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Elementscyclingandenergyflowaretheimportantresearchcontentsinecosystemfieldsandresiduade-compositionisthekeyprocessofnutrimentalelementscirculationSWIFTetal.1979.Theresiduade-compositionrateplaysanimportantroleindecidingtheproductivityandbiomassof… 相似文献
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INTRODUCTIONAxeniccultureofalgaeisrequiredformanyexperimentalstudiesandcellsuspensioncultures,andisessentialforgainingunderstandingoftherelationshipbetweenthealgaeandtheirepiphyticfloraandmicroorganisms,andforstudyingthegrowthanddevelopmentofalgae (Tat… 相似文献
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INTRODUCTIONVariouscausativefactors,suchasincreasedscientificawareness,utilizationofcoastalwatersforaquaculture,eutrophicationandcysttransportation (Hallegreaffetal.,1 995)hasledtoextens ivestudiesontheglobalincreaseinHAB (HarmfulAlgalBloom) .YettheHABmechani… 相似文献
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INTRODUCTIONBillard ( 1 986)studiedthespermatozoonultrastructuresinteleostsandfounddistinctdifferencesa mongdifferentspecies.Studyonspermatozoonmorphologyandfunctionisachallengebecauseofthesperm’sspecialenvironment (Gageetal.,1 998;WangandZhang,1 999) .Sinceleft ey… 相似文献
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INTRODUCTIONKnowledgeofgametogenesisinvaluablemarineanimalsisveryimportanttocommercialfish ery.Gametogenesisinbivalveswasextensivelystudiedatdifferentlevels (Dohmen ,1 983 ;DorangeandLePennec ,1 989a,b) .Scallopsandothermarinebivalveshavesimilarreproductivecycle… 相似文献
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1INTRODUCTIONWiththeaccelerationoftheeconomicglobaliza-tionthegradualshapingofthenewinternationaldivi-sionoflaborandthedevelopmentofthetransnationalcorporationstheworldurbansystemshavebegunanewroundofintegration.Ononehandthecitiesallovertheglobeare… 相似文献
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EFFECTS OF HARVEST STAGE ON THE TOTAL LIPID AND FATTY ACID COMPOSITION OF FOUR CYLINDROTHECA STRAINS
INTRODUCTIONPeopleshowedgreatinterestsinmicroalgaeduetotheirgoodcharacteristics,suchashigheffi ciencyofusingsolarenergy,smallsize ,nutritionalvalue ,rapidgrowthandmultiplicationrate .Mi croalgaehaveanimportantroleinmaricultureasfoodforlarvalstagesofcrusta… 相似文献
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1INTRODUCTIONInecosystemfragileecoenvironmentisdefinedasthe“interface"betweentwoormoresystemsofmatterenergystructureorfunctionandthetransitionregionextendingfromthisinterfaceNIU1989.ThefragileecoenvironmentoftheSongnenPlainissitu-atedonsuch… 相似文献
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INTRODUCTIONTheproductionofphytoplanktonisthefirsttacheintheproductionbymarineorganismsandinthemarinefoodchain .Knowledgeofprimaryproductioninmarinewatersisprerequisiteforexploitationandmanagementoftheocean’slivingresources.Theprimaryproductioninmarin… 相似文献
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INTRODUCTIONFromthe1990’s,thescallop,C.farreri,culturedinthenorthernChinaSea,deterioratedinsize,healthandoutputbecauseofhighstockingdensities,shortageofnaturalfoodanddiseases.Massmortalityof50%-90%occurredinJiaozhouBay,Qingdao,andSishiliwanBay,Yantai,fromJulyto… 相似文献
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1INTRODUCTIONForestlitterwhichisthephysicalmakeuppartofforestecosystempresentsmanyimportantactionsuponecosystem.Howeverifforestlitterisaccumulatedtoexcessitwillproducesomenonnegligiblenegativein-fluencewhichcouldbethecauseofaforestfireortheimpor… 相似文献
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RESEARCH ON DISTURBED MECHANISM OF THERMAL NOISES OF THE SURFACE IN ABRUPT GEOTHERMAL ANOMALY 总被引:3,自引:2,他引:1
1INTRODUCTIONGeothermalanomalyisaphenomenonthatunder-groundtemperatureandgeothermalgradientincreasesmuchmoreintheareathanitssurroundingsXIA1979.Thisisanormalglobalphysicalphenomenonintheactiveandthelatentvolcanicarea.Duringthewarningsignperiodofan… 相似文献
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VARIATIONS IN ISOTOPIC COMPOSITIONS OF CHLORINE IN EVAPORATION-CONTROLLED SALT
LAKE BRINES OF QAIDAM BASIN,CHINA 总被引:2,自引:0,他引:2
INTRODUCTIONChlorinehastwonaturallyoccuringstableisotopes, 35Cland 37Cl.Severalstudiesreportedthevariationsintheisotopiccompositionofchlorineinnature.However,intheearlyyearsOwenandSchaeffer(1955)reportednoobservabledifferenceinthe 37Cl35Clratiosintensamplesex… 相似文献
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INTRODUCTIONInrecentyears,co culture (integratedculture )ofmarinespecies (algaeandanimals)hasreceivedgreatattention .Inco culturesystemthealgaeactivelyuptakeCO2 andthemetabolicwastes(suchasNH4 +,NO2 - ,NO3- etc)asnutrientsources,andreleaseO2 tothesurroundingenviron … 相似文献
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EFFECT OF SULPHATE-REDUCING BACTERIA ON ELECTRO-CHEMICAL CORROSION BEHAVIOR OF 16Mn STEEL IN SEA MUD
INTRODUCTIONItwasgenerallyconsideredpreviouslythatthecorrosionofsteelinseamudwasnotserious.However,itwaslaterfoundthatthecorrosionrateofsteelinsomeseamudwashigherthanthatinseawater(King,1980;Sehmide,1982;Guoetal.,1997;Hou,1998).Therearesomereportsthatthecorrosionr… 相似文献
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1INTRODUCTIONNoonecandoubtthatoneofthemostexcitingsoundsinnineteenthcenturyAmericawasthewhistleofalocomotive.ThroughoutthewholecenturyespeciallyinthesecondhalfrailroadsplayedadramaticroleintransformingtheAmericanwestfromabarrenlandintoapopulatedone… 相似文献
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INTRODUCTIONOverthepastdecade ,Haematococcuspluvialishasbeenasubjectofnumerousinvestigationsbe causeitsconspicuousredcolorpointstoitspossibilityasahopefulregenerativebioresourceofastaxan thin .Extensivestudyofculturefactors (suchastemperature,illuminatio… 相似文献
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INTRODUCTIONPrawnfarminginChinaisanimportantmaricultureindustrywhoseannualproductionhaseverreachedtomorethan 2 .0× 1 0 5 t,inwhichsemi intensivecultureofChineseprawn (PenaeusorientalisKishinouye)contributedthegreatestpart.Butinrecentyearstheprawncultureindust… 相似文献
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ZHU Jin-hua 《中国地理科学(英文版)》2001,11(3):278-282
1INTRODUCTIONWiththerapiddevelopmentandapplicationofnewtechniquessuchascomputercartographyhasenteredthe21stcentury′sdigitalperiodfromcomputerassistmappinginthe1970straditionalmaprepresentationhastransformedfrom2Dmonomediumstaticinto3Dmultim… 相似文献
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INTRODUCTIONThelargeyellowcroakerPseudosciaenacroceaoncewasoneofthefourimportantmarinefish eryobjectsinChina (Hongetal.,1 983;HuangandCarl,1 983;ChenandGong ,1 983) .TheproductionofthewildP .croceain 1 974reached 1 971 78metrictons (MT)inChina (Li,1 998) .Becauseofoverfishing ,th… 相似文献