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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.
INTRODUCTIONTheintracellularsurfaceofacellcouldbeobservedbyusingscanningelectronmicroscope(SEM)andthefreezefracturetechnique .Exposingthecellsurfaceisthemostdirectapproach .Inthistechnique,allexposedsurfacescutopenduringsectioningcouldbeviewedbySEM (Russ…  相似文献   

4.
INTRODUCTIONTheworld’sshrimpcultureindustryhasbeensufferingfromviralepidemicdiseasesandfellintoadif ficultpositionforyears.Itisgenerallyacceptedtodaythatthediseaseswerecausedmainlybywaterpollu tioncreatedbyshrimpcultureitself,bothinshrimppondsandincoas…  相似文献   

5.
GAMMA-RAYS INDUCTION OF MUTATION IN CONCHOCELIS OF PORPHYRA YEZOENSIS   总被引:3,自引:0,他引:3  
INTRODUCTIONItisknownthatthereareseveraltypesofpigmentationmutantswithdifferentcolorascomparedwiththewildtypeinsomespeciesofPorphyra (Aruga,1 974 ;Miuraetal.,1 974 ;Miura,1 985) .InP .yezoensis,theyellowtypemutantwasobtainedinlaboratorybycrossingredandgreentypepigm…  相似文献   

6.
INTRODUCTIONVariouscausativefactors,suchasincreasedscientificawareness,utilizationofcoastalwatersforaquaculture,eutrophicationandcysttransportation (Hallegreaffetal.,1 995)hasledtoextens ivestudiesontheglobalincreaseinHAB (HarmfulAlgalBloom) .YettheHABmechani…  相似文献   

7.
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   

8.
INTRODUCTIONTheKuroshioisthewesternboundarycurrentintheNorthPacificandisthecounterpartoftheGulfStreamintheNorthAtlantic.TheoriginoftheKuroshioisthenorthwardflowingbranchoftheNorthEquatorialCurrentwhichisdividedintotwocurrentsonapproachingthewesternbo…  相似文献   

9.
INTRODUCTIONBillard ( 1 986)studiedthespermatozoonultrastructuresinteleostsandfounddistinctdifferencesa mongdifferentspecies.Studyonspermatozoonmorphologyandfunctionisachallengebecauseofthesperm’sspecialenvironment (Gageetal.,1 998;WangandZhang,1 999) .Sinceleft ey…  相似文献   

10.
Todaysustainabledevelopmentiscurentlypromoted,butprohibitedbyfragileenvironment.Soinrecentyears,thestudyincludingformationre...  相似文献   

11.
INTRODUCTIONKnowledgeofgametogenesisinvaluablemarineanimalsisveryimportanttocommercialfish ery.Gametogenesisinbivalveswasextensivelystudiedatdifferentlevels (Dohmen ,1 983 ;DorangeandLePennec ,1 989a,b) .Scallopsandothermarinebivalveshavesimilarreproductivecycle…  相似文献   

12.
Withthesocialdevelopment,humanbeingshadtopaymuchatentiontothecrisisofenvironmentastotheeconomiccrisis.Waterdeficiencyanddeser...  相似文献   

13.
INTRODUCTIONPeopleshowedgreatinterestsinmicroalgaeduetotheirgoodcharacteristics,suchashigheffi ciencyofusingsolarenergy,smallsize ,nutritionalvalue ,rapidgrowthandmultiplicationrate .Mi croalgaehaveanimportantroleinmaricultureasfoodforlarvalstagesofcrusta…  相似文献   

14.
INTRODUCTIONJohannes (1 965)firstshowedtheimportanceofprotozoaasremineralizersinmarineenvironments.Thesignificanceofprotozoainthefreshwaterfoodwebhasbeenknownforthepast2 0years.Protozoaisamainpredatorofplanktonicbacteriaandphytoplankton ,andalsoafoodsourceo…  相似文献   

15.
1INTRODUCTIONInecosystemfragileecoenvironmentisdefinedasthe“interface"betweentwoormoresystemsofmatterenergystructureorfunctionandthetransitionregionextendingfromthisinterfaceNIU1989.ThefragileecoenvironmentoftheSongnenPlainissitu-atedonsuch…  相似文献   

16.
INTRODUCTIONFromthe1990’s,thescallop,C.farreri,culturedinthenorthernChinaSea,deterioratedinsize,healthandoutputbecauseofhighstockingdensities,shortageofnaturalfoodanddiseases.Massmortalityof50%-90%occurredinJiaozhouBay,Qingdao,andSishiliwanBay,Yantai,fromJulyto…  相似文献   

17.
INTRODUCTIONTheproductionofphytoplanktonisthefirsttacheintheproductionbymarineorganismsandinthemarinefoodchain .Knowledgeofprimaryproductioninmarinewatersisprerequisiteforexploitationandmanagementoftheocean’slivingresources.Theprimaryproductioninmarin…  相似文献   

18.
INTRODUCTIONJiaozhouBayisashallowsemi closedbaywithtotalareaofabout 40 0km2 andaveragewaterdepthof7m .Themaximumwaterdepthisover 5 0matthecenterofthestraitconnectingtotheYellowSea.Thisstraitcenterwateriscalledbaymouthwater,thewaterinthenorthernpartofthestrai…  相似文献   

19.
1 INTRODUCTIONGuangdongProvincehasbeenwidelyknownasoneofthemostimportantindustrialbasesforexportinChina.IthasplayedanimportantroleineconomicreformanddevelopmentinChina.Inrecentyears,ithasattainedasustainableeconomicgrowthandkeptthefirstpositioninecon…  相似文献   

20.
1 INTRODUCTIONItisveryimportanttorealizethedistributionsofpollutantsbeforethepollutioncanbecontrolledsuc cessfully .Owingtothelackofsystematicalobserva tionsinabroadarea ,numericalsimulationhasbe comeapowerfultooltounderstandthedistributionsofpollutantsa…  相似文献   

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