简介:Anexperimentofadaptivepolarizationmodedispersion(PMD)compensationfor40-Gb/sreturn-to-zero(RZ)opticalcommunicationsystemisreported.Intheexperiment,degreeofpolarization(DOP)isusedasfeedbacksignalandparticleswarmoptimization(PSO)methodisadoptedaslogiccontrolalgorithm.Thecompensationtimeisabout200ms,thecompensateddifferentialgroupdelay(DGD)isupto30ps,andbiterrorrate(BER)of10^-9isreachedwhenPMDcompensationisemployed.
简介:Weexperimentallydemonstratea4-Gb/sradio-over-fiber(RoF)systemwith40-kmfiberand2-mwirelessdistancedownstreamat100-GHzcarrier.Tothebestofourknowledge,thisisforthefirsttimeinChinatorealizeopticalwirelesslinkat100GHz.Inthisletter,simpleintensitymodulatorwithdirectdetector(IM-DD)modulationisemployedandopticalpowerpenaltyafter40-kmsinglemodefiber(SMF)-28and2-mairlinkis3.2dBwithbit-error-rate(BER)at1×109.
简介:圆柱滚子是圆柱滚子轴承的主要组件之一,其质量的好坏,不仅影响轴承的旋转精度和性能,而且对轴承寿命的影响尤为突出。目前,各圆柱滚子轴承制造厂都在为提高滚子轴承寿命而不断提高滚子质量。特别是近几年,电机行业和机车行业要求供给低噪音、高精度寿命
简介:Aquasi-cycliclow-densityparitycheck(QC-LDPC)codeisconstructedbyanimp
简介:Weexperimentallydemonstrateall-opticalclockrecoveryfor100Gb/sreturn-to-zeroon–offkeyingsignalsbasedonamonolithicdual-modedistributedBraggreflector(DBR)laser,whichcanrealizebothmodespacingandwavelengthtuning.Byusingacoherentinjectionlockingscheme,a100GHzopticalclockcanberecoveredwithatimingjitterof530fs,whichisderivedbyanopticalsamplingoscilloscopefromboththephasenoiseandthepowerfluctuation.Furthermore,fordegradedinjectionsignalswithanopticalsignal-to-noiseratioaslowas4.1dBanda25kmlongdistancetransmission,good-qualityopticalclocksareallsuccessfullyrecovered.
简介:国家标准《机动车运行安全技术条件》(G87258)是我国机动车安全管理最基本的技术标准,其最新版本GB7258—2017于2017年9月29日由国家质量监督检验检疫总局、国家标准委公告发布,将自2018年1月1日起实施。GB7258是我国机动车国家安全技术标准的重要组成部分,GB7258-2017的发布和实施必将为我国进一步规范和加强机动车安全技术管理、预防和减少机动车因素引发的道路交通事故提供更有利的技术支撑。本文对GB7258-2017制修订背景、原则、主要修订内容、实施注意事项等进行了介绍。