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182 个结果
  • 简介:随着21世纪的临近,现代社会的发展已经向物理教育的内容、方法、手段、评价等提出了严峻的挑战,同时它也为物理教育的现代化创造了良好的条件。

  • 标签: 物理教育 创造 手段 挑战 内容 现代社会
  • 简介:Ti6Al4Visawidelyappliedinmedicalimplantssuchasbone,joint,andteethduetoitsexcellentmechanicalproperties,corrosionresistance,plasticityandthebiocompatibilityofthesurfaceoxide.However,thenativesurfaceoxidefilmisquitethin(about5nm)andtechniquessuchasmicroarcoxidation,plasmasprayedhydroxyapatitaeandplasmaimmersionionimplantationareusedtosynthesizethickersurfacetitaniumoxide.

  • 标签: 微弧氧化 生物活性 TI6A14V 氧化钛保护膜 金属材料
  • 简介:TheCADSdemofacilityisaimedtobuildaprototypelinacforthelowenergypartofthecontinuouswave(CW)superconductingprotonlinacanddemonstratetechnologyinthissection[1].IntheCADSroadmap,therealizationof25MeV10mAbeamisakeypoint.Thus,basedonthe10MeVCADSInjectorIIatIMP,IMPandIHEPwillbothcontributeacryomoduletoreach25MeVatthesiteofIMP[2].Todumpthebeamfromthelinac,webuildanewhighenergybeamtransportlinewithbendingangleof90°,toavoidback-scatteringgammaandneutronbeamstodamagethelinac.Fig.1showsthelayoutofthe25MeVdemofacility.

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  • 简介:对采用P栅增强技术的GaN功率晶体管进行了反应堆1MeV等效中子辐照效应实验。结果表明,在注量为1.5×10^15cm^-2的中子辐照后,器件的阈值电压没有发生明显变化;栅压较大时,辐照后的饱和漏电流变小,这与沟道电子迁移率降低和二维电子气2DEG的退化有关;当漏极电压小于200V时,器件的关态漏电流明显增加,表明中子辐照重掺杂P栅发生的载流子去除效应弱化了P栅在零栅压下对沟道电子的耗尽,但器件栅极反向泄漏电流在辐照后没有变化,说明其对中子辐照具有一定的免疫能力。

  • 标签: 氮化镓功率器件 增强型 栅注入晶体管 GAN 位移损伤效应
  • 简介:Inthiswork,SMAT(surfacemechanicalattritiontreatment)wasperformedonTi6Al4V.PlasmanitridingoftheSMATedsampleswasinvestigatedincomparisonwithcoarse-grainedsamples.Thesampleswerecharacterizedusingopticmicroscope,SEM,TEMandVickersmicrohardnesstester.TheresultsshowedthatasignificantlythickercompoundlayerwithhigherhardnesswasobtainedfortheSMATedsampleswhencomparedwithun-SMATedsamplesafternitriding.CorrosionresistanceofTi6Al4VinaRinger’ssolutionwasstudiedbyelectrochemicaltechniquesincludingopencircuitpotentialmeasurement,potentiodynamicpolarizationandEIS(electrochemicalimpedancespectroscopy).Overall,ourresultsidentifiedthebeneficialimpactsoftheduplexSMAT/nitridingtreatmentoncorrosionbehaviourofTi6Al4V.Weartestswerealsoperformedonaball-on-disctribometerwherethetreatedsampleswererubbedagainsta6mmdiameteraluminaballunderanormalloadof5NusingRinger’ssolutionaslubricantmedia.ThefrictioncoefficientoftheSMATedandnitridedsampleswasreducedcomparedtotheuntreatedsamples.WearratesdemonstratedthatSMATcombinedwithnitridingimprovedwearresistanceofTi6Al4Valloy.

  • 标签: Surface mechanical attrition treatment PLASMA NITRIDING
  • 简介:酒吧的气质永远是暧昧的粉红,情人节浪漫的约会场所。《风尚player》发扬粉红精神,为情人节的各位们,寻找最具电眼的醒目酒保,再通过秘密的大考验来挑选出TOP10有又有料的酒保。我们的目的只有一个,就是各位大饱眼福的同时,知道哪里有最有并有料的醒目酒保啦!毕竟养眼又能调美酒的酒吧,谁不愿意去呢?

  • 标签: TOP10 酒吧 PLAYER 情人节
  • 简介:Inthispaper,asurfacepotentialbasedthresholdvoltagemodeloffully-depleted(FD)recessed-source/drain(Re-S/D)silicon-on-insulator(SOI)metal-oxidesemiconductorfield-effecttransistor(MOSFET)ispresentedwhileconsideringtheeffectsofhigh-kgate-dielectricmaterialinducedfringing-field.Thetwo-dimensional(2D)Poisson’sequationissolvedinachannelregioninordertoobtainthesurfacepotentialundertheassumptionoftheparabolicpotentialprofileinthetransversedirectionofthechannelwithappropriateboundaryconditions.Theaccuracyofthemodelisverifiedbycomparingthemodel’sresultswiththe2DsimulationresultsfromATLASoverawiderangeofchannellengthsandotherparameters,includingthedielectricconstantofgate-dielectricmaterial.

  • 标签: MOSFET 电压模型 SOI 金属氧化物半导体场效应晶体管 空间 阈值
  • 简介:研制成功的6MeV高能工业CT集成检测系统采用磁控管驱动的6MeV射频加速器作为X射线源,成像系统与9MeV高能工业CT相同,扫描方式采用三维锥束扫描。主要技术指标与9MeV工业CT系统接近,其空间分辨率也达到21p/mm(10%的调制度下)。

  • 标签: 工业CT CT系统 面阵探测器 高能 射频加速器 空间分辨率
  • 简介:研究了YBaCu3O~7超导催化剂上CO2的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、CO和少量甲醚。利用XPS、XRD和AFM等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现,在反应过程中,YBa2Cu3O~7由orthombic相转变为tetragonal相。反应活性位可能是Cu(I)物种。反应后催化剂颗粒的分散程度明显提高

  • 标签: CO2加氢 YBa2Cu3O6~7超导催化剂 结构 活性位