简介：采用直流X射线连续能谱照射晶体,以极小的步进角,测量一定角度范围内,不同入射角度下的衍射能谱,通过提取各个角度衍射能谱中同一能量X射线的衍射强度,微分得到该能量的平晶摇摆曲线。与传统测量方法相比,该方法具有更大的X射线能量测量范围,可通过一次角度扫描,同时给出多个能量的摇摆曲线。利用该方法开展了16~21keV区间内LiF（200）平晶摇摆曲线的相对强度标定,结果表明,晶体摇摆曲线的半高宽随X射线能量增加而缓慢减小,而峰值强度随X射线能量增加则缓慢增加,在入射能谱强度变化较大区间内,该方法测量结果的不确定度较大。

简介：Theground-stateandthermodynamicpropertiesofquantummixed-spinchainsof1/2-1/2-1-1and3/2-3/2-1-1areinvestigatedbyaquantumMonteCarlosimulationwiththeloop-clusteralgorithm.For1/2-1/2-1-1chain,wefindithastwophasesseparatedbyanenergy-gapvanishingpointintheground-state.For3/2-3/2-1-1chain,thenumericalresultsshowtwoenergy-gapvanishingpointsisolatedbydifferentphasesinitsground-state.Ourcalculationsindicatethatallthesegroundstatephasescanbeunderstoodbymeansofvalence-bond-solidpicture,andthethermodynamicbehavioratfinitetemperaturesiscontinuousasafunctionofparameterα=J2/J1.

简介：1．河水总是向低处流，抛出的物体总会落向地面，这些现象说明，地球上的物体总是要受到________力的作用，该力的施力物体是______。

简介：In2014,theresearchersofTheoreticalPhysicsGroupatIMPhavecarriedouttheirresearchworkonnuclearphysics,heavyionphysicsandhadronphysics.Someimportantresultshavebeenobtained.Thethree-bodyforce(TBF)effectontheoff-shellbehavioroftheneutronandprotonmassoperatorsinasymmetricuclearmatterhasbeeninvestigatedwithintheframeworkoftheextendedBrueckner-Hartree-Fockapproach[1].Athighdensitieswellabovethenormalnuclearmatterdensity,theTBFisshowntoaffectsignificantlytheoff-shellehaviorofboththeprotonandneutronmassoperators.Thedensitydependenceofsymmetryenergyaroundtheuclearsaturationdensityhasbeenstudied[2].Anewapproachhasbeenproposedandappliedtodeterminetheymmetryenergycoefficientofheavynucleibasedontheavailableexperimentalnuclearmassesofheavynuclei.Theobtainedresultisadoptedtoanalyzethedensitydependenceofsymmetryenergyofnuclearmatteraroundtheaturationdensity.TheslopeparameteratthesaturationdensityisdeterminedtobeL=(50.515.5)MeV.

简介：随着材料科学技术的不断进步，新型高强度、高韧性的难加工材料不断出现。图1所示零件，材料为超高强高韧钢，孔深与孔径之比约为10：1，内孔为小锥度锥面，孔末端为异型回转曲面，外圆柱面和内孔有较高的同轴度要求。零件深孔加工中刀具细而长，刚性差，工件尺寸精度、表面质量不易保证。

简介：材料高压下的状态方程（EOS）在天体物理、材料科学和惯性约束聚变（ICF）等研究领域中都是十分重要的。2004年在“神光”-Ⅱ装置上进行了单路倍频激光直接驱动的Al-Cu阻抗匹配靶实验和Cu-Al阻抗反匹配实验，目的是提高冲击波速度的测量精度和准确性，同时校验测量方法的实用性和可靠性。

简介：In2010,theBESCollaboration[1]foundaclearenhancementintheK0K0massdistributionintheJ=ψ!ηK0K0decay.SuchanenhancementisusuallyasignatureofanL=0resonancearoundthreshold,whichinthiscasewouldcorrespondstoanh1statewithquantumnumbersIG(JPC)=0??(1+??).Thish1statewaspredictedbytheChiralUnitarytheoryintheKKinteraction.Becauseoftheconversationlaw,thisstatecanonlydecaytoK0K0channel,andcanbestudiedefficientlyintheJ=ψ!ηK0K0decay.

简介：Tostudytheelectromagnetic(EM)backscattercharacteristicsoffreakwavesatmoderateincidenceangles,weestablishanEMbackscatteringmodelforfreakwavesin(1+1)-dimensionaldeepwater.ThenonlinearinteractionbetweenfreakwavesandBraggshortwavesisconsideredtobethebasichydrodynamicspectramodulationmechanisminthemodel.NumericalresultssuggestthattheEMbackscatteringintensitiesoffreakwavesarelessthanthosefromthebackgroundseasurfaceatmoderateincidenceangles.Thenormalisedradarcrosssections(NRCSs)fromfreakwavesarehighlypolarisationdependent,evenatlowincidenceangles,whichisdifferentfromthesituationfornormalseawaves;moreover,theNRCSoffreakwavesismorepolarisationdependentthanthebackgroundseasurface.NRCSdiscrepanciesbetweenfreakwavesandthebackgroundseasurfacewithusinghorizontaltransmittinghorizomtal(HH)polarisationarelargerthanthoseusingverticaltransmittingvertical(VV)polarisation,atmoderateincidentangles.NRCSdiscrepanciesbetweenfreakwavesandbackgroundseasurfacedecreaseswiththeincreaseofincidenceangle,inbothHHandVVpolarisationradars.Asanapplication,inthesynthetic-apertureradar(SAR)imagingoffreakwaves,wesuggestthatfreakwavesshouldhaveextremelylowbackscatterNRCSsforthefreakwavefacetwiththestrongestslope.Comparedwiththebackgroundseasurface,thefreakwavesshouldbedarkerinHHpolarisationechoimagesthaninVVechoimages,inSARimages.FreakwavescanbemoreeasilydetectedfromthebackgroundseasurfaceinHHpolarisationimagesthaninVVpolarisationimages.Thepossibilityofdetectionoffreakwavesatlowincidenceanglesismuchhigherthanathighincidenceangles.

简介：ThesplittingofpotentialenergylevelsforgroundstateX2ΠgofOx2(x=+1,1)underspin–orbitcoupling(SOC)hasbeencalculatedbyusingthespin–orbit(SO)multi-configurationquasi-degenerateperturbationtheory(SO-MCQDPT).TheirMurrell–Sorbie(M–S)potentialfunctionsaregained,andthenthespectroscopicconstantsforelectronicstates2Π1/2and2Π3/2arederivedfromtheM–Sfunction.TheverticalexcitationenergiesforOx2(x=+1,1)areν[O+12(2Π3/2→X2Π1/2)]=195.652cm1,andν[O12(2Π1/2→X2Π3/2)]=182.568cm1,respectively.Allthespectroscopicdataforelectronicstates2Π1/2and2Π3/2aregivenforthefirsttime.

简介：当堂反馈1．如图所示，锤子对钉子的作用力的施力物体是——，受力物体是——．画出锤子对钉子的作用力的示意图．

简介：1．将手掌压在水平的桌面上，使手掌水平向前运动，会感到手掌受到桌面向__________（选填“前”或“后”）的作用力，此力称为______力．桌面越光滑，手掌受到的力越小，表明____________________________________。

简介：

简介：ThespectrumoftheΣ(1193)excitedstates,Σ,withisospinI=1andstrangenessS=??1isoneofthemostimportantissuesinhadronicphysics.TheΣresonancesaremostlyproducedandstudiedinK-inducedreactions.ManyΣresonancesarenowcatalogedbytheParticleDataGroup[1].However,ourknowledgeoftheseresonancesisstillverypoor.Intheenergyregionbelow2GeV,onlyafewofthemarewellestablished,suchastheΣ(1385)ofspin-parityJP=3=2+,Σ(1670)ofJp=3=2??andΣ(1775)ofJp=5=2??.Theothersarenotwellestablishedandsomeofthemareevenoflargeuncertaintiesontheirexistence.Thus,thestudyoftheΣresonancewiththeavailableexperimentaldataisnecessary.

简介：简要介绍了超高速碰撞现象及其关键科学问题。综述了航天器空间碎片超高速碰撞防护研究,详细评论了空间碎片防护结构、超高速碰撞下的碎片云模型及撞击极限方程的国内外进展。探讨了小行星撞击地球防御中超高速碰撞问题。展望了超高速碰撞研究及航天应用研究的发展趋势。

简介：

简介：WeinvestigatethesensitivityoftheangularrotationmeasurementwiththemethodofhomodynedetectioninSU（2）andSU（1,1）interferometersbyemployingorbitalangularmomentum（OAM）.BycombiningacoherentbeamwithavacuumbeaminanSU（2）interferometer,wegetthesensitivityoftheangularrotationmeasurementas1/(2N1/2l).WecansurpassthelimitoftheangularrotationmeasurementinanSU（1,1）interferometerbycombiningacoherentbeamwithavacuumbeamorasqueezedvacuumbeamwhentheprobebeamhasOAM.Withoutinjection,thesensitivitycanreach1/(2N1/2l).Inaddition,byemployinganotherconstructionofanSU（1,1）interferometerwherethepumpbeamhasOAM,withthesameinjectionofanSU（1,1）interferometer,thesensitivityoftheangularrotationmeasurementcanbeimprovedbyafactorof2,reaching1/（4Nl）.Theresultsconfirmthepotentialofthistechnologyforprecisionmeasurementsinangularrotationmeasurements.

简介：根据流体弹塑性内摩擦侵彻理论,系统地提出了超高速动能武器打击侵深、成坑范围和地冲击效应的计算方法,并通过实验获得了超高速弹体以速度为1000~5000m·s-1侵彻岩石的侵深、成坑范围和地冲击压力波时程曲线实验数据。将理论计算与实验结果进行对比,验证了理论模型和计算公式的准确性。建立了超高速动能武器打击地冲击效应与浅埋爆炸之间的等效计算关系,提出了抗超高速动能武器打击最小安全防护层厚度的计算方法与“软硬结合、分层配置”的遮弹防护技术方案。

简介：Onassumingthatweaksubstructurehasadynamicswhichissimilartoquantumchromodynamicsbutmuchstronger,weconcludethatunquenchingisindispensableforpredictionsonthespectrumofweak-substructureresonances[1].

简介：

简介：WeuseamodifiedBecke-JohnsonexchangeplusalocaldensityapproximationcorrelationpotentialwithinthedensityfunctionaltheorytoinvestigatetheelectronicstructuresofHg1-xCdxTeandIn1-xGaxAswithxbeing0,0.25,0.5,0.75,and1.Forbothofthetwoseries,ourcalculatedenergygapsanddielectricfunctions（realpartε1andimaginarypartε2）areinagreementwiththecorrespondingexperimentalresultswithxbeingbetween0and1.Thecalculatedzero-frequencyrefractiveindexvariesgreatlywithxforHg1-xCdxTe,butchangeslittlewithxforIn1-xGaxAs,whichisconsistentwiththerealpartsoftheirdielectricfunctions.Therefore,thisnewapproachissatisfactorytodescribetheelectronicstructuresandtheopticalpropertiesofthesemiconductors.