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绞股蓝属的染色体研究   总被引:11,自引:2,他引:9  
报道了葫芦科绞股蓝属(Gynostemma B1.)8种共20个居群的染色体数目,分别为2n=22,33,44,66,88多倍体现象极为普遍。两个亚属;绞股蓝亚属(Subgen.Gynostemma)和喙果藤亚属(Subgen.Triostellum)的染色体基数均为X=11,并结合该属植物形态特征、繁殖方式和地理分布,对普遍出现的多倍体现象进行了讨论。  相似文献   
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Nearly 1500 foliage samples were collected from a total of 156 plant species, distributed at 16 study sites representing a wide range of forests and woodlands in south-eastern Australia. Samples were collected in all months. Invertebrates present in samples were counted, sorted into 13 categories, and the number present (> 3 mm in length) converted into density estimates. Densities of all invertebrates combined and invertebrate diversity were also calculated. Despite high variability there were some obvious distributional patterns for most categories. Three major dichotomies affected abundance and distribution of invertebrates: these were presence or absence of flowers, whether the plant species was Eucalyptus or other, and if Eucalyptus, whether the plant species was Symphyomyrtus or Monocalyptus. The presence of flowers in foliage samples increased the abundance of most invertebrate taxa. Compared to foliage of non-Eucalyptus species, Eucalyptus foliage had more lerp-forming psyllids and miscellaneous larvae, but fewer Arachnida, Coleoptera, Psocoptera, Hemiptera (other), Thysanoptera, Diptera, and total arthropods. Foliage of Symphyomyrtus species had higher densities of most categories (and particularly lerp-forming psyllids) than that of Monocalyptus. There were seasonal variations in abundance in most invertebrate taxa, but these patterns were different for Eucalyptus and non-Eucalyptus species. For most sites abundance of all arthropods combined was lowest in winter, but this decline was not especially pronounced, and was reversed at more xeric sites. For most categories there were significant differences between study sites in abundance and for some this was related to position of sites on a moisture gradient. In general total arthropod densities were highest at intermediate and xeric sites. There were some significant differences in arthropod communities for the same plant species at different study sites. Sample height, plant height, and the ratio of these were relatively unimportant variables. Likewise, the ratio of leaf width: leaf length was not significantly correlated with abundance for any invertebrate category across 128 plant species, but mean leaf size was negatively correlated with densities of Arachnida and total invertebrates. The distributions of some invertebrate categories were inter-correlated.  相似文献   
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烟草花叶病毒蚕豆株系基因组全序列分析及结构特征   总被引:4,自引:1,他引:3  
根据已报道的TMV-U1株系核苷酸序列合成引物 ,利用RT-PCR技术获得了覆盖整个烟草花叶病毒蚕豆株系 (TMV-B)基因组的cDNA重组克隆 .结合末端测序技术 ,完成了TMV-B全基因组序列测定 .TMV-B全基因组共有 6 395个核苷酸组成 ,包括 4个开读框 (ORF) ,分别编码 1 2 6ku(含 1 1 1 6个氨基酸 )、1 83ku(含 1 6 1 6个氨基酸 )、30ku(含 2 6 8个氨基酸 )和 1 7.5ku蛋白 (含 1 5 9个氨基酸 ) .TMV-B与TMV-U1相比全基因组同源率达 99.4% ,两病毒基因组 5′ ,3′非编码区和CP基因完全相同 .TMV-B与TMV-U1之间在 1 2 6ku蛋白中有 6个氨基酸差异 ,5 4ku蛋白中有 2个差异 ,30ku蛋白中有 3个差异 .对导致TMV-B侵染蚕豆的可能致病机理进行了分析 .  相似文献   
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目的:探讨全面质量管理模式时老年心血管疾病患者的生活质量的改善情况所起的积极作用,为临床护理提供参考。方法:选择2011年2月至2012年12月在我院心血管内科接受住院治疗的老年患者60例,随机分为常规组和全面管理组。常规组采取基础护理模式,全面管理组在常规护理的基础上对患者进行心理干预、健康教育及饮食管理等。对比两组患者干预前后生活质量改善情况,并对护理服务的满意度进行问卷调查。结果:全面管理组患者的生活质量较干预前明显改善,且患者的心理功能、生活能力及社交功能评分均显著优于常规组,差异具有统计学意义(P〈0.05)。全面管理组患者对心理护理、饮食管理、健康教育及护患沟通的满意度均高于常规护理组,差异具有统计学意义(P〈0.05)。结论:采取全面质量管理的模式对老年心血管疾病患者进行康复指导具有显著的效果,可明显改善患者的生活质量,并且能够提高患者对护理服务的满意度,值得临床推广。  相似文献   
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A new species of Phylloscopus warbler, which we name Phylloscopus calciatilis Limestone Leaf Warbler, is described from central and northern Vietnam and central and northern Laos; it probably also breeds in southernmost China. In morphology, the new species is very similar to Sulphur-breasted Warbler Phylloscopus ricketti , but it is smaller with a proportionately larger bill and rounder wing. Its song and calls are diagnostic. Based on mitochondrial and nuclear DNA, the new species is most closely related to P. ricketti and Yellow-vented Warbler Phylloscopus cantator , and it is inferred to be sister to the latter. The mitochondrial divergences between these three species are at the low end of the variation found in other species of Phylloscopus and Seicercus warblers, but greater than in other taxa generally treated as subspecies. Possible introgressive hybridization between the new species and P. ricketti is discussed, but more data are needed to establish whether it does occur and, if it does, to what extent. The new species appears to have a restricted breeding range in limestone karst environments, where it is locally common and therefore not under any immediate threat. In view of the recognition of the new species, all previous records of P. ricketti sensu lato need to be re-evaluated.  相似文献   
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随着科学的发展,人造卫星的发射成功,人类开始迈向空间,为揭示太空的真实情况,国内、外学者已进行了大量的探索工作(鲁子贤 1988)。我们利用我国发射的人造卫星进行了搭载试验。本文报道空间环境对微生物生长与遗传性状影响的  相似文献   
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