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891.
随着生物多样性信息学的迅速发展,越来越多开放的生物数据可供科研人员使用。以一个公开数据平台为例分析我国生物多样性领域的研究热点与发展趋势,有助于生物多样性工作者和决策者及时了解我国生物研究的现状及动向,为生物多样性建设提供决策支持。该文以“国家标本资源共享平台(NSII)”及相关词为检索对象,对中国知网和谷歌学术上2013—2023年间的文献进行全文检索,共检索出1 070篇NSII支撑的文献,包括期刊论文(822篇)、学位论文(233篇)、科普文章(5篇)、会议文章(6篇)和报道(4篇)。基于NSII支撑的822篇期刊论文,通过文献计量学的手段和方法,从发文情况、研究主题与热点、研究机构等方面探究NSII支撑的生物多样性研究现状、热点与态势。关键词共现网络图谱分析结果显示,基于数据平台的生物多样性研究热点集中在物种分布分析和建模、气候变化、分类学、生物多样性研究、研究平台建设五个方面。当前我国生物多样性信息学领域发展较快,未来仍需从数据源建设、资源整合、共享能力、业务能力和国际合作等方面努力提升,持续推动生物多样性科学研究的发展。 相似文献
892.
L. Lgdberg E. Kaplan M. Drelich E. Harfeldt H. Gunn P. Ehrlich D. Dottavio P. Lake L.
stberg 《Journal of medical primatology》1994,23(5):285-297
The feasibility to raise nonhuman primate antibodies against selected components of the human immune system was tested. The immunogens were whole cells (human T lymphocytes) or purified, recombinant human proteins (cytokines: TNFα or GM-CSF; soluble forms of cell surface antigens: sCD4 or sCD25). Significant immunizations, yielding functionally relevant antibodies, were readily achieved in rhesus monkeys, but, not surprisingly, may be less frequent in chimpanzees. The results suggest a general strategy for production of therapeutically useful MAB. 相似文献
893.
S D Kaplan 《Mutation research》1984,134(2-3):167-168
894.
A Potamogeton hybrid recently discovered in Finland was proven to be a new taxon, which has a different parentage than the most similar P.×vepsicus (=P. natans×praelongus) described from Russia. Based on molecular and morphological investigation, the new hybrid was identified as P. alpinus×natans and is here described as P.×exilis nothosp. nov. The hybrid is known only from several nearby localities in a single river system. All discovered colonies almost certainly originate from a single hybridization event that occurred in the upper part of the river system. Other localities downstream have been established through fragmentation and dispersal of stems and rhizomes of this sterile hybrid. A detailed morphological comparison of the new hybrid with similar hybrids and species is provided. 相似文献
895.
为解析桃金娘表型性状多样性及其种源间关系,该文以20个不同来源的桃金娘为研究对象,在同质园栽培条件下,对其营养器官和花器官表型性状进行观测,采用方差分析、变异分析、Shannon-Wiener多样性指数分析和聚类分析等方法,探讨不同种源桃金娘表型性状多样性。结果表明:(1)不同种源桃金娘表型性状存在显著差异(P<0.05),Shannon-Wiener多样性指数均值在1.35以上,表型性状多样性丰富。(2)种源内表型性状变异系数均值在10.81%~63.75%之间,种源间的变异系数均值在13.08%~74.04%之间,种源间变异(23.33%)高于种源内变异(19.79%),营养器官变异(29.52%)高于花器官变异(14.06%)。(3)部分性状存在极显著或显著相关性,株高与分枝数呈极显著负相关,而与叶长、叶宽和叶面积等却呈显著正相关。(4)在欧式距离10处,20个种源桃金娘可分为A、B、C三类,A类包含8个种源,该类种源表现为植株高大、分枝少、叶大和花大等特征;B类包含11个种源,该类种源表现为株高中等、叶较大和花中等等特征;C类仅包含1个种源,表现为植株低矮、分枝多、叶小和... 相似文献
896.
Many herbivores elicit biochemical, physiological, or morphological changes in their host plants that render them more resistant
to co-occurring herbivores. Yet, despite the large number of studies that investigate how induced resistance affects herbivore
preference and performance, very few have simultaneously explored the cascading effects of induction on higher trophic levels
and consequences for prey suppression. In our study system, early-season herbivory by leafhoppers elevated plant resistance
to subsequent attack by chrysomelid beetles sharing the same host plant. Notably, beetles feeding on leafhopper-damaged plants
incurred developmental penalties (e.g., prolonged time in early larval instars) that rendered them more susceptible to predation
by natural enemies. As a result, the combined bottom-up effect of leafhopper-induced resistance and the top-down effect of
enhanced predation resulted in the synergistic suppression of beetle populations. These results emphasize that higher trophic
level dynamics should be considered in conjunction with induced resistance to better understand how plants mediate interspecific
interactions in phytophagous insect communities. 相似文献
897.
Glucan, water dikinase activity stimulates breakdown of starch granules by plastidial beta-amylases 总被引:6,自引:0,他引:6
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Edner C Li J Albrecht T Mahlow S Hejazi M Hussain H Kaplan F Guy C Smith SM Steup M Ritte G 《Plant physiology》2007,145(1):17-28
Glucan phosphorylating enzymes are required for normal mobilization of starch in leaves of Arabidopsis (Arabidopsis thaliana) and potato (Solanum tuberosum), but mechanisms underlying this dependency are unknown. Using two different activity assays, we aimed to identify starch degrading enzymes from Arabidopsis, whose activity is affected by glucan phosphorylation. Breakdown of granular starch by a protein fraction purified from leaf extracts increased approximately 2-fold if the granules were simultaneously phosphorylated by recombinant potato glucan, water dikinase (GWD). Using matrix-assisted laser-desorption ionization mass spectrometry several putative starch-related enzymes were identified in this fraction, among them beta-AMYLASE1 (BAM1; At3g23920) and ISOAMYLASE3 (ISA3; At4g09020). Experiments using purified recombinant enzymes showed that BAM1 activity with granules similarly increased under conditions of simultaneous starch phosphorylation. Purified recombinant potato ISA3 (StISA3) did not attack the granular starch significantly with or without glucan phosphorylation. However, starch breakdown by a mixture of BAM1 and StISA3 was 2 times higher than that by BAM1 alone and was further enhanced in the presence of GWD and ATP. Similar to BAM1, maltose release from granular starch by purified recombinant BAM3 (At4g17090), another plastid-localized beta-amylase isoform, increased 2- to 3-fold if the granules were simultaneously phosphorylated by GWD. BAM activity in turn strongly stimulated the GWD-catalyzed phosphorylation. The interdependence between the activities of GWD and BAMs offers an explanation for the severe starch excess phenotype of GWD-deficient mutants. 相似文献
898.
Henry SL Concannon MJ Kaplan PA Diaz-Arias AA 《Plastic and reconstructive surgery》2007,120(1):80-8; discussion 89-90
899.
900.
Murray RA Siddiqui MR Mendillo M Krahenbuhl J Kaplan G 《Journal of immunology (Baltimore, Md. : 1950)》2007,178(1):338-344
Leprosy presents with a clinical spectrum of skin lesions that span from strong Th1-mediated cellular immunity and control of bacillary growth at one pole to poor Ag-specific T cell immunity with extensive bacillary load and Th2 cytokine-expressing lesions at the other. To understand how the immune response to Mycobacterium leprae is regulated, human dendritic cells (DC), potent inducers of adaptive immune responses, exposed to M. leprae, Mycobacterium tuberculosis (Mtb), and Mycobacterium bovis bacillus Calmette-Guerin (BCG) were studied for their ability to be activated and to prime T cell proliferation. In contrast with Mtb and BCG, M. leprae did not induce DC activation/maturation as measured by the expression of selected surface markers and proinflammatory cytokine production. In MLR, T cells did not proliferate in response to M. leprae-stimulated DC. Interestingly, M. leprae-exposed MLR cells secreted increased Th2 cytokines as well as similar Th1 cytokine levels as compared with Mtb- and BCG-exposed cells. Gene expression analysis revealed a reduction in levels of mRNA of DC activation and maturation markers following exposure to M. leprae. Our data suggest that M. leprae does not induce and probably suppresses in vitro DC maturation/activation, whereas Mtb and BCG are stimulatory. 相似文献