简介：所谓“超宽带（UWB)”，即相对其中心频率有高比例的带宽。1990年，由美国“国防先进技术研究局”召集有关科学家讨论后认为，任何波形，只要带宽大于中心频率的25％，就可认为是“超宽带”。超宽带使用脉宽很窄的基带脉冲，典型为纳秒量级，能量稀薄地扩散在整个使用的带宽里。

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简介：ThetreatmentofsorbicacidmanufacturingwastewaterbyNDA-150resinwasinvestigated.Theexperimentsshowthatthisprocessissuitableforthetreatmentofsorbicacidmanufacturingwastewater.About98%sorbicacidand50%CODcrwereremovedunderoptimaloperatingconditions,and70%ofsorbicacidinsorbicacidmanufacturingwastewaterwasreclaimed.Thisprocessmakesitpossibletorecovervaluablematerialsfromthewastewaterandtoimprovethequalityofeffluentwater.

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简介：Thestructureandbindingenergyofcopperclustersofthesizerange70to150werestudiedbyusingtheembeddedatommethod.Thestabilityofthestructureoftheclusterswasstudiedbycalculatingtheaveragebindingenergyperatom,firstdifferenceenergyandseconddifferenceenergyofcoppercluster.Mostofthecopperclustersofthesizen=70-150adoptanicosahedralstructure.Theresultsshowthatthetrendsareinagreementwiththeoreticpredictionforcopperclusters.Themoststablestructuresforcopperclustersarefoundatn=77,90,95,131,139.

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简介：Wepresentanovelandsimplemethodtoobtainanultrawidefreespectralrange(FSR)siliconringresonatortogetherwithatuningrangecoveringtheentirespectrumfrom1500to1600nm.AringresonatorwithalargeFSRtogetherwithahighQfactor,hightuningefficiency,andlowfabricationcostandcomplexityisdesiredformanyapplications.Inthispaper,weintroduceanovelwaytomakesucharingresonator,whichtakesadvantageofthewell-knownresonance-splittingphenomenon.ItisasingleringresonatorwithanFSRofmorethan150nmaround1550nmandwhichhasaneasythermo-optictunabilitythatcanproduceatuningrangearound90nmorevenmore.Moreover,thedeviceissimpletoimplementandcanbefabricatedinstandardcomplementarymetal-oxidesemiconductortechnologywithoutrequiringanykindofcomplicatedprocessingorextramaterials.Thepotentialapplicationsincludesinglemodelasercavities,wavelengthdivisionmultiplexingfilters,(de)multiplexers,opticalsensors,andintegratedreflectors.