学科分类
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500 个结果
  • 简介:Therearemoreandmorecountriestoakeanefforttothestudiesofvanadiumalloyforfusionapplication.NIFSinJapanhasrecentlydevelopedan80kgheatV4Cr4Tialloy(NIFS-heat2)aftertheproductionofa500kgscaleV4Cr4TiinU.S.severalyearsago.PropertyevaluationofthealloyhasbeenputintoaninternationalcollaborationprogramunderthecoordinationofIEA(InternationalEnergyAgency).SWIPhasjoinedthecollabrationonthehydrogenembrittlementresistanceevaluationofthealloyt.

  • 标签: 钒合金 氢脆变 阻抗 NIFS
  • 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:ThehigherorderasymptoticfieldsatthetipofasharpV-notchinapower-hardeningmaterialforplanestrainproblemofModeⅠarederived.Theorderhierarchyinpowersofrforvarioushardeningexponentsnandnotchanglesβisobtained.Theangulardistributionsofstressforseveralcasesareplotted.Theself-similaritybehaviorbetweenthehigherordertermsisnoticed.ItisfoundthatthetermswithhigherordercanbenegleetedfortheV-notchangleβ>45°.

  • 标签: ASYMPTOTIC V-NOTCH higher order terms power-hardening
  • 简介:Thelowfrequencylinecomponentsoftheradiatednoisefromanunderwatertargetusuallyhavebothhighspectrumlevelandsustainedstability.Thisfeaturecouldbeusedtoincreasethedetectionperformanceofconventionalbroadbandenergyintegrationmethod.Therequiredspectrumlevelistheoreticallydiscussedwhenthedetectionperformanceoftheknownlinedetectionisbetterthanthatofbroadbandenergyintegrationmethod.Undertheconditionofthetargetcanbedetectedinlinespectrumband,therelationshipbetweenthelinespectrumlevelandsignaltonoiseratio(SNR)isalsodiscussed.ThispaperproposesalinespectrumtargetdetectionmethodthatamatrixusingDCjumptofluctuationsratiosofsub-bandspatialspectrumandbeamspaceoutputisconstructed.Thismatrixactsasafilterthatthelinespectrumtargetwithcertainfrequencyandazimuthispassedatmost.Byfusingwiththeothersubbandresults,theconventionaldetectionperformancecanbeimproved.Atthesametime,theapplicableconditionanddetectionperformanceareanalyzedinthepaper.Thesimulationandtheseatrialdataprocessingresultsshowthatthealgorithmcaneffectivelyextractweakgoallinespectrumtargetundertheconditionofmulti-interference.Thealgorithmdoesn’tneedmulti-framestatisticsandthedetectionperformanceisclosertotheoptimallinespectrummethod.

  • 标签: 检测性能 波束空间 波动率 空间谱 目标融合 直流
  • 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:证明了图2Kv的可旋转(4,6)圈系存在的充分必要条件为:v≥10,v≡0,5(mod10).更多还原

  • 标签: (4 6)圈系 1-可旋转
  • 简介:旗传递t-设计的分类是代数组合学的一个重要课题.本文主要讨论了旗传递5-(v,k,3)设计.由P.J.Cameron和C.E.Praeger的结论可知,此时设计的自同构群是3-齐次群.本文利用3-齐次群的分类,证明了设计的自同构群不能是仿射型群.

  • 标签: T-设计 自同构群 3-齐次群 仿射型群
  • 简介:<正>Someproblemsinusingv-supportvectormachine(v-SVM)forthepredictionofnonlineartimeseriesarediscussed.Theproblemsincludeselectionofvariousnetparameters,whichaffecttheperformanceofprediction,mixtureofkernels,anddecompositioncooperationlinearprogrammingv-SVMregression,whichresultinimprovementsofthealgorithm.ComputersimulationsinthepredictionofnonlineartimeseriesproducedbyMackey-GlassequationandLorenzequationprovidesomeimprovedresults.

  • 标签: v-SVM NONLINEAR time series prediction
  • 简介:设G是一个2—(v,11,1)设计的可解区传递但非旗传递自同构群,且G点一本原则,则v=p^n,G≤AГL(1,p^n)且p≠2。

  • 标签: 自同构群 传递 原则
  • 简介:介绍了阻变存储器及其I-V特性的测试分析方法。通过测量三明治结构的阻变存储器的I-V特性,采用多种拟合方法,与导电机制原理对比,可以判断器件的导电机制,便于深入分析阻变机理。

  • 标签: 电致阻变 I-V特性 导电机制
  • 简介:LetD(v)dentethemaximumnumberofquintuplesofav-setofpointsXwiththepropertythateverypairofdistinctpointsofXoccursinatmostonequintuple,LetB(v)=[v(v-1)/4]/5],ItisshownisthispaperthatD(v)=B(v)forallv≡0(mod4)with2exceptionsand13possibleexceptions.

  • 标签: 五元集 二元集 模同余 最大数 统计分布
  • 简介:本文要证明不存在一个非平凡2-(v,k,3)对称设计,它的旗传递自同构群的基柱是^2F4(q2)

  • 标签: 设计旗 传递 自同构群
  • 简介:Asidechainliquidcrystallinecopolysiloxane,whichwouldshowelectro-opticeffectsasknownfromlowmassliquidcrystal,wassynthesizedbyhydrosilylationreaction,andthetwohomologousmonomerswithdifferentlengthspacerscontainingSchiff’sbasemesogenwith—NO2terminatedgroupweregraftedtoapolysiloxanemainchain.Residualmonomerincrudeproductiseffectiveinreinforcingtheresponsetoanelectricfieldoverthatofpurepolymericliquidcrystal.

  • 标签: Liquid Crystalline POLYSILOXANE Schiff’s BASE MESOGENS
  • 简介:采用自洽场离散变分Xa(SCC-DV-Xa)方法对纯V2O5及夹层V2O5的能带结构、态密度、键强度、电子集居数等进行了研究.结果表明,Li+引入V2O2层间的最佳位置是在双键氧之下(或之上),且靠近层的中心位置,此时它与周围原子间的作用力非常微弱,并且材料的导电性增强,使夹层复合材料Li+注入/脱出具有很好的可逆性和较好的光学性质.

  • 标签: PEO 夹层复合材料 掺杂位置 电子结构 五氧化二钒 锂离子