学科分类
/ 25
500 个结果
  • 简介:AMonteCarlosimulation,withtheenergeticsdescribedbytheembeddedatommethod,hasbeenemployedtostudythephysicalbehaviourofboronatomsduringrelaxationoftheNi3AlBxgrainboundary,IthasalsobeenusedtocalculatenotonlythepeakconcentrationsofNiandBandthevalleyconcentrationofAlatthegrainboundary,butalsothedependenceofthegrainboundarycohesionontheBbulkconcentration.DuringrelaxationofimpureNi3Algrainboundaries,wesuggestthat,asthesegregatingspecies,theBatomseitherinsertintointersticesinthegrainboundaryorsubstituteNiatoms.Meanwhile,astheinducingspecies,theyinduceNiatomstosubstituteforAlatoms.Calculationsshowthatintheequilibrium,whentheBbulkconcentrationxincreasesfrom0.1to0.9thepeakconcentrationofBincreases,thepeakconcentrationofNimaximizeswhilethevalleyconcentrationofAlminimizesatx=0.5,Thecalculationsalsoshowthebestcohesionofthegrainboundaryatx=0.5。

  • 标签: Ai3AIBx结合能 对称晶粒边界 硼原子
  • 简介:或者方向性含蓄(ADI)计划通常在3D深度移植被使用。它切开3D沿着英文报纸之单行标题和嵌入的方向的方形根的操作员或者。在这糊,基于数据线,四方法的切开计划和他们的切开的错误为的理想有限差别(FD)方法和混合方法被调查。四方法的切开的计划的wavefieldextrapolation在一根数据线上被完成并且无条件地是稳定的。切开错误的数字分析证明双向FD迁居有可见数字各向异性的错误,和移植更不有的那四方法的FD比双向FD移植切开错误。为混合方法,在双向计划和四方法的计划之间的数字各向异性的错误的差别在更低的侧面的速度变化的情况中是小的。在这篇论文介绍的计划能在栈以后的3D或prestack深度移植被使用。3D深度移植的二数字计算被完成。一个人是四方法的FDand混合3D为推动回答的栈以后的深度移植,哪个各向异性的错误能在经常、可变的速度变化的情况中有效地被消除的表演。Theother是为有切开计划的two-wayhybrid的SEG/EAEG基准模型的3D射击侧面prestack深度迁居,它介绍好成像结果。基于射击数字传递接口(MPI)计划的消息被采用。

  • 标签: 3D深度偏移 多路分裂 数据线 波场计算 有限差分 数学分析
  • 简介:Spallationtargetrepresentsoneofthemostchallengingcomponentsinacceleratordrivensystems(ADS)sinceitisthecomponentcouplingtheacceleratorandthesub-criticalcore.Itissubjectedtobombardmentofintenseprotonbeamandveryhighthermalloadinastrongradiationfield.TheirradiatedLBEtargetposesseverehandlingproblemsforthemaintenancestaffandotherscientistsduetoitsresidualactivity[1].ToassistthedesignofADS,thegeneralradiologicalsafetyaspectsoflead,lead-bismutheutectic(LBE)andtungstenspallationtargetwerestudiedwithMCNPX2.7code[2].Thespallationtargetwasirradiatedbya250MeV,10mAprotonbeamproducedbyalinearprotonaccelerator.Theneutronyield,neutronspectrum,residualproductionandtimeevolutionfortheirradiatedtargetwereanalyzed.

  • 标签: Designed China ADS
  • 简介:Molybdenumoxidenanostructuredthinfilmsweregrownonfluorinedopedtinoxide(FTO),indiumdopedtinoxide(ITO)andordinaryglasssubstratesbythermalevaporationprocesswithoutvacuumandcatalystsusingmolybdenumtrioxide(MoO3)powderasasourcematerialandoxygenasacarriergas.Variousmorphologiesincludingnanobelts,disksandhexagonalrod-likenanostructureswereobtainedbychangingthesourceandsubstratetemperaturesduringthegrowthofMoO3thinfilms.Structuralparameters,morphology,compositionandsurfacefeaturesofthefilmswerecharacterizedbyXRD,SEM,EDAX,XPS,AFMandRamanspectroscopy.Thefilmswereorthorhombicinstructurewithpreferredorientationalong(010)plane.Morphologyanalysisrevealsrandomlyalignednanobeltswith40nminthicknessandawidthof800nmand3–12mminlength.Thediskshave1.5μmdiameters,1μmthicknessandhexagonalrod-likenanostructureswithalength,breathandwidthof2μm,1μmand100nmareformed.ThesampleswereinvestigatedunderdarkandphotocurrentconditionsinH2SO4aqueoussolutionasafunctionofappliedpotential.ThephotocurrentdensityofsamplespreparedonITOandFTOsubstratesampleswerecomparedandtheresultsarediscussed.

  • 标签:
  • 简介:现在的纸为与快速的3D片和格子生成器(RAPID3DGRID)相结合的turbomachinery的空气动力学的设计描述优化方法论,一个N.S解答者,一个片parameterization方法(BPM),一个基于坡度的analyseparameterization方法(GPAM),有激增的一个反应表面方法(RSM)算法和一个简单坡度方法。由片parameterization方法的使用,一个接近音速的压缩机转子能被一套多项式表示,然后它使我们能转变表示坐标的片数据到表示参数然后减少参数的数字。与改变任何一个参数,我们能获得几组样品。这里,仅仅十个参数被认为寻找一个优化压缩机转子。由于优化,断热的效率被1.73%增加。

  • 标签: 跨音速压气机 转子 叶片参数 空气动力学设计 优化
  • 简介:Thisletterobtainsatyphoon-likevortexsolutionbysolvingtheBragg-Hawthorneequation.ThesolutiondescribesspiralpathsoffluidmaterialelementontheBernoullisurface,whereassomenewexactsolutionsareobtainedwhichareboundedinthewholeregion.Thefirstoneisacontinuedumbrellavortexsolution,whichisatyphoon-likevortex.Thesecondoneisamulti-planarsolution,whichisperiodicinz-coordinate.Withineachlayer,thereisanumbrellavortexsolutionsimilartothefirstone.Theabove...

  • 标签:
  • 简介:运用多种方法、多种基组对PF(X3∑-)的平衡结构进行优化计算.用QCISD/6—311G(df)方法得到的平衡结构为RPF=0.1589nm,与实验值RPF=0.15897nm进行比较,最为接近,得出QCISD/6—311G(d,)基组为最优基组;然后对PF(X3∑-)进行单点能扫描计算,用正规方程组拟合Murrell-Sorbie函数,得到相应电子态的势能函数解析式,由势能函数计算了与PF(X3∑-)态相对应的光谱常数,结果与实验数据较为一致.这些数据为反应动力学提供了理论依据.

  • 标签: 离解能 Murrell—Sorbie函数 光谱常数
  • 简介:Wehavefoundthattheexcitedenergyfromthegroundstatewith1f7=2configurationtothefirstexcitedstatewith2p3=2configurationin37SisobviouslylowercomparedwiththatinnearbyN=21isotones35Si,39Arand41Ca(seeFig.1,Theinsertindicatestherelevantsingle-particleorbitsofprotonandneutron).ThisinterestingphenomenonmayresultfromthecollapseofN=28closure,whichgivesthesufficientvalencespaceforcollectivedeformationwhichcanbeenrevealedfromtheB(E2)value.Therefore,toobtaintheB(E2),weperformtheexperimentsformeasuringthelifetimeofthefirstexcitedstatein37S.

  • 标签: LIFETIME MEASUREMENT EXCITED
  • 简介:1,2-rearrangementsofcarbenes:CCH2X(X=CH2,NHandO)arestudiedbyusingabinitiogradientmethod.HeteroatomsNandOstabilizethecarbeneanddecreaseitsreactivity,mainlybychangingfrontiermolecularorbitals,butretainthewayofthereaction.ThereactionstartsfromtheattackofthemigratinghydrogenonthecarbenepAOandendswiththeentranceofthehydrogenintothecarbeneσorbital.ReactivitiesareintheorderofX=CH2>NH>O.Thereactionisexothermicorendothermicaccordingtowhethertheproductisa4n+2or4nπelectronmolecule.

  • 标签: membered stabilize reactivity orbital shorter FRONTIER
  • 简介:InthispaperwestudythecomputationalperformanceofvariantsofanalgebraicadditiveSchwarzpreconditionerfortheSchurcomplementforthesolutionoflargesparselinearsystems.Inearlierworks,thelocalSchurcomplementswerecomputedexactlyusingasparsedirectsolver.Therobustnessofthepreconditionercomesatthepriceofthismemoryandtimeintensivecomputationthatisthemainbottleneckoftheapproachfortacklinghugeproblems.InthisworkweinvestigatetheuseofsparseapproximationofthedenselocalSchurcomplements.TheseapproximationsarecomputedusingapartialincompleteLUfactorization.Suchanumericalcalculationisthecoreofthemulti-levelincompletefactorizationsuchastheoneimplementedinpARMS.Thenumericalandcomputingperformanceofthenewnumericalschemeisillustratedonasetoflarge3Dconvection-diffusionproblems;preliminaryexperimentsonlinearsystemsarisingfromstructuralmechanicsarealsoreported.

  • 标签: 稀疏逼近 三维 代数 求解器 舒尔补 SCHUR补
  • 简介:我们在场散布效果的杂质的系统的研究在超导体SrPt3P。用一固态反应方法,我们制作了做Pd的超导体Sr(磅1xPdx)3P.We发现剩余抵抗力0快速增加,Pd做,而剩余抵抗比率(RRR)显示戏剧的减小。另外,霍尔抵抗力xy的非线性的地依赖者行为和在低温度的霍尔系数RH的强壮的温度依赖被做的Pd压制。所有试验性的结果能被由做导致的杂质散布的增加解释。我们的结果建议磅位置对在现在的系统的搬运人传导很关键。

  • 标签: 散射效应 p掺杂 超导体 杂质 PD 固相反应法
  • 简介:FK01isanewstrainofoil-sunflowerwithcytoplasmicmalesterilelineHAasfemaleparentandcytoplasmicmalesterilerestorerline19540asmaleparent.19540isamutantirradiatedbycarbonionwhichseedoilcontentincreases.FK01joined2014Gansuprovinceregionaltestofoil-sunflowerandplantedinsixsites:Jingyuanagriculturaltechniquespreadingcenter,Minqinagriculturaltechniquespreadingcenter,Jingtaiagriculturaltechniquespreadingcenter,Jiuquanagriculturalsciencesresearchinstitute,Tianshuiagriculturalsciencesresearchinstitute,andHuanxianseedcontrolstation.

  • 标签: OIL-SUNFLOWER NEW STRAIN FK01
  • 简介:Conventionalchloromethylation,paraformaldehyde/hydrogenchlorideinaceticacidmedium,wasappliedto1,2-dimethoxybenzene.Chloroform-solublepoly(3,4-dimethoxy-o-tolylene)wasobtainedwithanintrinsicviscosityof0.034dLg~(-1).ThepolymerwasevaluatedasacondensationredoxpolymerprecursorformedbyaFriedel-Craftsreaction.Cleavageofthemethoxygroupspresentinthispolymerresultedinpoly(3,4-dihydroxy-o-tolylene)whichmanifestedagreatair-oxidationresistance.Theredoxpropertyofthelatterpolymerwasfoundtobe1017mVbypotentiometrictitrationwith0.05Ncericammoniumnitrateat25℃.Thismidpotentialwascomparedtothatofcatechol,amonomericanalogue,underthesametitrationconditions.

  • 标签: 合成 聚(3 4-二甲氧基-o甲代亚苯基) 氧化还原剂聚合体 氯甲基化
  • 简介:Catalyticcombustionofpropane-airmixturewasinvestigated.Platinumcatalystsoveraflatstainlesssteelwithγ-aluminawashcoatwereemployed.Theemployedburnerhasthreecatalystssetparalleltothemixtureflow,spacedatanintervalof5,10and15mm.Bothexperimentandnumericalsimulationweremadeatinlettemperatureof553K,inletvelocityof3to7m/sandequivalenceratioof0.3to0.5.Inthenumericalsimulation,two-dimensional,steadystatemodelwasdevelopedtocalculatethetemperatureandspeciesconcentrationingas-phase.Inthismodel.chemicalreactiononthecatalystsurfaceandthatinthegasphasewereassumedtooccurinthree-steps.Thenumericalresultsshowgoodagreementwithexperimentalresults.Itwasfoundthatthepropertiesofthecatalyststronglyaffectthecatalystsurfacetemperature.Especially,thethermalconductivityofcatalysthasagreateffect,whiletheemissivityofcatalysthaslesseffect.

  • 标签: 燃气透平 催化燃烧 C3H8-空气混合
  • 简介:在水的答案的Co3+水和上的详细理论调查借助于模拟基于原子契约electronegativity均等方法熔化了进分子的力学(ABEEM/MM)的分子的动力学(MD)被执行了。有效Co3+离子水潜力被为离子的簇适合到abinitio结构和有约束力的精力构造了。然后离子水相互作用潜力与ABEEM-7P水模型一起在联合被用于单个Co3+(aq)答案的分子的动力学模拟,设法复制答案的许多试验性的结构、动态的性质。这里,不是仅仅共有的财产(光线的分发功能,尖分发功能和solvation精力)获得了因为在ABEEM-7P水答案的Co3+在对从试验性的方法和另外的分子的动力学模拟而且费用分布的很有趣的性质的那些的好同意,水分子的几何学,氢债券,散开系数,震动的系列被ABEEM/MM调查模型。

  • 标签: 水溶液 钴离子 分子动力学模拟 ABEEM/MM模型
  • 简介:Inthispaper,wegivesomedecompositionsoftriplesofZpnorZ3pnintocyclictriplesystems.Newconstructionsofdiferencefamiliesaregiven.Someinfniteclassesofsimplecyclictriplesystemsareobtainedfromthesedecompositions.

  • 标签: 循环设计 n次方 分解 三元系 新建筑 无限类
  • 简介:Theshiftinthepercolationthresholdofcompressedcompositeswasstudiedbya3Dcontinuumpercolationmodel.AMonteCarlo(MC)methodwasemployedinthesimulations.Thepercolationthresholdwasfoundtorisewiththecompressionstrain,whichcapturesthebasictrendincompression-inducedconductivityvariationfromtheexperiments.Bothfiberbendingandtextureformationcontributetothepercolationthreshold.Theresultssuggestthatfillerswithahighaspectratioaremoredesirableforsensorandelectricalswitchapplications.

  • 标签: 蒙特卡洛模拟 压缩应变 复合材料 渗滤阈值 三维 漂移