简介：Inthispaper,weproposeandexperimentallydemonstrateamethodtorealizeapolarizationdetectorbyusingacommerciallyavailablepolymethylmethacrylate(PMMA)pipe.Anasymmetricpolarization-relatedstructureisfabricatedbyetchingdifferentgratingstructuresontheexternalsurfaceofthepipe.Theresultsshowthatwhenthepiperotatesupto90°,thepeakofthetransmissionspectrumcanevidentlyshifttowardsthelowfrequency,whichmeansthepipewithgratingstructurescanserveasapolarizationdetector.Thisdesignpossessesthemeritsofasimplestructureandeasyfabrication.

简介：WedemonstratethegenerationofQ-switchedpulsesfromanytterbium-dopedfiberlaser(YDFL)usingquantumdot(QD)CdSeasapassivesaturableabsorber(SA).TheCdSeQDisfabricatedbythesynthesisofCdO,Se,andmanganeseacetateandparaffinoilandoleicacidasthesolventandsurfactant,respectively.TheCdSeQDisthendopedintopoly-methyl-methacrylate(PMMA)viaanemulsionpolymerizationprocess.APMMAhostedCdSeQDthinflakewithahomogeneousendsurfaceisthenformedandplacedbetweentwoferrulesandassembledinaYDFLcavitytoachievetheQ-switchingoperationwitharepetitionrateof24.45to40.50kHzwhilevaryingthepumppowerfrom975to1196mW.Thepulsewidthchangesfrom6.78to3.65μswithamaximumcalculatedpulseenergyat0.77μJatapumppowerof1101mW.ThisworkmaybethefirstdemonstrationofCdSeQD-basedQ-switchinginanall-fiberconfigurationthatshouldgiveproportionalinsightintosemiconductorQDmaterialsinphotonicsapplications.

简介：目的分析直入式骨水泥注入椎体强化方法在体外提高螺钉稳定性的效果。方法采用新鲜尸体脊柱标本共24个椎体,一侧椎弓根采用直入式注入PMMA骨水泥强化椎弓根钉固定作（试验组）,另一侧椎弓根采用常规椎弓根螺钉固定（对照组）,两侧进行最大轴向拔出力试验、最大旋出力矩试验、周期抗屈试验生物力学测试,比较两组测试结果。结果骨水泥强化组中螺钉的稳定性均显著强于单纯常规椎弓根螺钉组（P〈0.05）。结论应用PMMA行椎体强化椎弓根钉固定有利于增强对椎弓根钉的把持力,可有效防止椎弓根钉的松动及脱落,具有良好的临床效果。

简介：ThisarticleaddressesthesynthesisoforganicallytailoredNi-Allayereddoublehydroxide(ONi-AlLDH)anditsuseinthefabricationofexfoliatedpoly(methylmethacrylate)(PMMA)nanocomposites.ThepristineNi-AlLDHwasinitiallysynthesizedbyco-precipitationmethodandsubsequentlymodifiedusingsodiumdodecylsulfatetoobtainONi-AlLDH.NanocompositesofPMMAcontainingvariousamountsofmodifiedNi-AlLDH(3wt%?7wt%)weresynthesizedviasolventblendingmethodtoinvestigatetheinfluenceofLDHcontentonthepropertiesofPMMAmatrix.SeveralcharacterizationmethodssuchasX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),Fouriertransforminfraredspectroscopy(FTIR),rheologicalanalysis,differentialscanningcalorimetry(DSC)andthermogravimetricanalysis(TGA),wereemployedtoexaminethestructural,viscoelasticandthermalpropertiesofPMMA/OLDHnanocomposites.TheresultsofXRDandTEMexaminationconfirmtheformationofpartiallyexfoliatedPMMA/OLDHnanocomposites.TheFTIRresultselucidatethatthecharacteristicbandsforbothpurePMMAandmodifiedLDHarepresentinthespectraofPMMA/OLDHnanocomposites.Rheologicalanalyseswerecarriedouttoexaminetheadhesionbetweenpolymermatrixandfillerspresentinthenanocompositesample.TheTGAdataindicatethatthePMMAnanocompositesexhibithigherthermalstabilitywhencomparedtopurePMMA.ThethermaldecompositiontemperatureofPMMA/OLDHnanocompositesincreasesby28KcomparedtothatofpurePMMAat15%weightlossasapointofreference.IncomparisonwithpurePMMA,thePMMAnanocompositecontaining7wt%LDHdemonstratesimprovedglasstransitiontemperature(Tg)ofaround3K.Theactivationenergy(Ea),reactionorders(n)andreactionmechanismofthermaldegradationofPMMA/OLDHnanocompositeswereevaluatedusingdifferentkineticmodels.WateruptakecapacityofthePMMA/OLDHnanocompositesislessthanthatofthepurePMMA.