简介：让n和k(n≥k>1)是二个非否定的整数。n顶点上的k-multi-hypertournament是对(V，一)，在V是有|V的一套顶点的地方|=n，和A是顶点的一套k元组，为V的任何k子集S叫了弧，A包含至少一个(至多k!)k！其条目属于S的k元组。为是某k-multi-hypertournament的外面度顺序(在里面度顺序)的非否定的整数的一个不减少的序列的必要、足够的条件被给。

简介：DNAcondensationisanimportantprocessinmanyfieldsincludinglifesciences,polymerphysics,andappliedtechnology.Inthenucleus,DNAiscondensedintochromosomes.Inpolymerphysics,DNAistreatedasasemi-flexiblemoleculeandapolyelectrolyte.Manyagents,includingmulti-valentcations,surfactants,andneutralpoorsolvents,cancauseDNAcondensation,alsoreferredtoascoil–globuletransition.Moreover,DNAcondensationhasbeenusedforextractionandgenedeliveryinappliedtechnology.ManyphysicaltheorieshavebeenpresentedtoelucidatethemechanismunderlyingDNAcondensation,includingthecounterioncorrelationtheory,theelectrostaticzippertheory,andthehydrationforcetheory.Recentlyseveralsingle-moleculestudieshavefocusedonDNAcondensation,sheddingnewlightonoldconcepts.Inthisdocument,themulti-fieldconceptsandtheoriesrelatedtoDNAcondensationareintroducedandclarifiedaswellastheadvancesandconsiderationsofsingle-moleculeDNAcondensationexperimentsareintroduced.

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简介：题目：一种多振子超声电机的设计目的：对超声电机而言，当多个压电振子并联时，由于以同一设计方案制作的电机振子往往具有不同的动态特性，因此会使得多振子电机的效率有所下降。即多振子电机工作的关键是如何使多个振子协同一致地驱动转子。为提高集成型多振子电机的效率和简化电机结构，提出一种构造贴片式多振子旋转超声电机的方法。创新点：1．提出圆周面内驱动的概念，发展已有的面内驱动概念（x-y面）；2．提出一种模态转换方法，通过多个振子弯曲振动的叠加形成设计电机的扭转振动；3．电机工作时，不仅各个振子处于共振状态，而且连接而成的定子同样处于共振状态，有利于提高电机的效率；4．验证多振子同步驱动的机理。方法：1．振子采用贴片式结构，由极化方向沿厚度方向的压电陶瓷和金属基体粘结而成；与使用兰杰文振子相比，使用贴片式振子易于简化电机的结构。2．各个振子首尾相连形成电机的定子，既可用于构造直线电机，又可转换成旋转电机。3．通过有限元方法对不同振子数构成的电机定子进行性能比较，并且分析设计电机的驱动机理；此外，通过仿真分析确定电机的最优尺寸。4．根据设计结果，加工原理样机，并且对加工的样机进行实验研究，探讨设计方法的可行性。结论：1．根据仿真分析结果，最终加工的电机定子包含5个振子。2．定子中各个振子的振动特性完全相同，振子同步工作。3．样机定子的内径为28mm，外径为35mm，高为30min；测得定子的纵振和扭转频率分别为44．42kHz和43．83kHz；当激励电压的频率为43．9kHz、峰值为100V时，电机的空载转速为45r／min，堵转力矩为0．3N·m，最大效率约为30％。4．本文所设计的电机，是一种多振子并行驱动的整体式电机，具有结构紧凑和多�

简介：在这份报纸，我们在存在上解决一个问题结合线性多步方法(LMSM)的symplecticity，否定结果被获得。[从作者抽象]

简介：Bymeansoffirst-principlesdensityfunctionaltheory(DFT)calculationsandmoleculardynamics(MD)simulations,aseriesofcoronalmulti-walledsiliconnanotubes(MWSiNTs)withoutorwithhydrogenterminationsaresystematicallyidentified.Notably,coronalMWSiNTs,wheretheinteractionbetweenthewallsispreferablethroughcovalentbondsratherthanweakinteraction,showbetterstabilitythanCNT-likeSiNTs.Moreover,theyexhibitgoodelasticitywithsmallYoung’smodulus.Theinvestigationoftheelectronicstructuredemonstratesthattheypresentmetalliccharacteristics,whichisinstrikingcontrasttobulksilicon.Thus,theMWSiNTsmayfindimportantapplicationsinelectronicdevices.

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简介：InthefieldofComptonscatterimaging,theproblemofhowtogetameaningfulimagefromlarge-scaleobjectisstillnotfullysttled.Thedifficultymainlyliesinthemethodofthecompensationoftheattenuation,Basedontheprincipleofsmall-angleforwardscattering,anewattenuationcorrectionmethodisdeducedinthispaper,wecandistinguishairfromothermaterialsevenitisdeepinsidealarge-scaleobject.Toverifyourmethod,wedesignamodelofaone-meter-longobjectandperformMonteCarlosimulationswithMCNPsoftware.

简介：GyroscopicdynamicsystemcanbeintroducedtoHamiltoniansystem.BasedonanadjointsymplecticsubspaceiterationmethodofHamiltoniangyroscopicsystem,anadjointsymplecticsubspaceiterationmethodofindefiniteHamiltonianfunctiongy-roscopicsystemwasproposedtosolvetheeigenvalueproblemofindefiniteHamiltonianfunctiongyroscopicsystem.ThecharacterthattheeigenvaluesofHamiltoniangyroscopicsystemareonlypureimaginaryorzerowasused.TheeigenvaluesthatHamiltonianfunctionisnegativecanbeseparatedsothattheeigenvalueproblemofpositivedefiniteHamiltonianfunctionsystemwaspresented,andanadjointsymplecticsubspaceiterationmethodofpositivedefiniteHamiltonianfunctionsystemwasusedtosolvetheseparatedeigenvalueproblem.Therefore,theeigenvalueproblemofindefiniteHamiltonianfunctiongyroscopicsystemwassolved,andtwonumericalexamplesweregiventodemonstratethattheeigensolutionsconvergeexactly.

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简介：Aschemeofverycompactstoreforlarge-scaleprimelistisgivenandtwoalgorithmsforrapidgeneratingthelistareprovided.

简介：BasedonArnoldi’smethod,aversionofgeneralizedArnoldialgorithmhasbeendevel-opedforthereductionofgyroscopiceigenvalueproblems.Byutilizingtheskewsymmetryofsystemmatrix,averysimplerecurrencescheme,namedgyroscopicArnoldireductionalgorithmhasbeenob-tained,whichisevensimplerthantheLanczosalgorithmforsymmetriceigenvalueproblems.Thecomplexnumbercomputationiscompletelyavoided.Arestarttechniqueisusedtoenablethereductionalgorithmtohaveiterativecharacteristics.Ithasbeenfoundthattherestarttechniqueisnotonlyef-fectivefortheconvergenceofmultipleeigenvaluesbutitalsofurnishesthereductionalgorithmwithatechniquetocheckandcomputemissedeigenvalues.Bycombiningitwiththerestarttechnique,theal-gorithmismadepracticalforlarge-scalegyroscopiceigenvalueproblems.Numericalexamplesaregiv-entodemonstratetheeffectivenessofthemethodproposed.

简介：Amild,regioselective1,3-dipolarcycloadditionprotocolforthepreparationofphenylselenomethylisoxazolinesthroughsubstitutedallylphenylselenidesandnitrileoxideswasreported.

简介：Atheoreticalinvestigationiscarriedouttostudytheexistence,formationandbasicpropertiesofionacoustic(IA)doublelayers(DLs)inamagnetizedbi-ionplasmaconsistingofwarm/coldionsandBoltzmanndistributedelectrons.Basedonthereductiveperturbationtechnique,anextendedKortewegde-Vries(KdV)equationisderived.Thepropagationoftwopossiblemodes(fastandslow),andtheirevolutionareinvestigated.Theeffectsofobhqueness,magnitudeofthemagneticfield,ionconcentration,polarityofions,andiontemperatureontheIADLprofileareanalyzed,andthentherangesofparametersforwhichtheIADLsexistareinvestigatedindetails.

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简介：最近，测量效率的方法上有更多的争论。这篇论文的主要目的是为不同边疆模型做敏感度分析并且比较从为特定的应用估计多产量边疆的不同方法获得的结果。方法包括随机的距离函数边疆，随机的光线边疆，和数据包封分析。有或没有效果建模的无效的随机的边疆回归也被比较并且测试。结果显示在从其他的评价方法获得的结果之间有显著相关。

简介：Amulti-channelACpowerSupplycontrolerdevelopedrecentlybyuswasintrodueedbrieftyinthispaper.Thiscontrollerisacomputercontrolledmulti-electronic-switchdevice.Thecontrollercontains16independentchannelsinastandardbox(440W×405D×125Hmm).Thereisanelectronicswitchineachchannel,theratedloadpoweris≤1kW.Themainfunctionofthecontrolleristosetthestateofelectronicswitch(ON/OFF)

简介：TheneutronTimeOfFlight(nTOF)facilityatCERNisahighfluxspallationneutronsourcecommissionedinNov2000andAPr2001.ForthecommissioningphasesaninnovativemultipurposeDAQsystemwasdevelopedandused.Thissystemiscapableofhandlinghighdatarated(10Mb/s)withtheuseoftheNationalInstrumentsPCI-VXIinterfaceboardtocommunicatewiththeVMEcrates.ThegraphicaluserinterfaceisbasedonJava^TMandROOTallowingimmediatevisualizationofthedataandprovidingaflexiblewayofcreatingconfigurationsforvariousexperimentalsetups.

简介：Longwavesgeneratedbyamovingatmosphericpressuredistribution,associatedwithastorm,incoastalregionareinvestigatednumerically.Forsimplicitythemovingatmosphericpressureisassumedtobemovingonlyinthealongshoredirectionandthebeachslopeisassumedtobeaconstantintheon-offshoredirection.Bysolvingthelinearshallowwaterequationsweobtainnumericalsolutionsforawiderangeofphysicalparameters,includingstormsize(2a),stormspeed(U),andbeachslope(α).Basedonthenumericalresults,itisdeterminedthatedgewavepacketsaregeneratedifthestormspeedisequaltoorgreaterthanthecriticalvelocity,Ucr,whichisdefinedasthephasespeedofthefundamentaledgewavemodewhosewavelengthisscaledbythewidthofthestormsize.ThelengthandthelocationofthepositivelymovingedgewavepacketisroughlyUt/2≤y≤Ut,whereyisinthealongshoredirectionandtisthetime.Oncetheedgewavepacketisgenerated,thewavelengthisthesameasthatofthefundamentaledgewavemodecorrespondingtothestormspeedandisindependentofthestormsize,whichcan,however,affectthewaveamplitude.Whenthestormspeedislessthanthecriticalvelocity,theprimarysurfacesignatureisadepressiondirectlycorrelatedtotheatmosphericpressuredistribution.