学科分类
/ 16
316 个结果
  • 简介:Usingsevenworkingfluids,asystematicexperimentalstudywasperformedtoinvestigatethelocalconvectiveheattransferfromverticalheaterstoimpingingcircularsubmergedjetsintherangeofReynoldsnumberbetween1.17×10^2and3.69×10^4withtheemphasisplacedontheexaminationofPrandtlnumberdependence.Heattransfercoefficientsatthestagnationpointwerecollectedandcorrelatedwiththeplateheldwithinandbeyondthepotentialcore.Radialdistributionofthelocalheattransfercoefficientwasmeasuredwithfivetestliquids.Basedonthemeasuredprofilesofthelocalheattransfer,acorrelationwasdevelopedtocovertheentirerangeoftheadialdistance.Basidesthepresentdata,thecorrelationsdevelopedinthisworkwerealsocomparedwithalargequantityofavailabledataofcircularairjets.Generalagreementwasobservedbetweentheairdataandthecorrelations.

  • 标签: 热传导 喷射 冷却剂
  • 简介:ThepaperisparticularlyfocusedonexaminingtheroleofadulteducationprogrammeintheeconomicdevelopmentofruralwomentherebyenhancingtheprocessofrecoveringNigeria’seconomyfromrecession.Thestudyadoptedasurveyresearchdesignandemployedtheuseofquestionnairetocollectresponsesfrom60respondentswhoarewomenfromJema’aLocalGovernmentAreaofKadunaStateNigeriathathaveundergonetheadulteducationprogramme.Responseswerecollatedandanalyzedusingthemeanscore.Findingsshowedthat,theprogrammehasaverypositiveimpactinhelpingthewomentochangetheireconomicandsocialstatusaswellastheirgeneralwellbeing.Itequallyprovidedthemwithopportunitytoacquireskillsrelevantforself-relianceandtomanagetheirsmallbusinessasaresult,enhancingtheprocessofeconomicrecoveryinNigeria.

  • 标签: ADULT education ECONOMIC RECESSION ECONOMIC recovery
  • 简介:Ceriumoxidenanoparticlescoatedbysodiumbis(2-ethylexyl)sulphosuccinate(AOT)werepreparedbyusingamicroemulsionmethod.Transmissionelectronmicroscopyrevealedanaverageparticlesiaeof2-3nm.X-raydiffractionshowedthattheceriumoxidenanoparticlesretaintheCeF2-typecubicstructureslikethebulkcrystal.Theintermediatevalenceofformallytetravalentcompoundshadbeendetectedbyx-ray-absorptionnear-edgestructetravalentcompoundshadbeendetectedbyx-ray-absorptionnear-degestructure(XANES)spectraofCeLIIIabsorptioninbulkCeO2andtheceriumoxidenanoparticles.Twowellresovedwhitelinescanbeassignedtotheelectronconfigurationsof4f^0Land4f^1L,respectively,whereLdenotesaligandhole.Atthesametime,theceriumoxidenanoparticlesalsoshowedthestructuralfeatresoftrivalentcompounds,incomparisontothetrivalentCe(NO3)3·6H2O.FuorLorentzianfunctionsandtwoarctanfunctionswereusedtofitthenormalizedXANESspectra.Theextendedx-ray-absorptionfine-structure(EXAFS)techniquewasusedtoprobethelocalatomicstructuresaroundtheabsorberCe.ThemultielectrornexcitationeffectontheEXAFSspectrawaseliminated.Acor-shellmodelwasusedtodeducethenear-neighbourstructuralparametersaroundcerium.BulkCeO2witheightoxygenatomslocatedat2.343AwasusedasthereferencesampletoextractthebackscatteringamplitudeandphaseshiftoftheCe-Obond.OnehalfoftheatomelocateatthecorepartwiththeCeF2-typecubicstructures(eightoxyensat2.343AaroundCe),theotherhalfoftheatomsareamorphousphaselocatedintheshellpart(surfaceofthenanoparticles)withapproximatelyCe2O3structuralfeatures(averageedsevenoxygensat2.50AaroundCe).

  • 标签: 氧化铈纳米晶 表面活性剂 X射线近边吸收谱分析 XANES EXAFS 扩展X射线吸收精细结构
  • 简介:摘 要:地方铁路连乐铁路在燕岗车站接入成昆铁路,从而实现与国铁路网的互联互通。燕岗地区同时开工建设的项目有燕岗车站的扩能改造及成昆增建双线工程,在这样一种特殊的历史背景下,更增添了该处接轨方案的不平凡和特殊色彩。接轨方案从2013年开始报批至2021年铁路总公司才最终予以审定,期间各种审查,修改,完善,蜿蜒曲折、辗转反侧,也充分反映了该方案的复杂性。本文从方案的研究思路出发,综合考虑既有铁路、在建铁路、本线特点,以行车组织为导向的前提下,寻求最终经济合理的工程方案。

  • 标签: 地方铁路 燕岗接轨 方案研究。
  • 简介:当时,本地联合不稳定性将发生吸收边界状况和地波浪方程的数字计划允许精力自发地进入计算领域。也就是说,二个计划支持普通波浪解决方案,组速度指了进计算域。消除联合不稳定性的本地人的钥匙是避免如此的波浪答案。为块团在2D波导的P-SV波浪运动的有限元素模拟,为高顺序的稳定的实现的一条途径多播送的公式被提供。与一个一致矩形的网孔,它被证明并且验证那高周波的本地联合不稳定性能被设置等于或比\大的元素尺寸的比率消除(\sqrt2\)乘到S波浪速度的P波浪速度的比率。这些结果能为发另外的吸收边界条件导致的不稳定性问题是珍贵的。

  • 标签: 多次透射公式 P-SV波 有限元模拟 耦合失稳 波导 二维
  • 简介:Ameshlessradialbasisfunction(RBF)collocationmethodbasedontheEringennonlocalelasticitytheoryisdevelopedtocalculatethebandstructuresofternaryandquaternarynanoscalemulti-layeredphononiccrystals(PNCs)withfunctionallygraded(FG)interlayers.Detailedcalculationsareperformedforanti-planetransversewavespropagatinginsuchPNCs.TheinfluencesofFGandhomogeneousinterlayers,componentnumber,nonlocalinterfaceimperfectionsandnanoscalesizeoncut-offfrequencyandbandstructuresareinvestigatedindetail.Numericalresultsshowthatthesefactorshavesignificanteffectsonbandstructuresatthemacroscopicandmicroscopicscales.

  • 标签: 非局部弹性理论 径向基函数 能带结构 纳米尺寸 声子晶体 功能梯度
  • 简介:Objective:Toexaminetheeffectsofratmarrowstromalcells(rMSCs)ongeneexpressionoflocalbrain-derivedneurotrophicfactor(BDNF)andnervegrowthfactor(NGF)afterinjectionofrMSCsintoCisternMagnumofadultratssubjectedtotraumaticbraininjury(TBI).Results:GroupcelltransplantationhadhigherBDNFandNGFgeneexpressionsthanGroupsalinecontrolduringaperiodoflessthan3weeks(P<0.05).Conclusions:rMSCstransplantationviaCisternMagnuminratssubjectedtotraumaticbraininjurycanenhanceexpressionsoflocalbrainNGFandBDNFtoacertainextent.

  • 标签: 基因表达 外伤性脑损伤 神经营养因子 神经生长因子
  • 简介:

  • 标签:
  • 简介:AbstractBackground:Percutaneous local tumor ablation (LTA) and stereotactic body radiotherapy (SBRT) have been regarded as viable treatments for early-stage lung cancer patients. The purpose of this study was to compare the efficacy and safety of LTA with SBRT for early-stage non-small cell lung cancer (NSCLC).Methods:PubMed, Embase, Cochrane library, Ovid, Google scholar, CNKI, and CBMdisc were searched to identify potential eligible studies comparing the efficacy and safety of LTA with SBRT for early-stage NSCLC published between January 1, 1991, and May 31, 2021. Hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were applied to estimate the effect size for overall survival (OS), progression-free survival (PFS), locoregional progression (LP), and adverse events.Results:Five studies with 22,231 patients were enrolled, including 1443 patients in the LTA group and 20,788 patients in the SBRT group. The results showed that SBRT was not superior to LTA for OS (HR = 1.03, 95% CI: 0.87-1.22, P = 0.71). Similar results were observed for PFS (HR = 1.09, 95% CI: 0.71-1.67, P = 0.71) and LP (HR = 0.66, 95% CI: 0.25-1.77, P = 0.70). Subgroup analysis showed that the pooled HR for OS favored SBRT in patients with tumors sized >2 cm (HR= 1.32, 95% CI: 1.14-1.53, P = 0.0003), whereas there was no significant difference in patients with tumors sized ≤2 cm (HR = 0.93, 95% CI: 0.64-1.35, P = 0.70). Moreover, no significant differences were observed for the incidence of severe adverse events (≥grade 3) (OR = 1.95, 95% CI: 0.63-6.07, P = 0.25) between the LTA group and SBRT group.Conclusions:Compared with SBRT, LTA appears to have similar OS, PFS, and LP. However, for tumors >2 cm, SBRT is superior to LTA in OS. Prospective randomized controlled trials are required to determine such findings.INPLASY Registration Number:INPLASY202160099

  • 标签: Stereotactic body radiotherapy Percutaneous local tumor ablation Lung cancer
  • 简介:ZnOfilmscontainingErandGenanocrystals(nc-Ge)weresynthesizedandtheirphotoluminescence(PL)propertieswerestudied.Visibleandnear-infraredPLintensitiesarefoundtobegreatlyincreasedinnc-Ge-containingfilm.Er-related1.54μmemissionhasbeeninvestigatedunderseveralexcitationconditionsupondifferentkindsofGe,ErcodopedZnOthinfilms.1.54μmPLenhancementaccompaniedbytheappearanceofnc-Geimpliesasignificantcorrelationbetweennc-GeandPLemissionofEr3+.Theincreasedintensityof1.54μminGe:Er:ZnOfilmisconsideredtocomefromthejointeffectofthelocalpotentialdistortionaroundEr3+andthepossibleenergytransferfromnc-GetoEr3+.

  • 标签: