简介：

简介：

简介：

简介：Pulsatilebloodflowsincurvedatheroscleroticarteriesarestudiedbycom-putersimulations.Computationsarecarriedoutwithvariousvaluesofphysiologicalparameterstoexaminetheeffectsofflowparametersonthedisturbedflowpatternsdownstreamofacurvedarterywithastenosisattheinnerwall.Thenumericalre-suitsindicateastrongdependenceofflowpatternonthebloodviscosityandinletflowrate,whiletheinfluenceoftheinletflowprofiletotheflowpattemindownstreamisnegligible.

简介：Ｒｉｖｅｒｓｗｉｔｈｈｅｔｅｒｏｇｅｎｅｏｕｓｂｅｄｓｅｄｉｍｅｎｔｓｔｙｐｉｃａｌｌｙｓｈｏｗａｓｙｓｔｅｍａｔｉｃｄｏｗｎｓｔｒｅａｍｖａｒｉａｔｉｏｎｉｎｃｈａｒａｃｔｅｒｉｓｔｉｃｇｒａｉｎｓｉｚｅｗｈｅｎｓｕｂｊｅｃｔｅｄｔｏａｇｇｒａｄａｔｉｏｎｏｒｄｅｇｒａｄａｔｉｏｎ．Ｒｅｃｅｎｔｌｙｔｈｅａｕｔｈｏｒｓｒｅｐｏｒｔｅｄｏｎａｄｅｃｏｕｐｌｅｄｎｕｍｅｒｉｃａｌｍｏｄｅｌｂａｓｅｄｏｎｔｈｅａｓｓｕｍｐｔｉｏｎｏｆｎｏｎｕｎｉｆｏｒｍｆｌｏｗｗｈｉｃｈｒｅｐｒｏｄｕｃｅｄｔｈｅｒｅｓｕｌｔｓｏｆａｓｅｔｏｆｅｘｐｅｒｉｍｅｎｔｓｏｎｇｒａｉｎｓｏｒｔｉｎｇ．Ｔｈｅｓａｍｅｅｘｐｅｒｉｍｅｎｔｓｃａｎａｌｓｏｂｅｒｅｐｒｏｄｕｃｅｄｕｓｉｎｇａｎｕｍｅｒｉｃａｌｍｏｄｅｌｆｏｒｗｈｉｃｈｍｕｃｈｏｆｔｈｅｆｌｏｗｄｏｍａｉｎｉｓａｐｐｒｏｘｉｍａｔｅｄａｓｑｕａｓｉｎｏｒｍａｌ．Ｔｈｅｋｅｙｔｏｔｈｉｓｓｉｍｐｌｉｆｉｃａｔｉｏｎｉｓｔｈｅｕｓｅｏｆｓｈｏｃｋｆｉｔｔｉｎｇｔｏｌｏｃａｔｅｔｈｅｄｏｗｎｓｔｒｅａｍｆｒｏｎｔｏｆｇｒａｖｅｌａｇｇｒａｄａｔｉｏｎ．Ｏｎｃｅｔｈｅｓｈｏｃｋｈａ?

简介：这研究的主要目的是通过一系列斜槽模型实验在河床上理解地基的稳定的效果。从结果，尽管检查水坝有能力控制在上游的沉积，搬运，到高出的分泌物的免费秋天生产的集体精力仍然引起强壮的本地人结构下游地搜索，并且这搜索导致检查水坝的不稳定性。因此，这研究在连续地基的各种各样的类型上进行了模型实验决定适当间距最好保护下游的床。基于隧道地形学和沉积的观察和分析，这研究结束了下列结果：1)连续地基完美地减少沉积运输能力，特别在一条温和隧道下面，与24装备的坡度预定平均隧道宽度间隔。要不是陡峭的斜坡，合适的间距应该被弄短到乘平均隧道宽度的12，这被建议。2)地基能有效地保护streambed免受在一个合适的装备条件下面搜索的伤害，指导的概念搜索并且河床惯性在最佳的地基间距的分析被使用。

简介：Thispapersummarizesthelatestdevelopments,futureprospects,andproposedcountermeasuresofreservoirsedimentationandchannelscourdownstreamoftheThreeGorgesReservoir(TGR)ontheYangtzeRiverinChina.Threekeyresultshavebeenfound.(1)TheincomingsedimentloadtotheTGRhasbeensignificantlylowerthanexpected.(2)TheaccumulatedvolumeofsedimentdepositionintheTGRissmallerthanexpectedbecausetheoverallsedimentdeliveryratioisrelativelylow,andthedepositioninthenear-damareaoftheTGRisstilldeveloping.(3)RiverbedscourintheriverreachesdownstreamoftheGezhoubaDamisstilloccurringandchannelscourhasextendedtoreachesasfardownstreamastheHukoureach.Significantly,sedimentationoftheTGRislessproblematicthanexpectedsincethestartofoperationoftheTGRontheonehand;ontheotherhand,thepossibleincreasesinsedimentrisksfromdependenceonupstreamsedimentcontrol,depositioninthereservoir,andscouralongmiddleYangtzeRivershouldbepaidmoreattention.(1)SedimenttrappedbydamsbuiltalongtheupperYangtzeRiverandbilliontonsofloosematerialsonunstableslopesproducedbytheWenchuanEarthquakecouldbenewsedimentsourcesfortheupperYangtzeRiver.Moreseriously,possiblereleaseofthissedimentintotheupperYangtzeRiverduetonewearthquakesorextremeclimateeventscouldoverwhelmtheriversystem,andproducecatastrophicconsequences.(2)IncreasingsedimentdepositionintheTGRisharmfultothesafetyandefficiencyofprojectoperationandnavigation.(3)ThedrasticscouralongthemiddleYangtzeRiverhasintensifiedthedown-cuttingoftheriverbedanderosionofrevetment,ithasalreadyledtoincreasingrisktofloodcontrolstructuresandecologicalsafety.ItissuggestedtocontinuetheFieldObservationProgram,toinitiateresearchprogramsandtofocusonrisksofsedimentation.

简介：China’sethyleneoxideindustryanditsdeepprocessingsectorareexperiencingaquickdevelopmentphasewithbroadprospectsforthedevelopmentoftheirdesignatedchemicalsmarket.In2006theEOproductioncapacityinChinahad

简介：1ProductionandRunningStatusoffChina’sRefractoriesIndustryin2012____________________________1.1RefractoriesOutputIn2012.China’srefractoriesoutputwas28.189milliontonsdecreasingby4.43%YOY,inwhichtheoutputsofdenseshapedrefractoryproducts,insulating

简介：Thispaperinvestigatestheeffectofupstreamwakeonunsteadyseparatedflowfieldofdownstreamadjacentvanesbysolving2DunsteadyReynolds-averagedNavier-Stokesequationsdiscretizedbyahigh-orderscheme.Theresultsindicatedthatthemaximumrelativereductionoflosscoefficientwas27.2%whentherelativepassingfrequency(theratioofwakepassingfrequencytothecharacteristicfrequencyoftrailing-vortexsheddingofdownstreamadjacentrotor)islessthan2.5.Theamplitudeofwakedefectexistsathresholdvalueandtheaerodynamicperformanceisenhancedmonotonicallywiththeamplitudeofwakedefectbasically.Theeffectiverangeofincidencemustbegreaterthan8°,whichisnearthestallboundary.

简介：动态带宽分配(DBA)是在以太网被动光网络(EPON)的一个开、热的话题，它为下一代的存取networks.However被认为是最好的选择之一，大多数建议DBA计划忽略服务(QoS)的质量为在在上游的光下面的即时交通和下游的带宽利用的最大的延期和延期神经质上的保证在EPON.In的负担这份报纸，一个新DBA计划，QoS保证适应下游的带宽得到了利用(QoS-ADBU)，是pr

简介：沉积负担在河的词法进化起一个主要作用。因此，和水力的结构的沉积负担相互作用的分析具有主要重要性以便提高鱼产地和河的保藏词法特征。现在的学习处于实时的床条件一个块斜面下游地分析scour机制，当来临的流动供应的沉积被从scour洞搬运的沉积平衡时。实验在scour几何学上在模型斜槽和来临的沉积集中的效果被执行被分析。scour特征深深地取决于来临的沉积集中，这被观察，四种主要侧面配置被区分。试验性的数据被分析，实验关系被形成以便为不同水力、几何的条件从斜面脚趾评估一个scour洞，沙丘高度和最大的沙丘高度的横过的节的距离的深度和长度。一个scour洞的动态平衡形状不取决于沉积负担时间历史，这也被证明。

简介：TheShanxiSanweiGroupCo.,Ltd.intendstoinvestaround820millionRMBintheconstructionofa9-kt/acoalgasifica-tionunitanda30kt/apolytetrahydrofuranexpansionproject,

简介：Opticssurfacephasedefectsinducedintensitymodulationinhigh-powerlaserfacilityforinertialconfinementfusionresearchisstudied.Calculationsandexperimentsrevealanexactmappingofthemodulationpatternsandtheopticsdamagespotdistributionsfromthesurfacephasedefects.Originsarediscussedduringtheprocessesofopticsmanufacturinganddiagnostics,revealingpotentialimprovementsforfutureopticsmanufacturingtechniquesanddiagnosticindex,whichismeaningfulforfusionlevellaserfacilityconstructionanditsoperationsafety.

简介：Thispaperproposesakindofmodulationarchitectureforwavelength-division-multiplexingpassiveopticalnetwork(WDM-PON)employingopticaldifferentialquadraturephaseshiftkeying(DQPSK)downstreamsignalsandtwodifferentmodu-lationformatsofre-modulatedupstreamsignals.Attheopticallineterminal(OLT),10Gbit/ssignalismodulatedwithDQPSK.Attheopticalnetworkunit(ONU),partofthedownstreamsignalisre-modulatedwithon-offkeying(OOK)orinverse-return-to-zero(IRZ).SimulationresultsshowtheimpactonthesystememployingNRZ,RZandcarrier-suppressedreturn-to-zero(CSRZ).Theanalysesalsoreflectthatthearchitecturecanrestrainchromaticdispersionandchannelcrosstalk,whichmakesitthebestarchitectureofaccessnetworkinthefuture.

简介：Airentrainmentisknowntobeoneofefficientandinexpensivemethodstopreventcavitationdamagesinhydropowerprojects.Theshapeofsuddenexpansion-fallisusedasacommondeviceformitigatingcavitationerosions.Thecomplexflowpatternswithcavitationarenumericallysimulatedbyusingtherealizablek-εturbulencemodelandtheair-watermixturemodel.Thecalculatedresultsarecomparedwellwiththeexperimentalresultsaswellasthoseobtainedwiththek-εturbulencemodelwiththeVolumeOfFluid(VOF)Model.Thecalculatedresultsagreewellwiththeexperimentaldatafortheaerationcavityandwallpressure.Moreover,theairconcentrationnearsidewallissimulatedbyamixturemodel.ItisfoundthatthemixtureturbulencemodelissuperiortotheVOFturbulencemodel.

简介：我们试验性地表明并且分析10Gbit/s完整的双波长部门multiplexing被动光网络(WDM-PON)系统。non-return-to-zero调音的微分阶段移动(NRZ-DPSK)调整技术首先为downlink方向被利用，然后downlink信号每隧道与10Gbit/s的数据率用调音的开关(OOK)的紧张调整技术为uplink方向被重新调制。一个有效无色WDM-PON完整的双传播系统与低力量惩罚在25km的距离上与60GHz的隧道间距每隧道为10Gbit/s的数据率被完成。

简介：

简介：Thisletterpresentsalowcostsolutionforwavelengthdivisionmultiplexedorthogonalfrequencydivisionmultiplexedpassiveopticalnetwork(WDM-OFDM-PON)withwidelytunableopticalfilterandlinearsmallform-factorpluggable(SFP)module.With9-nmtunablerangefrom1551to1560nm,thetunablefiltercansupportupto10-channel100-GHzspacingWDMPONsystem.Alinearavalanchephotodiode(APD)basedSFP+moduleisdesignedforopticalOFDMsignaldemodulation,whichcanprovidebetterreceiverperformancecomparedwithlimitingAPDmodule.Experimentalresultsshowthat～34dBpowerbudgetcanbeachievedin4×5-GbpsWDM-OFDM-PONsystem,whichcansatisfythetransmissionrequirementsofnextgenerationPONsystem.

简介：Retrogressiveerosion,awidespreadphenomenonofsedimenttransportinreservoirs,oftenimpactsonboththereservoircapacityandthesedimentationinthedownstreamriverchannel.BasedonfielddatafromtheSanmenxiaReservoirandtheLowerYellowRiveroverthepastdecades,threecoursesofretrogressiveerosionwithdistinctivefeatureswereanalyzed.Theresultsindicatethatretrogressiveerosion,especiallycausedbyrapidreductioninthewaterleveltillthereservoirisempty,oftenresultsintheserioussiltationofthelowerYellowRiverandthreatensthesafetyofthefloodcontrolintheLowerYellowRiver.Unreasonableoperationofthereservoirandincominghyperconcentratedfloodsaccompaniedbyretrogressiveerosionalsoaggravatethesiltationofthemainchanneloftheriver.However,areasonableoperationmodeofthereservoirsonamed”storingtheclear(lowsedimentconcentration)waterinthenon-floodseason,andsluicingthemuddy(highsedimentconcentration)waterinthefloodseason”wasfound,whichmightmitigatethedepositioninboththereservoirandtheLowerYellowRiver.Thisoperationmodeprovidesimportantexperienceforthedesignandoperationoflargereservoirsinotherlargeriverscarryinghugeamountsofsediment.