学科分类
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16 个结果
  • 简介:ApeaknormisdefinedforLpspacesofE-valuedBochnerintegrablefunctions,whereEisaBanachspace,andbestapproximationsfromasuntoelementsofthespacearecharacterized.Applicationsaregiventosomefamiliesofsimultaneousbestapproximationproblems.

  • 标签: 万州
  • 简介:BasedontheEigenandCrow-Kimuramodelswithasingle-peakfitnesslandscape,weproposethefitnessvaluesofallsequencetypestobeGaussiandistributedrandomvariablestoincorporatetheeffectsofthefluctuationsofthefitnesslandscapes(noiseofenvironments)andinvestigatetheconcentrationdistributionanderrorthresholdofquasispeciesbyperforminganensembleaveragewithinthistheoreticalframework.Wefindthatasmallfluctuationofthefitnesslandscapecausesonlyaslightchangeintheconcentrationdistributionanderrorthreshold,whichimpliesthattheerrorthresholdisstableagainstsmallperturbations.However,forasizablefluctuation,quitedifferentfromthepreviousdeterministicmodels,ourstatisticalresultsshowthatthetransitionfromquasi-speciestoerrorcatastropheisnotsosharp,indicatingthattheerrorthresholdislocatedwithinacertainrangeandhasashifttowardalargervalue.Ourresultsarequalitativelyinagreementwiththeexperimentaldataandprovideanewimplicationforantiviralstrategies.

  • 标签: 误差极限 高斯分布式随机变量 原子物理学 原子结构
  • 简介:Theoriginofpseudopeakwasstudiedbymeansofmicellarelectrokineticcapillarychromatographywithcetyltrimethylaminiumbromideasthepseudostationaryphase.Ithasbeenpointedthattwopeaksmayappearforonecomponentundercertainconditions.Experimentsshowedthattherelativeareasofthetwopeaksofanalytedependedonthetimeandthetemperatureofreactionbetweenanalyteandsurfactant,andtheconcentrationofsurfactantinthesamplesolution.Itmeansthattheinteractionbetweentheanalyteandthesurfactantisaslowprocess,andastablesubstancecanbeproducedfromtheinteraction.Itisthesubstanceandtheanalytethatmayleadtotheformationoftwopeaks.Thefastinteractionmechanismbetweenthesoluteandthemicellarshouldbequeriedfromtheexperimentresult.

  • 标签: 毛细管色谱 表面活性剂 动力学 色谱峰 假峰
  • 简介:ForthefamousFeigenbaum’sequations,inthispaper,weestablisheditsconstructivetheoremofthepeak-unimodal,thenwefoundoutotherpathstoexplorethepeak-unimodalsolutions.Forexample,weproceedonthedirectiontotrythenon-symmetricalcontinuouspeak-unimodalsolutionsandC~1solutions.

  • 标签: SYMMETRICAL proceed bifurcation CHAOTIC chaos doubling
  • 简介:我们采用nonequilibrium格林的函数方法理论上在一个使变形的分子学习Kondo效果,它被当作一个电子声子相互作用(EPI)系统。为声子部分的自我精力在标准许多身体被计算图解的扩大直到在EPI力量的第二份订单。我们发现多重帮助声子的Kondo卫星除平常的Kondo回声以外产生。在反平行的磁性的配置切开主要Kondo山峰和帮助声子的卫星仅仅发生因为不均匀的点铅couplings,而是它从为平行磁性的配置的对称是免费的。EPI力量和震动的频率能提高主要Kondo和卫星切开的旋转。压制的零偏爱的Kondo回声能被使用一个外部磁场恢复,这被显示出,其大小显著地依赖于phononic效果。尽管在隧道联合的不对称现象没有贡献到Kondo山峰切开的纺纱的恢复,它能缩小需要交换在大否定剧降和大积极山峰之间的通道磁致电阻比率的外部地。

  • 标签: 自旋分裂 铁磁电极 耦合 分子 变形 量子点
  • 简介:Thediscreteiterativemapmodelofpeakcurrent-modecontrolledbuckconverterwithconstantcurrentload(CCL),containingtheoutputvoltagefeedbackandrampcompensation,isestablishedinthispaper.BasedonthismodelthecomplexdynamicsofthisconverterisinvestigatedbyanalyzingbifurcationdiagramsandtheLyapunovexponentspectrum.Theeffectsoframpcompensationandoutputvoltagefeedbackonthestabilityoftheconverterareinvestigated.Experimentalresultsverifythesimulationandtheoreticalanalysis.Thestabilityboundaryandchaosboundaryareobtainedunderthetheoreticalconditionsofperiod-doublingbifurcationandbordercollision.Itisfoundthattherearefouroperationregionsinthepeakcurrent-modecontrolledbuckconverterwithCCLduetoperiod-doublingbifurcationandborder-collisionbifurcation.Researchresultsindicatethatrampcompensationcanextendthestableoperationrangeandtransfertheoperatingmode,andoutputvoltagefeedbackcaneventuallyeliminatethecoexistingfast-slowscaleinstability.

  • 标签: 峰值电流控制模式 电流模式控制 降压转换器 复杂动力学 恒流负载 BUCK变换器
  • 简介:Usingcryogeniclasertechnology,itisnowpossibletodesignanddemonstratelasersthathaveconcomitanthighaverageandpeakpowers,withnear-diffraction-limitedbeamquality.WerefertothesenewlasersystemsasHAPPlasers.Inthispaper,wereviewimportantlasercrystalmaterialspropertiesatcryogenictemperature,withanemphasisonYblasers,anddiscusstheimportantdesignconsiderations,includingthelaser-induceddamagethreshold,nonlineareffectsandthermaleffects.Acomprehensivemodelispresentedtodescribediodepulsedpumpingwitharbitrarydurationandrepetitionrate,andisusedwiththeFrantz–Nodvikequationtodescribe,tofirstorder,theperformanceofHAPPlasersystems.Acomputercodewithrepresentativeresultsisalsodescribed.

  • 标签: CRYOGENIC LASERS high-average-power LASERS high-peak-power LASERS
  • 简介:模式获得光谱被Fourier系列扩大方法forInAs/GaAs量点(QD)测量有在不同注射水流的QD的七栈的激光。有特殊山峰的Gainspectra在大约1210nmand1300nm的短、长的波长被观察。为有1060亩m的洞长度的QD激光,长波长的山峰获得首先慢慢地增加或甚至快速作为短波长度增加的山峰获得与注射水流减少,并且当注射水流进一步增加,最后在接近浸透的价值前快速增加。

  • 标签: 波长 量子点 散射 光电子学
  • 简介:Pulsecontrastisacrucialparameterofhighpeak-powerlaserssincetheprepulsenoisemaydisturblaser–plasmainteractions.Contrastmeasurementisthusaprerequisitetotacklethecontrastchallengeinhighpeak-powerlasers.Thispaperpresentstheprogressreviewofsingle-shotcross-correlator(SSCC)forreal-timecontrastcharacterization.WebeginwiththekeytechnologiesthatenableanSSCCtosimultaneouslypossesshighdynamicrange(1010),largetemporalwindow(50–70ps)andhighfidelity.WealsosummarizetheinstrumentationofSSCCprototypesandtheirapplicationsonfivesetsofpetawattlaserfacilitiesinChina.Finally,wediscusshowtoextendcontrastmeasurementsfromtimedomaintospatiotemporaldomain.Real-timeandhigh-dynamic-rangecontrastmeasurements,providedbySSCC,cannotonlycharacterizevariouscomplexnoisesinhighpeak-powerlasersbutalsoguidethesystemoptimization.

  • 标签: fiber array HIGH dynamic range PULSE
  • 简介:Wereportonthedesign,realization,andoutputperformanceofadiode-pumpedhigh-peak-powerpassivelyQ-switchedNd:YAG∕Cr4+:YAGcompositemediummonolithiclaserwithfour-beamoutput.Theenergyofalaserpulsewashigherthan3mJwithdurationof0.9ns.Theproposedsystemhastheabilitytochooseindependentlythefocusofeachbeam.Suchalaserdevicecanbeusedformultipointignitionofanautomobilegasolineengine,butcouldalsobeofinterestforignitioninspacepropulsionorinturbulentconditionsspecifictoaeronautics.

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  • 简介:Bysimultaneouslyemployingbothanelectro-opticmodulatorandcarbonnanotubesaturableabsorber(CNT-SA)inadual-lossmodulator,asubnanosecondsinglemode-lockingpulseunderneathaQ-switchedenvelopewithhighpeakpowerwasgeneratedfromadoublyQ-switchedandmode-locked(QML)Nd:Lu0.15Y0.85VO4laserat1.06μmforthefirsttime,toourknowledge.CNTswithdifferentwallstructures—single-walledCNTs(SWCNTs),double-walledCNTs(DWCNTs),andmulti-walledCNTs(MWCNTs)—wereusedasSAsintheexperimenttoinvestigatethesinglemode-lockingpulsecharacteristics.Atpumppowerof10.72W,themaximumpeakpowerof1.312MWwasobtainedwiththeDWCNT.

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