共查询到20条相似文献,搜索用时 31 毫秒
1.
Untilnow,allmachiningmethodsusedarephysicalorchemicalorphysicochemical.Thetechnologysystemofnaturalsciencecanbeclassifiedintothefollowingthreesubsidiarysystems:physics,chemistryandbiology.Thereforeabiologicalmachiningtechnologywillbeabrandnewbranchinma… 相似文献
2.
持续农业与中国的生态农业 总被引:6,自引:0,他引:6
持续农业与中国的生态农业李萍萍,章熙谷(南京农业大学农学系,210014)SustainableAgricultureandChina’sEcologicalAgriculture¥.LiPingping;ZhangXigu(NanjingAgricul-turalUniversity,210014).ChineseJournaJofEcolegy,1993,12(2):16-18.Thebackground,conceptandcharacteristicsofsustainableagriculturearediscussed,anditssimilaritiesanddifferencestoChina’secologicalagriculturearedescribed.It’sconsideredthatChina’secologicalagri-cultureisaconcretereflectionofsustainableagricultureandasuccessfulmodelforagriculturaldevelop-ment.Keywords:sustainableagricult 相似文献
3.
Proteincrystalgrowthhasbeenofgreatimportanceinexploitationofstructuresofbiologicalmacromolecules.Themicrogravityenvironmentinspaceisanidealplacetostudythecomplicatedproteincrystallizationprocessandtogrowgoodqualityproteincrystals.Sincethe1980s,noticeabl… 相似文献
4.
Nicotinic acetylcholine receptor is involved in acetylcholine regulating stomatal movement 总被引:4,自引:0,他引:4
Receptor,theprimarysiteofcellperceivingexternalsignals,controlsthecommunicationbetweencellsandenvironment[1].Acetylcholineisanimportantneurotransmitterinvolvedinthetransmissionofsignalsatjunctionsbetweennervesandbetweennerveandmuscle.Theactionofacetylch… 相似文献
5.
Breeding technology of alloplasmic wheat 总被引:4,自引:0,他引:4
Thenucleiofcultivatedwheatcouldbetransferredintocytoplasmofheterogenicspeciesorgeneraviasubstitutionbackcrossandothertechniques,thusTriticinaeexhibitswidegeneticdiversityofcytoplasm.Thisdiversityhadboththeoreticandbreedingvalueandcouldbeusedinalloplas… 相似文献
6.
Chromatinismadeupofregularlyspacedsubunits,nucleosomes.Ineukaryoticcells,chromatinisassembledimmediatedlyafterDNAreplication,butincellfreesystems,itcanbeassembledindependentofDNAreplicationwhenexogenousDNAwasaddedtoeggoroocyteextractsofXenopuslaevis.The… 相似文献
7.
Osmotinisa24kubasicproteinthatwasoriginallyidentifiedasthemostprominentpolypeptidepresentinsaltadaptedtobaccocells.Theexpressionofosmotinisinducedbymanystressesandenvironmentalfactorsincludingpathogeninfection,ethylene,ABA,Methyljasmonate,salicylicacid,w… 相似文献
8.
Saccharomycescerevisiaeisanindustrialstrainwidelyusedintheproductionofethanol,breweryandsinglecellprotein(SCP).Butitisunabletofermentstarchduetothelackofamylolyticenzymes.Thestarchmustfirstbecooked,liquifiedandconvertedintoglucoseandthenutilizedincommer… 相似文献
9.
Themicroenvironmentconstitutedbythymicstromalcellsisanimportantsiteforthedevelopmentofthymocytes.95%ofthymocytesdieinthethymuseveryday,inthewayofapoptosis[1].Thecelldeathismainlycausedbythedefaultofpositiveselectionandtheactionofnegativeselectionswhichar… 相似文献
10.
Amolecularmarkercanbedesignatedascodominantordominanttypeaccordingtothegenotypicinformationprovided[1—4].Foracodominantmarker,threebandpatternscanbeobservedinelectrophoreticgels,whichcorrespondtotwocopiesoftheDNAsegmentsonthislocusbeinghomozygousP1type,h… 相似文献
11.
《人类学学报》2002,(Z1)
1 IntroductionIntheearlyyearsofhumanhistory ,Paleolithicstoneartifactswerethemainculturalsymbols ,andtheyplayedtheleadingroleinearlyhominidactivitythroughouttheperiod .WithrespecttotheformingcausesofthePaleolithicindustrialfeaturesofasite ,manyscholarshaverecognizedtheimpor tanceofthenaturalenvironment[1] anddifferenthumaneconomicactivities[2 ] ,buttherelationshipbe tweenrawmaterialsandPaleolithicindustrialfeatureshasnotbeensufficientlyexplored[3] .Inalargenumberofresearchreports ,thestonematerialsareonlyid... 相似文献
12.
Moststudiesonthereceptivefield(RF)organizationofvisualcortexneuronshavefocusedonitsspatialstructure.Stimuliinthenaturalvisualworld,however,includebothspatialandtemporalaspects.Foramorecompletefunctionaldescriptionofthevisualneurons,itisnecessarytoinvest… 相似文献
13.
Alan Walker 《人类学学报》2002,(Z1)
1 IntroductionAmongthefourMiocenehominoidsitesofKaiyuan ,Lufeng ,YuanmouandBaoshaninYunnanProvinceofChina ,LufengandYuanmouaretherichestfossilsites .Sinceitsfirstdiscoveryin 1 975,manycolleaguesaroundtheworldhavebeeninvolvedinthestudyofLufengpithecusfossils .However,noagreementhasbeenreachedontherelationshipofLufengpithecustootherMiocenehominoidsfoundaroundtheworldoronitsphylogeny .WuRukangbelievesthatthereareaseriesofmorphologicaldif ferencesbetweenLufengpithecusandtheSivapithecusspecimensfoundinTurkeyandP... 相似文献
14.
生态位理论及其在森林生态学研究中的应用 总被引:47,自引:4,他引:43
生态位理论及其在森林生态学研究中的应用朱春全(中国林业科学研究院林业研究所,北京100091)NichcTheoryanditsApplicationinForestEcology¥.ZhuChunquan(InslituteofForestry,ChineseAcademyofForestrySciences,Beijing100091),ChineseJournalofEcology,1993,12(4):41-46.Thedevelopmentofnichetheoryanditsapplicationinforestecologicalstudyarereviewedinthispaper.Itispointedoutthatthefunctionalactionofplantunitwasnotinvolvedinpreviousnicheconcepts,Theparticularitiesofnicheofplantunitarediscussedandanewmethodisdevelopedtodetermineitwithpho-tosyntheticproductionasafunct 相似文献
15.
Scaffoldassociatedregion(SAR)andmatrixattachmentregion(MAR)areknownascisactingDNAelements,whichspecificallybindtonuclearscaffoldornuclearmatrix.SAR/MARareusually300—1000bplong,ATrich,andcontainingtopoisomeraseIIconsensussequenceandotherATrichsequencemotifs[1].… 相似文献
16.
陆生脊椎动物生态学研究的过去、现在和将来(前苏联科学院动物进化形态学与生态学研究所,莫斯科)Past,PresentandFutureofEcologicalResearchonTerrcstrialVctebratcs¥.(InstituteofAnimalEvolutionaryMorphologyandEcology,theFormerAcademyofSclencesofSovietUnion).ChineseJournalofEcology,1993,12(4):66-71。Thispaperdescribesthemainstages,directionsanditemsofecologicalresearchintheformersovietU-nion.EcologicalresearchinthecountrywasrestrodedbymanysuUectiveandoUectivefactorsandstilllagsbehindtheworldlevelinmanyaspectssuchaspopulationdynamicstheory,communityresearch,eco- 相似文献
17.
生态学的精神价值 总被引:1,自引:0,他引:1
生态学的精神价值陈清硕(江苏农学院扬州225001)SpiritualValueofEcology¥.ChenQingshuo(JiangsuAgriculturalCollege,Yangzhou225001):ChineseJournalofEcology,1993,12(3):68-72.Thispaperdescribesthefunctionsofecologyintheprogressofsocialideologyandcivilization.Ecologyhelpsbringintobeingtheconstructionofascientificworldoutlookandincreasetheecologicalconscious-nessofmankind.Italsosuppliesatotaldevelopmentalpointofviewforthesocietyandprovidesagreataestheticvalue.Thespiritualvalueofecologyshouldneverbeneglected.Keywords:socialecology,ecol 相似文献
18.
日本对虾野生种群和养殖群体的同功酶遗传变异 总被引:12,自引:0,他引:12
PenaeidshrimpPenaeusjaponicus ,commonlynamedasFloweryShrimporBandedShrimp ,isoneofthemostcommer ciallyimportantspeciesofmarinecrustaceanfisheryinChina .Beingofthewarm waterspeciesconductingshortdistancemigra tion,theanimalismainlydistributedinthecoastalwa… 相似文献
19.
Insectsarethemostsuccessfulanimalgroupintermsofnumbersofspecies.Althoughmanyfactorsmustcontributetotheprofusionofinsectspecies,onekeyelementisprobablyadevelopmentalplanthatincorporatesmetamorphosisanddiapause.Diapauseisacomplexadaptativeresponsewhichi… 相似文献
20.
Electro-acupuncture-mediated gene transfer 总被引:2,自引:0,他引:2
Somaticgenetherapyisbecomingincreasinglyimportantforpotentialtreatmentofgeneticandacquireddisorders,whichispromisinginclinicalapplication.GenetransferisoneofthekeytechniquesingenetherapythatallowsinstallationandexpressionofDNAdeliveredintotargetcells[1… 相似文献