简介：上班族对“五一”肯定拥有特别的好感。因为在这个日子里，终于可以将工作上的酸甜苦辣抛在脑后，尽情享受自己的节日了!那么，我们本期就来学一些与工作和“五一”相关的语句。

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简介：Inbiosciencepapers,besidestheotherscientificmisconductissues,replicationofthemethodsectionisacommonproblembecauseduplicationisalwaysbeingdetectedinthesectionMaterialsandMethods.Weeditorsoftenreceivecommentsandqueriesfromauthorswhothinkthatitisamatterofcoursetocopytheirownpublishedmaterialsasopposedtocopyingthoseofothers.Howshouldeditorshandlesuchpaperswithsimilarcontentinthemethodsectionandhowtoguideauthorsinwritingthemethodsectionwithoutbeingaccusedofplagiarism?Whatisright?Whatiswrong?Herewestudiedanexampletoexplainthisproblem.

简介：比诗先抑后扬，作者非常小心细致处理每件事，可却得不到自由，从而认识到是太认真了的结果!为比，我们对待事物要一分为二，不能走极端。整首诗中，充满着幽默恢谐之意，富有夸张之手法，寓事于理之中，看后记忆深刘，感触颇深。

简介：Swimmingisverypopularinsummer.Peoplelikeswimminginsummerbecausewatermakesthemfeelcool.Ifyoulikeswimmingandswiminawrongplace,itmaybenotsafe.Theseyears,morethantenpeoplediedwhiletheywereenjoyingthemselvesinthewater.Andmostofthemwerestudents.

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简介：Numericalsimulationofcarefulparallelarithmeticofoilresourcesmigration-accumulationofTanhaiRegion(three-layer)wasdone.Carefulparalleloperatorsplitting-upimplicititerativescheme,parallelarithmeticprogram,parallelarithmeticinformationandalternating-directionmeshsubdivisionwereputforward.ParallelarithmeticandanalysisofdifferentCPUcombinationsweredone.Thisnumericalsimulationtestandtheactualconditionsarebasicallycoincident.Theconvergenceestimationofthemodelproblemhassuccessfullysolvedthedifficultprobleminthefieldsofpermeationfluidmechanics,computationalmathematicsandpetroleumgeology.

简介：Thevisibleandnear-UVemissionspectroscopyofmethane(CH4)inducedbyafemtosecondintenselaserfield(800nm,40fs,1014W∕cm2)isstudied.BymeasuringthedecayprofilesoftheneutralfragmentproductCH(A2Δ→X2Π),tworeactionpathways,i.e.,theelectron-ionrecombinationthroughe-tCHt4andthedirectdisintegrationofCHt4arefoundtoberesponsibleforpopulatingtheelectronicexcitedstatesoftheneutralfragmentproductCH,whichgivesrisetothephotoemissions.Ourresultsprovidecomplementaryinformationonpreviousunderstandingofthestrong-field-inducedphotoemissionmechanismofCH4throughneutraldissociationofsuperexcitedstates.

简介：Anionbeamhastheuniquefeatureofbeingabletodeposititsmainenergyinsideahumanbodytokillcancercellsorinsidematerial.However,conventionalionacceleratorstendtobehugeinsizeandcost.Inthispaper,afutureintenselaserionacceleratorisdiscussedtomakethelaser-basedionacceleratorcompactandcontrollable.Theissuesinthelaserionacceleratorincludetheenergyefficiencyfromthelasertotheions,theionbeamcollimation,theionenergyspectrumcontrol,theionbeambunching,andtheionparticleenergycontrol.Inthestudy,eachcomponentisdesignedtocontroltheionbeamqualitybyparticlesimulations.Theenergyefficiencyfromthelasertoionsisimprovedbyusingasolidtargetwithafinesub-wavelengthstructureoranear-critical-densitygasplasma.Theionbeamcollimationisperformedbyholesbehindthesolidtargetoramulti-layeredsolidtarget.Thecontroloftheionenergyspectrumandtheionparticleenergy,andtheionbeambunchingaresuccessfullyrealizedbyamulti-stagelaser–targetinteraction.

简介：Inthepaper,relativisticfilamentationofintenselaserbeamininhomogeneousplasmaisinvestigatedbasedonthenonparaxialregiontheory.Theresultsshowthat,relativisticnonlinearityplaysamainroleinbeamfilamentation,andplasmainhomogeneityfurtherreinforcesthebeamfilamentation.Thecombinationeffectsofrelativisticnonlinearityandplasmainhomogeneitycangenerateparticularlyintenseandshortpulselaser.However,plasmainhomogeneityleadstoobviousfilamentationinstability.

简介：Ashortoverviewofthetheoryofaccelerationofthinfoilsdrivenbytheradiationpressureofsuperintenselasersispresented.Asimplecriterionforradiationpressuredominanceatintensitiesaround5×1020Wcm-2isgiven,andthepossibilityforfastenergygainintherelativisticregimeisdiscussed.

简介：TheexcitonicopticalabsorptionofGaAsbulksemiconductorsunderintenseterahertz(THz)radiationisinvesti-gatednumerically.Themethodofsolvinginitial-valueproblems,combinedwiththeperfectmatchedlayertechnique,isusedtocalculatetheopticalsusceptibility.InthepresenceofadrivingTHzfield,inadditiontotheusualexcitonpeaks,2preplicaofthedark2pexcitonandeven-THz-photon-sidebandsofthemainexcitonresonanceemergeinthecontinuumabovethebandedgeandbelowthemainexcitonresonance.Moreover,tounderstandtheshiftofthepositionofthemainexcitonpeakunderintenseTHzradiation,itisnecessarytotakeintoconsiderationboththedynamicalFranz-KeldysheffectandacStarkeffectsimultaneously.Formoderatefrequencyfields,themainexcitonpeakdecreasesandbroadensduetothefield-inducedionizationoftheexcitonswithTHzfieldincreasing.However,forhighfrequencyTHzfields,thecharacteristicsoftheexcitonrecurevenunderverystrongTHzfields,whichaccordswiththerecentexperimentalresultsqualitatively.

简介：OurexperimentsshowthatexternalfocusingandinitiallaserenergystronglyinfluencesfilamentgeneratedbythefemtosecondTi–sapphirelaserinair.Theexperimentalmeasurementsshowthefilamentlengthcanbeextendedbothbyincreasingthelaserenergyandfocallengthoffocusinglens.Ontheotherhand,theplasmafluorescenceemissioncanbeenhancedbyincreasingthelaserenergywithfixedfocallengthordecreasingthefocallength.Inaddition,thecollapsedistancemeasuredexperimentallyarelargerthanthecalculatedonesowingtothegroup-velocity-dispersioneffect.Inaddition,wefindthatthelinewidthsofthespectrallinesfromN2isindependentoffilamentpositions,laserenergiesandexternalfocusing.

简介：'Althoughvariousrisks,suchaspolicyrisk,demandchangingrisk,marketcompetitionrisk,pricefluctuationriskofrawmaterialandfinancialriskexisttovaryingdegrees,theinvestmentcrazeonthermalpowerprojectswouldnotcooldown,'anexpertwithChinaPowerEngineeringConsultingGroupCorporationsaid.

简介：Inourpreviouswork,aplasmaapproachforsingleattosecondpulse(AP)generationwasproposed.Afew-cyclerelativisticcircularlypolarizedlaserpulsewillinduceasingledrasticoscillationofplasmaboundary,fromwhichhigh-orderharmonicsandfurthermoreanultra-intensesingleAPcanbegeneratednaturallyafteritisreflected.Analyticalmodelandsimulationsbothdemonstratethattheprocessismostlyefficientasthepulsedurationisclosetotheplasmarespondingtime.Theeffectsofplasmadensityrampareanalyzedhere,suggestingthattheproposalisstillquiteefficientwithappropriatedensitygradientintheramp.Atlast,acombinedapproachisemployedtoobtainsingleAPwith30fsincidentlaser.Therelativelylarge-durationpulseisfirstlyshortenedbyadensitydroppingthinfoil,andthenreflectedfromanoverdenseplasmatarget.One-dimensionalsimulationshowsthata600assinglelightpulseisgeneratedwithpeakintensityof3×1020W/cm2.

简介：The45°scatteringofafemtosecond(60fs)intenselaserpulsewitha20nmFWHM(thefullwidthathalfmaximum)spectrumcenteredat790nmhasbeenstudiedexperimentallywhilefocusedinargonclustersatintensity～1016W/cra2.Scatteringspectraunderdifferentbackingpressuresandlaser-plasmainteractionlengthswereobtained,whichshowedspectralblueshifting,beamrefractionandcomplexmodulation.Theseionization-inducedeffectsrevealthemodulationoflaserpulsespropagatinginplasmasandtheexistingobstacleinlaserclusterinteractionathighlaserintensityandhighelectrondensity.

简介：Wepresentaninterferometrysetupandthedetailedfringeanalysismethodforintenseshortpulse(SP)laserexperiments.Theinterferometryschemewasrefinedthroughmultiplecampaignstoinvestigatetheeffectsofpre-plasmasonenergeticelectronsattheJupiterLaserFacilityatLawrenceLivermoreNationalLaboratory.Theinterferometerusedafrequencydoubled(λ=0.527μm)0.5pslongopticalprobebeamtomeasurethepre-plasmadensity,aninvaluableparametertobetterunderstandhowvaryingpre-plasmaconditionsaffectthecharacteristicsoftheenergeticelectrons.Thehardwareofthediagnostic,dataanalysisandexampledataarepresented.ThediagnosticsetupandtheanalysisprocedurecanbeemployedforanyotherSPlaserexperimentsandinterferograms,respectively.

简介：Strongfluorescenceemissionswereobservedfornitrogen,carbonmonoxide,andcarbondioxidemoleculesinintensefemtosecondlaserfields.Theseemissionscanbeassignedtothetransitionsofthemolecularionsfromtheexcitedelectronicstatestothegroundelectronicstates.Theformationmechanismswerediscussedandthelifetimesweremeasuredfortheseexcitedmolecularionsinintenselaserfields.

简介：Twocompactandintense2.45GHzpermanentprotonsourcesandtheircorrespondinglowenergybeamtransport(LEBT)systemsweredevelopedsuccessfullyforChinaAcceleratorDrivenSub-criticalsystem(C-ADS)in2014,oneofwhichwasbuiltatIMP,LanzhouandtheotheratIHEP,Beijing.Bothprotonsourcescandeliverstable10mA/35keVprotonbeamsatCWmodetotheentrancesofthedownstreamRFQs.AsshowninFig.1,thebeamsextractedbya3-electrodeextractionsystemaretransportedbytheLEBTsystem,whichiscomposedof2identicalsolenoids,andintothe3.2or2.1MeVradio-frequencyquadrupole(RFQ).Inordertoensuresuperconductingcavitiescommissioningandprotection,anelectrostatic-chopperhasbeendesignedandinstalledintheLEBTlinethatcanchopthecwbeamFig.2Totalhydrogenionbeamcurrentversusinputpower.intoapulsedone.Theachievedfall/risetimeofthechopperislessthan20ns.

简介：Atechniqueofelectronaccelerationinthecone-shapedstationarylaserfieldisproposed.Anelectronaccelerationinthislaserisstudied,whichshowsthatthereisnoelectronbunchingbutthereexistselectroncaptureinthislaserfield.