidwitharatebelow1μLmin-1.Characteristicsandapplicationsoftheinjectorsaredescribed.
简介:ThispaperdealswiththeapproximatesolutionoftheFredholmequationLu=fofthesecondkindwithf∈H’(Γ).First,wegivetheorderofthen-theoptimalradiusintheworstcasesetting.Then,weshowthattheGalerkinmethodusing2n+1innerproductsoffhasminimalerror.Finally,wegivetheestimateoftheε-complexityoftheFredholmproblemofthesecondkindandGalerkinmethodintheworstcasesetting.
简介:Araucariaangustifolia(Bertol.)O.Kuntzeexhibitsdimorphisminitsstemstructure,wherethetrunkisorthotropicandbranchesandbranchlets(primaryandsecondarybranches)areplagiotropic.Thesestemsexhibitdifferentbehaviorwhenusedforvegetativepropagation,andonlysegmentsoftrunkcanformacompleteplant.Thephysiologicalandbiochemicalmechanismsthatcharacterizethesestemsarestilllittleknown.Theaimofthisstudywastodescribethefreeaminoacidprofilesintrunks,branches,andbranchletsofA.angustifolia.Segmentsof5cminlengthwereexcisedfromyoungindividualsbelowthestemapex.Theneedleswereremovedandsampleswerefrozenandlyophilized.Thedeterminationsweremadebyhigh-performanceliquidchromatography,andtheresultswereexpressedaslg/gfreshweight(FW).Thetrunksandbrancheshadthehighestcontentoftotalaminoacids,whichwere112.23±20.57lg/gFWand111.97±27.78lg/gFW,respectively.Theaminoacids—glutamine,aspartateandc-aminobutyricacidandtyrosine—werenoticeablyhigherinthethreetypesofstems.Inthetrunk,ahigheramountofasparagineandtryptophan,wasalsodetected.Glutamicacidandglutaminewerefoundinhigherquantitiesinthebranches.Thebranchletshadverylowtotalaminoacidcontent(30.79±4.19lg/gFW),whereinasparagineistheonlyaminoacidnotdetected.Thus,itwasobservedthattheprofileofthefreeaminoaciddiffersamongtrunks,branches,andbranchletsinA.angustifolia,indicatingthattheyperformdifferentfunctions.
简介:免费生活的海洋的线虫的五种是redescribed并且在中国的黄海说明同样新的记录。这些种类包括一monhysterid,在家庭Diplopeltidae的Campylaimusgerlachi和四enoplids在家庭Oxystominidae的种类,Oxystominaelongata,Oxystominaelegans,Halalaimuslutarus和Halalaimuswodjanizkii。生态、分类的讲话与原来的描述比较被提供并且讨论。类Campylaimus的所有已知的种的关键被给。我们的调查结果离开犯错到benthic生态学和生物多样性的线虫的分类信息黄海学习。
简介:Financialcrisis-thedrivetointegrationofregionaleconomiesTwosalientfeaturesareillustratedintoday'sglobaleconomypattern,whichis,economicglobalizationandtheintegrationofregionaleconomies.Theintegrationofregionaleconomiesstimulatestheglobalization,whileontheotherhandintegratingcountriesthataregeographicallycloseaimstofightagainstthenegativeimpactfromglobalization,includingthefinancialcrisis.
简介:Inholographicencryption,doublerandom-phaseencodingintheFresneldomain(DRPEiFD)isaprevalentencryptionmethodbecauseitislenslessandsecure.However,noisesbringadverseeffectsduringdecryption.Inthisletter,weintroducequick-response(QR)codingduringencryptiontoresistnoises.WetransformtheoriginalinformationintoaQRcodeandthenencryptthecodeasahologramthroughDRPEiFD.Toretrievetheinput,wedecryptthehologramintheoppositemannertotheencryptionandsubsequentlyobtainaQRcodewithnoises.Byscanningthiscodewithproperapplicationsinsmartphones,wecanobtainanoise-freeretrieval.Numericalexperimentsandimagesscannedbyasmartphoneareshowntovalidateourproposedmethod.
简介:Certificatelessencryptionattractsalotofattentionsofarbyeliminatingthekeyescrowprobleminidentity-basedencryptionandpublickeycertificatesinthetraditionalpublickeycryptography.Byconsideringthethreatfromthekeyexposure,itisdesirabletoincorporatetheideaofkey-insulatedcryptosystemintothecertificatelessencryption.Inthispaper,wehavedesignedanefficientcertificatelesskeyinsulatedencryption(CL-KIE)schemetoachievethisgoal.Byourapproach,thecomputationalperformanceofourschemehasbeenimprovedsignificantlyintermsofreductiononrunningtimeandstorage.WealsogavethesecurityproofofthenewCL-KIEschemeagainstthechosenplaintextattacks(CPAs)intherandomoracle,consideringtheassumptionofthecomputationalDiffie-Hellman(CDH)problem.
简介:AbstractBackground:Deregulation of miRNA-21 expression has been reported to be associated with vascular smooth muscle behavior and cytoskeletal stability. This study is aimed to investigate the density of serum miRNA-21 in patients with different phases of intracranial aneurysms (IAs) and explore its warning function for IA rupture.Methods:A total of 16 in 200 IA patients were selected and categorized into 4 groups based on the phase of IA. Microarray study was carried out using serum miRNA and differentially expressed miRNAs were identified. Another 24 samples from a cohort of 360 patients were added and real-time polymerase chain reaction (RT-PCR) was performed on expanded sample size (n = 40) for miRNA-21 validation. Potential gene targets of miRNA-21 were screened out from Gene Ontology (GO) database and literatures.Results:Microarray study identified 77 miRNAs with significantly different expression levels between experimental groups and the control group. RT-PCR assays validated significant downregulation of miRNA-21 in experimental groups, among which miRNA-21 expression level of daughter aneurysm group decreased the most. Bioinformatic analyses revealed that several target genes related with miRNA-21 may be involved in IA formation and rupture.Conclusions:This study suggested that miRNA-21 had a protective effect for intracranial vascular wall against remodeling and warning function for intracranial aneurysm rupture. Significant suppression of serum miRNA-21 in IA patients may provide diagnostic clues for aneurysm rupture and guide clinical intervention.
简介:Inthispaper,thebendingproblemofrectangularthinplateswithfreeedgeslaidontensionlessWinklerfoundationhasbeensolvedbyemployingFourierserieswithsupplementaryterms.Byassumingproperformofseriesfordeflection,thebasicdifferentialequationwithgivenboundaryconditionscanbetransformedintoasetofinfinitealgebraicequations.Becausetheboundaryofcontactregioncannotbedeterminedinadvance.theseequationsareweaknonlinearones.Theycanbesolvedbyusingiterativeprocedures.