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1.
光对4种木本植物叶片清除有机自由基能力的影响   总被引:3,自引:0,他引:3  
生长在没光强下的4种木本植物荷对(Schima superba Gardn.et Champ.)、黧蒴(Castanopsis fissa (Champ.ex Benth.)Rehd.et Wils.)(乔木)和九节(Psychotriarubra (Lour。.)Poir),罗伞(Ardisia quinquegona B1.)(林下灌木)幼苗(盆栽)或幼树(自然林下)叶片的50%乙醇提取液具  相似文献   

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农业系统生产力(ASP)的量化及其现状分析   总被引:6,自引:0,他引:6  
农业系统生产力(ASP)的量化及其现状分析卢进登,韩纯儒(北京农业大学农学系,100094)QuantificationofAgrosystemProductivity(ASP)andAnalysisonitsCurrentSituationinCbina¥.LuJin-deng;HanChunru(BeijingAgriculturalUniversityfBeijing100094).ChineseJournalofEcology,1993,12(2):21-22.BasedonabriefanalysisontheformationprocessofASP,itsconceptisdescribedandanintegratedindi-catorforitsquantification—ASP2isputforwards.Fromthose,theASPlevelsinvariousregionsofChinaareanalyzedand8levelsaredividedbyusing.Hierarchicclusteringmethod.It’s:clarifiedthatAS-PIisamore  相似文献   

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ConformationalStudiesofArabinoglucuronomannology(AGM)ImshikLee;BaiChunli;WangChen(InstituteofChemistry,ChineseAcademyofScienc...  相似文献   

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重庆地区“双千田”组合模式及效益分析郑钦玉,朱自均,胡声荣,袁可(西南农业大学,重庆630716)雷炎,李登国,程世宇,温永学,刘官堂(四川省巴县农业局)CombinationModelsof"TonGrainYieldingField"inChongqingAreaandTkeirBenefitAnalysis¥.ZhengQinyu;ZhuZhijun;HuShengrong;YuanKe(SouthwestAgriculturalUniversity,Chongqing630716),LeiYan,LiDengguo,ChengShiyu,WenYongxue,LiuGuantang(BaxianBureauofAgriculture,SichuanProvince).ChineseJoumalofEcolegy,1993,12(2):34—36.Inthelightoftheeffectsandproblemsofdevelopingwinter-croppingpaddyfieldsinChongqingareaandinordertosearchaftertheoptimummodelofref  相似文献   

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曲周县畜牧业规模效益分析   总被引:1,自引:0,他引:1  
曲周县畜牧业规模效益分析曹志平(北京农业大学生物学院100094)BenefitAnalysisonAnimalHusbandryScalesinQuzhouCounty¥.CaoZhiping(CollegeofBiology,BeijingAgr...  相似文献   

6.
包永德  朱辉 《生理学报》1996,48(4):401-404
我们以两栖类卵母细胞为功能表达系统,通过注射鲫鱼(Carassiuscarassius)视网膜mRNA,利用电压箝及药物灌流手段,系统地研究了鲫鱼视网膜内氨基酸受体的类型和特征,结果如下:(1)Glu受体:KA可以诱发明显的去极化电流,而且Diazoxide能增强KA诱导的反应,这提示鲫鱼视网膜内某些Clu受体是AMPA选择性亚型(AMPA-preferringsubtype)。(2)CABA受体:GABA能诱发一个快速、光滑的内向电流,绝大部分对GABA的反应可被bicuculline所压抑,而GABA_B受体的激动剂baclofen则无任何作用,这提示,鲫鱼视网膜内大部分是GABA_A受体。  相似文献   

7.
瓦草中三个新环肽   总被引:10,自引:3,他引:7  
从云南民间中草药瓦草(Sileneszechuensis)的根中分离鉴定了3个新的环肽,分别命名为瓦草环肽A,B,C(sileninsA,B,C)用光谱和化学方法确定它们均为环八肽,其结构分别为:sileniaA-cyclo-(Pro-Leu-Ser-Phe-Pro-Tyr-Leu-Val),sileninB--cyclo-(Phe-Leu-Ala-Pro-Leu-Pro-Phe-Pro),sil  相似文献   

8.
X. C. ZHANG 《植物研究》1998,18(1):107-117
GENUSANTROPHYUMKAULF.FROMCHINAANDNEIGHBORINGREGIONSX.C.ZHANG(Theherbarium(PE),InstituteofBotany,ChineseAcademyofSciences,Bei...  相似文献   

9.
对普通小麦(TriticumaestivumL.)基因组(AABBDD)最可能的供体-T.uratrtuThum.(AA)、T.monoccumvar.boeoticum(Boiss.)MK(AA)、AegilopsspeltoidesTausch.和Ae.tauschii(Coss.(DD)的核糖体RNA基因ITS区进行了PCR扩增和克隆,并测定了ITS1和ITS2的DNA序列,讨论和纠正了前人  相似文献   

10.
里骆林区常绿阔叶林和人工杉木林气候水文效应   总被引:11,自引:2,他引:11  
里骆林区常绿阔叶林和人工杉木林气候水文效应黄承标,文受春(广西农学院林学分院南宁530001)(广西龙胜县林业局541700)ClimaticandHydrologicalEffectsofEvergreenBroad-leavedandArtificialChineseFirForestsinLiluoForestedRegion¥HuangChengbiao(ForestryCollege,CuangxiAgriculturalUniversity,Nanning530001),WenShouchun(ForestryBureau,LongshengCounty,Guangxi541700);ChineseJournalofEcol-ogy,1993,12(3):1-7.Siteinvestigationsandresearchesin1980-1990showthatevergreenbroad-leavedandartificialChinesefirfOrestsinLiluoforestedregioncanreducethevariationrangeofatmosphericandsoilt  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

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For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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