简介:TheNd2O3nanoparticleswhichmodifiedbyAOTwaspreparedusingmicrioemulsionmethodinthesystemofwater/xylene.L3edgeXAFSwasusedtodeterminethedifferenceofthelocalstructurearundNd^3+ionandtheelectricalstructurebetweenthenanocystallineNd2O3andthecoarsebulkmicrocrystallineNd2O3.ItwasfoundthatNd-Odistanceincreasedwiththeformofnanocrystalliteandtheintensityofabsorptionedgealsoenhancedatthesametime.
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).
简介:目的探讨应用股骨髁部角度钢板与解剖钢板治疗股骨髁部C型骨折的疗效差异.方法对我院1993年12月~2003年6月间治疗的股骨髁部C型骨折患者56例进行回顾性研究.将患者分两组,一组为切开复位角度钢板内固定(23例),另一组为切开复位解剖钢板内固定(33例).通过随访收集56例患者相关临床资料、临床表现及影像学资料,并进行膝关节活动度测定,应用t检验和x2检验比较两组关节活动度差异和患膝功能康复情况.结果术后患者的膝关节平均活动度:角度钢板内固定组为57.17°±17.63°,解剖钢板内固定组为86.09°±26.55°;解剖钢板内固定组患膝功能康复的优良率为90.9%,而角度钢板内固定组的优良率为73.9%.t检验和x2检验结果证明,两组膝关节术后平均活动度及患膝功能康复程度差异均有显著性意义(P<0.05).应用解剖钢板组术后膝关节平均活动度及患膝功能康复明显优于角度钢板组.结论应用解剖钢板内固定比角度钢板内固定治疗股骨髁部C型骨折在术后可获得更好的膝关节活动度和功能康复.