简介：Theeffectsofionmotiononthegenerationofshort-cyclerelativisticlaserpulsesduringradiationpressureaccelerationareinvestigatedbyanalyticalmodelingandparticle-in-cellsimulations.Studiesshowthattherearpartofthetransmittedpulsemodulatedbyionmotionissharpercomparedwiththecaseoftheelectronshutteronly.Inthisstudy,theionsfurthermodulatetheshort-cyclepulsestransmitted.A3.9fslaserpulsewithanintensityof1.33×1021Wcm-2isgeneratedbyproperlycontrollingthemotionsoftheelectronandioninthesimulations.Theshort-cyclelaserpulsesourceproposedcanbeappliedinthegenerationofsingleattosecondpulsesandelectronaccelerationinasmallbubbleregime.

简介：Carbon-manganesesteelisoftenappliedincomponentsofpipesinnuclearplant.Ultrasonicfatiguetestsfollowinglowcyclefatigue(LCF)cyclesdamagedareusedtostudythestrengthofveryhighcyclefatigure(VHCF).ThecomparisonoftestresultsofsimpleVHCFandcumulativefatigue(LCFplusVHCF)showsthatLCFloadinfluencesthefollowingVHCFstrength.ContinuumdamagemechanicsmodelisextendedtoVHCFregion.TheeffectofLCFloadonVHCFisstudiedbyanimprovedcumulativedamagemodel.

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简介：决定一张图什么时候是Gromov夸张一般来说，是一个很难的问题。在这份报纸，我们为短图的集合解决这个问题(以一个非正式的方法，如果在G的周期的捷径有长度，图G是r短的不到r)：如果并且仅当S9r(G)是有限的，r短的图G是夸张的，在的地方SR(G):=啜{L(C)：C是在G的一个R等轴的周期}并且我们说周期C是R等轴的如果dC(x，y)dG(x，y)为每x的+R，yC。

简介：Intheapplicationsofaircrafts,automobiles,railways,biomedicineandoff-shorestructures,manycomponentsmayexperiencecyclicloadingconditionsoveralongperiodoftime,runninguptoseveralhundredmillioncycles.1Determinationoflonglifefatiguebehaviorbecomesextremelyimportantforbetterunderstandinganddesignofcomponentsandstructures.

简介：ThedirectedmotionofaBrownianparticleinaflashingpotentialwithvarioustransitionprobabilitiesandwaitingtimesinoneoftwostatesisstudied.AnexpressionfortheaveragecycleperiodisproposedandthesteadycurrentJoftheparticleiscalculatedviaLangevinsimulation.Theresultsshowthattheoptimalcycleperiodrm,whichtakesthemaximumofJ,isshiftedtoasmallvaluewhenthetransitionprobabilityλfromthepotentialontothepotentialoffdecreases,themaximalcurrentappearsinthecaseoftheaveragewaitingtimeinthepotentialonbeinglongerthaninthepotentialoff,andthedirectionofcurrentdependsontheratiooftheaveragetimeswaitingintwostates.

简介：Inthispaper,thecycle’sstructureofembeddedgraphsinsurfacesarestudied.Accordingtothemethodoffundamentalcycles,thesetC(Ccontainsallshortest)isfound.AundirectedgraphGwithnverticeshasatmostO(n5)manyshortestcycles;IftheshortestcycleofGisoddcycle,thenGhasatmostO(n3)manyshortestcycles;IfGhasbeenembeddedinasurfaceSg(Ng,gisaconstant),thenithasatmostO(n3)shortestcycles,moreover,iftheshortestcycleofGisoddcycle,then,GhasatmostO(n2)manyshortestcycles.WecanfindacyclebaseofG,thenumberofoddcyclesofG,thenumberofevencyclesofG,thenumberofcontractiblecyclesofG,thenumberofnon-contractiblecyclesofG,arealldecided.IftheΠ-embeddedgraphGhasΠ-twosidedcycles,then,CcontainsashortestΠ-twosidedcycleofG,thereisapolynomiallyboundedalgorithmthatfindsashortestΠ-twosidedcycleofaΠ-embeddedgraphG,thenewandsimplesolutionsabouttheopenproblemofBojanMoharandCarstenThomassenareobtained.

简介：Inthispaper,westudyRényi'sproblemandotherrelatedproblemsabouttheadditivefunctionsinshortintervals.Ascorollaries,weimproveIvic'sresults.

简介：Wepresentasufficientandnecessaryconditionforaso-calledCnkpatterntohavepositivesemidefnite(PSD)completion.SincethegraphoftheCnkpatterniscomposedbysomesimplecycles,ourresultsextendthosegivenin[1]forasimplecycle.WealsoderivesomeresultsforapartialToeplitzPSDmatrixspecifyingtheCnkpatterntohavePSDcompletionandToeplitzPSDcompletion.

简介：Thefatiguelifeofnumerousaerospace,locomotive,automotiveandbiomedicalstructuresmaygobeyond10~8cycles.Determinationoflonglifefatiguebehaviorbecomesextremelyimportantforbetterunderstandinganddesignofthecomponentsandstructures.Initially,beforetheinventionofultrasonicfatiguetesting,mostoftheengineeringmaterialsweresupposedtoexhibitfatiguelifeupto10~7cyclesorless.Thispaperreviewscurrentunderstandingofsomefundamentalaspectsonthedevelopmentofacceleratedfatiguetestingmethodanditsapplicationinultra-highcyclefatigue,crackinitiationandgrowthmechanismsofinternalfracture,S-Ndiagram,fatiguelimitandlifeprediction,etc.

简介：<正>ItisprovedthateverylargeintegerN≡5（mod24）canbewrittenasN=p12+…+p52witheachprimepjsatisfying|pJ-（N/5|）1/2≤N11/23.ThisgivesashortintervalversionofHua’stheoremonthequadraticWaring-Goldbachproblem

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简介：Thispaperstudiesaclassofquarticsystemwhichismoregeneralandrealisticthanthequarticaccompanyingsystem.x′=-y+ex+lx~2+mxy+ny~2,y′=x(1-Ay)(1+Cy~2),(*)whereC>0.Sufficientconditionsareobtainedfortheuniquenessoflimitcycleofsystem(*)andsomemorein-depthconclusionsuchasHopfbifurcation.

简介：Muonsproducedbyashortpulselasercanserveasanewtypeofmuonsourcehavingpotentialadvantagesofhighintensity,smallsourceemittance,shortpulsedurationandlowcost.Tovalidateitinexperiments,asuitablemuondiagnosticssystemisneededsincehighmuonfluxgeneratedbyashortpulselasershotisalwaysaccompaniedbyhighradiationbackground,whichisquitedifferentfromcasesingeneralmuonresearches.Adetectionsystemisproposedtodistinguishmuonsignalsfromradiationbackgroundbymeasuringthemuonlifetime.Itisbasedonthescintillatordetectorwithwaterandleadshields,inwhichwaterisusedtoadjustenergiesofmuonsstoppedinthescintillatorandleadtoagainstradiationbackground.AGeant4simulationontheperformanceofthedetectionsystemshowsthatefficiencyupto52%couldbearrivedforlow-energymuonsaround200MeVandthisefficiencydecreasesto14%forhigh-energymuonsabove1000MeV.Thesimulationalsoshowsthatthemuonlifetimecanbederivedproperlybymeasuringattenuationofthescintillalightofelectronsfrommuondecaysinsidethescintillatordetector.

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简介：制造在上的影响张力并且3种制造方法生产的铜电影的疲劳行为被调查。张力、高的周期疲劳测试用作者开发的测试机器被执行。幼仔的moduli(72，71和69GPa，分别地)比文学价值低(108鈥?45GPa)当收益力量象358，350和346MPa一样高时，分别地并且最终的力量作为462，456和446MPa分别地。在3种电影的张力的性质没有许多差别。在3种电影的疲劳性质有小差别，但是他们之一在低周期区域比其它在高周期区域和更长的疲劳生活比其它过更短的疲劳生活。

简介：Theaimofthisresearchistocharacterizethedevelopmentoffatiguedamagebymeansofstress-strainhysteresis.Experimentswereconductedon14specimensmadeofcold-finishedunannealedAISI1018steel.Resultsdemonstratethatthemechanicalhysteresisloopareas,whenplottedasafunctionofthenumberofloadingcycles,showsignificantvariationsanddemonstratethethreeprincipalstagesconcerningtheprogressofthefatiguefailure—initialaccommodation,accretionofdamageandterminalfailure.ThesethreestagesoffatiguearemarkedbythetransitionsatcyclesN2andN3.ExperimentalresultsshowthatalthoughfatiguelifeNfrangesfrom2644cyclesto108992cycles,theratiosofN2/NfandN3/Nftendtobestable:N2/Nf=10.7%,N3/Nf=91.3%.

简介：MeasuresynchronizationisanewphenomenonfoundincoupledHamiltoniansystemsrecentlyanditisinterestingtounderstanditspropertiescomprehensively.Wediscussthemeasuresynchronizationofacoupledpairofstandardmapsinhighperiodquasi-periodorbits,andthemeasuresynchronizationtransitionisassociatedwiththetransitionofcoupledsystemsfromquasi-periodicitytochaos.ThisbehaviourisverydifferentfromthatfoundbyHamptonandZanette[Phys.Rev.Lett.83(1999)2179].