简介:选取三江平原典型沼泽湿地——毛苔草沼泽,通过人工施加氮肥和磷肥来模拟农田污水排入沼泽湿地后,沼泽植物对污水的净化效果。从植物营养吸收角度进行野外实地污水净化模拟研究,对植物直接吸收利用的营养成分NH4^+-N、PO4^3--P进行了测试分析。研究表明毛苔草沼泽对水中的NH4^+-N、PO4^3--P的净化随时间的推移呈现明显的指数衰减下降趋势,随着氮、磷含量的增加,沼泽湿地对污水净化逐渐变慢,净化所需时间增长,曲线数值方程模拟效果较好。
简介:用22年(1973~1994年)观测资料,由循环主振荡型分析(CSPOP)揭示了东半球500hPa环流、雪盖和中国降水量耦合系统的3~4年振荡的循环过程。结果表明,环流-冰雪-降水系统耦合振荡(ASRO)存在显著的欧亚太平洋(EUP)和中国东部型(EC)耦合移动波列,其中500hPa高度与雪盖波列空间位相相反,但一致向东南方向移动,而中国降水波列由北向南传播。这反映出欧亚雪盖异常影响欧亚大陆和海洋加热对比,并通过大气内部动力过程激发的耦合空间波的能量频散途径。
简介:AppendixA:Thederivationofequation(4)InFourierdomain,d2(x)=2x2istransformatedintod2(kx)=-k2x(A1)Whenequation(3)isnumericalyc...
简介:一、地震基本参数表1 地震基本参数表发震时间年月日时分秒震 中 位 置微 观宏 观东经北纬东经北纬参考地名震级(MD)震源深度(Km)震中烈度 地震类型 199203030602228118°10′24°06′118°06′24°12′漳浦海外(厦门南)48Ⅴ孤立型 表1中宏观震中是根据陆地上勾划的等震线推测的,在微观震中的北西20公里左右。二、地震烈度分布本次地震的波及面很广,闽东南沿海地区均明显有感,调查在Ⅴ、Ⅳ度两个区内进行。由于地震影响场只有一小半在陆地上,勾勒出的是Ⅴ、Ⅳ度两条等震线的半椭圆弧线(见图14-1)。图14-1 1992年3月3日漳浦海外地震等震线图Ⅴ度区:震中位于海上
简介:<正>所谓3S技术即GPS、GIS、RS技术。GPS(全球定位系统)是英文缩写词NAVSTAR/GPS(NAVigationSystemTimeAndRanging/GlobalPositioningSystem)的简称。全称应为“测时测距导航系统/全球定位系统”。GPS是由美国研制,并投入实际应用的最新卫星定位系统。其主要目的是为飞机和船舶导航定位。也可以用于其它多种目的。GPS技术已在航空、航天、航海、军事、地质、石油、勘探、交通、测绘等领域得到广泛的应用。美国于1993年6月26日已将GPS21颗卫星和3颗备用卫星全部发射入轨。
简介:Therehavebeen12possiblelocationsoftheearthquakesoccurringintheSouthYellowSeasince1505.Inthispaper,thelocationoftheearthquakethatoccurredin1505hasbeendeterminedbythecollectionofmorehistoricaldataoftheinfluencedfield,referringtheisoseismaldataofearthquakeswiththeepicentralintensityⅨandcombininggeophysicalfielddatawithtectoniccondition,duetoitsgreatinfluenceonseismicsafetyassessmentofsomesignificantengineering.
简介:CH4emissionrateshavebeenmeasuredcontinuouslyfortheearlyriceof1988andlatericesof1987and1988duringentiregrowingseasonsinaricepaddyfieldinHangzhou,ZhejiangProvince,China,byusinganautomaticsamplingandanalyzingsystem.DuringmostpartsoftheseasonsCH4emissionratesshowedstrongdiurnalvariations.Bi-modepatternswiththehighestvalueintheafternoonandasecondpeakatmid-nightweregenerallyfoundfortheearlyrice,whilethehighestvalueswerealmostalwaysfoundinthenightforthelaterice.Bi-modepatternswithasecondpeakintheafternoonwerealsofoundduringthereproductivephaseofthelatericeplants.Thesediurnalvariationsmaybeexplainedbythediurnalvariationsofthesoiltemperatureandtheactivityofriceplants.Strongseasonalvariationswithonepeakinthetilleringstageandtwoduringthereproductivephaseofriceplantswereobservedforallthethreegrowingseasons.Theseasonalvariationsmaybeexplainedbytheactivityofriceplants,availabilityoforganicsubstratesinthesoil,andtheactivityofsoilbacteriarelatedtosoiltemperatures,FertilizationdidnotshowsignificanteffectsonthetotalseasonalCH4emissionsbutslightlychangedthepatternoftheseasonalvariationsoftheCH4emissionrates.Averagedoverthemeasuringperiodsand8spots,CH4emissionratesof7.8mgm-2h-1fortheearlyriceand28.6mgm-2h-1forthelatericewereobtained.Basedonthesemeasureddata,thetotalglobalemissionofCH4fromricepaddiesisestimatedtobeabout90Tg/yrrangingfrom70to110,accountingfor20%ofthetotalsourceofCH4.
简介:Acomprehensivestrengthmonitoringsystemusedonafixedjacketplatformispresentedinthispaper.Thelong-termmonitoringofW-11-4Aplatformachieved.Structuralresponses(strainandacceleration)atselectedlocations,aswellasassociatedenvironmentalparameters,havebeenobtained.Theemphasisofthepaperisplacedonthesystemdesign,andtheinstrumentationandoperationmethodologyemployedinthemonitoringofthestructuralresponses.Theperformanceofthesystemandthecharacteristicresultsobtainedduringits13-monthoperationarealsosummarized.
简介:Abrandnewexpertsystemforearthquakeprediction,calledESEP3.0,wassuccessfullydevelopedrecently,inwhichthefuzzytechnologyandneuralnetworkconceptionwereincorporatedandthesteeringinferencemechanismwasintroduced.Inadditiontothefunctionsofsymbolinferenceandexplanationofthefirstgenerationoftheexpertsystemandtheknowledgelearningofthesecondgeneration,ESEP3.0hasstrongerhuman-machineinteractionfunction.Itconsistsofknowledgeedition,machinelearning,steeringfuzzyinferenceengineandsynchronousexplanationsubsystems.Inthispaper,thecomponentsandthegeneraldescriptionofthesystemareintroduced.