简介:AprototypeRamanlidarwasdesignedformonitoringtroposphericCO_2profileandotherscientificin-vestigations.ThethirdharmonicofNd:YAGlaser(354.7-nmwavelength)wasusedasstimulatedlightsourcetoprovidenighttimemeasurements.FilterwithhighrejectionratioperformancewasusedtoextractCO_2RamansignalsfromRayleigh-Miescatteringsignalseffectively.Toimprovetherealtimemonitoringfunction,atwo-channelsignalcollectionsystemwasdesignedtocollectCO_2andN_2Ramanscatteringsig-nalssimultaneously.TheN_2Ramanscatteringsignalswereusedtoretrieveaerosolextinctioncoefficient.TypicalfeaturesofCO_2concentrationprofileandaerosolextinctioncoefficientinHefeiwerepresented.ThemixingratioofatmosphericCO_2inHefeicanreachabout360-400ppmv.
简介:Tris-(8-hydroxyquinoline)-aluminumeAlq3T–basedorganiclight-emittingdiodeswithCoelectrodearefabricated.Thepositivemagneticelectroluminescence(MEL)andmagneticconductance(MC)areobservedinthesamples,reaching4.35%and1.67%underthefieldof42mTat50K,respectively,andtheMELandMCtracescanbefittedtonon-Lorentzianlineshapes.TheMELvariesasafunctionoftheCothicknessandreachestheoptimalvalueat10nm.TheMELandMCdependenceonvoltageandtemperatureisalsoinvestigated.Theelectron-holepairmodelandthespin-polarizedinjectionmechanismareusedtounderstandtheexperimentalresults.
简介:EnergystorageandheatdepositioninCr,Yb,Erco-dopedphosphateglasswerereported.Amodelbasedonrateequationswasusedtodeterminetheenergystoragefromthefree-oscillatingoutputenergycharacteristics.Theheatdepositionwascalculatedbymeasuringthetemperatureriseoftheglassrod.TheresultsprovidedimportantinformationfortheglassoperatinginQ-switchedmode,andalsoforcalculatingthetemperatureprofilesandcoolingrequirementsoftheglassundersingleshotandrepetitivepulsedconditions.
简介:Becausepulserepetitionrateaffecteddirectlythemomentumcouplingcoefficientoftransverselyexcitedatmospheric(TEA)CO2laserpropulsion,adoublepulsetrigger,controllinghighvoltageswitchoflaserexcitationcircuit,wasdesigned.Thepulseintervalrangedbetween5and100ms.Themomentumcouplingcoefficientforair-breathingmodelaserpropulsionwasstudiedexperimentally.Itwasfoundthatthemomentumcouplingcoefficientdecreasedwiththepulserepetitionrateincreasing.
简介:目前汽车助力装置的主流是真空助力和气压助力。真空助力结构小巧,但存在安全隐患;气压助力安全性好,但结构庞大。高液压存储仓的日的是提供一种小巧且安全性兼顾的装置。高液压存储仓的基本工作原理是利用制冷剂的瓜力特性,用制冷剂充当储压剂来储存压力液的能量。使整罐压力液能够以高达20~25MPa的准恒压向外作功。讨论了液压仓的基本结构和工作原理、储压剂选择的难题、抑制泄漏的措施、超临界CO2的特性,在此基础上,提出了存储高液压的超临界CO2液压仓的设计思路,用超临界CO2和温控相配合,得到了准恒高压压力液,实现了小巧且安全性兼顾,由此产生新型的制动、转向、离合助力器。
简介:Twosilicahostmagnesium(Mg)-aluminum(Al)-germanium(Ge)co-dopederbium-dopedfibers(EDFs)havebeenfabricated,whichhavedifferentMgconcentrations.Theconcentrationofallthecompositionsinthepreformismeasuredthroughelectronicsprobemicroanalysis(EPMA).ThemaximumMgconcentrationsoffibersAandBare3.98and1.28mol%,respectively.Theperformancecharacteristicsincludingabsorptionspectrumandgainaremeasuredandanalyzed.TheabsorptioncoefficientsoffibersAandBare13.3and14.3dB/mrespectivelyatwavelengthof1532nm.Themaxgainsofthesetwoerbium-dopedfiberamplifiers(EDFAs)are30.1and35.9dBwithinputsignalpowerof-30dBmandpumppowerof100mWat980nm.FiberBwithmaximumMgconcentration1.28mol%hasbetterperformancethanfiberA.FiberBhashighabsorptioncoefficientandhighgaincharacteristics.TheoptimumfiberBlengthofC-bandEDFAis7mandthatofL-BandEDFAisabout30m,whichismuchshorterthanstandardcommercialEDFAs.TheresultofexperimentsshowedthatafewMgaddedtosilicahostEDFcanincreasetheconcentrationoferbiumions,whichwillshortentheEDFlengthmuch,butnotdegradetheperformancecharacteristics.
简介:利用超高效液相色谱质谱联用仪研究了包装材料BOPA/CPP中的抗氧化剂的辐解行为;结果表明BOPA/CPP中的抗氧化剂Irganox1076,Irgafos168,Irganox1010随辐照剂量的增大含量减小;其中抗氧化剂Irganox168可能降解为2,4-二叔丁基苯酚和1,3-二叔丁基苯;抗氧化剂Irganox1076、Irganox1010降解为4-乙基,2,6-二叔丁基苯酚和2,6-二叔丁基对苯醌。