学科分类
/ 4
70 个结果
  • 简介:这研究向动人的表面为三维的麦克斯韦液体集中于热和集体流动的Cattaneo-Christov理论。有可变热电导率的不可压缩的laminar流动被考虑。流动产生由于表的双向拉长。热和集体运输的联合现象被说明。热和集体散开的Cattaneo-Christov模型被用来开发精力和集体种类的表情。在集体种类方程的一阶的化学反应术语被考虑。边界层假设导致管理数学模型。homotopic模拟被采用设想无尺寸的流动方程的结果。速度,温度,和集中的图显示出不同产生参数的效果。一个数字基准被介绍设想计算结果的会聚的价值。结果证明集中和温度地为热和集体散开的Cattaneo-Christov理论被腐烂。

  • 标签: 数学模型 化学反应 热通量 三维 液体 水动力
  • 简介:ASouthChinaSea(SCS)localTC(SLT)isdefinedasatropicalcyclone(TC)thatformswithintheSCSregionandcanreachthegradeoftropicalstorm(TS)orabove.ThestatisticalfeaturesoftheSLTsfrom1985to2007areanalyzedfirst.ItisfoundthatovertheSCSabout68%oftheTCscandevelopintoTSs.TheSLTintensityisrelativelyweakandassociatedwithitsgenesislatitudeaswellasitstrack.TheSLTmonthlynumberpresentsaseasonalvariationwithtwopeaksinMayandJulytoSeptember.BasedonthedailyheatfluxdatafromtheWoodsHoleOceanographicInstitution_ObjectivelyAnalyzedair-seaFluxes(WHOI_OAFlux)inthesameperiod,theair-seaexchangeduringtheprocessofgenerationanddevelopmentoftheSLTisstudied.Resultsshowthattheheatfluxesreleasedtotheatmosphereincreasesignificantlydaybydaybeforecyclogenesis.TheoceantothesouthtotheTCcenterprovidesthemainenergy.AlongwiththedevelopmentofSLT,theregionswithlargeheatfluxesspreadclockwisetothenorthofTC,whichreflectstheenergydispersionpropertyofvortexRossbywavesintheperipheryoftheTC.OncetheSLTformstheheatfluxesarenotintensifiedasmuch.Duringthewholeprocess,thenetheat,latentheatandsensibleheatfluxdisplayasimilarevolution,whilethelatentheatfluxmakesamaincontributiontothenetheatflux.Themaximumair-seaheatexchangealwaysoccursattheleftsideoftheTCmovingdirection,whichmayreflecttheinfluenceoftheSCSsummermonsoononTCstructure.

  • 标签:
  • 简介:Thepurposeofthepaperistoestablishatheoryoftheconstantheatfluxratioacrossthefrozenlayerbasedonthedimensionalanalysisofthesystemequationsdescribingthefreezingprocesses.Ananalyticalmodelisthendeveloped,utilizingthistheory,forsolvingtheplanar,cylindricalandsphericalfreezingproblemswithbothinwardandoutwardfreezing.Asthereisnoexactsolutionavailableforthecylindricalandsphericalfreezingprocesses,thetemperaturedistributionintheplanarsolidificationobtainedfromthemodeliscomparedwiththeexactsolution.Theyareinexcellentagreement.Forthecylindricalandsphericalfreezing,thecompleteinwardsolidificationtimescalculatedbythemodelarecomparedwiththoseobtainedfromreferences.Theresultsareingoodagreement.Thegreatadvantageoftheproposedmodelisitssimplicityandissufficientlyaccurateformostpracticalapplications

  • 标签: analytical PLANAR CYLINDRICAL SPHERICAL solidification theory
  • 简介:染色体17q21.31倒置是普通结构的多型性首先在欧洲人口发现了的900-kb。尽管在倒置区域以内的基因流动被假定可观压制,它关于在H1(非转换的顺序)和H2(转换顺序)之间的基因交换的细节仍然是不清楚的这倒置的haplotypes。这里,我们在17q21.31区域以内描述在一些基因安排之间的基因交换的一张精制地图。用1,546单个核苷酸多型性的HapMap阶段II数据,我们成功地由加入邻居的树重建在欧洲样品推出了96H1和24H2haplotypes。而且,我们分别地与相互、非相互的基因交换识别了15和26条候选人道。在怀有相互的交换的所有15个区域,haplotypes由克隆定序重建了没支持这些交换事件,建议这在某些异质接合的个人在二个姐妹染色体之间的交换发信号被分阶段执行错误区域引起。在另一方面,与非相互的基因流动越过26条道中的4个定序的完成的克隆证实这种基因交换被基因变换引起。在摘要,更加作为在一些基因安排之间的转线路被压制了,基因变换可能是为在17q21.31的基因交换的最重要的机制。

  • 标签: 人类基因组单体型图 反转区 遗传 欧洲 人口 H2
  • 简介:Thetemporalandspatialvariationsoftheten-daymeansurfacelatentheatflux(TMLH)havebeenanalyzedinthispaperbasedonthedataofNCEPfromJanuaryof1979toDecemberof1995intheSouthChinaSea(SCS)monsoonregion.ItisfoundthatthereexistmaximumcentersofTMLHstandarddeviationinthenorthwestIndochinaandtheIndianPeninsulaaswellasthewesternPacific,SCS,theIndianOceanandtheBayofBengal,andtheirlocationsandstrengthschangesignificantlyduringtheperiodofSCSmonsoononset.ApositivezonaldeviationofTMLHoccursfirstintheIndochinaPeninsula,apparentlyearlierthanthatintheIndianPeninsula.TheappearanceofmaximumpositivezonaldeviationsofTMLHapproximatelycoincideswiththesummermonsoononset.OvertheIndochinaandIndianPeninsulas,theTMLHincreasesgraduallywithasmallamplitudeofvariationbeforetheonsetofsummermonsoon,andtherateofincreaseissignificantlyenhancedaftertheonsetofthemonsoon;whereasovertheocean,TMLHdecreasesbeforethemonsoononset,varieslittleduringtheperiodofmonsoonandincreasesgraduallyaftertheendingofmonsoon.Therefore,itseemsthatthesurfacelatentheatfluxplaysanimportantroleinthemaintenanceofthesummermonsoon,anditsvariationisanphenomenonaccompanyingtheonsetofsummermonsoon.

  • 标签: South China Sea monsoon surface LATENT
  • 简介:Li1.3Al0.3Ti1.7(PO4)3pelletssinteredwithdifferentmolefractionsofLiBO2werepreparedbysol-gelmethod.Thestructuralidentification,surfacemorphology,ionicconductivity,andactivationenergyofthepelletswerestudiedbyX-raydiffraction,scanningelectronmicroscopy,andelectrochemicalimpedancespectroscopy.TheresultsshowthatalltheLi1.3Al0.3Ti1.7(PO4)3pelletssinteredwithdifferentmolefractionsofLiBO2havesimilarX-raydiffractionpatterns.ThesinteredpelletbecomesdenserandtheboundaryandcorneroftheparticlesbecomeillegiblewiththeincreaseofLiBO2.AmongtheLi1.3Al0.3Ti1.7(PO3)4pelletssinteredwithdifferentmolefractionsofLiBO2,theonesinteredwith1mol%LiBO2showsthehighestionicconductivityof3.95×10-4S.cm-1andthelowestactivationenergyof0.2469eV.

  • 标签: 溶胶凝胶法 烧结焊剂 制备 离子导电性 X射线衍射 表征
  • 简介:Ca-dopedBaMgAl10O17:Eu2+,Mn2+(BAM)bluephosphorsweresynthesizedbyfluxassistedsolid-statereactionmethodusingCaF2andBaF2asco-flux.GooddispersityandparticlesizehomogenizationofhexagonalpurephaseBAMwereobtainedbysinteringat1400℃.TheeffectsoftheCa2+ionscontentonthestructure,morphologyandphotoluminescencepropertiesofthephosphorswerestudied.TheresultsindicatedthattheincorporationofCacoulddecreasethelatticeconstant,improvethehomogeneityanddispersityandenhancethephotoluminescence(PL)intensityofthephosphoreffectively.TheoptimumBa0.86Ca0.04Mg0.97Al10O17:0.1Eu2+,0.03Mn2+PLintensitywasenhancedforabout30%andrelativebrightnesswasimprovedabout4%.Furthermore,thesynthesizedBAMandcommercialBAMphosphorswereannealedfor30minat600oCinair.TheCa-dopedphosphorshadstrongeremissionintensity,higherbrightnessandbetterchromaticitystabilitythanthatofthecommercialphosphor.TheseresultsindicatedthatCa-dopedbluephosphorshadgoodpotentialapplicationsinthecommercialtricolorfluorescentlampsaswellasinotherdisplayandlamps.

  • 标签: 光致发光特性 蓝色荧光粉 钙掺杂 氟化钡 氟化钙 蓝色荧光体