学科分类
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106 个结果
  • 简介:<正>平面直角坐标系确定了平面内点的位置,使数与形结合起来,实现了运用代数方法解决几何问题,也实现了借助图形直观地探索数量关系的规律性,在数学史上具有重大的意义.因此,平面直角坐标系中确定点的位置的量--坐标,就是中考必考的内容.

  • 标签: 专题复习 平面直角坐标系 数学史 数量关系 数形结合思想 代数方法
  • 简介:ThepreparationoftwotypesofmolecularsievesAlPO4-11andMAPO-11isreported.Theparticlesizeofthelatterishundredsofmicrons,about10timeslargerthanthatoftheformer.TheXRD,IRandDTAspectrahavedemonstratedthatmagnesiumhasbeenintroducedintotheframeworkofAlPO4-11.ThesuccessfulpreparationoflargesinglecrystalofMAPO-11willopenupanewareaforthepreparationoflargemolecularsievescrystalsinthefuture.ThelargeMAPO-11crystalcompoundisapromisinghostforthehost-guestassemblyofcompositematerials.

  • 标签: 单晶体 磷酸铝-11 MAPO-11 分子筛 晶体生长
  • 简介:2006年8月,“ICPE2006国际物理教育大会”在日本东京召开,东南大学恽瑛教授在会议上作题为《通过双语物理教学培养大学一年级学生的创新能力》的报告,恽瑛教授带领的2005级本科生李鑫、杜源、胡特、姜坤也分别作了口头报告和张贴报告。他们在会议上的精彩发言与会议期间的表现,引起了与会代表和著名的《Science》杂志的极大兴趣。

  • 标签: 《SCIENCE》 大学一年级 日本东京 物理教育 创新能力 物理教学
  • 简介:著名数学家陈景润英年早逝,1996年3月19日病故,终年63岁.这对于一个有建树的科学家来说,实在是太短暂了……。

  • 标签: 陈景润 建树 文章 数学家 著述 科学家
  • 简介:134Csabranchingpointins-processpathwhichisshowninFig.1.Thebranchingratioisdefinedasfβ=λβ/(λβ+λn).Itcouldbededucedfromtheabundanceof134Baand136Basince136Bagoesthroughbothdecayandneutroncaptureof134Cswhile134Baonlyexperiencesdecaychannel[1].Duetoboth134Baand134Baarepures-processnuclei,thisbranchingpointisagoodapproachtodeterminethes-processparameters.Withtemperaturedependentβ-decayrateof134Cs,thetemperatureofs-processcouldbededuced.

  • 标签: PATH GOES IS BE
  • 简介:InstitutionofModernPhysics(IMP)hasdesigned,fabricatedandinstalledthefirstSRFcavityelectropolishingsystemofChina.It’ssizedfor1.3GHzSRFcavities,andalsocanworksformultiplecellcavitieswithfurtherupgradeofstructure.

  • 标签: Electro-polishing SYSTEM IMP
  • 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.

  • 标签: THEORETICAL PHYSICS GROUP
  • 简介:A题:计划生育政策调整对人口数量、结构及其影响的研究人口的数量和结构是影响经济社会发展的重要因素。20世纪70年代后期以来,我国鼓励晚婚晚育,提倡一对夫妻生育一个孩子。该政策实施30多年来,有效地控制了我国人口的过快增长,对经济发展和人民生活的改善做出了积极的贡献。但另一方面,其负面影响也开始显现。如小学招生人数(1995年以来)、高校报名人数(2009年以来)逐年下降,劳动人口绝对数量开始步入下降通道,人口抚养比的相变时刻即将到来。这些对经济社会健康、可持续发展将产生一系列影响,引起了中央和社会各界的重

  • 标签: 夏令营题目 建模夏令营 数学建模
  • 简介:TheprogressofresearchgoingoninGroupofEnergyMaterials(GEM),MaterialResearchCenter,in2014isinthefollowingthreeaspects.1.FacilitydevelopmentInordertopushforwardourstudyonfusionreactormaterials,weupgradedtheirradiationterminal(128#)ofthesectorfocusedcyclotron(SFC)atHIRFL,bydevelopinganewspecimenstagespecificforirradiationwithlow-fluencescatteredions.Sofartheterminaliscapableofirradiationtobothverylowfluences(106ions/cm2)andveryhighfluences(typically1016ions/cm2)forvariousmaterials.SpecimentemperaturecanbereadilycontrolledusingtheL-N2coolingstageorthethehigh-Tstage(upto600oC).Ourrecentinvestigationwithtransmissionelectronmicroscopy(TEM)ofthedefectsproducedbyhigh-energyNeionsinsteelspecimensprovidesaclearevidencethatdefectswereproduceduniformlyalongthedepthinthespecimen,indicatingthattheenergydegraderoftheterminalworkseffectivelytodispersetheionenergyinawiderange.AphotooftheterminaltogetherwithaSRIMestimateofdepthprofilesofdamageinan8%Crreducedactivationferritic/martensiticsteel(RAFMS)isshowninFig.1.

  • 标签: RESEARCH PROGRESS ENERGY
  • 简介:HierarchicalZSM-11microsphereswithintercrystallinemesoporouspropertiesandrod-likecrystalsintergrowthmorphologyhavebeensynthesizedusingaspotoftetrabutylammoniumasasingletemplate.XRD,FTIR,SEM,TEMandN2adsorptionanalysisrevealedthateachindividualparticlewascomposedofnanosizedrodcrystalsinsertingeachotherandtheintercrystallinevoidsexistingamongrodsgaveasignificantmesoporesizedistribution.Steamtreatmentresultdemonstratedtheexcellenthydrothermalstabilityofsamples.Variouscrystallizationmodesincludingconstanttemperaturecrystallization(one-stagecrystallization)andtwo-stagetemperature-varyingcrystallizationwithdifferent1ststagedurationswereinvestigated.TheresultssuggestedthatthecrystallizationmodesweremainlyresponsiblefortheadjustableparticlesizeandtexturalpropertiesofsampleswhilethesmallamountoftetrabutylammoniumbromidewasmainlyusedtodirecttheformationofbothZSM-11frameworkanditsintergrowthmorphology.Furthermore,theperformanceofoptimalZSM-11asanactivecomponentforthecatalyticpyrolysisofheavyoilwasalsoinvestigated.Comparedwiththecommercialpyrolysiscatalyst,thehierarchicalZSM-11catalystexhibitedahighselectivitytodesiredproducts(LPG+gasoline+diesel),aswellasamuchlowerdrygasandcokeyield,plusahighselectivityandyieldoflightolefins(C=3C=4)andverypoorselectivitytobenzene.Therefore,fullyopenmicropore-mesoporeconnectivitywouldmakesuchhierarchicallyporousZSM-11zeolitesveryattractiveforapplicationsincleanpetrochemicalcatalysisfield.

  • 标签: intercrystalline MESOPORE ROD-LIKE crystal single TEMPLATE