简介：Anultrathin,planar,broadbandmetalenscomposedofmetalrectangularsplit-ringresonators(MRSRRs)hasbeendesigned,whichshowsdual-polaritycharacteristicsfordifferenttypesofcircularlypolarized(CP)lightincidence.Thedesignedmetalenscanbeconsideredasthefocusinglensandthediverginglensunderleft-handedCPandright-handedCPlightincidence,respectively.Thephasediscontinuityofthecross-polarizedtransmissionlightisproducedbyoptical-axisrotationthroughmodulatingtwoarms’lengthsoftheMRSRR.TheMRSRRmetalenspossessesawavelength-controllablefocallengthandarelativelylargerchromaticaberrationcomparedwiththeconventionallenses.Andthefocallengthchangesfrom9to7μmwithincidentwavelengthfrom740to950nm.Thedual-polarityflatmetalensopensadoorfornewapplicationsofphasediscontinuitydevices,anditwillpromotethefabricatingcapabilityofon-chiporfiber-embeddedopticaldevices.

简介：Inthiswork,themorphologiesandporestructuresofaseriesofcorncob-derivedactivatedcarbonsandzeolitetemplatedcarbonwithultrahighsurfaceareawerecarefullyinvestigatedbySEM,HRTEMandN2-sorptioncharacterizationtechnologies.Thehigh-pressurehydrogenuptakeperformancewasanalyzedusingstandardPressure-Composition-Temperatureapparatusinordertostudytheporesizeeffectsonhydrogenuptake.Theseas-obtainedporouscarbonsshoweddifferentcharacteristicsofporesizedistributionaswellasspecificsurfacearea.Theresultsindicatethatthemosteffectiveporesforadsorbinghydrogendependedonthestoragepressure.Theseultramicropores(0.65-0.85nm)couldbethemosteffectiveporesonexcessH2uptakeat1bar,however,micropores(0.85-2nm)wouldplayamoreimportantroleinexcessH2uptakeathigherpressureat77K.Atroomtemperature,poresizeeffectsonH2uptakecapacitywereveryweak.BothspecificsurfaceareaandtotalporevolumeplaymoreimportantrolesthanporesizeforH2uptakeatroomtemperature,whichwasclearlydifferentfromthatat77K.Forapplicationsinfuture,thecorncob-derivedactivatedcarbonscanbemoreavailablethanzeolitetemplatedcarbonsat77K.ElementdopingenhancedhydrogenuptakecouldbemainresearchdirectionforimprovingH2uptakecapacityatroomtemperature.更多还原

简介：Ultra-lowcarbon(ULC),cold-rolledsheetsteelsforporcelainenamelingcontainingalloysoftitaniumandboronarestudied.Themicrostructure,mechanicalproperties,inclusions,andprecipitatesofthesheetsteelsareanalyzed.Thehydrogenpermeationtimeofthesheetsteelsas-annealedandafterskin-passedorcold-rolledatdifferentreductionsaremeasured.Itisshownthatthesheetsteelspossessdifferentfeaturesofenamelingpropertiesinhydrogenpermeability,fishscaleresistance,andpinholeresistance.

简介：Weproposeanultra-simpledual-channelconfigurationforsimultaneouslyevaluatingtwobranchesofamultifunctionalintegratedopticchip(MFIOC).Intheconfiguration,theMFIOCisemployedasabeamsplittertoconstructthedemodulationinterferometertogetherwitha2×2fibercoupler.InterferencehappensbetweenpolarizationmodestravelingthroughdifferentchannelsoftheMFIOC.Thecross-couplingsofeachchannelarerespectivelycharacterizedbytheinterferencepeakswhichdistributeonoppositesidesofthecentralinterferencepeak.TemperatureresponsesoftheMFIOCareexperimentallymeasuredfrom-40°Cto80°C.Resultsshowthattheproposedconfigurationcanachievesimultaneousdual-channeltransientmeasurementswithresolutionof-90dBanddynamicrangeof90dB.Inaddition,thetwochannelsoftheconfigurationhaveconsistentmeasuringperformance,andthetwobranchesoftheMFIOChavedifferentresponsestotemperaturevariation.

简介：ThestatusoftheEuropeanX-rayFree-ElectronLaser(EuropeanXFEL),underconstructionnearHamburg,Germany,isdescribed.ThestartofoperationsoftheLCLSatSLACandofSACLAinJapanhasalreadyproducedimpressivescientificresults.TheEuropeanXFELfacilityispoweredbya17.5GeVsuperconductinglinearacceleratorthat,comparedtothesetwooperatingfacilities,willgeneratetwoordersofmagnitudemorepulsespersecond,upto27000.Itcanthereforesupportmodesofoperationswitchingthebeamupto30timespersecondamongthreedifferentexperiments,providingeachofthemwiththousandsofpulsespersecond.Thescientificpossibilitiesopenedupbythesecapabilitiesarebrieflydescribed,togetherwiththecurrentinstrumentaldevelopments(inoptics,detectors,lasers,etc.)thatarenecessarytoimplementthisprogram.