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1.
Elementscyclingandenergyflowaretheimportantresearchcontentsinecosystemfieldsandresiduade-compositionisthekeyprocessofnutrimentalelementscirculationSWIFTetal.1979.Theresiduade-compositionrateplaysanimportantroleindecidingtheproductivityandbiomassof…  相似文献   

2.
INTRODUCTIONAxeniccultureofalgaeisrequiredformanyexperimentalstudiesandcellsuspensioncultures,andisessentialforgainingunderstandingoftherelationshipbetweenthealgaeandtheirepiphyticfloraandmicroorganisms,andforstudyingthegrowthanddevelopmentofalgae (Tat…  相似文献   

3.
INTRODUCTIONVariouscausativefactors,suchasincreasedscientificawareness,utilizationofcoastalwatersforaquaculture,eutrophicationandcysttransportation (Hallegreaffetal.,1 995)hasledtoextens ivestudiesontheglobalincreaseinHAB (HarmfulAlgalBloom) .YettheHABmechani…  相似文献   

4.
INTRODUCTIONBillard ( 1 986)studiedthespermatozoonultrastructuresinteleostsandfounddistinctdifferencesa mongdifferentspecies.Studyonspermatozoonmorphologyandfunctionisachallengebecauseofthesperm’sspecialenvironment (Gageetal.,1 998;WangandZhang,1 999) .Sinceleft ey…  相似文献   

5.
INTRODUCTIONKnowledgeofgametogenesisinvaluablemarineanimalsisveryimportanttocommercialfish ery.Gametogenesisinbivalveswasextensivelystudiedatdifferentlevels (Dohmen ,1 983 ;DorangeandLePennec ,1 989a,b) .Scallopsandothermarinebivalveshavesimilarreproductivecycle…  相似文献   

6.
THE URBAN FUNCTION OF SUZHOU ON BASIS OF THE SHANGHAI-SUZHOU RELATIONSHIP   总被引:1,自引:0,他引:1  
1INTRODUCTIONWiththeaccelerationoftheeconomicglobaliza-tionthegradualshapingofthenewinternationaldivi-sionoflaborandthedevelopmentofthetransnationalcorporationstheworldurbansystemshavebegunanewroundofintegration.Ononehandthecitiesallovertheglobeare…  相似文献   

7.
INTRODUCTIONPeopleshowedgreatinterestsinmicroalgaeduetotheirgoodcharacteristics,suchashigheffi ciencyofusingsolarenergy,smallsize ,nutritionalvalue ,rapidgrowthandmultiplicationrate .Mi croalgaehaveanimportantroleinmaricultureasfoodforlarvalstagesofcrusta…  相似文献   

8.
1INTRODUCTIONInecosystemfragileecoenvironmentisdefinedasthe“interface"betweentwoormoresystemsofmatterenergystructureorfunctionandthetransitionregionextendingfromthisinterfaceNIU1989.ThefragileecoenvironmentoftheSongnenPlainissitu-atedonsuch…  相似文献   

9.
INTRODUCTIONTheproductionofphytoplanktonisthefirsttacheintheproductionbymarineorganismsandinthemarinefoodchain .Knowledgeofprimaryproductioninmarinewatersisprerequisiteforexploitationandmanagementoftheocean’slivingresources.Theprimaryproductioninmarin…  相似文献   

10.
INTRODUCTIONFromthe1990’s,thescallop,C.farreri,culturedinthenorthernChinaSea,deterioratedinsize,healthandoutputbecauseofhighstockingdensities,shortageofnaturalfoodanddiseases.Massmortalityof50%-90%occurredinJiaozhouBay,Qingdao,andSishiliwanBay,Yantai,fromJulyto…  相似文献   

11.
1INTRODUCTIONForestlitterwhichisthephysicalmakeuppartofforestecosystempresentsmanyimportantactionsuponecosystem.Howeverifforestlitterisaccumulatedtoexcessitwillproducesomenonnegligiblenegativein-fluencewhichcouldbethecauseofaforestfireortheimpor…  相似文献   

12.
1INTRODUCTIONGeothermalanomalyisaphenomenonthatunder-groundtemperatureandgeothermalgradientincreasesmuchmoreintheareathanitssurroundingsXIA1979.Thisisanormalglobalphysicalphenomenonintheactiveandthelatentvolcanicarea.Duringthewarningsignperiodofan…  相似文献   

13.
INTRODUCTIONChlorinehastwonaturallyoccuringstableisotopes, 35Cland 37Cl.Severalstudiesreportedthevariationsintheisotopiccompositionofchlorineinnature.However,intheearlyyearsOwenandSchaeffer(1955)reportednoobservabledifferenceinthe 37Cl35Clratiosintensamplesex…  相似文献   

14.
INTRODUCTIONInrecentyears,co culture (integratedculture )ofmarinespecies (algaeandanimals)hasreceivedgreatattention .Inco culturesystemthealgaeactivelyuptakeCO2 andthemetabolicwastes(suchasNH4 +,NO2 - ,NO3- etc)asnutrientsources,andreleaseO2 tothesurroundingenviron …  相似文献   

15.
INTRODUCTIONItwasgenerallyconsideredpreviouslythatthecorrosionofsteelinseamudwasnotserious.However,itwaslaterfoundthatthecorrosionrateofsteelinsomeseamudwashigherthanthatinseawater(King,1980;Sehmide,1982;Guoetal.,1997;Hou,1998).Therearesomereportsthatthecorrosionr…  相似文献   

16.
1INTRODUCTIONNoonecandoubtthatoneofthemostexcitingsoundsinnineteenthcenturyAmericawasthewhistleofalocomotive.ThroughoutthewholecenturyespeciallyinthesecondhalfrailroadsplayedadramaticroleintransformingtheAmericanwestfromabarrenlandintoapopulatedone…  相似文献   

17.
INTRODUCTIONOverthepastdecade ,Haematococcuspluvialishasbeenasubjectofnumerousinvestigationsbe causeitsconspicuousredcolorpointstoitspossibilityasahopefulregenerativebioresourceofastaxan thin .Extensivestudyofculturefactors (suchastemperature,illuminatio…  相似文献   

18.
INTRODUCTIONPrawnfarminginChinaisanimportantmaricultureindustrywhoseannualproductionhaseverreachedtomorethan 2 .0× 1 0 5 t,inwhichsemi intensivecultureofChineseprawn (PenaeusorientalisKishinouye)contributedthegreatestpart.Butinrecentyearstheprawncultureindust…  相似文献   

19.
1INTRODUCTIONWiththerapiddevelopmentandapplicationofnewtechniquessuchascomputercartographyhasenteredthe21stcentury′sdigitalperiodfromcomputerassistmappinginthe1970straditionalmaprepresentationhastransformedfrom2Dmonomediumstaticinto3Dmultim…  相似文献   

20.
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   

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