简介:MonovalentionsLi+,Na+,andK+,aschargecompensators,areintroducedintoCaYAl3O7:M(M=Eu3+,Ce3+)inthisletter.TheircrystalphasesandphotoluminescencepropertiesofdifferentalkalimetalionsdopedinCaYAl3O7areinvestigated.Inaddition,theinfluenceofchargecompensationionLi+whichhasamoreobviousroleinimprovingluminescenceintensityonCaYAl3O7:Eu3+phosphorisintentionallydiscussedindetailandapossiblemechanismofchargecompensationisgiven.Theenhancementofredemissioncenteredat618nmbelongingtoEu3+isachievedbyaddingalkalimetalionLi+under393-nmexcitation.
简介:Weprovidethefirstdemonstrationofpureredemissioninthevisiblelightregionviathree-photonexcitationinmonodisperseNa_3ZrF_7:Ernanoparticles(NPs)byusingalaseroperatinginthetelecommunicationband.NPsof~22nmindiameteraresynthesizedat260°Cbythethermaldecompositionmethod.TheexperimentalresultsrevealthattheNa_3ZrF_7:ErNPsexhibitpureredemissioninthevisibleregionunder1480nmlaserexcitation,andtheemissionintensityissignificantlyinfluencedbytheEr~(3+)ionconcentration.Thedecaytimesofthe~4S_(3∕2)→~4F_(15∕2)and~4F_(9∕2)→~4F_(15∕2)transitionsoftheEr~(3+)ionsat540and655nm,respectively,arereducedbyincreasingtheEr~(3+)ionconcentrationintheNa_3ZrF_7:ErNPs.Thesuppressedemissionintensityresultfromthedefect-relatedquenchingeffect:whentrivalentEr~(3+)ionsreplactetravalentZr~(4+)ions,extraNationsandFvacanciesareformedtore-balancethechargeintheNa_3ZrF_7matrix.TheemissioncoloroftheNa_3ZrF_7:ErNPsisrelatedtothecrossrelaxationbetweenEr~(3+)ions.Theseresultsprovideanimportantsteptowardmoreeffectivebiologicalimagingandphotodynamictherapybyminimizingthescatteringoftheexcitationlightandincreasingthepenetrationdepth.
简介:本刊讯BrittonChance生物医学光子学研究中心最新成果被OSA出版物网站选为ImageoftheWeek(Feb.,2,2009)。星形胶质细胞是大脑中数量众多的一类非电兴奋性细胞群体,它们通过钙信号的形式在神经元和其他脑细胞间起到至关重要的桥梁作用,从而积极参与脑功能活动。然而,目前研究星形胶质细胞所用到的刺激方法,包括机械刺激、电刺激、解笼锁和药物刺激等,不能满足对其基本功能包括机械刺激、电刺激、解笼锁和药物刺激等的细致研究。曾绍群教授、周炜副教授领导的研究团队提出了利用飞秒激光脉冲刺激星形胶质细胞的新方法。
简介:2013年5月25-26日,第六届国际光子与光电子会议(The6thInternationalPhotonicsandOp—toElectronicsMeetings,POEM2013)在武汉光电国家实验室召开。开幕式上,美国光学学会的首席执行官ElizabethA.Rogan女士和华中科技大学副校长、武汉光电国家实验室常务副主任骆清铭教授到会致辞。4名本领域权威专家作全体大会报告,分别是:澳大利亚科学院院士、工程院院士、国际电工委员会委员,澳大利亚新南威尔士大学教授及超高效光电学研究中心执行研究主任MartinGreen,澳大利亚科学院院士、工程院院士、澳大利亚桂冠院士