简介:WehavecomprehensivelyinvestigatedthefrustratedJ1-J2-J3Heisenbergmodelonasimplecubiclattice.Thismodelallowsthreeregimesofmagneticorder,viz.,(π;π;π),(0;π;π)and(0;0;π),denotedasAF1,AF2,andAF3,respectively.Theeffectsoftheinterplayofneighboringcouplingsonthemodelarestudiedintheentiretemperaturerange.Thezerotemperaturemagneticpropertiesofthismodelarediscussedutilizingthelinearspinwave(LSW)theory,nonlinearspinwave(NLSW)theory,andGreen’sfunction(GF)method.ThezerotemperaturephasediagramsevaluatedbytheLSWandNLSWmethodsareillustrated,andareobservedtoexhibitdifferentparameterboundaries.Incertainregionsandalongtheparameterboundaries,thepossiblephasetransformationsdrivenbytheparametersarediscussed.TheresultsobtainedusingtheLSW,NLSW,andGFmethodsarecomparedwiththoseobtainedusingtheseriesexpansion(SE)method,andareobservedtobeingoodagreementwhenthevalueofJ2isnotclosetotheparameterboundaries.ThegroundstateenergiesobtainedusingtheLSWandNLSWmethodsareclosetothatobtainedusingtheSEmethod.Atfinitetemperatures,onlytheGFmethodisemployedtoevaluatethemagneticproperties,andthecalculatedphasediagramisobservedtobeidenticaltotheclassicalphasediagram.Theresultsindicatethatattheparameterboundaries,atemperature-drivenfirst-orderphasetransitionbetweenAF1andAF2mayoccuralongtheboundaryline.AlongtheAF1-AF3andAF2-AF3boundarylines,AF3islessstablethanAF1andAF2.OurcalculatedcriticaltemperatureagreeswiththatobtainedusingMonteCarlosimulationsandpseudofermionfunctionalrenormalizationgroupscheme.
简介:Inthispaper,weobtainaresultthatimprovestheresultsofGovilandNwaeze,QaziandtheclassicalresultofRivlin.
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简介:AJ-CONVEXSUBSETWHICHISNOTPSH-CONVEXBuShangquan(步尚全)(Departmentofappliedmathematics,TsinghuaUniversity,Beijing100084,China)Abs...
简介:Letp(z)=a_0+a_1z+a_2z~2+a_3z~3+···+a_nz~nbeapolynomialofdegreen.Rivlin[12]provedthatifp(z)≠0intheunitdisk,thenfor0
简介:Thehighrepetitionrate10J/10nsYb:YAGlasersystemanditskeytechniquesarereported.Theamplifiersinthissystemhaveamulti-passV-shapestructureandtheheatintheamplifiersisremovedbymeansoflaminarwaterflow.Inthemainamplifier,thelaserisfour-pass,andanapproximately8.5J/1Hz/10nsoutputisachievedintheprimarytest.Thefar-fieldoftheoutputbeamisapproximately10timesthediffractionlimit.Becauseofthehigherlevelsofamplifiedspontaneousemission(ASE)inthemainamplifier,theoutputenergyislowerthanexpected.Attheendwediscusssomemeasuresthatcanimprovethepropertiesofthelasersystem.
简介:Theconstitutiveequationunderthelow-cyclefatigue(LCF)wasdiscussed,andatwo-dimensional(2-D)modelforsimulatingfatiguecrackextensionwasputforwardinordertoproposeanewcyclicJ-integral.Thedefinition,primarycharacteristics,physicalinterpretationsandnumericalevaluationofthenewparameterwereinvestigatedindetail.Moreover,thenewcyclicJ-integralforLCFbehaviorswasvalidatedbythecompacttension(CT)specimens.ResultsshowthatthecalculatedvaluesofthenewparametercancorrelatewellwithLCFcrackgrowthrate,duringconstant-amplitudeloading.Inaddition,thephenomenonoffatigueretardationwasexplainedthroughtheviewpointofenergybasedontheconceptofthenewparameter.
简介:Veryrecently,theBelleandBESIIIexperimentsobservedanewcharmonium-likestateX(3823),whichisagoodcandidatefortheD-wavecharmonium(13D2).BecausetheX(3823)isjustneartheDˉDthreshold,thedecayX(3823)!J=+??canbeagoldenchanneltotestthesignificanceofcoupled-channeleffects.Inthiswork[1],thisdecayisconsideredincludingboththehidden-charmdipionandtheusualquantumchromodynamicsmultipoleexpansion(QCDME)contributions.
简介:Inthispaperwereviewthedesignanddevelopmentofa100J,10Hznanosecondpulsedlaser,codenamedDiPOLE100X,beingbuiltattheCentralLaserFacility(CLF).This1kWaveragepowerdiode-pumpedsolid-statelaser(DPSSL)isbasedonamasteroscillatorpoweramplifier(MOPA)design,whichincludestwocryogenicgascooledamplifierstagesbasedonDiPOLEmulti-slabceramicYb:YAGamplifiertechnologydevelopedattheCLF.Thelaserwillproducepulsesbetween2and15nsindurationwithprecise,arbitrarilyselectableshapes,atpulserepetitionratesupto10Hz,allowingreal-timeshapeoptimizationforcompressionexperiments.Oncecompleted,thelaserwillbedeliveredtotheEuropeanX-rayFreeElectronLaser(XFEL)facilityinGermanyasaUK-fundedcontributioninkind,whereitwillbeusedtostudyextremestatesofmatterattheHighEnergyDensity(HED)instrument.
简介:相对增益阵列(RGA)大多数应用的矩阵阶数都是较小的(n=2,3或4).我们从矩阵方程Φ(A)=1/2J2的实数解出发,应用矩阵方程Φ(A)=1/nJn的实数解在G-等价下的不变性和实数解的分块构造法,研究了Φ(A)=1/4J4的实数解的一些问题.