学科分类
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7 个结果
  • 简介:BABAR[1]usestwoformatsforitsdata:ObjectivitydatabaseandROOT[1]files.Thisposterconcernsthedistributionofthelatter-forObjectivitydatasee[3].TheBABARanalysisdataisstoredinROOTfiles-oneperphysicsrunandanalysisselectionchannel-maintainedinalargedirectorytree,CurrentlyBABARhasmorethan4.5TBytesin200,000ROOTfiles.Thisdatais(mostly)producedatSLAC,butisrequiredforanalysisatuniversitiesandresearchcentresthroughouttheUSandEurope.TwobasicproblemsconfrontuswhenweseektoimportbulkdatafromSLACtoaninstitute'slocalstorageviathenetwork.Wemustdeterminewhichfilesmustbeimported(dependingonthelocalsiterequirementsandwhichfileshavealreadybeenimported),andwemustmaketheoptimumuseofthenetworkwhentransferringthedata,Basicftp-liketools(ftp,scp,etc)donotattempttosolvethefirstproblem.Moresophisticatedtoolslikersync[4],thewidely-usedmirror/synchronisationprogram,comparelocalandremotefilesystems,checkingforchanges(basedonfiledate,sizeand,ifdesired,anelaboratechecksum)inordertoonlycopynewormodifiedfiles,Howeverrsyncallowsforonlylimitedfileselection.Alsowhen,asinBABAR,anextremelylargedirectorystructuremustbescanned,rsynccantakeseveralhoursjusttodeterminewhichfilesneedtobecopied.Althoughrsync(andscp)provideson-the=flycompression,itdoesnotallowustooptimisethenetworktransferbyusingmultiplestreams,abjustingtheTCPwindowsizeorseparatingencryptedauthenticationfromunencrypteddatachannels.

  • 标签: 分布式数据库 BABAR实验合作 文件管理工具
  • 简介:ThedetailedreactionpathwayandcokeformationmechanismoverPt/metaloxidenanoparticlesduringthesteamreformingofethanol(SRE)at300℃werestudied.ThecatalystswerepreparedbyincipientwetnessimpregnationmethodandwerecharacterizedwithCOpulsechemisorption,BETsurfacemeasurement,oxygenadsorption,ethanol-TPD,NH3-TPD,andTPO.TheSREactivityofthecatalystswithsteam/ethanolmolarratioof3/1wastestedusingacontinuousfixed-bedreactor.StronginteractionbetweenPtandsupportscauseslowerH2productiontemperaturesandnoC2H4formation,whileweakinteractionleadstoC2H4formationandstrongbondedCOonPtparticlesduringethanol-TPD.H2productionoverPt-basedcatalystsismainlyresultedfromthedecompositionanddehydrogenationofethanol,anddecarbonylationofacetaldehyde.Meanwhile,cokecanbeformedfromacetaldehyde,acetone,C2H4andCO.However,whentheinteractionbetweenPtandsupportsisweak,morecokeisformedespeciallyfromacetone,C2H4andCO.Whentheinteractionisstrong,nocokeformationisobservedduetohighoxygenstoragecapacityofthecatalyst.

  • 标签: 活性位点 乙醇 焦炭 产氢 强相互作用 NH3-TPD
  • 简介:TheDNA-dependentproteinkinasecatalyticsubunit(DNA-PKcs)playsamajorroleinDNAdamagesignalingandrepair,andisalsofrequentlyover-expressedintumormetastasis.WeusedisogeniccelllinesexpressingdifferentlevelsofDNA-PKcstoinvestigatetheroleofDNA-PKcsinmetastaticdevelopment.Interestingly,ourresultsshowedthatX-rayirradiationinducedthemetastasisofDNA-PKcspositive(M059K)butnotnegative(M059J)cells;however,genisteincouldsuppresstheradiation-inducedmetastaticpotentialofM059Kcells(Fig.1).Theconcretemechanismsunderlyingthisphenomenonwillbeinvestigatednextyear.

  • 标签: DNA-PKCS POSITIVE CELLS
  • 简介:为制作的一个templating方法二维(2D)微米大小的金戒指的数组被报导。微观结构被无电的plating在从包装结束的硅石获得的硅底层上在通过多孔的聚合物膜形成胶体的水晶。我们的结果证明金戒指的尺寸能被为多孔的聚苯乙烯膜改变无电的plating条件改变。而且,我们用是在重入的地点的优先的成核的古典水晶生长理论解释金戒指的生长机制。

  • 标签: 三维排列 金属环 成核作用 固体物理学
  • 简介:ThehighlydispersedPt–ReOX(x≤1)sitesca.0.5nminsizewereformedviaasuccessiveandstronginteractionoftheReprecursorwithtitaniaandthenofthePtcomplexwithdepositedlow-valentrheniumoxideclusters.Thesize,chargeandchemicalcompositionwerecharacterizedbymeansofHRTEM/STEMwithEDXmapping,XPS,andFTIRS.ThesesiteswithRe/Pt=2wereshowntobehighlyactiveandselectiveinthehydrogenationofcarboxylicacidtoalcoholunderverymildconditions(T=130°C,P=50bar).ThereactionrateconstantforthehydrogenationofhexanoicacidincreasedlinearlywiththePtcontent.Asforthehomogeneouspincer-typeRu-organiccomplexes,theactivePt–ReOXsitescandissociateheterolyticallythemolecularhydrogenwiththeformationofhydroxylgroupsandPthydrideforhydrogenationofthecarboxylicgroup.Indeed,TOFof20h-1andselectivityof98%–99%areapproachingthevaluestypicalofhomogeneouscatalysts.Thefirstorderkineticsdescribedwelltheexperimentaldataobtainedinawiderangeofreactionconditions.

  • 标签: 选择性加氢催化剂 铂络合物 活性位点 二氧化钛 再氧化 羧酸
  • 简介:Tonguesquamouscellcarcinoma(ToSCC)isthemostcommontypeofheadandnecksquamouscellcarcinomaandisthesixthleadingcauseofcancerdeathsworldwide[1].Inclinicaloncology,radiationtherapyisastandardtreatmentusedfortumors.Numerousstudieshaveshownthatconventionalradiotherapyusedincancertreatmentmayincreasetheriskofmetastasisofmalignanttumorcells[2–4].Toimprovepatientsurvival,thepotentialformetastasisoftumorsinresponsetoradiationneedstobeaddressed.

  • 标签: SQUAMOUS Cell CARCINOMA