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14 个结果
  • 简介:Inthispapertheauthorsgeneralizetheclassicrandombipartitegraphmodel,anddefineamodeloftherandombipartitemultigraphsasfollows:letm=m(n)beapositiveinteger-valuedfunctiononnandζ(n,m;{pk})theprobabilityspaceconsistingofallthelabeledbipartitemultigraphswithtwovertexsetsA={a_1,a_2,...,a_n}andB={b_1,b_2,...,b_m},inwhichthenumberst_(ai),b_joftheedgesbetweenanytwoverticesa_i∈Aandb_j∈BareidenticallydistributedindependentrandomvariableswithdistributionP{t_(ai),b_j=k}=pk,k=0,1,2,...,wherepk≥0and∞Σk=0pk=1.TheyobtainthatX_(c,d,A),thenumberofverticesinAwithdegreebetweencanddofG_(n,m)∈ζ(n,m;{pk})hasasymptoticallyPoissondistribution,andanswerthefollowingtwoquestionsaboutthespaceζ(n,m;{pk})with{pk}havinggeometricdistribution,binomialdistributionandPoissondistribution,respectively.Underwhichconditionfor{pk}cantherebeafunctionD(n)suchthatalmosteveryrandommultigraphG_(n,m)∈ζ(n,m;{pk})hasmaximumdegreeD(n)inA?underwhichconditionfor{pk}hasalmosteverymultigraphG(n,m)∈ζ(n,m;{pk})auniquevertexofmaximumdegreeinA?

  • 标签: 独立随机变量 多重图 最小度 概率空间 泊松分布 几何分布
  • 简介:Puretungsten(PW)andW-1wt%La2O3(WL10)werepreparedbypowdermetallurgicalroutefollowedbytheswaging+rollingprocess.Thelogarithmicstrainsare0,0.37,0.58,and0.98forWL10and0,0.58forPW.Heattreatmentswereperformedattemperaturesvariedfrom1,573to2,173Ktodeterminetherecrystallizationtemperature.Recrystallizationtemperaturesare1,973and2,173KforWL1(logarithmicstrainof0.37)andWL3(logarithmicstrainof0.98),respectively.ButinthecaseofWL2(logarithmicstrainof0.58),fullrecrystallizationisnotachievedattemperatureofabove2,173K.Furthermore,therecrystallizationtemperatureofPWwithlogarithmicstrainof0.58isatleast300KlowerthanthatoftheequivalentWL10sample.Moreover,theincreaseofrecrystallizationtemperatureinhibitsthestrengthdegradationofWL2:sampleslose4%and22%strengthwhenannealedat1,573and1,973Kcomparedwithroomtemperature(RT)sample.Finally,thetextureevolutionfortheswaged+rolledWL10issignificantlyrelatedtothedeformationdegree:thedominatedorientationis<001>forWL2while<110>forWL3.

  • 标签: 再结晶温度 变形程度 纯钨 对数应变 轧制工艺 强度退化
  • 简介:Withrespecttothedecisionmakingproblemswherealotoffuzzyandgreyinformationalwaysexistsinthereal-lifedecisionmakinginformationsystem,itisdifficultforsuchuncertaintymethodsasfuzzymathematics,probability,andintervalnumberstodealwith.Tothisend,basedonthethoughtandmethodofgreynumbers,greydegreesandintervalnumbers,theconceptofdominancegreydegreeisdefined.Andthenamethodofrankingintervalgreynumbersbasedonthedominancegreydegreeisproposed.Afterdiscussingtherelevantproperties,thepaperfinallyusesanexampletodemonstratetheeffectivenessandapplicabilityofthemodel.Theresultshowsthattheproposedmodelcanmoreaccuratelydescribeuncertaintydecisionmakingproblems,andrealizethetotalorderingprocessformultiple-attributedecision-makingproblems.

  • 标签: 区间灰数 灰色度 多属性决策问题 基础 决策信息系统 模糊数学
  • 简介:AbstractObjectives:To demonstrate three-hundred and sixty degrees of maxillary sinus (MS) surgical approaches using cadaveric dissections, highlighting the step-by-step anatomy of each procedure.Methods:Two latex-injected cadaveric specimens were utilized to perform surgical dissections to demonstrate different approaches to the MS. The procedures were documented with macroscopic images and endoscopic pictures.Results:Dissections were performed to approach the MS medially (endoscopic maxillary antrostomy and ethmoidectomy), anteriorly (Caldwell-Luc), superiorly (transconjunctival/transorbital approach), inferiorly (transpalatal approach), and posterolaterally (preauricular hemicoronal approach).Conclusion:A number of approaches have been described to address pathology in the MS. Surgeons should be familiar with indications, limitations, and surgical anatomy from different perspectives to approach the MS. This paper illustrates anatomic approaches to the MS with detailed step-by-step cadaveric dissections and case examples.

  • 标签: anatomy Caldwell-Luc dissection endoscopic sinus surgery infratemporal fossa maxillary sinus pterygopalatine fossa
  • 简介:在这篇论文,我们与都应当是与有限的基本的组一起的3-manifolds的S3-geometry,manifolds的可能的自我印射的度决定了所有。这是一个工程的部分决定所有关上的东方的所有可能的自我印射的度在Thurston的图画的有能力的3-manifold。

  • 标签: 几何 定位 三维流形 自映射 基本群 有限
  • 简介:Azero-dimensionalmodelwhichincludes56speciesofreactantsand427reactionsisusedtostudythebehaviorofchargedparticlesinatmosphericplasmaswithdifferentionizationdegreesatlowaltitude(near0km).TheconstantcoefficientnonlinearequationsaresolvedbyusingtheQuasi-steady-stateapproximationmethod.Theelectronlifetimesareobtainedforafterglowplasmawithdifferentinitialvalues,andthetemporalevolutionsofthemainchargedspeciesarepresented,whicharedominantinreactionprocesses.Theresultsshowthattheelectronnumberdensitydecaysquickly.Thelifetimesofelectronsareshortenedbyabouttwoorderswithincreasingionizationdegree.Electronsthenattachtoneutralparticlesandproducenegativeions.Whentheinitialelectrondensitiesareintherangeof1010~1014cm3,thenegativeionshavesufficientlyhighdensitiesandlonglifetimesforairpurification,disinfectionandsterilization.Electrons,O2,O4,CO4andCO3arethedominantnegativespecieswhentheinitialelectrondensityne0≤1013cm3,andonlyelectronsandCO3areleftwhenne0≥1015cm3.N+2,N+4andO+2aredominantinthepositivechargesforanyionizationdegree.Otherpositivespecies,suchasO+4,N+3,NO+,NO+2,Ar+2andH3O+·H2O,aredominantonlyforacertainionizationdegreeandinacertainperiod.

  • 标签: 大气等离子体 低海拔地区 带电粒子 电离度 电子数密度 演变
  • 简介:Inthisletter,apiezoaeroelasticenergyharvesterbasedonanairfoilwithdoubleplungedegreesoffreedomisproposedtoadditionallytakeadvantageofthevibrationalenergyoftheairfoilpitchmotion.Ananalyticalmodeloftheproposedenergyharvestingsystemisbuiltandcomparedwithanequivalentmodelusingthewell-exploredpitch-plungeconfiguration.Thedynamicresponseandaveragepoweroutputoftheharvesterarenumericallystudiedastheflowvelocityexceedsthecut-inspeed(flutterspeed).Itisfoundthattheharvesterwithdouble-plungeconfigurationgenerates4%–10%morepowerwithvaryingflowvelocitieswhilereducing6%ofthecut-inspeedthanitscounterpart.

  • 标签: 振动能量 双自由度 收割机 翼型 等效模型 功率输出
  • 简介:Itisawell-knownfactthatcharactersofafinitegroupcangiveimportantinformationaboutthestructureofthegroup.Itwasalsoprovedbythethirdauthorthatafinitesimplegroupcanbeuniquelydeterminedbyitscharactertable.Heretheauthorsattempttoinvestigatehowtocharacterizeafinitealmost-simplegroupbyusinglessinformationofitscharactertable,andsuccessfullycharacterizetheautomorphismgroupsofMathieugroupsbytheirordersandatmosttwoirreduciblecharacterdegreesoftheircharactertables.

  • 标签: 自同构群 字符 订单 信息描述 不可约 作者
  • 简介:Pointabsorberwaveenergydevicewithmultipledegreesoffreedom(DOF)isassumedtohaveabetterabsorptionabilityofmechanicalenergyfromoceanwaves.Inthispaper,acoaxialsymmetricarticulatedpointabsorberwaveenergyconverterwithtwodegreesoffreedomispresented.Themechanicalequationsoftheoscillationbuoywithpowertake-offmechanism(PTO)inregularwavesareestablished.Thethree-dimensionalnumericalwavetankisbuiltinconsiderationofthebuoymotionbasedupontheCFDmethod.Theappropriatesimulationelementsareselectedforthebuoyandwaveparameters.ThefeasibilityoftheCFDmethodisverifiedthroughthecontrastbetweenthenumericalsimulationresultsoftypicalwaveconditionsandtestresults.Insuchcase,thebuoywithsingleDOFofheave,pitchandtheircouplingmotionconsideringfree(noPTOdamping)anddampedoscillationsinregularwavesaresimulatedbyusingtheverifiedCFDmethodrespectively.Thehydrodynamicandwaveenergyconversioncharacteristicswithtypicalwaveconditionsareanalyzed.Thenumericalresultsshowthattheheaveandpitchcanaffecteachotherinthebuoycouplingmotion,hydrodynamicloads,waveenergyabsorptionandflowfield.ThetotalcapturewidthratiowithtwocoupledDOFmotionishigherthanthatwithasingleDOFmotion.ThewaveenergyconversionofacertainDOFmotionmaybehigherthanthatofthesinglecertainDOFmotioneventhoughthewaveisattheresonanceperiod.Whenthewaveperiodsarehighenough,theinteractionbetweenthecoupledDOFmotionscanbeneglected.

  • 标签: CFD simulation wave energy CONVERSION numerical
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  • 简介:在这份报纸,CD衍生物的三种不同类型作为原子转移激进分子聚合(ATRP)被综合开始者或可逆增加破碎链转移聚合(木排)链转移。为每衍生物的替换的度小心地被描绘通过<啜class=“a-plus-plus”>1H-NMR,<啜class=“a-plus-plus”>13C-NMR光谱学和飞行团spectrometry(MALDI-TOF-MS)的帮助矩阵的激光解吸附作用/电离时间。影响替换的度的因素被讨论。而且,在ATRP和木排之间的比较在N-isopropylacrylamide(NIPAM)的聚合被显示出。

  • 标签: MALDI-TOF-MS RAFT ATRP 链转移 原子转移自由基聚合 合成