简介:Supercontinuum(SC)generationhasattractedasignificantscientificinterestinthepastdecadesduetoitspromisingapplicationscoveringthefieldsofmetrology,spectroscopy,defense,aswellasmedicaltreatments.Todate,researchersaredevotedtoimprovingthespectralwidthandflatnessofSCgenerationbyusingspecialtyopticalfibers.Theflatnessofthespectrumisofimportancebecauseitcanimprovetheaccuracyofmeasurementinpracticalapplications.ThispapersummarizesthetheoryofSC,thestateoftheartofflatSCgenerationusingopticalfiberincludingphotoniccrystalfibers,softglassfibersaswellasgermania-dopedfibers,andsuggeststhefutureresearchdirectionofflatSClightsource.
简介:Inmarineengineering,thestrengthofasubmarinesedimentisanindispensableparameterforassessmentofconstruction.Inthisstudy,afree-fallconepenetratornamedIPenwasdevelopedtorealizearapidandefficientmeasurementofsedimentstrength.Theequipmentischaracterizedbymodulardesignandself-containeddataacquisition.Itisequippedwithanaccelerationsensor,awaterpressuresensor,andapiezoconepenetrationtest(CPTu)probe.Itisdesignedtobereleasedfromnearseabedsurfacewithareleaserandthenfallfreelytoprovideahigherpenetrationvelocity.Itsmaximumworkingdepthisapproximately2500mandmaximumpenetrationdepthisapproximately3m.Toderivethecorrelationbetweenpenetrationresistanceandsedimentstrength,acalibratorwasdevisedtodeterminethepenetration-ratefactor.Inaddition,thefactorapplicabletoinsitutestpointswasdeterminedinlaboratoryexperiments.InJune2016,theIPenwastestedinsituintheSouthYellowSea,China,duringasharedvoyagefundedbytheNationalScienceFoundation.Meanwhile,undisturbedcolumnsampleswerecollectedforlaboratorytests.Basedontheinsitutestresults,itwasdemonstratedthattheIPencouldaccuratelyrecordtheworkingstatesofvarioussensorsduringthefreelyfallingcourse.IPentestresultsreliablyreflectedthesedimentstrengthatallthetestingpointswhencomparedwithlaboratorycalibrationtests,insituvanetestsandpenetrationtests,laboratorypenetrationtests,andunconsolidatedandundrainedtriaxialcompressiontests.
简介:Thenextgenerationofadvancedlightsourcesrequiresphotonswithlargeaveragefluxandhighbrightness,whichneedsadvancedelectrongunmatchedwithexcellentphotocathodematerials.K2CsSbphotocathodehastheadvantagesofhighquantumefficiency,longlifetimeandinstantaneousresponse.ThisstudyintroducesthedesignofasetofK2CsSbphotocathodepreparationsystemsanddetailedpreparationprocessofK2CsSbphotocathodes,includingsequentialdepositionprocessandco-depositionprocess,andfinallydevelopsaK2CsSbphotocathode.Theinfluenceoflaserpoweronthequantumefficiencyisalsoinvestigated.
简介:000yearsofChina.ThemediadevelopmentinShanghai,Theyearof1978isawatershedforChinesepoliticsandmediadevelopment(Lee,forthemediadevelopmentinChina.TheexperienceoftheShanghaiModelisnowradiatingacrosswholeChina.ThoughthejournalisticreformsmayappearinadifferentformsinotherpartsofChina