简介：二轨道的哈伯德模型被在真实空间和动量空间使用Hartree-Fock近似数字地学习，并且碱金属的地面状态性质熨硒化物半导体的KFe1.5Se2被调查。有，顺序被发现的stripetypeantiferromagnetic(AFM)的一份菱形类型Fe空缺订单在散布实验的中子被观察[J.赵，等，Phys。加快。Lett。109，267003(2012)]。跳跃参数被在真实空间适合试验性地观察的条纹AFM阶段获得。这些跳跃参数然后被用来在动量空格学习半导体的地面状态性质。是有大所在地的库仑排斥U的一个强烈相关的系统被发现，类似于莫特·阿夫姆绝缘体铜氧化物超导体的父母混合物。我们也发现在dxz和dyzorbitals的电子职业数字和磁化同时变得不同，显示轨道的订什么时候U>Uc(3.4eV)。这些结果暗示在二orbitals之间的旋转对称被轨道的订打破并且因此驾驶磁性的联合的强壮的anisotropy被实验观察了并且在这混合物的条纹类型AFM顺序可以被和观察大anisotropy的轨道的订引起。

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简介：HydrogenabsorptionsofLaFe11.5Si1.5compoundin1-atmhydrogengasatdifferenttemperaturesareinvestigated.Thehydrogencontentinthehydrogenatedsampledoesnotincreasewiththeincreaseoftemperatureofhydrogenabsorptionbutchangescomplicatedly.Thecharacteristicoffirst-ordertransitioninLaFe11.5Si1.5compoundisweakenedafterhydrogenabsorption.Itleadsthepeaksofmagneticentropytobecomewiderandthehysteresislosstoreducesignificantly,butrelativecoolingpower(RCP)isnotchangedconsiderably.

简介：Generallyspeaking,mainflowpathofgasturbineisassumedtobeperfectforstandard3Dcomputation.Butinrealengine,theturbineannulusgeometryisnotcompletelysmoothforthepresenceoftheshroudandassociatedcavityneartheendwall.Besides,shroudleakageflowisoneofthedominantsourcesofsecondaryflowinturbomachinery,whichnotonlycausesadeteriorationofusefulworkbutalsoapenaltyonturbineefficiency.Ithasbeenfoundthatneglectshroudleakageflowmakesthecomputedvelocityprofilesandlossdistributionsignificantlydifferenttothosemeasured.Evenso,theinfluenceofshroudleakageflowisseldomtakenintoconsiderationduringtheroutineofturbinedesignduetoinsufficientunderstandingofitsimpactonendwallflowsandturbineperformance.Inordertoevaluatetheimpactoftipshroudgeometryonturbineperformance,a3Dcomputationalinvestigationfor1.5-stageturbinewithshroudedbladeswasperformedinthispaper.Thefollowinggeometryparameterswerevariedrespectively:-Inletcavitylengthandexitcavitylength,-Shroudoverhangupstreamoftherotorleadingedgeanddownstreamofthetrailingedge,-Shroudradialtipclearance,Theaimofthispaperistoisolatetheinfluenceofshroudandcavitygeometrymodificationsonturbineaerodynamicperformanceandtoobtaincleartrendsofefficiencychangescausedbydifferenttipshroudgeometry.Moreover,interactionbetweenleakageflowandmainstreamfordifferentshroudconfigurationisalsohighlightedinordertopenetrateintothephysicalmechanismsproducingthem.Duetothelimitationsofthemodelselectedinthispaper,theaimofresearchisnottoputforwardthedesignrulesofturbineshroud.However,theresultsobtainedfromthisworkwillbeusefultotheintegrateddesignandoptimizationofturbinewithshroudedblades.

简介：ThestimulatedBrillouinscattering(SBS)thresholdenhancementfactorinapurewhitenoiselinewidthbroadeningYb-dopedfiberamplifier(YDFA)withashortlargemodeareafiberistheoreticallyandexperimentallystudied.Wedemonstratea1064.08nm,11.6GHzlinewidth,1.5kWoutputpowerYDFAwithanSBSthresholdenhancementof~57(26WSBSthresholdwithsinglefrequencyseed).Theoutputbeamisnear-diffractionlimitedwithabeamqualityfactorofM~2=1.15andaslopeefficiencyofupto87%.NoSBSorstimulatedRamanscatteringeffectsareobservedinthewholepowerrange.Furtherpowerscalingislimitedbytheavailablepumppowerinoursystem.

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