简介:Withinthescopeofthisstudy,itisaimedtocontributetotheeffortsforformingadatabaseincludingthenaturalradiationlevelsthroughoutthecountryanddevelopingafoundationforradiationsafety.KarasuportionoftheEuphratesvalleywithintheprovincialborderofErzincanwaschosenfortheinvestigationandnaturalradiationlevelsweredetectedbyanalyzingthesamplestakenintermsofradioactivity,naturalenvironment’sradiationstreams.ThroughouttheregionofKarasu,29differentsamplesfromthewaterand17fromthesoilweretakenandtheirtotalalpha,betaactivitiesweredetected.Totakesamplesfromthewaterandthentheyweremeasuredbylowbackgroundcounter(BertholdbrandLB77010-channelcounter).Totalalphaandbetaanalysesweremadeaccordingtothestandardmethods.Averagevaluesofalphaandbetaconcentrationsofsamplesweremeasuredas0.0421Bq/Land1.806Bq/L,respectively.ForthesoilsamplesHPGegammaspectrometersystemwasusedandradioisotopeactivityconcentrationswerefoundwithintheintervalsof2.7-27.8Bq/kgfor226Ra;3.2-39.4Bq/kgfor232Th;98-714Bq/kgfor40K;<0.4-57.8Bq/kgfor137Cs,respectively.Differentradioisotopesweredetectedinsomeofthesamplestakenfromstreamingbedsjoiningriverwater.
简介:Theoreticalmodelsofstellarevolutionpredictnegligiblequantitiesof6Li,9Be,and11Binthehydrogenburningphasesofastar’sevolution[1].TheprimordialBig-Bangnucleosynthesis(BBN)modelmightbemoregenerousinitsproductionoftheseelements[2].Theradiative-capturecrosssectionforprotoncaptureon11Bleadingto12CissmallatastrophysicallyinterestingenergiesbecauseofthelargeCoulombbarrier.
简介:PE3340芯片是Peregrine公司研制的一款低噪声、高性能整数分频锁相环,工作频率可高达3GHz,用20引脚TSSOP封装形式,芯片约6.5mm×6.4mm。PE3340内含一个双模前置分频器、R和M计数器以及鉴相器,可通过串行接口对芯片进行编程。遥测发射机设计是用Xilinx公司的CPLD芯片XC9536对PLL芯片PE3340进行预置数据编程。发射机设计用准两点注入式锁相调频技术,包括PE3340、XC9536、温补晶振(TCXO)、有源积分滤波器电路(LF)、VCO、缓冲放大器(Buffer)和S波段功放(PA)等电路模块。发射机电路原理框图如图1所示(虚线框内为PE3340)。
简介:我们理论上由认为Rashba是纺纱轨道在一个极极的半导体的接口附近学习极化子的扎根的州的精力(那么)结合theLee-Low-Pines中间的联合方法。我们的数字结果证明在异种结构从倒置不对称现象发源的RashbaSOinteraction切开极化子的扎根的州的精力。到总数的SOinteraction的比率的真实密度和向量依赖扎根了的电子州的精力或另外的精力作文是明显的。一个人能看到甚至没有任何外部磁场,扎根的州的精力能被RashbaSOinteraction切开,并且这切开不是一个单身者但是复杂的。自从礼品声子,其精力把否定贡献给极化子的家,极化子的切开纺纱的状态比电子的家更稳定。
简介:一个广泛地集成的40G-ROF和10-Gb/sWDM-PON多服务存取系统被建议并且试验性地示威了。这个计划由同时播送无线的独立2.5-Gb/s和10-Gb/s电线信号的40G-ROF和10-Gb/sWDM-PON的一个综合系统组成。在基础车站,它采用调整在DPSK下游的信号上策划在上游的OOK信号,它被remodulating完成,到减少基础车站的费用。传播实验在25-km-long单身者模式纤维(SMF-28)上被执行。下游的PON和ROF的敏感表明的结果表演是[?]14.5dBm并且[?]21.5dBm,分别地并且在上游的信号的敏感是[?]25.3dBm。[从作者抽象]
简介:AnovelSr2CuInO3Soxysulfidep-typesemiconductorphotocatalysthasbeenpreparedbysolidstatereactionmethodanditexhibitsintriguingvisiblelightabsorptionpropertieswithabandgapof2.3eV.Thep-typesemiconductorcharacterofthesynthesizedSr2CuInO3SwasconfirmedbyHallefficientmeasurementandMott-Schottkyplotanalysis.First-principlesdensityfunctionaltheorycalculations(DFT)andelectrochemicalmeasurementswereperformedtoelucidatetheelectronicstructureandtheenergybandlocations.Itwasfoundthattheas-synthesizedSr2CuInO3Sphotocatalysthasappreciateconductionandvalencebandpositionsforhydrogenandoxygenevolution,respectively.Photocatalytichydrogenproductionexperimentsunderavisiblelightirradiation(λ>420nm)werecarriedoutbyloadingdifferentmetalandmetal-likecocatalystsonSr2CuInO3SandRhwasfoundtobethebestoneamongthetestedones.
简介:MeisymmetryandMeiconservedquantityforanon-holonomicsystemofnon-Chetaev'stypewithunilateralconstraintsintheNielsenstylearestudied.Thedifferentialequationsofmotionforthesystemaboveareestablished.ThedefinitionandthecriteriaofMeisymmetry,conditions,andexpressionsofMeiconservedquantitydeduceddirectlyfromtheMeisymmetryaregiven.Anexampleisgiventoillustratetheapplicationoftheresults.
简介:Thedevelopment,theunderlyingtechnologyandthecurrentstatusofthefullydiode-pumpedsolid-statelasersystemPOLARISisreviewed.Currently,thePOLARISsystemdelivers4Jenergy,144fslonglaserpulseswithanultra-hightemporalcontrastof5×1012fortheASE,whichisachievedusingaso-calleddoublechirped-pulseamplificationschemeandcross-polarizedwavegenerationpulsecleaning.Bytightlyfocusing,thepeakintensityexceeds3.5×1020Wcm-2.TheseparameterspredestinePOLARISasascientifictoolwellsuitedforsophisticatedexperiments,asexemplifiedbypresentingmeasurementsofacceleratedprotonenergies.Recently,anadditionalamplifierhasbeenaddedtothelaserchain.Intheramp-upphase,pulsesfromthisamplifierarenotyetcompressedandhavenotyetreachedtheanticipatedenergy.Nevertheless,anoutputenergyof16.6Jhasbeenachievedsofar.
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简介:Althoughmanyliteratureshavebeenfocusedontheunderneathflowandlossmechanism,veryfewexperimentsandsimulationshavebeendoneundertheengines'representativeworkingconditionsorconsideringtherealcavitystructureasawhole.Thispaperaimsatrealizingthegoalofdesignofefficientturbineandscrutinizingthevelocitydistributioninthevicinityoftherimseal.Withtheaidofnumericalmethod,anumericalmodeldescribingtheflowpatternbothinthepurgeflowspotandwithinthemainstreamflowpathisestablished,fluidmigrationanditsaccompaniedflowmechanismwithintherealisticcavitystructure(withrimsealstructureandconsideringmainstream&secondaryairflow'sinteraction)isusedtoevaluateboththeflowpatternandtheunderneathflowmechanismwithintheinwardrotatingcavity.Meanwhile,theunderneathflowandlossmechanismarealsostudiedinthecurrentpaper.Thecomputationalresultsshowthatthesealingairflow'singestionandejectionarehighlyinterwoundwitheachotherinbothupstreamanddownstreamflowoftherimseal.Boththedownstreamblades'potentialeffectsaswellastheupstreamblades'waketrajectorycanbringabouttheingestionofthehotgasflowwithinthecavity,abruptincreaseofthestaticpressureisbelievedtobethemainreason.Also,theresultsindicatethatsealingairflowejectedthroughtherearcavitywillcauseunexpectedlossneartheoutletsectionofthebladesinthedownstreamoftheHProtorpassages.
简介:Boundarylayerseparationandreattachmentisoftenanunavoidablefeatureoflowpressure(LP)turbine,oneofthemaincausesofthisphenomenonisthehighaltitudelowReynoldsnumberexperiencedbythemodernLPturbinestageinaero-engine.Althoughanexcellentturbineairfoildesigncanavoidflowseparationoncertainextent,butwithinflightenvelope,LPturbine'scharacteristicReynoldsnumbermayvariedgreatly,soitwillbestillundertheriskofthepresenceofseparationbubble.Inthistwopartspaperanewconceptofslotted-bladewasraisedtotestifythegainofthebladeslotting.AhighaerodynamicloadingLPturbinebladeIET-LPTAwasunderinvestigatedwithdifferentReynoldsnumber.ComputationalresultsrevealthatthebladeslottingcouldbeawayofchoicetosuppressseparationbubbleandreduceprofilelossundertheconditionoflowReynoldsnumber,althoughitspositionandgeometryneedtobefurtherinvestigated.
简介:TheZ-backlighterlaserfacilityprimarilyconsistsoftwohighenergy,high-powerlasersystems.Z-Beamletlaser(ZBL)(Ramboetal.,Appl.Opt.44,2421(2005))isamulti-kJ-class,nanosecondlaseroperatingat1054nmwhichisfrequencydoubledto527nminordertoprovidex-raybacklightingofhighenergydensityeventsontheZ-machine.Z-Petawatt(ZPW)(Schwarzetal.,J.Phys.:Conf.Ser.112,032020(2008))isapetawatt-classsystemoperatingat1054nmdeliveringupto500Jin500fsforbacklightingandvariousshort-pulselaserexperiments(seealsoFigure10forafacilityoverview).Withthedevelopmentofthemagnetizedlinerinertialfusion(MagLIF)conceptontheZ-machine,theprimarybacklightingmissionsofZBLandZPWhavebeenadjustedaccordingly.Asaresult,wehavefocusedourrecenteffortsonincreasingtheoutputenergyofZBLfrom2to4kJat527nmbymodifyingthefiberfrontendtonowincludeextrabandwidth(forstimulatedBrillouinscatteringsuppression).TheMagLIFconceptrequiresawell-defined/behavedbeamforinteractionwiththepressurizedfuel.HencewehavemadegreateffortstoimplementanadaptiveopticssystemonZBLandhaveexploredtheuseofphaseplates.WearealsoexploringconceptstouseZPWasabacklighterforZBLdrivenMagLIFexperiments.Alternatively,ZPWcouldbeusedasanadditionalfusionfuelpre-heaterorasatemporallyflexiblehighenergypre-pulse.AlloftheseconceptsrequiretheabilitytooperatetheZPWinananosecondlong-pulsemode,inwhichthebeamcanco-propagatewithZBL.Someoftheproposedmodificationsarecompleteandmostofthemarewellontheirway.
简介:Basedonloadseparationtheory,theloadseparationparameterSpbmethodisaneffectiveapproachforestimatingtheJ-resistancecurvefromrecordsofloadversusdisplacementdirectly,usingonesharpcrackedspecimenandanadditionalreferencebluntcrackedspecimen.However,theeffectofthereferencebluntcrackedspecimenonJ-resistancedeterminationwasnotexplicitlyconsideredinpastwork.Inthispaper,amodifiedloadseparationparameterSpbmethodwasdevelopedtoeliminatethiseffect,andthenauniqueestimationofinstantaneouscracklengthforonesharpcrackedspecimencouldbeobtained.Furthermore,aforcedbluntingcalibrationmethodwasalsoadoptedtodeterminetheinstantaneouscracklengthintheloadinseparableregion,referringtoanormalizationmethod.ExperimentsonsteamturbinerotatorsteelCr2Ni2MoVwerecarriedouttoestimateJ-resistancecurvesusinganunloadingcompliancemethod.Byremovingunloadandreloaddatafromload-displacementrecords,theJ-resistancecurveforthesamesharpcrackedspecimenwasestimatedusingthemodifiedseparationparameterSpbmethod.TheresultsindicatethatthemodifiedSpbmethodcompletelyeliminatestheeffectofthereferencebluntcrackedspecimenontheinstantaneouscracklengthdeterminationofthesharpcrackedspecimen.However,differentJ-resistancecurvesinasmallrangeofcrackextensionarepresentwhendifferentbluntingcoefficientsareusedinthebluntinglineequation.TheJ-resistancecurveobtainedfromthemodifiedSpbmethodagreeswellwiththatobtainedfromthecompliancemethod.