简介:Thispaperreportstheabsorption,accumulation,distributionandcycleofCu,Pb,Zn,CrandNiinS.apetala+S.caseolaris,mangrovecommunityatFutianMangroveNatureReserveofShenzhen,TheCu,Pb,Zn,CrandNicontentsinforestsoilincreasefrombottomtosurfacelayers,andthestorageofthefiveheavymetalsinthesurfacelayer(depth0-30cm)isZn>Pb>Ni>Cr>Cu.TheconcentrationabilityisS.caseolaris>S.apetala>K.candel.TheexistingaccumulationofCu,Pb,Zn,CrandNiinthecommunityis23019.63μg/m^2,23429.66μg/m^2.177870.42μg/m^2,6835.80μg/m^2,and12995.22μg/m^2,respectively.Theannualabsorptionis6592.57μg/m^2,2664.80μg/m^2,23123.56μg/m^2,853.24μg/m^2,and1990.95μg/m^2,respectively.Theannualreturnis3179.50μg/m^2,1300.65μg/m^2,7401.31μg/m^2,398.99μg/m^2,and646.20μg/m^2respectively.TheannualnetretentionaccumulationofCu,Pb,Zn,CrandNiinthecommunityis3413.07μg/m^2,1364.15μg/m^2,15722.25μg/m^2,454.25μg/m^2,and1344.75μg/m^2,respectively,TheturnoverperiodsofCu,Pb,Zn,CrandNiare8,19,15,18and21years,respectively.
简介:Inordertodeterminethedegreeofreturning-to-zerooftemperaturesofdeformedcalcite,aseriesofrock-breakingexperimentsweredesignedtotestcalcite-richlimestonesamplesunderfixedconfiningpressuresanddifferenttemperatures.Theconsolidateddeformedsamplesintheirinitialstatewereobservedunderamicroscopeandthemicroscopicindicatorsindifferentzero-returningstateswereputforward,thusprovidingamicroscopicfoundationforevaluationofreliabilityofdatingvaluesofdeformationincalcite.Atlast,thecorrectionofdatingvaluesofdeformationforsampleswhosetemperaturehasnotyetreturnedtozeroisdiscussed.
简介:ThewildPorphyrayezoensiscollectedfromtheQingdaocoastwasusedtoprepareprotoplastsbyenzymedigestion.Thepurelinewasconstructedbycultivatingtheprotoplasts.The18SrDNAoftheP.yezoensispurelinewasclonedandsequenced.Sequenceanalysiswasexecutedforthissequenceandother22sequencesretrievedfromGenBank.Aphylogenetictreewasconstructedusingtheneighbor-joiningmethod.Theresultsrevealedahighdiversityof18SrDNAsequencesingenusPorphyraandtheconsiderablevariationof18SrDNAsequencesindifferentstrainsofthesamespeciesP.yezoensisandP.tenera.Significantdifferenceof18SrDNAsequencewasobservedbetweenP.yezoensisfromQingdao,China,andthetwostrainsofP.yezoensisfromJapan,butthethreestrainsofP.yezoensisformedastablecladeinthephylogenetictree.TheseresultsindicatethepossibilityofinterspeciesandintraspeciesdiscriminationofPorphyrausingthe18SrDNAsequences.
简介:18SribosomalDNA基因(18SrDNA)序列(近似在长度的1300bp)从从与线虫大批从Qingdao海岸的内部潮汐的沉积收集的免费生活的海洋的线虫提取的DNA被放大特定的教材。PCR产品被克隆,重新放大,与Rsa消化了我和Hin6我限制endonucleases和分开的inagarose胶化。在17种限制碎片长度类型之中,打1,2和6盖住61.2%,分别地,当时,克隆的14.4%and9.3%分析了留下14仅仅盖住21克隆,它说明了15.1%总数。24代表性的克隆andphylogenetically被定序由指在RDP和GenBank数据库当前可得到的那些分析了。尽管它是难的由于已知的海洋的免费生活的线虫的18SrDNA顺序数据的缺乏把这些序列分到已知的种类或类,获得的序列被分到Adenophorea的线虫。在他们之中,12个序列接近了PontonemavulgareandAdoncholaimussp,四到Daptonemaprocerus并且二(相同)到Enoplusbrevis。我们的结果证明免费生活的海洋的线虫差异能被检索的PCR决定,18SrDNA的分析定序,仅当免费生活的海洋的线虫的18SrDNA序列被积累到某程度,一个18SrDNA序列能被分到种或一个类。
简介:利用福建省1986、1993、2000年的TM影像和2004年的中巴地球资源卫星影像,在RS、GPS和GIS技术支持下,结合福建省生态环境特征,选取了斑块面积指标、形状指标、破碎化程度指标、聚散性指标、多样性指标等5类景观生态学指数,研究福建省1986—2004年湿地景观格局演变规律.结果表明:(1)福建省湿地面积总体呈下降趋势.1986—2004年各期湿地总面积分别是:1793793.06hm^2、1665966.28hm^2、1609862.77hm^2、1618760.97hm^2.各景观面积指数表现出不同程度的变化,其中灌溉地、河流、河漫滩、沼泽、盐田景观面积呈现下降趋势,蓄水区、海水养殖景观面积增大,其他类型波动变化;(2)受人类活动的影响,景观优势组分对景观整体的控制作用有所减弱.Shannon-Wiener多样性指数4个时期分别为0.6681、0.7375、0.8165、0.8301,ShannonWiener均匀度指数分别为0.3041、0.3356、0.3716、0.3778,斑块面积变异系数由1986年的882.0695%下降到2004年的516.3157oA;(3)湿地景观受外界干扰程度加大,破碎化程度加剧;同时,湿地原始形态也受到了较复杂的影响.边缘密度由1986年的5.9981m/hm^2上升到2004年的6.6982m/hm^2,平均形状指数也从2.1758略微下降到1.9910;(4)各斑块类型和周围相邻斑块类型的空间连接程度进一步降低,湿地景观被分隔态势增强.蔓延度指数下降,4个时期分别为83.3695、81.9283、79.8908、79.8203,斑块结合度从1986年的99.2029连续降至2004年的9R5459
简介:FollowingtherecommendationoftheInternationalCommissiononStratigraphy(16votesYes[94%],1abstention,2votesnotreceived),theGlobalboundaryStratotypeSectionandPoint(GSSP)forthebaseoftheTuronianStageoftheCretaceousSystemisdefinedasthebaseofbed86oftheBridgeCreekLimestoneMemberoftheGreenhornLimestoneFormationatthewesternendoftheDenverandRioGrandeRailroadcutnearthenorthboundaryofthePuebloReservoirStateParkRecreationArea,westofPueblo,Colorado,USA.ThisGSSPhorizonisalsoexposedandprotectedintheadjacentstaterecreationarea.ItcoincideswiththefirstoccurrenceoftheammoniteWatinocerasdevonense,isinthemiddleofaglobalpositiveexcursioninCarbon-13isotopes,andisbracketedbywidespreadbentonitesthathaveyieldedagesof93to93.5Ma.
简介:IntheSoutheastMarginoftheTibetanPlateau,low-velocitysedimentarylayersthatwouldsignificantlyaffecttheaccuracyoftheH-κstackingofreceiverfunctionsarewidelydistributed.Inthisstudy,weuseteleseismicwaveformdataof475eventsfrom97temporarybroadbandseismometersdeployedbyChinArrayPhaseItoobtaincrustalthicknessesandPoisson’sratioswithintheChuxiong-SimaoBasinandadjacentarea,employinganimprovedmethodinwhichthereceiverfunctionsareprocessedthrougharesonance-removalfilter,andtheH-κstackingistime-corrected.Resultsshowthatthecrustalthicknessrangesfrom30to55kminthestudyarea,reachingitsthickestvalueinthenorthwestandthinningtowardsouthwest,southeastandnortheast.TheapparentvariationofcrustalthicknessaroundtheRedRiverFaultsupportstheviewofsoutheasternescapeoftheTibetanPlateau.RelativelythincrustalthicknessinthezonebetweenChuxiongCityandtheRedRiverFaultindicatespossibleupliftofmantleinthisarea.ThepositivecorrelationbetweencrustalthicknessandPoisson’sratioislikelytoberelatedtolowercrustthickening.Comparisonofresultsobtainedfromdifferentmethodsshowsthattheimprovedmethodusedinourstudycaneffectivelyremovethereverberationeffectofsedimentarylayers.
简介:Comparedtotowedstreamers,ocean-bottomseismometers(OBS)obtainbothS-wavedataandricherwavefieldinformation.Inthispaper,theinducedpolarizationmethodisusedtoconductwavefieldseparationonOBSdataobtainedfromtheShenhuareaintheSouthChinaSea.AcomparisonofthechangesinP-andS-waves,andacomprehensiveanalysisofgeologicalfactorswithinthearea,enableanalysisanddescriptionoftheoccurrenceofnaturalgashydrateinthestudyarea.ResultsshowanincreaseinP-wavevelocitywhennaturalgashydrateexistsintheformation,whereastheS-wavevelocityremainsalmostconstant,asS-wavescanonlypropagatethroughtherockskeleton.Therefore,thebottom-simulatingreflection(BSR)responseoftheP-waveisbetterthanthatoftheS-waveinthefrequencyanalysisprofile.Inawide-anglesection,therefractivewaveofthehydratelayerisevidentwhenusingP-wavecomponentsbutidentificationisdifficultwithS-wavecomponents.ThisvelocitymodelillustratesthesensitivityofPandS-wavecomponentstogashydrate.TheuseofthispolarizationmethodandresultsofanalysisprovidetechnicalandtheoreticalsupportforresearchonhydratedepositsandothergeologicalfeaturesintheShenhuarea.
简介:摘要富源信德矿区上部地层结构松散、破碎、钻孔坍塌严重。而且存在少量石灰岩,灰岩裂隙大,漏水严重。而设计的钻孔深度大。给施工带来很大困难,通过采取多级钻孔结构,并在钻进参数,冲洗液、钻头扩孔器上的合理应用,解决了施工难题,顺利完成了1204米深ZK502#钻孔。
简介:Asthestrongestsubseasonalatmosphericvariabilityduringborealwinter,threeremarkablesuddenstratosphericmajorwarming(SSW)eventsinthe2000sareinvestigatedintermsoftheBrewer–Dobsoncirculation(BDC)response.Ourstudyshowsthatthechangesofcross-isentropicvelocityduringtheSSWsarenotonlyconfinedtothepolarregion,butalsoextendtothewholeNorthernHemisphere:enhanceddescentinthepolarregion,aswellasenhancedascentinthetropics.WhentheaccelerationofthedeepbranchoftheBDCdescendstothemiddlestratosphere,itsstrengthrapidlydecreasesoveraperiodofonetotwoweeks.TheaccelerationofthedeepbranchoftheBDCisdrivenbytheenhancedplanetarywaveactivityinthemid-to-high-latitudestratosphere.DifferentfromtherapidresponseofthedeepbranchoftheBDC,tropicalupwellinginthelowerstratosphereacceleratesupto20%–40%comparedwiththeclimatology,20–30daysaftertheonsetoftheSSWs,andtheaccelerationlastsforonetothreemonths.Theenhancementoftropicalupwellingisassociatedwiththelarge-scalewave-breakinginthesubtropicsinteractingwiththemidlatitudeandtropicalQuasi-BiennialOscillation–relatedmeanflow.
简介:Inthispaper,basedonGansuDigitalSeismicNetworkdatasince1990,wecalculatedb-valueand⊿b-valueoftheneighborhoodareabeforethe2013Minxian-ZhangxianM_S6.6,earthquake.Theresultsshowthattheearthquakeoccurredatthemarginofthesignificantlylowerb-valueareainsoutheastofGansuandbeforetheearthquaketheneighborhoodareahadanobviouslyabnormal⊿b-value.Fromtheearthquakeandthespatialdistributionoflowb-value,theregionstillhasthepossibilityofgeneratingdangerousstrongearthquakes.