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23 个结果
  • 简介:In1874FrancisGalton,aBritishpolymath,analysedasampleofEnglishscientistsandfoundthevastmajoritytobefirst-bornsons.Thisledhimtospeculatethatfirst-bornchildrenenjoyedaspeciallevelofattentionfromtheirparentsthatallowedthemtothriveintellectually.HalfacenturylaterAlfredAdler,anAustrianpsychologist.

  • 标签: 高校 英语学习 学习方法 阅读知识 阅读材料
  • 简介:ExperimentsontheNationalIgnitionFacilityshowthatmulti-dimensionaleffectscurrentlydominatetheimplosionperformance.Lowmodeimplosionsymmetryandhydrodynamicinstabilitiesseededbycapsulemountingfeaturesappeartobetwokeylimitingfactorsforimplosionperformance.Onereasonthesefactorshavealargeimpactontheperformanceofinertialconfinementfusionimplosionsisthehighconvergencerequiredtoachievehighfusiongains.Totackletheseproblems,apredictableimplosionplatformisneededmeaningexperimentsmusttrade-offhighgainforperformance.LANLhasadoptedthreemainapproachestodevelopaone-dimensional(1D)implosionplatformwhere1Dmeansmeasuredyieldoverthe1Dcleancalculation.Ahighadiabat,lowconvergenceplatformisbeingdevelopedusingberylliumcapsulesenablinglargercase-to-capsuleratiostoimprovesymmetry.Thesecondapproachisliquidfuellayersusingwettedfoamtargets.Withliquidfuellayers,theimplosionconvergencecanbecontrolledviatheinitialvaporpressuresetbythetargetfieldingtemperature.Thelastmethodisdoubleshelltargets.Fordoubleshells,thesmallerinnershellhousestheDTfuelandtheconvergenceofthiscavityisrelativelysmallcomparedtohotspotignition.However,doubleshelltargetshaveadifferentsetoftrade-offversusadvantages.Detailsforeachoftheseapproachesaredescribed.

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  • 简介:一家全球企业必须连续地改进在供应链合作者之间的逻辑操作的效率。在供应链集成逻辑服务,资源,和必要信息流动保证效率和功效对这些公司极其重要。全球逻辑服务公司从他们的顾客面对挑战提供合算的逻辑服务,精确,并且无缝地集成材料,信息和现金流动。在这研究,为包罗一切的逻辑服务的一个改进框架系统地被设计,分析,并且评估。包罗一切的逻辑服务框架,在四定义模型,被开发在全球供应链上下文以内向企业提供综合、全面的服务。服务重要性的层次用四张范畴问询表被估计。这研究在分发工业提供包罗一切的逻辑服务的实现的案例研究并且表明在不同需求条件下面操作的框架。最后,系统动力学原因的评估被用来评估逻辑服务框架的优点。

  • 标签: 包罗一切的逻辑服务 逻辑管理 供应链管理 系统动力学建模
  • 简介:轧了nanorods被磁控管劈啪作响和加氨系统综合,并且Tb中间的层的厚度被改变学习效果在上轧了nanorods。结果被扫描电子测试显微镜学(SEM),X光检查衍射(XRD),传播电子显微镜学(TEM),高分辨率的传播电子显微镜学(HRTEM),和光致发光(PL)系列。结果证明Tb层的厚度在形式,质量,和光性质上有明显的效果轧了nanorods。在房间温度的PL系列在368点显示出一座很强壮的排放山峰?nm和弱排出物在387点达到顶点?当Tb层是20时,为生产样品的山峰的nm,和紧张到达最大值?nm。最后,20的最佳的厚度?为综合的Tb中间的层的nm轧了nanostructures被完成。

  • 标签: GAN纳米棒 中间层 高分辨透射电子显微镜 厚度 TB 合成
  • 简介:Ahybridmodeofone-andtwo-surfacemultipactoronthegrooveddielectricsurfaceisstudiedindetailusingbothananalyticalapproachandtwo-dimensionalparticle-in-cell(2DPIC)simulations.WhenthegroovewidthLeE0/(4πmef2),bothslopesmayhavethemultipactors.TheelectronsurfacedensityofthemultipactordischargehasasharpincreaseatthelengthL=eE0/(4πmef2).

  • 标签: 介质表面 混合模式 倍增 刻槽 电子密度 PIC
  • 简介:一项新的研究发现,在耶鲁首次发现的renalase蛋白,可以保护细胞免遭导致心脏病和肾衰竭的严重损伤。一直以来,高血压、中风和糖尿病呈高发趋势,具有氧化还原活性的renalase的单核苷酸基因多态性,与这些疾病相关联。

  • 标签: 心脏病 E蛋白 肾衰竭 PLOS 单核苷酸基因多态性 严重损伤
  • 简介:双人脚踏车催化系统,由乙烯二度(indenyl)组成有二不同cocatalysts,alkylaluminum(diethylaluminium氯化物或trialkylaluminum)和methylaluminoxane的锆二氯化物,在作为唯一从乙烯准备分叉的聚乙烯被采用单体。催化系统racet(Ind)2ZrCl2/AlEt2Cl/MAO展出了高加入(29.0/1000C)。oligomerization和copolymerization反应在双人脚踏车调节催化系统,以及不同cocatalysts,在催化活动和获得的聚合物的性质有效果例如融化温度,crystallinity,分子的重量和分子的重量分发。而且,oligomerization反应条件是在改变聚乙烯的性质和结构的主要因素。

  • 标签: 支化聚乙烯 助催化剂 金属茂催化剂 串联 制备 甲基铝氧烷
  • 简介:这份报纸表明D不变的多项式subspaces的二个班的等价,即,subspaces的这二个班是宽度一个的不同代表D不变的subspace。而且,作者为宽度一个在理想的插值解决分离近似问题D不变的subspace。也就是,作者发现点以便在这些点的评估functionals的限制空间是给定的D不变的subspace导致的功能的空间,当评估点都在一个点联合。

  • 标签: 宽度一个 D 不变的多项式 subspace 分离近似问题 理想的插值
  • 简介:OrderedmesoporouscopperincorporatedAl2O3(Cu/Al2O3)withhighCudispersionwerepreparedbyafacilesolutioncombustionsynthesismethodusingaluminumnitrateandcoppernitrateasoxidantsandureaasfuel.Itisafacileandgreenroutetosynthesizecatalystsfordimethyletherdirectlyfromsyngas.Cu/Al2O3catalystswerecharacterizedbyXRD,N2adsorption–desorption,SEM-EDS,andH2-TPR.Theresultsindicatethatthecatalystsobtainanorderedmesoporousstructureandcopperishomogenouslydispersed.ThemesoporousCu/Al2O3catalystswereutilizedasbifunctionalcatalystsinsyngastodimethyletherreaction(STD).ThecoppercontentaffectsthecatalyticperformanceinSTDreaction.TheCOconversionandDMEselectivityofCu/Al2O3with15%coppermolarratioachieve52.9%and66.1%,respectively.Moreover,themesoporousCu/Al2O3catalystsshowexcellentstabilityinSTDreaction.

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  • 简介:Thispaperisconcernedwithasingularlimitfortheone-dimensionalcompressibleradiationhydrodynamicsmodel.ThesingularlimitweconsidercorrespondstothephysicalproblemoflettingtheBouguernumberinfinitewhilekeepingtheBoltzmannnumberconstant.InthecasewhenthecorrespondingEulersystemadmitsacontactdiscontinuitywave,WangandXie(2011)[12]recentlyverifiedthissingularlimitandprovedthatthesolutionofthecompressibleradiationhydrodynamicsmodelconvergestothestrongcontactdiscontinuitywaveintheL∞-normawayfromthediscontinuitylineatarateofε14,asthereciprocaloftheBouguernumbertendstozero.Inthispaper,WangandXie’sconvergencerateisimprovedtoε7/8byintroducinganewaprioriassumptionandsomerefinedenergyestimates.Moreover,itisshownthattheradiationfluxqtendstozerointheL∞-normawayfromthediscontinuityline,ataconvergencerateasthereciprocaloftheBouguernumbertendstozero.

  • 标签: 流体力学模型 收敛速度 辐射通量 可压缩 一维 接触面
  • 简介:Aseriesofmetalsalt-modifiedcarboncatalystshadbeenpreparedtostudytheselectivetransformationofvariouscarbohydratesintoethyllevulinateinanethanolmedium.ThespecifictexturalandchemicalcharacteristicsofpreparedcarbonsampleswereidentifiedbyRaman,XRD,XPS,NH3-TPD,FT-IRandnitrogenphysisorption.Variousparameterssuchasethanol/watervolumeratio,NaCladdition,reactiontemperature,andcatalystdosageplayedagreatroleinethyllevulinateproduction.Adesirableethyllevulinateyieldof58.0mol%withahighestROF(rateofethyllevulinateformationpergramofcatalystperhour)valueof2148.3μmol/(gcat·h)wasachievedat468KoverFeCl3modifiedcarboncatalystwithrespecttofructoseconversion.Therecyclingexperimentsrevealedthatthesulfonatedcarboncatalystsexhibitedrelativelysatisfiedactivityandstability.

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  • 简介:AIM:Todeterminereallifeclinicaloutcomesinpoorlyresponsiveandtreatment-naveneovascularage-relatedmaculardegeneration(nvAMD)patientsusingbimonthlyfixeddosingafliberceptregimen.METHODS:Thiswasaretrospectivestudyof165eyeswithnvAMDstartedonafliberceptatSouthamptonEyeUnitbetweenJune2013andJune2014.Patientswereeitherswitchedfromprorenata(PRN)ranibizumab/bevacizumabduetopoorresponse(107eyes),ortreatment-nave(58eyes).Patientsinitiallyreceived3-monthlyintravitrealafliberceptinjectionsfollowedby2-monthlyfixeddoses.Clinicvisitswerescheduledatmonth0,4,10and12.Meanchangeinbest-correctedvisualacuity(BCVA)andcentralretinalthickness(CRT)frombaselinewereassessedusingtheWilcoxonsignedranktest.TheproportionofpatientsmaintainingBCVA(<15lettersloss)at12mowasalsoevaluated.RESULTS:MeanBCVAchangeatmonth12was+3.29and+4.67lettersintheswitchedandnaveafliberceptgroupsrespectively(P<0.01).BCVAwasmaintainedin95.3%ofswitchedand96.6%ofnavepatients.CRTatmonth12showedadecreaseof-6.16μmintheswitchedgroupand-35.36μminthenavegroup(P<0.01).Patientspreviouslytreatedwithranibizumab/bevacizumabhadonaveragereceived7.4ranibizumab/bevacizumabinjectionsover12.6mo,attending10clinicvisits.Thefixeddosingafliberceptregimenrequiredanaverageof7.1injections(navegroup),7.5injections(switchedgroup)and4clinicvisitsperyear.CONCLUSION:Fixedbimonthlyafliberceptiseffectiveinbothtreatment-naveandpoorlyresponsivenvAMDpatients.Adoptingafixeddosingregimencanreducepatientburdenwithoutcompromisingonoutcomes.

  • 标签: AGE-RELATED MACULAR DEGENERATION RANIBIZUMAB AFLIBERCEPT anti-vascular
  • 简介:2013年12月,经过长时期整修的克利夫兰艺术博物馆(TheClevelandMuseumofArt)重新向公众开放,这使得它作为美国中西部艺术重镇的地位更加巩固。

  • 标签: 艺术博物馆 观众互动 ONE 中西部
  • 简介:New[1+1]and62-membered[2+2]Schiffbasemacrocyclescontaininga2,6-diamidopyridinesubunithavebeensynthesizedbycondensationreactionoftheprecursorspyridine-2,6-dicarboxamideand1,10-bis(20-formylphenyloxy)decaneinthepresenceofphosphoricacidviaaone-potprocess.Thecyclocondensedproductswereeffectivelyisolatedbygelcolumnchromatographyandcharacterizedby~1HNMR,FTIR,massspectrometryandX-rayanalysis.Thetwomacrocycleshaveatwistedstructure,andnotanopen‘circular’conformationinthesolidstate.

  • 标签: 大环化合物 一锅法合成 凝胶柱层析 X射线分析 反应合成 FTIR