简介:ThispaperdealswiththedevelopmentandevolutionofmodemYellowRiverdeltaandtheerosionordepositionratesofitsdifferentsections.InJune,1996,YellowRiversterminalcoursewasartificiallyturnedeastwardstoemptyintotheseaandthenthe11thlobeofthemodernYellowRiverdeltabegantoform.Thiscoursechangemaymarkthebeginningofthe3rdsubdeltaformation.Asaresultofthat,theYellowRiverdeltaadvancestowardseastbynorthwiththe1st,2ndand3rdsubdeltasarrangedinsuccession.Coastzoneinthedeltaicareaisdividedinto7differentsectionsaccordingtotheirdifferenterosionordepositionrates:therelativelystablesectionfromDakouRivertoShunjiangStream,theweaklyretreatingsectionfromShunjiangStreamtotheTiaoheRivermouth,thestronglyretreatingsectionfromtheTiaoheRivermouthtothestation106,theartificiallystablesectionduetostonedamprotectionfromthestation106toGudongOilfield,thestrongdepositionsectionfromGudongOilfieldtoDawenliuHaipu,theweaklydepositionsectionfromDawenliuHaiputotheZimaiStreammouth,andthestablesectionfromtheZimaiStreammouthtotheJiaolaiRivermouth.Itispredictedthattheerosionanddepositionsituationsofthesectionswillnearlyremainthesamein10years,buttheretreatingandsilting-uprateswilltendtobecomeslowergradually.Humanactivitieshaveanevidentinfluenceonthechangesofthecoastline.
简介:Fossildiatomgroupsfrom85samplesofdrillholesand13samplesoftheknowndepositionalenvironmentareanalysed.TheboundaryoftheZhujiangDeltaisdiscussedfromthedistributionoffossildiatom.ThehorizonalvariationofHolocenesedimentaryfaciescanbedividedintofourkindsofdepositionalenvironmentcorrespondingtothedeltaplainsubfaciesandthedeltafrontsubfacies.TheverticalvariationofHolocenedepositionalfaciesshowstwicechangesoftransgressionfromweaktovigorous.
简介:Thepotentialforharvestingenergyfromaflexibledeltawingusingapiezoelectricbimorphisexperimentallyinvestigated.Differentconfigurationsoftheproposedharvestingsystemweretestedinawindtunneloverabroadrangeofairspeeds.Inadditiontoevaluatingthelevelofharvestedpower,ananalysisisperformedtoextractcriticalaspectsfortherelationbetweenspeed,flexibility,geometryandthepotentialpowerthatcanbeharvestedfromaclamped,cantileveredflexibledeltawingatlowanglesofattackandlowspeeds.Thisanalysisprovidesaninsightintoparametersthatimpactenergyharvestingfromflexiblemembranesorelements.
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简介:Throughoneandhalfyearcontinuousin-situmeasurements,thedistributionsandvariationsofsurfaceozoneanditsprecursorsatatypicalmixedagriculturalandmetropolitanarea-Changshu,YangtzeDeltaregion,werestudied.Thepreliminaryanalysisontheconcentrationlevelsandvariationsofsurfaceozoneindicatedtheobviousseasonalanddiurnalcyclesduringtheexperiment.Thehourlyaveragedconcentrationsofsurfaceozonewerehigh,inabout17%oftotalvalidhoursthesurfaceozoneconcentrationexceeded50ppb,andin22daysthehourlyaveragedozoneconcentrationwasgreaterthan100ppb.Therewereabout40%ofthedaysinthatthedailymaximum8-hourozoneconcentrationwasgreaterthan50ppb.Thedayswithdailymaximum8-hourozoneconcentrationgreaterthan80ppbwereabout33daysthataccountedforabout8%oftheobservationaldays.Thevariationsof5-daymovingaveragedozoneconcentrationsdependedbothontheweatherconditionsandonthechangesofozoneinbackgroundatmosphere.Photochemicalprocesshadthesignificantimpactsonozoneproductions.
简介:长江三角洲(UA-YRD)上的城市的凝块在水,土地,生态的环境,地点和交通的方面有一些优点。依靠资源环境库和另外的优点,UA-YRD完成了大开发。基于索引系统和全面评估的模型,自从1978,纸计算UA-YRD的发展水平。从1978~2007,开发水平以0.0333的年度率逐年增加了的结果表演,和开发的进程能被划分成三个阶段,即低速度的开发舞台(19781991),快速的开发舞台(19912000),并且高速度的开发舞台(20002007)。速度分别地是0.0083,0.0356和0.0766。在30年的发展期间,外国经济活动在开发有最大的效果,由交通,工业经济活动和电信列在后面(有序)。另外,不同驱动力在不同阶段有不同效果。纸建议更多的注意应该对高速度的发展阶段和重要驱动力被给予驾驶它的发展。同时,资源和环境的限制不应该被忽视,长有效的机制需要被证实在UA发展,资源利用和环境保护之中支撑和谐开发。一些比较研究应该着急地被执行有效地支持并且支持UA的持续开发,特别向进化,驱动力和braking力量。
简介:Thepoleassignmentinaspecifieddiskbystatefeedbackforuncertaindelta-operatorsystemsisstudied.BymakinguseofalgebraRiccatiequations,asufficientandnecessaryconditionofpoleassignmentforakindofparameteruncertaindelta-operatorsysteminaspecifieddiskbystatefeedbackispresented.Andthedesignmethodofstatefeedbackcontrollerisalsodeveloped.Theproposedmethodcanunifysomepreviousrelatedresultsofcontinuousanddiscretetimesystemsintothedeltaframework.Theefficiencyofthedesignmethodisillustratedbyanumericalexample.
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简介:从1992~2003基于non-radiance-calibratedDMSP/OLS夜间光形象,城市的陆地区域统计数据,气象学的数据;陆地地面温度数据由MODIS检索了;NOAA/AVHRR数据,在长江三角洲(YRD)的温度的地区性的气候的趋势上的都市化的影响被分析。结论如下:1)在YRD从1992~2003有一个重要都市化过程。Nanjing-Zhenjiang-Yangzhou的四城市簇,Suzhou-Wuxi-Changzhou,上海;Hangzhou海湾形成一条之字形城市带。在城市带的年平均气温的增加率是从1991~2005的0.280.44°C/10a,它比non-city-belt的远大。2)在不同季节的地区性的吝啬的气温上的城市的热岛(UHI)效果是summer>autumn>spring>winter。3)UHI紧张;城市的全部的人口对数美满地被相关。4)成为地区性的年平均气温的UHI效果从1961~2005增加了0.072°C,它从1991~2005的0.047°C,;年度最大的气温增加了0.162°C,它从1991~2005的0.083°C。所有这些显示当严肃的气候发信号,在从1991~2005的YRD的城市的扩大可以被考虑。