简介:Inthiswork,weinvestigatethemethodstoimprovetheperformanceofthesweptsourceat1.0μmbasedonapolygonscanner,includingin-cavityparametersandboosterstructuresoutofthecavity.Thethreein-cavityparametersarethecavitylength,therotatingspeedofthepolygonscanner,andthein-cavityenergy.Withthedecreaseofcavitylength,thespectrumbandwidthbecomeswiderandthedutycyclebecomeshigher.Withtheincreaseoftherotatingspeedofthepolygon,thespectrumbandwidthbecomesnarrower,andthedutycyclebecomeslowerbuttherepetitionratebecomeshigher.Withmoreenergyin-cavity,thespectrumbandwidthbecomeswiderandthedutycyclebecomeshigher.Theboosterstructuresincludethebufferedstructure,secondaryamplifier,anddual-semiconductoropticalamplifierconfiguration,whichareusedtoincreasethesweepfrequencyto86kHz,theoutputpowerto18mW,andthetuningbandwidthto131nm,respectively.
简介:PM_(1.0)(好粒子,与直径<1μm),PM_(2.5)(好粒子,与直径<2.5μm)并且PM_(10)(粗糙的粒子,与直径<10μm)是在香港的一条高交通的道路附近的测量at24小时间隔,从2004年10月到2005年9月。Massconcentrations为三粒子部分被决定,平均为PM_(1.0),PM_(2.5)和PM_(10),分别地44.5±18.4,55.4±25.5和81.3±37.7μg·m~(-3)。PM_(2.5)是3.7times美国EPA“s15μg·m~的年度NAAQS(-3)。总的来说,PM_(1.0)占了44~69%(一般水准57%)PM_(10),当PM_(2.5)占了58~82%时,(一般水准71%)在这学习。Theparticulate群众在冷季节与高集中显示出明显的季节的模式并且在温暖的季节低,PM_(2.5-10)的特别高的集中在冷季节期间。PM_(2.5)的集体集中的Diurnalvariations在7月期间是坚定的,证明二个学生在早上和下午上下班时间达到顶点。
简介:远程FEA服务系统的总体结构采用B/S模式的3层网络体系结构,如图l所示,主要的网络管理功能和应用程序等都集中在服务中心。其工作流程为:用户通过浏览器访问FEA服务中心的Web服务器进行登录,系统验证用户身份后,根据用户权限进入操作页面。如果用户有委托分析的合作意向,可通过在线商务功能模块与服务中心采用视频会议、电子白板或NetMeeting等形式进行初步的分析任务描述和讨论,确定分析结果的形式、完成时间以及费用等,并最终签订委托合同,由服务中心分配给该客户唯一的分析任务编号和密钥。授权合同用户通过E—mail或FTP等文件传输工具将零件电子图纸和文档、使用条件和分析要求等数据和信息上传到服务中心后,分析服务功能模块必须根据客户提交的信息及委托的分析任务需求经过FEA过程规划和优化决策出最佳的分析方案,
简介:Ultrathinfree-standingelectrospuncarbonnanofiberweb(ECNFW)usedfortheelectrodesofthevanadiumflowbattery(VFB)hasbeenfabricatedbytheelectrospinningtechniquefollowedbythecarbonizationprocessinthisstudytoreducetheohmicpolarizationoftheVFB.Themicrostructure,surfacechemistryandelectrochemicalperformanceofECNFWcarbonizedatvarioustemperaturesfrom800to1400°Chavebeeninvestigated.TheresultsshowthatECNFWcarbonizedat1100°CexhibitsthehighestelectrocatalyticactivitytowardtheV2+/V3+redoxreaction,anditselectrocatalyticactivitydecreasesalongwiththeincreaseofcarbonizationtemperatureduetothedroopingofthesurfacefunctionalgroups.WhilefortheVO2+/VO2+redoxcouple,theelectrocatalyticactivityofECNFWcarbonizedabove1100°Cbarelychangesasthecarbonizationtemperaturerises.ItindicatesthatthesurfacefunctionalgroupscouldfunctionasthereactionsitesfortheV2+/V3+redoxcouple,buthavenotanycatalyticeffectfortheVO2+/VO2+redoxcouple.AndthesinglecelltestresultsuggeststhatECNFWcarbonizedat1100°CisapromisingmaterialastheVFBelectrodeandtheVFBwithECNFWelectrodesobtainsasuperlowinternalresistanceof250mΩcm2.
简介:Ba1.0Co0.7Fe0.2Nb0.1O3-δ(BCFN)oxidewithperovskitecubicstructurewassynthesizedbysolidstatereactionmethod.CO2corrosionofBCFNmembranewasinvestigatedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),diffusereflectanceinfraredFouriertransformedspectroscopy(DRIFT)andX-rayabsorptionfinestructurespectroscopy(XAFS).Cobalt(Co)K-edgeabsorptionspectraofBCFNannealedinCO2revealthattheoxidationstatesofCoinallthesampleswerelargerthan+3andtheydecreasedwiththeincreaseofcalcinationtime.At800℃,1%CO2introducedintoHecouldspeedupthereductionofCocationsincomparisonwithpureHe.Inaddition,sulfateionsinthebulkofBCFNmembranepreferredtomigratetothesurfaceunderCO2calcinationandformmonoclinicBa(CO3)0.9(SO4)0.1besidesorthorhombicwitherite.Moreover,SEMresultsindicatethatthenucleationandgrowthofcarbonatesgrainsstartedatthegrainboundaryofthemembrane.