简介：Thispapermainlydealswiththesimulationonthestrengthoftheconcretearmorblockinmodeltest.Accordingtotherequirementforthestrengthofblocksinmodelswithvariousscales,thecomponentsofmaterialsformodelblocksandtheirproportionsaredetermined.Thefailureofarmorblocksonrubble-moundbreakwatersisreproducedbymodeltests.

简介：Basedontheone-dimensionalsalinitytransportequationwithconstantdiffusioncoefficient,andseparatedwaterflowvelocityintorunoffandtidalcurrentwiththesingle-frequencyinanidealizedestuary,thesimplestunsteadyanalyticalsolutionofsalinityintrusionisdeducedandtheestimationformulaofdiffusioncoefficientisobtainedinthispaper.Theunsteadysolutionindicatesthatsalinityprocessinestuariesresultsfromtheinteractionofrunoffandtidalcurrent,anditsamplitudeisindirectproportiontotheproductofthevelocityofrunoffwaterandtheamplitudeoftidalflowvelocityandininverseproportiontothediffusioncoefficientandthetidalangularfrequency,anditsphaselagtidalflowwithπ/2whichrevealsthebasicfeaturesofthemaximumsalinityappearingafterfloodslackandtheminimumsalinityappearingbeforeebbslackundertheeffectofrunoff(theadvanceorlagtimeisrelativetothemagnitudeofrunoffandtidalflow).Accordingtothemeasuredflowvelocityandsalinitydata,thesalinitydiffusioncoefficientcouldbeestimated.Finally,withthefielddataofobservingsitesonthedeepwaternavigationchanneloftheYangtzeEstuary,thediffusioncoefficientiscalculatedandacomparativeanalysisofsimulatedandmeasuredofsalinityprocessismade.Theresultsshowthatthesolutioncancomprehensivelyreflectsthebasiccharacteristicsandprocessesofsalinityintrusionundertheinteractionofrunoffandtidalflowinestuaries.Thesolutionisnotonlysuitablefortheoreticalresearch,butalsoconvenientforestimatingreasonablephysicalparametersandgivingtheinitialconditioninthesalinityintrusionnumericalsimulation.

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：Aciladivaricata(Hinds,1843)andA.mirabilis(AdamsandReeve,1850)arecommonbenthicbivalvesinChina.Anumberofresearchershaveproposedthatthelatterspeciesisajuniorsynonymoftheformerspecies.Becauseofmorphologicalsimilarities,itisdifficulttodistinguishthesetwospeciesbasedonvisualexaminationonly.Forbetterunderstandingoftheirtaxonomy,themitochondrialCOIgenefragmentsoffiveindividualsofA.divaricatafromtheEastChinaSeaandsixindividualsofA.mirabilisfromtheYellowSeaweresequencedinthisstudy.ThephylogeneticrelationshipsoftheobtainedCOIsequences,togetherwithnineteensequencesofthreespeciesofthegenusNucula,wereanalyzed.Thepairwiseintra-andinter-specificdistancesfortheCOIsequencesrangedfrom0.002to0.017andfrom0.128to0.134,respectively,andnooverlapwasfound.Phylogenetically,A.divaricataandA.mirabilisformdistinctcladesandclusterintoasistertoallotherNuculaspecies.TheresultsindicatedthatA.divaricataandA.mirabilisaretwodistinctspecies.Thedifferencesinthemorphologyanddistributionbetweenthetwospecieswerebrieflydiscussed.

简介：Mangrovesaccumulatesedimentarysequences,wherecorescanprovidehistoricalrecordsofmangroveevolutionwithpastclimatechangeandhumanactivity.ThestudytracedthehistoryofmangroveevolutionduringthepastonehundredyearsinamangroveswampofMaoweiSea,SWChina.Thesedimentationrates(0.38-0.95cmyr-1)werecalculatedonthebasisofln(210Pbxs/Al)andmassdepthinthecoresediments.Chemicaltracers,suchasδ13CorgandC:Nvalues,wereutilizedtotracethecontributionofmangrove-derivedorganicmatterusingaternarymixingmodel.Becauseofpotentialdiageneticalterationand/oroverlapintheisotopicsignaturesofdifferentcomponents,simultaneoususeofmangrovepollendiagramscanhelptosupplementsomeoftheselimitations.Combinedwithmangrovepollen,mangroveevolutionwasreconstructedandcouldbedividedintothreestages:flourishment（1886-1905AD）,slightdegradation（1905-1949AD）andrapiddegradationperiod（1949-2007AD）,whichwasconsistentwithpreviousreports.Thereclamationofmangroveswampstoshrimppondswasthemajorreasonforrapiddegradationofmangroveecosystemsinrecentyears,ratherthanclimatechangeintheregion.