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简介：<正>ChinaDailyreportedthatgovernmentministriesaresteppingupthepaceofworkingoutdetailsofthe"BroadbandChina"project,whichis

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简介：Inthispaper,abroadbandmultimediaapplicationplatform,BaMAP,isintroduced.TheBaMAPaimstooffercontentandserviceprovidersagoodintegratedenvironmentforefficientcontentproduction,management,deliveryandsharing.Itsupportslarge-scalehierarchicalstorage,aswellasmechanismsforcontentdistributionandqueriesfromremotenodes.Theon-demandservice,partoftheBaMAP,offerstwoaccessinterfaces,DVB-CandIP,whichallowtheplatformtorunonmostoftheexistingaccessnetworks.

简介：Abroadbandreflectivepolarizationconverterisproposed.Theunitcellofpolarizationconverteriscomposedofasingle-splitresonantring,adouble-splitresonantring,adielectricsubstrateandametallicground.Thesimulatedresultsshowthatthepolarizationconvertercanconvertx-polarizedwavesintoy-polarizedwavesandobtainabroadbandpolarizationconversionfrom0.5010THzto1.3900THzwiththepolarizationconversionratio(PCR)beyond80%atnormalincidence.Moreover,thesurfacecurrentdistributionsareinvestigatedtoexplainthepolarizationconversionmechanism.Finally,agoodagreementisachievedbetweensimulatedandmeasuredresults.Thepolarizationconvertercanbeappliedinterahertzimaging,communicationandstealthytechnology.

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简介：Polarizationmanipulationisessentialindevelopingcutting-edgephotonicdevicesrangingfromopticalcommunicationdisplaystosolarenergyharvesting.Mostpreviousworksforefficientpolarizationcontrolcannotavoidutilizingmetalliccomponentsthatinevitablysufferfromlargeohmiclossandthuslowoperationalefficiency.ReplacingmetalliccomponentswithMieresonance-baseddielectricresonatorswilllargelysuppresstheohmiclosstowardhigh-efficiencymetamaterialdevices.Here,weproposeanefficientapproachforbroadband,highqualitypolarizationrotationoperatingintransmissionmodewithall-dielectricmetamaterialsintheterahertzregime.Byseparatingtheorthogonalpolarizationcomponentsinspace,weobtainrotatedoutputwaveswithaconversionefficiencyof67.5%.Theproposedpolarizationmanipulationstrategyshowsimpressiverobustnessandflexibilityindesigningmetadevicesofbothlinear-andcircular-polarizationincidences.

简介：在这份报纸，我们基于保角的mappings建议幻想光学的一个简单方法。由小心地与特定的保角的mappings开发图案，一个人能让一个目标与显著地不同的形状看起来像另外一个。另外，幻想光设备能在频率的一条宽带工作。

简介：Thehigh-temperaturesensitivityofthesiliconmaterialindexlimitstheapplicationsofsilicon-basedmicro-ringresonatorsinintegratedphotonics.Torealizealowbutbroadbandtemperature-dependent-wavelength-shiftmicroringresonator,designingabroadbandathermalwaveguidebecomesasignificanttask.Inthiswork,weproposeabroadbandathermalwaveguidethatshowsaloweffectivethermo-opticalcoefficientof1×10-6∕Kfrom1400to1700nm.Theproposedwaveguideshowsalow-lossperformanceandstablebroadbandathermalpropertywhenitisappliedtoringresonators,andthebendinglossofringresonatorswitharadiusof>30μmis0.02dB/cm.

简介：Transformationacousticsareconcentratedforthepurposeofdesigningnovelacousticdevicestotailoracousticwavestoachievedesirablecharacteristics.However,thesedevicesrequirefluidorfluid-likematerialswithananisotropicdensitythatgenerallydoesnotexistinnature.Therefore,weintroducepentamodemetamaterialsintoanalternatingmultilayerisotropicmediummodeltobuildfluid-likemetamaterialswithananisotropicdensity.A2Dacousticbendingbasedontransformationacousticsisestablishedandinvestigatedtoverifyourmethod.Thisideaprovidesamethodtodesignbroadbandandphysicallyrealizableacousticmetamaterialswithananisotropicdensityandismeaningfulforthedesignofacousticmetamaterials.

简介：Ｍｏｍｅｎｔ　ｔｅｎｓｏｒ　ｉｎｖｅｒｓｉｏｎ　ｏｆ　ｎｅａｒ－ｓｏｕｒｃｅ　ｂｒｏａｄｂａｎｄ　ｄａｔａ（吴忠良）（陈运泰（倪江川）（王培德）（王鸣）Ｍｏｍｅｎｔｔｅｎｓｏｒｉｎｖｅｒｓｉｏｎｏｆｎｅａｒ－ｓｏｕｒｃｅｂｒｏａｄｂａｎｄｄａｔａ￥Ｚ...

简介：Interestinthenonlinearpropertiesofmulti-modeopticalwaveguideshasseenarecentresurgenceonaccountofthelargedimensionalityaffordedbytheplatform.Thelargevolumeofmodesinthesewaveguidesprovidesanewspatialdegreeoffreedomforphasematchingnonlinearopticalprocesses.However,thisspatialdimensionisquantized,whichnarrowstheconversionbandwidthsofintermodalprocessesandconstrainsspectralandtemporaltailoringofthelight.Hereweshowthatbyengineeringtherelativegroupvelocitywithinthespatialdimension,wecantailorthephase-matchingbandwidthofintermodalparametricnonlinearities.Wedemonstrategroup-velocity-tailoredparametricnonlinearmixingbetweenhigher-ordermodesinamulti-modefiberwithgainbandwidthsthataremorethananorderofmagnitudelargerthanthatpreviouslythoughtpossibleforintermodalfour-wavemixing.Asevidenceofthetechnologicalutilityofthismethodology,weseedthisprocesstogeneratethefirsthigh-peak-powerwavelength-tunableall-fiberquasi-CWlaserintheTi:sapphirewavelengthregime.Moregenerally,withthecombinationofintermodalinteractions,whichdramaticallyexpandthephase-matchingdegreesoffreedomfornonlinearoptics,andintermodalgroup-velocityengineering,whichenablestailoringofthebandwidthofsuchinteractions,weshowcaseaplatformfornonlinearopticsthatcanbebroadbandwhilebeingwavelengthagnostic.

简介：TheStokesspectruminthestimulatedRamanscattering(SRS)isverycomplicated.Inthisarticle,weusebothGaussianandLorentzapproximationtoinvestigatethegainpropertiesofmulti-pumpingbroadbandRamanamplifier,andpresentsomeschemesforflatteningthegain.Alltheresultsshowthattheflatnessofthegainspectrumiscloselyrelatedtothepumpingfrequencygrid.ByresearchingthegainpropertiesofRamanamplifiersofsuchITU-TfibersasG.652,G.653,G.655andlargeeffectiveareanon-zerodispersionflatteningfiber,wefindthattheRamangainisassociatedwiththefibertypeanditstransmissioncharacteristics,especiallyitdecreaseswiththeincreaseoftheeffectivecorearea.

简介：Anovelbroadbandtransmissionmethodtodeterminepolymerfilmthicknessduringmanufacturingisproposed,andameasurementsystemisdevelopedbasedonthismethod.TherelationshipbetweenbroadbandopticalpowerandfilmthicknessisdeducedaccordingtotheLambert-Beerlaw.Thesystemiscomposedofahalogenlightandanopticalpowermeter.Resultsshowthatthemeasurementerrorofthismethodisapproximately1μm,andtheresolutionofthesystemisbelow0.4μmforpolymerfilmswithlessthan100-μmthickness.

简介：一个宽带数组的健全的地分发用女性的声学和BEM被计算。FEM-BEM模型被建立因为一个九元素的飞机数组和它在变换器之中的精明的相互的放射阻抗的数字方法被给。影响声学表演的相互的放射阻抗的变化法律被分析。飞机数组的择向性和横梁宽度在三回声频率被计算。一条宽带有九个元素的稠密的飞机数组用三重地反响的变换器被开发。飞机数组的输入阻抗和择向性在无回声的水坦克被测量。结果证明根据一半设计数组是合理的数组元素的第一回声频率的波长。数字答案同意测量结果很好，它显示FEM-BEM方法是可行的计算健全的地分发并且分析相互的阻抗。

简介：直角的频率部门multiplexing(OFDM)为它高速度传播的能力正在吸引更多的注意。然而，OFDM在它山峰力量的高比率拥有明显的缺乏到平均力量(PAPR)，它成为了保持它回到的主要问题被用于宽带卫星通讯系统。OFDM与时间部门multiplexing(TDM)结合了，及时划分进一些块的OFDM的副载波调子，能减少OFDM的高PAPR。同时，OFDM的优点能被保存。在这份报纸，OFDM/TDM被用于宽带卫星通讯系统。这份报纸理论上在PAPR上分析OFDM/TDM系统模型以及它的制止的效果，并且建议频率领域复合飞行员(频分多路复用飞行员)隧道评价算法。在宽带卫星通讯系统的模拟结果表演OFDM/TDM让同意性能并且减少PAPR。

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