简介：中国气象科学研究院灾害性天气研究所与安徽四创电子股份有限公司合作研制的C波段双基地气象雷达系统于2005年1月31日通过由安徽省科技厅组织的技术鉴定。

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简介：Netprimaryproduction(NPP)ofcroprepresentsthecapacityofsequestratingatmosphericCO_2inagro-ecosystem,anditplaysanimportantroleinterrestrialcarboncycling.BylinkingtheCrop-CmodelwithclimatechangescenarioprojectedbyacoupledGCMFGOALSviageographicalinformationsystem(GIS)techniques,cropNPPinChinawassimulatedfrom2000to2050.ThenationalaveragedsurfaceairtemperaturefromFGOALSisprojectedtoincreaseby1.0℃overthisperiodandthecorrespondingatmosphericCO_2concentrationis535ppmby2050undertheIPCCAIBscenario.Withaspatialresolutionof10×10km~2,modelsimulationindicatedthatanannualaverageincreaseof0.6TgCyr~(-1)(Tg=10~(12)g)wouldbepossibleundertheAIBscenario.TheNPPinthelate2040swouldincreaseby5%(30TgC)withinthe98×10~6hm~2croplandareaincontrastwiththatintheearly2000s.AfurtherinvestigationsuggestedthatchangesintheNPPwouldnotbeevenlydistributedinChina.AhigherincreasewouldoccurinamajorityofregionslocatedineasternandnorthwesternChina,whileaslightreductionwouldappearinHebeiandTianjininnorthernChina.ThespatialcharacteristicsofthecropNPPchangeareattributedprimarilytotheunevendistributionoftemperaturechange.

简介：ThisstudyinvestigatesclassificationanddiurnalvariationsoftheprecipitationechoesoverthecentralTibetanPlateaubasedontheobservationscollectedfromaC-bandvertically-pointingfrequency-modulatedcontinuous-wave(C-FMCW)radarduringtheThirdTibetanPlateauAtmosphericScientificExperiment(TIPEX-Ⅲ)2014-IntensiveObservationPeriod(2014-IOP).Theresultsshowthat51.32%oftheverticalprofileshavevalidechoeswithreflectivity>-10dBZ,and35.06%ofthevalidechoprofilesproduceprecipitationattheground(precipitationprofiles);stratiformprecipitationwithanevidentbright-bandsignature,weakconvectiveprecipitation,andstrongconvectiveprecipitationaccountfor52.03%,42.98%,and4.99%oftheprecipitationprofiles,respectively.About59.84%oftheprecipitationoccursintheafternoontomidnight,while40.16%oftheprecipitationwithweakerintensityisobservedinthenocturnalhoursandinthemorning.Diurnalvariationofoccurrencefrequencyofprecipitationshowsamajorpeakduring2100-2200LST(localsolartime)with59.02%beingthestratiformprecipitation;thesecondarypeakappearsduring1300-1400LSTwith59.71%beingtheweakconvectiveprecipitation;thestrongconvectiveprecipitationoccursmostly(81.83%)intheafternoonandeveningwithtwopeaksover1200-1300and1700-1800LST,respectively.Startingfromapproximately1100LST,precipitationechoesdevelopwithenhancedverticalairmotion,elevatedechotop,andincreasingradarreflectivity.Intenseupwardairmotionoccursmostfrequentlyin1700-1800LSTwithasecondarypeakin1100-1400LST,whilethetopsofprecipitationechoesandintenseupwardairmotionreachtheirhighestlevelsduring1600-1800LST.Theatmosphericconditionsintheearlymorningaredisadvantageousforconvectiveinitiationanddevelopment.Aroundnoon,theconvectiveavailablepotentialenergy(CAPE)increasesmarkedly,convectiveinhibition(CIN)isgenerallysmall,andasuper-dry-adiabaticlayerispresentnear

简介：1前言短波单边带数传系统是"9210"工程业务系统的重要组成部分,在"9210"工程实施过程中,我中心承担了短波单边带电台的技术验收工作,由于所采用的FT-80C型电台在业务使用中主要承担数传任务,因此对电台的部分技术指标有一定特殊要求:发射机载波频率误差≤10Hz、接收机调制接收带宽≥2.6kHz.