简介:TheCDFcollaborationattheFermilabTevatronanalysesproton-antiprotoninteractionsatacenter-of=massenergyof2TeV.duringthethecolliderrunstartingthisyeartheexperimentexpectstorecord1Petabyteofdataandassociateddatasamples,TheDataHandling(DH)systemhasonlineandofflinecomponents.TheDHofflinecomponentprovidesaccesstothestoreddata,tostoredreconstructionoutput,tostoredMonte-Carlodatasamples,anduserowneddatasamples.Itservesmorethan450physicistsofthecollaboration.TheextrarequirementstotheofflinecomponentoftheDataHandlingsystemaresimplicityandconvenienceforusers.Morethan50millioneventsoftheCDFRunIIdatahavebeenalreadyprocessedusingthissystem.
简介:Theeffectofpressureoncombustionandheattransferisanalyzed.Theresearchisbasedonthebasiccombustionandheattransfertheorem.Acorrectionfortheheatcalculationmethodforpressurizedfurnaceismadeonthebasisofthenormalpressurecase.Thecorrectiontakestheeffectofpressurizingintoaccount.Theresultsshowthatthecorrectionisreasonableandthemethodisapplicabletocombustionandheattransferofthemarinesuperchargedboiler.
简介:AdualSshapedmicrostripantennawitharealisticfeedisproposedforgenerationoftiltedbeamradiationpatternpertainingforbeamsteeringapplications.Toachievethis,fourfeedingpointsarelocatedatadistanceof5.6mmfromtheantennacentre.Thesefeedingpointswhenexcitedonebyonegeneratefourtiltedbeamsinfourdifferentspacequadrants,thusyieldingabeamsteerableantenna.Importantly,sincetheproposedantennaissymmetricalinthestructure,allthefourtiltedbeamshavethesameradiationpatterncharacteristics.Afurtherenhancementoftheantennabandwidthisalsoachievedusing100-μmcapacitivecouplingbetweenthefeedandtheantennastrip.
简介:Inagasturbineenginecombustor,highlyswirlingcombustionisusuallyadoptedtostabilizeflameandreducepollutantemissions.Swirlcup,asanairblastatomizer,iswidelyusedtoprovideauniformpresentationoffueldropletstothecombustordome.Thispaperinvestigatedtheeffectofsecondaryswirlerontheflowfielddownstreamoftheswirlcupusingparticleimagevelocimetry(PIV).Threeswirlcups’non-reactingflowfieldwerestudied:caseA,BandCwithsecondaryswirlervaneangle53°,60°and68°respectively.Detailedmeanandtransientvelocitiesandvorticityinthecenterplanewereobtained.FromthePIVresults,asharpcontrastflowfieldwasobtainedforcaseAtoothertwocasesduetothelowersecondaryswirlingintensity.TherecirculationzoneiscollapsedindisorderforthecaseA.Ignitiontestsofthethreecupswerecompletedinasinglecupcombustor.Ingeneral,theignitionperformanceincreaseswiththeincreasingofthesecondaryswirlingintensity.ForcaseA,theignitionperformanceisveryunstableandhasmuchrandomnessandthereisnoclearleanignitionboundarycanbegenerated.Thisworkcanfurtherunderstandtheswirlbehaviorandignitionmechanism.
简介:Small-angleX-rayscattering(SAXS)usingsynchrotronradiationasX-raysourcehasbeenemployedtocharactcizcthemicroscopicstructrureoforgano-modifiedmesoporousmolecularsieves(organo-MSU-X)preparedbyaone-pottemplate-directedsynthesis.ItisshownthattheSAXSprofileishardlyconstantwithPorod’slawshowinganegativeslope,i.e.,negativedeviation.Thissuggeststhatthereisdiffuseinterfaciallayerlocatedbetweentheporesandthematrix.Thissuggeststhattheorganicgroupsremaincovalentlylinkedtothematrix,asindicatedby^29SiCPMASNMRandFT-IR.Theaveragethicknessoftheinterfaciallayerwasfoundtobeabout1nmforeachofthethreesampleswithdifferentkindsandthesameamounts(20?oforganicgroups.Thiskindofmaterialhasalsobeenprovedtopossessbothsurfaceandmassfractalstructureoftheamophousporoussilicamaterials.2001ElsevierScienceB.V.Allrightsreserved.
简介:Compositesofcarbonaerogelandgraphiteoxide(GO)weresynthesizedusingaself-assemblymethodbasedondispersiveforces.Theirsurfacewasmodifiedbytreatmentinhydrogensulfideat650and800℃.Thesamplesobtainedwerecharacterizedbyadsorptionofnitrogen,TA-MS,XPS,potentiometrictitration,andHRTEMandtestedascatalystsforoxygenreductionreactions(ORR)inanalkalinemedium.Thesynergisticeffectofthecomposite(electricalconductivity,porosityandsurfacechemistry)leadstoagoodORRcatalyticactivity.Theonsetpotentialforthecompositeofcarbonaerogelheatedat800℃isshiftedtoamorepositivevalueandthenumberofelectrontransferwas2e-atthepotential0.68VversusRHEanditincreasedto4e-withanincreaseinthenegativevaluesofthepotential.Anexcellenttolerancetomethanolcrossoverwasalsorecorded.
简介:ItisshownthatananomalyofthespectrumtakesplaceintheinterferencefieldwhenYoung'sdouble-slitinterferenceexperimentisilluminatedbyspatiallycoherentpolychromaticlight.Specifically,drasticspectralchanges(i.e.thespectralshiftsexhibitarapidtransition)occurinthevicinityofthedarkfringes.Thepotentialapplicationsofthisspectralanomalyarealsoconsidered.