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500 个结果
  • 简介:开展多轴振动台的随机振动控制,以6自由度液压振动台(简称振动台)为典型受控对象,对设计的多输入多输出(简称MIMO)随机振动控制算法,进行了算法研究与验证。在研究,考虑振动台为非完全解耦系统。

  • 标签: 随机振动控制 液压振动台 6自由度 MIMO 仿真 多输入多输出
  • 简介:考虑介质漏电情况,分析和研究非平行板电容器的漏电性能,给出漏电电阻和热功率密度的分布,证明在非平行板电容器内的热功率能量损耗仍是通过场传输的。

  • 标签: 非平行板电容器 漏电性能 能量传输
  • 简介:本文以碱金属钠原子光谱线系的理论公式和实验数据结果为基础,对用光谱项作碱金属原子能级的常用方法及存在问题作了分析,并给出了改进办法。

  • 标签: 碱金属 钠原子 光谱项 线系限 能级图
  • 简介:ThefirststarsintheearlyUniversewereformedabout400millionyearsafterthebigbang.VerificationoftheexistenceofthesestarsisimportantforourunderstandingoftheevolutionoftheUniverse[1].IthasbeenpredictedthatforPopulation-IIIstellarproductionyields,theabundancesofodd-Zelementsareremarkablydeficientcomparedtotheiradjacenteven-Zelements[2].Astronomersaresearchingforlong-lived,lowmassstarswiththeuniquenucleosyntheticpatternmatchingthepredictedyields[3].

  • 标签: FIRST DIRECT MEASUREMENT
  • 简介:Radiotherapyisacommontreatmentmodalityforheadandneckcancers,nasopharyngealcancers,primarybraintumorsandbrainmetastases.Alargenumberofpatientsintheworldwithprimaryormetastaticbraintumorswillrequirelargevolumeorwholebrainirradiationeveryyear.However,therapeuticirradiationnotonlykillstumorcells,butalsoinjuresnormalbraintissue,whichiscommonlyassociatedwithsignificantfunctionalmorbidityanddecreasedqualityoflifeinpatientstreatedwithbrainradiotherapy[1].

  • 标签: Protective Effects Hydroxysaffor
  • 简介:Theabinitiogeneralizedgradientapproximation(GGA)+Ustudyofmultiferroic(La0.5Bi0.5)2FeCrO6inpnmastructureandferri-magneticorder,includingHubbardcorrections(U-4.1eV)fortransitionmetal/rareearthd-electronswith20atomscell,showsoptimumlocalmagneticmomentsof(Cr^3+,Fe^3+)equalto(-2.56,4.14)#Bandanidealspin-downbandgapof1.54eV.Tuned-bandgapLa-substituteddoubleoxideperovskitesBFCOshouldexhibitenhancedvisible-lightabsorptionandcarriermobility,thuscouldbeconvenientlightabsorbersandthenefficientalternativestowide-gapchalcopyriteabsorber-basedsolarcellsfailingtoachievehighestpowerconversionefficiencies,andevencompetewiththeirmetal-organichalideperovskitescounterparts.

  • 标签: OPTIMAL Bandgap Double Perovskite La-Substituted Bi2FeCrO6
  • 简介:H+-restackednanosheetsandnanoscrollspeeledfromK4Nb6O17displaydifferentstructuresandsurfacecharacters.Thetworestackedsampleswithincreasedsurfaceareashaveanamazingvisible-lightresponseforthephotodegradationofdyes,whichissuperiortocommercialTiO2(P25)andNb2O5.Bycomparison,H+/nanosheetshavearelativelyfasterphotodegradationrateoriginatedfromlargeandsmoothbasalplane.Theworkrevealsthatdyeadsorbedontheunfoldednanosheetscaneffectivelyharvestsunlight.Duetofacilepreparation,low-costandhighphotocatalyticefficiency,H+/nanosheetsandH+/nanoscrollsmightbeusedforthevisiblelight-drivendegradationoforganicdyesasasubstituteforTiO2inindustry.

  • 标签: 可见光降解 染料吸附 纳米 堆栈 压入 可见光响应
  • 简介:“应用一探究一应用创新”教学模式强调学生在简单的应用实例中提出问题,引发探究,获取知识,并进行应用创新,从而培养学生的创新精神、实践能力.文中以笔者受邀在2011年浙江师范大学主办的“睿智大讲坛”全国中小学学科名师教学峰会上的展示课《电路》为例,简单介绍了本教学模式的具体应用及效果.

  • 标签: 应用 探究 应用创新
  • 简介:Wehavereportedthemassmeasurementsofneutron-deficientnuclides79Y,81;82Zr,83;84Nbinthisyear’sAnnualReport.However,fortheN=ZnuclidesclosetoA=80,theyieldismuchlowerandeveniftheycanbeproduced,thereisstillgreatdifficulttoidentifythembecauseoftheirquitesimilarmass-to-chargeratioandrevolutiontimes.However,theirmassareextremelyimportantforrapidprotoncaptureprocess,forexample,80Zrand84Moarewaitingpointsofrp-process.Theirmassescangreatlyeffectthereactionflowofprotoncaptureonthemandthentheabundanceoftheheaviernuclides.Inaddition,theseparationenergyof84Mo(determinedbythemassof80Zrand84Mo)hasastrongimpactonthe83Nb(p,α)reactionrateandplaysakeyroleintheformationofZr-NbFig.

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  • 简介:合成了一维绳梯链状双金属化合物[Ni(en)2]3[Fe(CN)6]2·2H2O,并对其变温穆斯堡尔谱进行了研究,结果表明该分子磁体中铁的电子态为低自旋Fe3+,而大的四极分裂值(QS)表明此化合物的[Fe(CN)6]3-单元对称结构发生了形变,低温时出现的磁弛豫谱,给出了在该温度点附近出现铁磁耦合相互作用的信息。

  • 标签: 穆斯堡尔谱 磁弛豫 形变
  • 简介:在“浮力”,我们容易混淆以下几个概念,正确地区分这些概念对我们解浮力题是很有必要的.

  • 标签: 中等教育 物理 教学方法 浮力