简介:对只接收到一组GPS卫星广播星历的情况下应用广播星历拟合计算卫星在轨位置的方法进行了研究,通过与精密星历进行比较,对拟合计算的精度进行了说明。
简介:源于大气的碳的升起的层次,海洋使发酸成为了一个全球问题。它在海洋的有机体的发展,幸存,生长和生理学有重要影响。因此,一个高精确的传感器着急地被需要测量海水的pH。有0.25公里的一条直径的铱电线被用作底层,和红外/红外(哦)xpH电极被一出一步舞准备在在房间温度的一个LiOH答案的电气化学的方法。扫描电子显微镜(SEM)观察表明它与nanoscale粒子是涂的。在实验室测试,电极展出很有希望的pH回答,与理想的Nernst在测试pH的斜坡(56.14-59.52),快反应,好稳定性和长寿命缓冲答案。为海试用,四个pH电极和电极Ag/AgCl参考电极与一个白手起家的化学药品传感器,和将近70m的侧面察觉是综合的在Newport附近被实现港口,加利福尼亚在2015年8月3日。结果思考pH价值由传感器测量了,这离加CTD的海鸟911给的数据很靠近,与从的差别价值0.000075~0.064719。并且传感器显示出在0-40m水深度匹配度的一个更好的数据。另外,传感器的高精确和精确性使在海洋观察地里使用可能。
简介:Thegrowth,biochemicalcontentandbioaccumulationquantityof2,2’,4,4’-tetrabromodiphenylether(BDE-47)inSkeletonemacostatumwerestudiedunderdifferentN:Pratios(1,4,16,64and128).AllcellularbiochemicalcontentsofS.costatumpresenteddecreasingtrendovercultivationtime.Atearlystageofcultivation,thecellularprotein,carbohydrateandlipidinS.costatumpresentedhighervaluesintreatmentsofN:P=4and16.However,theywerelowerinthesetreatmentsatthelatestage,buthigherintreatmentsN:P=1and128.Similarly,BDE-47levelspercellofS.costatumwerehigherintreatmentsofN:P=4and16atearlystageofcultivation,whichwere3.8and3.7ng(106cells)-1,respectively.Atthemiddlestageofcultivation,theBDE-47levelperS.costatumcelllowered;anditfurtherreducedinthetreatmentsofN:P=4and16atthelatestagewiththevalues0.6and0.5ng(106cells)-1,respectively.However,itroseinN:P=128,reachingupto2.3ng(106cells)-1.ComparedwithBDE-47percell,BDE-47peralgalvolumeunderdifferentN:Pratiosdidnotpresentobviousdifference.ThequantityBDE-47accumulatedpercellofS.costatumwaspositivelycorrelatedwithprotein,carbohydrateandlipidpercell;meanwhile,theBDE-47pervolumehadapositivecorrelationwithbiochemicalcontentpervolume.ThevariationofbioaccumulationabilityofBDE-47inS.costatumcanbeexplainedbybiochemicalchangesduetoN:Pratios.
简介:对于高精度测量和导航,GPS载波相位整周模糊度的快速求解仍然是一个难点,尤其对于单频接收机。提出一种快速求解整周模糊度的方法,其基本思想采用分步求解,首先应用最小二乘模糊去耦调节法(LAMBDA)搜索出来的模糊度作为初始值,然后应用卫星分组方法降低搜索维数,并应用极大似然准则,构造搜索函数,最后应用最优化原理,搜索出最优的模糊度参数,并从三个方面对其进行检验,即RATIO检验,OVT检验,多项式拟合残差检验。为验证该算法,我们用单频GPS接收机进行了实验,利用本文方法在11s以内正确确定了模糊度,其基线长误差小于3mm,表明该方法不但可以改进模糊度的搜索速度,而且可以进一步提高其可靠性和成功率。该方法可广泛应用于定向及姿态测量。
简介:TiO2filmswereformedonmetallictitaniumsubstratesbytheanodicoxidationmethodinH2SO4solutionunderthe80VD.C..PhasecomponentandmicrostructurewerecharacterizedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM).Watercontactanglesontitaniumoxidefilmsurfaceweremeasuredunderbothdarkandsunlightilluminationconditions.Corrosiontestswerecarriedoutinseawaterunderdifferentilluminationconditionsbyelectrochemistryimpedancespectrum(EIS)andpolarizationcurves.TheresultshowedthattheTiO2filmpreparedbytheanodicoxidationmethodwasanatasewithauniformstructureandwithoutobviousporesorcracksonitssurface.Theaveragewatercontactangleofthefilmwas116.4?indark,incontrasttoanangleof42.7?undertheUVilluminationfor2hours,whichdemonstratesgoodhydrophobicproperty.Theanti-corrosionbehavioroftheTiO2filmwasdecliningwiththeextendedimmersiontime.Underdarkconditions,however,thehydrophobicTiO2filmretardedthewaterinfiltratingintothesubstrate.Theimpedancechangedslowlyandthecorrosioncurrentdensitywas2ordersofmagnitudelowerthanthatwiththefilmilluminatedbysunlight.AllofthosementionedaboveindicatethattheTiO2filmpossessesmuchbetterperformanceunderdarkcondition,anditcanbeappliedasanengineeringmaterialunderdarkseawaterenvironment.
简介:CarboncycleisconnectedwiththemostimportantenvironmentalissueofGlobalChange.Asoneofthemajorcarbonreservoirs,oceansplayanimportantpartinthecarboncycle.Inrecentyears,ironseemstogiveusagoodnewsthatoceanicironfertilizationcouldstimulatebiologicalproduc-tivityasCO2sinkofhuman-producedCO2.Oceanicironfertilizationexperimentshaveverifiedthataddingironintohighnutrientlowchlorophyll(HNLC)seawaterscanincreasephytoplanktonproductionandexportorganiccarbon,andhenceincreasecarbonsinkofanthropogenicCO2,toreduceglobalwarming.Insixtydays,theexportorganiccarboncouldreach10000timesforaddingironbymodelpredictionandinsituexperiment,I.e.TheatmosphericCO2uptakeandinorganiccarbondrawdowninupperseawatersalsohavethesamemagnitude.Therefore,oceanicironfertilizationisoneofthestrate-giesforincreasingcarbonsinkofanthropogenicCO2.Thepaperisfocusedontheironfertilization,es-peciallyinsituoceanironexperimentsinorderthatthefutureresearchismoreefficient.
简介:Astochastictwo-dimensionalFornasini-Marchesini'sModelⅡ(2-DFMMⅡ)withmultiplicativenoiseisgiven,andafilteringalgorithmforthismodel,whichisoptimalinthesenseoflinearminimum-variance,isdeveloped.Thestochastic2-DFMMⅡwithmultiplicativenoisecanbereducedtoa1-Dmodel,andtheproposedoptimalfilteringalgorithmforthestochastic2-DFMMⅡwithmultiplicativenoiseisobtainedbyusingthestateestimationtheoryof1-Dsystems.Anexampleisgiventoillustratethevalidityofthisalgorithm.
简介:Thispaperpresentsthedetaildesignconditions,designcriteriaandmethodsaswellasdesignconclusionsoftheprocess,structureandcorrosionoftheproductionflowlinesandhighpressurewaterinjectionlinesinBZ34-2/4oilfieldinBohaiBay.AtpresentthisdesignrepresentsthedesigncapabilityandlevelinthefieldofthesubmarinepipelineengineeringofChina.
简介:Inthisstudy,thecombinedactionsofwavesandtidalcurrentsinestuarineandcoastalareasareconsideredanda2Dmathematicalmodelforsedimenttransportbywavesandtidalcurrentshasbeenestablishedinorthogonalcurvilinearcoordinates.Non-equilibriumtransportequationsofsuspendedloadandbedloadareusedinthemodel.Theconceptofbackgroundconcentrationisintroduced,andtheformulaofsedimenttransportcapacityoftidalcurrentsfortheOujiangRiverestuaryisobtained.TheDouGuorenformulaisemployedforthesedimenttransportcapacityofwaves.SedimenttransportcapacityintheformofmudandtheintensityofbacksiltingarecalculatedbyuseofLuoZaosen'sformula.Thecalculatedtidalstagesareingoodagreementwiththefielddata,andthecalculatedvelocitiesandflowdirectionsof46verticallinesfor8crosssectionsarealsoingoodagreementwiththemeasureddata.Onsuchabasis,simulationsofbacksiltingafterexcavationofthewaterwaywithasandbarundercomplicatedboundaryconditionsinthenavigationchannelinducedbysuspendedload,bedloadandmudbywavesandtidalcurrentsarediscussed.
简介:TheDiverGasRecoverySystem(DGRS)isanimportantaccessoryequipmentofthe300mSaturationDiveSystem.Thesystemfacilitatestherecyclingofthebreathinggasesfordivers,therefore,ithasgreateconomicbenefits.InApril1995,a300munmannedtestanda100mmannedtestontheHY2031DGRSwerecarriedoutsuccessively.Tenmonthslater,anothermannedtestontheHY2032DGRS
简介:AninvivofluorescencediscriminationtechniqueforphytoplanktonpopulationwasdevelopedbyusingWaveletpackettransform,clusteranalysisandnon-negativeleastsquares.Thetechniquewasusedtoanalyzewatersamplesfromdifferentsearegions.Forsimulativemixtures,whendominantspeciesaccountfor60%,70%,80%,90%atthedivisionlevel,thecorrectdiscriminationratios(CDRs)are83.0%,99.1%,99.7%and99.9%withtherelativecontentsof58.5%,68.4%,77.7%and86.3%,respectively;whenthealgaedominanceare60%,70%,80%,90%,100%atthegenuslevel,theCDRsare86.1%,94.9%,95.2%,96.8%and96.7%,respectively.Forlaboratorymixtures,theCDRsare88.1%and78.4%atthedivisionandgenuslevel,respectively.Forfieldsamples,theCDRswere91.7%and80%atthedivisionandgenuslevel,respectively(mesocosmexperiments),andtheCDRswere100%and66.7%atthedivisionandgenuslevel,respectively(JiaozhouBay).ThefluorometrictechniquewasusedtoestimatethephytoplanktoncommunitycompositionandrelativeabundanceofdifferentclassesfortheApril2010cruiseintheYellowSeawiththeresultsagreeingwiththoseinpublishedpapersbyotherauthors.
简介:针对传统地图面状符号色彩设计中理论研究与评价方法滞后、缺少定量分析和个性化差异研究的瓶颈问题,提出了一种基于方差分析的研究方法。首先对地图面状符号色彩真实度认知及性别差异分析现状和存在的问题进行总结。然后采用德尔菲法(专家意见法)确定问卷设计问题;采用问卷调查法收集实验数据;通过描述性统计分析验证地图面状符号色彩设计真实度对于地图整体设计效果的重要性;通过方差分析对地图面状符号色彩真实度感受性别差异的显著性进行研究。实验结果表明:地图面状符号色彩设计真实度非常重要,而且对其感受存在性别差异,与心理学领域的相关结论一致。研究结果对于指导地图面状符号色彩设计和地图个性化设计研究具有重要的参考价值。
简介:Inthispaper,thefocusedwavegroupswithdifferentparametersandtheiractionsonaverticalcylinderareexperimentallystudied.Theharmonicwavecharacteristicsofthefocusingwavesareanalyzedbytheadditionandsubtractionofthecrestandtroughfocusingwaves.Theanalyzedresultsshowthathigherorderharmonicscanbegeneratedbecauseoftheinteractionofcomponentwaves.Nonlinearityincreaseswiththeinputtedwaveamplitudeandthefrequencywidthincrement.Further,thewaverun-uparoundtheverticalcircularcylinderisexperimentallystudied.Itincreaseswiththewavesteepnessandtherelativecylinderdiameterincrease.However,thevariationsofwaverun-uparoundthecircularcylinderaredifferent.Theresearchesprovideareferenceforfurthernumericalstudies.
简介:TostudytheTaiwanStrait(TS),anunusualseaarea,thenumericalmodelinmarginalseasofChinaisusedtosimulateandanalyzethetidalwavemotioninthestrait.ThenumericalmodelingexperimentsreproducetheamphidromicsystemoftheM2tideinthesouthendoftheTaiwanstrait,andconsequentlyconfirmtheexistenceofthedegenerateamphidromicsystem.Onthisbasis,furtherdiscussionisconductedontheM2systemanditsformationmechanism.ItcanbeconcludedthatthetidalwavesoftheTSisconsistedoftheprogressingwavefromthenorthentranceandthedegenerateamphidromicsystemfromthesouthentrance,inwhichtheprogressingwavefromthenorthentrancedominatesthetidalwavemotioninthestrait.Exceptfortheconvergenteffectcausedbythelandformandboundary,thedegenerateamphidromicsystemproducedinthesouthofthestraitisanotherimportantfactorforthefollowingphenomena:thelargetidalrangeinthemiddleofthestrait,theconcentrativezoneofco-amplitudeandco-phaselineinthesouthofthestrait.ThedegenerateamphidromicsystemismainlyproducedbytheincidentPacificOceantidalwavefromtheLuzonstraitandtheactionbytheshorelineandlandform.Thepositionoftheamphidromicpointiscompelledtomovetowardsouthwestuntildegeneratingbythepowerfulprogressingwavefromthenorthentrance.