简介:1.IntroductionRecently,singleserverqueueswithvacationshavebeenstudiedextensivelyfromtheirowntheoreticalinterestaswellastheirapplicationstomanyengineeringsystemssuchascomputers,communicationnetworksandmanufacturingsystems.FOrtheM/G/lqueueingsystemswit...
简介:Inthispaper,asteady-stateMarkovianmulti-serverretrialqueueingsystemwithBernoullivacationschedulingserviceisstudied.Usingmatrix-geometricapproach,variousinterestingandimportantsystemperformancemeasuresareobtained.Further,theprobabilitydescriptorslikeidealretrialandvainretrialareprovided.Finally,extensivenumericalillustrationsarepresentedtoindicatethequantifyingnatureoftheapproachtoobtainsolutionstothisqueueingsystem.
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简介:在从高度掉落以后介绍给我们的35岁女性。她抱怨了颈疼痛和完全的四肢瘫痪并且作为有C6-C7的spondyloptosis被诊断。骨胳的拖拉在她上被执行。显示出的CT扫描C5,C6,和C7折断脊椎的身体。病人经历了前面的途径有从ipsilateral的前面的颈的锁住板和神气grafting的部分corpectomy肠骨的冠。Intraoperatively,圆盘完全被破裂,有硬脑膜的眼泪和脑髓的液体漏缝,这被发现。她的手术后的时期由脑髓的液体收集是复杂的,以后的乐器学没由于差的一般条件被执行。她没在最后后续有神经恢复。Spondyloptosis是有三列ligamentous混乱的严重、高度不稳定的损害并且可能复杂,与硬脑膜的眼泪,作为在我们的情况中。这些案例的管理与复杂并发症是充满的,并且为神经恢复的预后是忧郁的。
简介:DDRSDRAM和266MHz总线的1、1.2、1.3GHzAthlon已发布,支持这些内存和CPU的主板的上市是期待之中的事。本文将介绍华硕最近推出的两款使用最新芯片组、支持DDRSDRAM和1GHz以上Athlon的主板A7M266和A7V133。A7M266是一款采用AMD760芯片组SocKetA架构的ATX主板,可以支持以266MHz外频工作的Athlon。此外,通过调整外频的设置值,它也可以支持以往的EV6200总线的Athlon和Duron处理器。板上有2个DDRSDRAM用的DIMM插槽,用于插PC1600或PC2100内存;但要注意:当FSB为200MHz时,即使是PC2100内存也只能当PC1600内存使用。板载的最大
简介:A.simplicialmesh(triangulation)isconstructedthatgeneralizesthetwo-dimensional4-directionmeshtoR~m.Thismesh,withsymmetric,shift-invariantvaluesatthevertices,isshowntoadmitaboundedC~1interpolantifandonlyifthealternatingsumofthevaluesattheverticesofany1-cubeiszero.Thisim-pliesthaiinterpolationattheverticesofanm-dimensional,simplicialmeshbyaC~1piecewisepolynomialofdegreem+1withonepiecepersimplexisunstable.
简介:Theequilibriumgeometries,relativestabilities,andelectronicpropertiesofMnAgm(M=Na,Li;n+m≤7)aswellaspureAgn,Nan,Lin(n≤7)clustersaresystematicallyinvestigatedbymeansofthedensityfunctionaltheory.Theoptimizedgeometriesrevealthatfor2≤n≤7,therearesignificantsimilaritiesingeometryamongpureAgn,Nan,andLinclusters,andthetransitionsfromplanartothree-dimensionalconfigurationsoccuratn=7,7,and6,respectively.Incontrast,thefirstthree-dimensional(3D)structuresareobservedatn+m=5forbothNanAgmandLinAgmclusters.Whenn+m≥5,astrikingfeatureisthatthetrigonalbipyramidbecomesthemainsubunitofLinAgm.Furthermore,dramaticodd-evenalternativebehavioursareobtainedinthefragmentationenergies,secondorderdifferenceenergies,highestoccupiedandlowestunoccupiedmolecularorbitalenergygaps,andchemicalhardnessforbothpureanddopedclusters.Theanalyticresultsexhibitthatclusterswithanevenelectronicconfiguration(2,4,6)possesstheweakestchemicalreactivityandmoreenhancedstability.
简介:Inthispaper,MPt/C(M=La,Nd)catalystsofPEMFCweresynthesizedbymicrowaveradiationprocess.ThecrystallinityandstructureofcatalystswererespectivelyanalyzedbyXRDandnitrogenadsorptiontests.Theactivityofcatalystswasinvestigatedbyelectrochemistryexperiment.Theresultsshowedthat:1)comparedwithPt/Ccatalystpreparedbytypicalimpregnation-reductionprocess,thesizeofMPt/CcatalystparticledecreasedandtheavailablecrystalforO2reductionincreased;2)theMPt/CcatalystshadrelativelyhighBETsurfaceareas;and3)thesecrystaltransformationsoftheMPt/Ccatalystbroughthightheelectrocatalyticactivity,andasaresult,improvedthepowerofPEMFC.