简介:Alowcost8×10-Gb/stransmissionsystemover1500kmonconventionalfiberusingchirpedfiberBragggrating(CFBG)asdispersioncompensatorisdemonstrated.Thebiterrorrate(BER)below10-10at1500kmisobtained.Thechannelspacingis0.8nmandtheopticalamplifierspacingis100km.Only16erbium-dopedfiberamplifiers(EDFAs)areused.
简介:中跑项目是一项要求运动员长时间保持较高速度跑进的项目,是对运动员的速度耐力、协调、灵敏、柔韧性和放松能力要求极高的体能类速度耐力性运动项目。需要强调的是,中跑项目是一项比速度的中长距离跑项目,具备良好的速度能力,与耐力素质一样,也是运动员取得优异的中跑成绩的专项基础。
简介:""Mensaytheyhatetoshop,""saysZhukin,CityUniversityofNewYorkSociology(社会学)professor.""Yetwhenyouaskthemdeeperquestions,itturnsoutthattheyliketoshop.Mengenerallyliketoshopforbooks,musicandhardware.Butifyouaskthemabouttheshoppingtheydoforbooksormusic,they'llsay,'Well,that'snotshopping.That'sresearch.'""