简介:Fifty-sevenstations(48gridstationsandninestratifiedstations)weresampledacrossthestudyregion(67.000°–88.394°N,152.500°–178.643°W)duringthe4thChineseNationalArcticResearchExpedition(CHINARE4)fromJulytoAugust2010bytheicebreakerR/VXuelong.Atotalof24speciesofHydromedusaewereidentifiedfrom130zooplanktonsamples,ofwhichsevenspeciesbelongedtoAutomedusa,eightspeciestoAnthomedusae,fourspeciestoLeptomedudae,andthreespeciestoSiphonophora.CatablemamulticirratumKishinouye,1910,BougainvilliabitentaculataUchida,1925,andEuphysajaponica(Maas,1909)wererecordedforthefirsttimeintheArcticsea.Inthepresentpaper,18speciesofHydromedusaeweredescribedandillustrated,ofwhichthreespeciesweredescribedforthefirsttimeintheArcticsea,and15speciesweredescribedforthefirsttimeinChina.
简介:Theneonflyingsquid,Ommastrephesbartramii,isaspeciesofeconomicallyimportantcephalopodintheNorthwestPacificOcean.Itsshortlifespanincreasesthesusceptibilityofthedistributionandabundancetothedirectimpactoftheenvironmentalconditions.Basedonthegeneralizedlinearmodel(GLM)andgeneralizedadditivemodel(GAM),thecommercialfisherydatafromtheChinesesquid-jiggingfleetsduring1995to2011wereusedtoexaminetheinterannualandseasonalvariabilityintheabundanceofO.bartramii,andtoevaluatetheinfluencesofvariablesontheabundance(catchperuniteffort,CPUE).TheresultsfromGLMsuggestedthatyear,month,latitude,seasurfacetemperature(SST),mixedlayerdepth(MLD),andtheinteractionterm(SST×MLD)weresignificantfactors.TheoptimalmodelbasedonGAMincludedallthesixsignificantvariablesandcouldexplain42.43%ofthevarianceinnominalCPUE.Theimportanceofthesixvariableswasrankedbydecreasingmagnitude:year,month,latitude,SST,MLDandSST×MLD.Thesquidwasmainlydistributedinthewatersbetween40?Nand44?NintheNorthwestPacificOcean.TheoptimalrangesofSSTandMLDwerefrom14to20℃andfrom10to30m,respectively.Thesquidabundancegreatlyfluctuatedfrom1995to2011.TheCPUEwaslowduring1995–2002andhighduring2003–2008.Furthermore,thesquidabundancewastypicallyhighinAugust.Theinterannualandseasonalvariabilitiesinthesquidabundancewereassociatedwiththevariationsofmarineenvironmentalconditionsandthelifehistorycharacteristicsofsquid.
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:Acomprehensivestrengthmonitoringsystemusedonafixedjacketplatformispresentedinthispaper.Thelong-termmonitoringofW-11-4Aplatformachieved.Structuralresponses(strainandacceleration)atselectedlocations,aswellasassociatedenvironmentalparameters,havebeenobtained.Theemphasisofthepaperisplacedonthesystemdesign,andtheinstrumentationandoperationmethodologyemployedinthemonitoringofthestructuralresponses.Theperformanceofthesystemandthecharacteristicresultsobtainedduringits13-monthoperationarealsosummarized.
简介:Thispaperpresentsthedetaildesignconditions,designcriteriaandmethodsaswellasdesignconclusionsoftheprocess,structureandcorrosionoftheproductionflowlinesandhighpressurewaterinjectionlinesinBZ34-2/4oilfieldinBohaiBay.AtpresentthisdesignrepresentsthedesigncapabilityandlevelinthefieldofthesubmarinepipelineengineeringofChina.
简介:Onthebasisofthetemperatureobservationsduring1961-2000inChina,sevencoupledgeneralcirculationmodels'(GCMs)extremetemperatureproductsareevaluatedsuppliedbytheIntergovernmentalPanelonClimateChange's4thAssessmentReport(IPCC-AR4).Theextremetemperatureindicesinusearefrostdays(FD),growingseasonlength(GSL),extremetemperaturerange(ETR),warmnights(TN90),andheatwavedurationindex(HWDI).Resultsindicatethatallthesevenmodelsarecapableofsimulatingspatialandtemporalvariationsintemperaturecharacteristics,andtheirensembleactsmorereliablethananysingleone.Amongthesevenmodels,GFDL-CM2.0andMIROC3.2performancesaremuchbetter.Besides,mostofthemodelsareabletopresentlineartrendsofthesamepositive/negativesignsastheobservationsbutforweakerintensities.Thesimulationeffectsaredifferentonanationwidebasis,with110°Nasthedivision,east(west)ofwhichtheeffectsarebetter(worse)andthepoorerovertheQinghai-TibetanPlateauinChina.Thepredictionsforthe21stcenturyonemissionsscenariosshowthatexceptdecreasesintheFDandETR,otherindicesdisplaysignificantincreasingtrend,especiallyfortheindicesofHWDIandTN90,whichrepresentthenotableextremeclimate.Thisindicatesthatthetemperature-relatedclimateismovingtowardstheextreme.Inthelate21stcentury,theGSLandTN90(HWDI)increasemostnotablyinsouthwestChina(theQinghai-TibetanPlateau),andtheFDdecreasemostremarkablyintheQinghai-TibetanPlateau,northwestandnortheastofChina.ApartfromSouthChina,theyearlychangerangeoftheextremetemperatureisreducedinmostofChina.
简介:根据2006-2007年“国家908”专项台湾海峡4个航次调查,分析该海域浮游甲藻的种类组成、群落结构和时空分布特征。共鉴定甲藻18属131种,其中高温高盐种为主体,占总种数的72.52%,其次为广温广盐种,占总种数的25.19%,近岸种仪占2.29%。夏季甲藻的种类最丰富,而春季甲藻的丰度最高。平均丰度为404.96×10^2cells/m3,其平面分布呈现从近岸向外海、从北向南递增的趋势。与1984-1985年的调查结果相比较,甲藻丰度的平面分布格局和季节变化趋势没有明显变化,但丰度增加3.01倍。从季节变化看,冷季甲藻丰度增加较为显著;从平面分布看,台湾海峡北部增加较多。此外,该海域甲藻群落结构也发生变化,种类多样性指数和均匀度上升,其丰度占浮游植物总丰度的比例由0.55%上升到1.02%。
简介:有些文献指出:“赤潮发生起因因种而异,但大体上气候气象条件诸如温度、风力、风向,季风转换、气压等;海况、潮汐、流等以及海水的理化特征,如盐度、营养元素等,这些皆会成为某种赤潮爆发的因子或诱导因素”。根据赤潮监控区监测资料分析:在南海赤潮多发区,海水富营养化条件已经具备,因此气象、水文要素条件就成为赤潮爆发的重要启动因子,而天气环流的维持与变化决定了气象、水文要素因子的稳定与变化,再根据赤潮生物培养试验,从初期繁殖到后期的爆发性繁殖,直至达到赤潮生物密度,这一过程一般都需要4—5d的时间。针对这一现象,通过对近10a的赤潮发生个例进行统计分析,统计其生成前期的天气环流形势和水文气象要素,分析出赤潮生成前期的环流模式和筛选出诱发赤潮爆发的重要因子,并依此来作为预报赤潮生成的方法,依照此方法对2003年的赤潮进行预报,其效果是另人满意的。
简介:自2000年以来,渤海海域每年都有赤潮发生,这往往使渤海沿海水域受其影响.卫星遥感技术和海洋水色观测卫星图像,已经成功地用于识别和观测赤潮的发生、发展和消亡.然而,由于研究的水体、使用的遥感数据和建模方法都各不相同,因此需针对渤海海域的水体特点建立特定的赤潮反演模型.本文利用MODIS光谱反射率数据和渤海海域实测叶绿素a浓度进行了相关分析,选择表达式(B10-B8)/(B13-B8)作为渤海海域赤潮反演的指标,相关系数达到0.7815,呈现显著相关结果.研究发现2014年渤海海域赤潮灾害的时空分布特征较为明显.其中渤海海域赤潮大规模爆发的主要原因归结于其半封闭型的地理形态导致的水交换不畅和沿岸径流的大量陆源物质输入,河流输入是陆源污染入海的主要来源.然后,本文利用云覆盖较少的GOCI遥感数据,建立了-个改进型赤潮指数的赤潮反演模型,并且证明了在浑浊水域中描述赤潮的有效性.2014年5月15日、26日和30日的每小时RI图像在-天中呈现出基本-致的赤潮变化,并且-天中渤海海域的赤潮面积变化非常明显,赤潮藻类优势种的垂直迁移可能是导致赤潮表面表达短期变化的主要原因.