学科分类
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446 个结果
  • 简介:到HOCN的HNCO的反应,到HSCN的HNCS和到HSeCN的HNCSe在MP2/6-311++G被学习了(2df,pd)//B3LYP/6-311++G(2df,pd)水平。反应物,转变状态和产品的几何学被优化了,转变状态的几何学第一次被报导。HNCO和HNCS容易被检测而不是HOCN和HSCN的原因被解释了。HNCSe将更容易比HSeCN被检测,这被预言。在反应的化学契约的破裂和形成被电子密度的拓扑的分析方法讨论了。在反应有二种结构转变状态(圣)的计算结果表演学习了。

  • 标签: 分子结构 原子结构 原子物理 能级
  • 简介:ThispaperusesPoincaréformalismtoextendtheLevi-Civitatheoremtocopewithnonholonomicsys-temsadmittingcertaininvariantrelationswhoseequationsofmotioninvolveconstraintmultipliers.Sufficientcondi-tionsallowingsuchextensionareobtainedand,asanapplicationofthetheoryageneralizationofRouth’smotionispresented.

  • 标签: NONHOLONOMIC DYNAMICAL systems Levi-Civita’s THEOREM POINCARÉ
  • 简介:BoththeexpansiveNewton'sinterpolatingpolynomialandtheThiele-Werner'sin-terpolationareusedtoconstructakindofbivariateblendingThiele-Werner'soscula-toryrationalinterpolation.Arecursivealgorithmanditscharacteristicpropertiesaregiven.Anerrorestimationisobtainedandanumericalexampleisillustrated.

  • 标签: 二元混合插值法 有理插值 误差估计 Thiele-Werner插值
  • 简介:TheformationmechanismfortheoctahedralcentralstructureoftheHe7^+clusterisproposedanditstotalenergycurveiscalculatedbythemethodofamodifiedarrangementchannelquantummechanics(MACQM).TheenergyisafunctionofseparationRbetweentwonucleiatthecenterandanapexoftheoctahedralcentralstructure.TheresultofthecalculationshowsthatthecurvehasaminimMenergy-19.7296a.u.atR=2.40α0.ThebindingenergyofHe7^+withrespecttoHe^++6Hewascalculatedtobe0.6437a.u.ThismeansthatthedusterofHe7^+maybeformedinthestableoctahedralcentralstructurewithR=2.40α0.

  • 标签: 形成机制 He7^+ 氦离子群 结合能 八面体中心结构 原子物理学
  • 简介:AmethodforremovimgglucorapheninfromtheextractofRadishpigmentbyanionexchangeresin201×7wasstudied.Theadsorptioncapacityof201×7resinforglucorapheninwas72.8mg/mlresin,theequilibriumtime55minutes,andtheoptinumpH5.5.Allglucorapheninthathadbeenadsorbedon201×7resinwaselutedby1.5BV.hr^-1,eluentinwhincconcentrationofNaOHwas0.05mol·L^-1attheflowrateof1.5BV/h.Extractingsolutionofdeglucorapheninwasenrichedbyvacuumandspraydrying.ApowderproductofRadishpigmentwasobtainedandE1cm^1%=4.30.

  • 标签: 萝卜苷 萝卜甙 红色素 萝卜色素提取 阴离子交换树脂201× 7
  • 简介:牛顿的重复为单个Toeplitz矩阵的组逆的计算被修改。在每次重复,重复矩阵被一个矩阵与一个低排水量等级接近。因为重复矩阵的排水量结构,涉及牛顿的重复的thematrix向量增加能高效地被做。我们证明修改牛顿重复的集中仍然是很快的。数字结果被介绍表明建议方法的快集中。

  • 标签: 牛顿迭代 群逆转 TOEPLITZ矩阵 位移秩
  • 简介:我们学习形式的非线性的堕落椭圆形的问题的解决方案的存在结果,—div(一(x,u,∇u))在Ω的=F,在Ω是ℝN,N≥的一个围住的领域的地方2,一:Ω×ℝ×ℝN→ℝN是Carathéodory功能令人满意自然生长条件和coercivity调节,但是他们验证仅仅大单音的强健。第二条款F属于W−1,p′(Ω,w*)。存在结果被使用L1-version证明薄荷的词根。

  • 标签: 退化问题 引理 索伯列夫空间 计算方法 数学理论
  • 简介:ThisvolumeisdedicatedtoProfessorXiaqiDing,anacademicianoftheChineseAcademyofSciences,ontheoccasionofhiseightiethbirthday.ProfessorXiaqiDingwasbornonMay25,1928,inTaoJiangcounty,Hunanprovince.Hewasgraduatedin1951fromtheDepartmentofMathematics,WuhanUniversity.Becauseofhisoutstandingacademicperformance,hewasselectedrightaftercollegeforhisstudyandresearchat

  • 标签: 院士 数学 教授 生日
  • 简介:Inagasturbineenginecombustor,highlyswirlingcombustionisusuallyadoptedtostabilizeflameandreducepollutantemissions.Swirlcup,asanairblastatomizer,iswidelyusedtoprovideauniformpresentationoffueldropletstothecombustordome.Thispaperinvestigatedtheeffectofsecondaryswirlerontheflowfielddownstreamoftheswirlcupusingparticleimagevelocimetry(PIV).Threeswirlcups’non-reactingflowfieldwerestudied:caseA,BandCwithsecondaryswirlervaneangle53°,60°and68°respectively.Detailedmeanandtransientvelocitiesandvorticityinthecenterplanewereobtained.FromthePIVresults,asharpcontrastflowfieldwasobtainedforcaseAtoothertwocasesduetothelowersecondaryswirlingintensity.TherecirculationzoneiscollapsedindisorderforthecaseA.Ignitiontestsofthethreecupswerecompletedinasinglecupcombustor.Ingeneral,theignitionperformanceincreaseswiththeincreasingofthesecondaryswirlingintensity.ForcaseA,theignitionperformanceisveryunstableandhasmuchrandomnessandthereisnoclearleanignitionboundarycanbegenerated.Thisworkcanfurtherunderstandtheswirlbehaviorandignitionmechanism.

  • 标签: 点火性能 反应流场 旋流器 粒子图像测速技术 燃气涡轮发动机 空气雾化喷嘴
  • 简介:Small-angleX-rayscattering(SAXS)usingsynchrotronradiationasX-raysourcehasbeenemployedtocharactcizcthemicroscopicstructrureoforgano-modifiedmesoporousmolecularsieves(organo-MSU-X)preparedbyaone-pottemplate-directedsynthesis.ItisshownthattheSAXSprofileishardlyconstantwithPorod’slawshowinganegativeslope,i.e.,negativedeviation.Thissuggeststhatthereisdiffuseinterfaciallayerlocatedbetweentheporesandthematrix.Thissuggeststhattheorganicgroupsremaincovalentlylinkedtothematrix,asindicatedby^29SiCPMASNMRandFT-IR.Theaveragethicknessoftheinterfaciallayerwasfoundtobeabout1nmforeachofthethreesampleswithdifferentkindsandthesameamounts(20?oforganicgroups.Thiskindofmaterialhasalsobeenprovedtopossessbothsurfaceandmassfractalstructureoftheamophousporoussilicamaterials.2001ElsevierScienceB.V.Allrightsreserved.

  • 标签: 中孔材料 SAXS 小角X射线散射分析 界面层 结构特征 有机中孔分子筛