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步氏巨猿的上犬齿与下第一前臼齿的咬合关系有两种主要类型:一是相似于“猿类”的,另一相似于“人类”的。前者为雄性个体所具有,后者为雌性个体所具有。另有少数个体的则是中间类型。上犬齿与下第一前臼齿的咬合特征的分类学上的意义是可疑的。至少就绝大部分雄性步氏巨猿个体来说,很难认为其犬齿是参与臼齿的功能。步氏巨猿下第一前臼齿之所以呈双尖类型,与其犬齿并无直接的关系。 相似文献
67.
选用甜椒的小孢子单核期花药,用100、300、500、2000ppm的马来酰肼溶液浸泡处理,并设对照,进行无激素MS固体培养基培养。分别取样用各种组化方法对花药内部多糖、蛋白质、核酸及ATP酶进行组化反应和形态学上的观察。与对照组相比,处理组花药外部形态和内部结构出现许多变异。小孢子内多糖,蛋白质含量减少;绒毡层无明显变化;两组中,核酸的含量均无明显变化;ATP酶的活性低于对照组。可能,马来酰肼对于花药中ATP酶等产生抑制作用,致使花药败育。 相似文献
68.
通过过聚乙二醇6000-磷酸钾缓冲液双相分离、Sephadex G-100凝胶过滤、DEAE-Sephadex A-50离子交换层析、羟基磷灰石层析及SephadexG-100凝胶过滤等提纯步骤,从海枣曲霉(Aspergillus phoenicis)麦麸培养物抽提液中提纯得到凝胶电泳均一的β-半乳糖苷酶。该酶的最适pH为3.5—4.0,最适温度为60℃(反应15分钟),在pH5.0—8.5之间及60℃以下稳定。在65℃和70℃保温时失活50%的时间分别为27和2分钟。用SDS凝胶电泳法和梯度凝胶电泳法分别测得该酶的分子量为115,000和118,000。薄层凝胶等电聚焦法测得其等电点为pH4.6。 相似文献
69.
Y. W. Han D. J. Gallagher A. G. Wilfred 《Journal of industrial microbiology & biotechnology》1987,2(4):195-200
Summary Phytase production byAspergillus ficuum was studied using solid state cultivation on several cereal grains and legume seeds. The microbial phytase was used to hydrolyze the phytate in soybean meal and cotton seed meal. Wheat bran, soybean meal, cottonseed meal and corn meal supported good fungal growth and yielded a high level of phytase when an adequate amount of moisture was present. The level of phytase production on solid substrate was higher than that obtained by submerged liquid fermentation. Higher levels of phosphorus (more than 10 mg Pi/100 g substrate) in the growth medium (static culture) inhibited phytase synthesis, and the degree of phosphorus inhibition was less apparent in semisolid medium than in liquid medium. A static cultivation on semisolid substrate produced a higher level of phytase (2-20-fold) than that obtained by agitated cultivation. The minimal amount of water required for growth and enzyme production on those substrates was about 15%, while the optimum level for phytase production was between 25 and 35% and that for cell growth was above 50%. Optimum pH for phytase production was between 4 and 6.A ficuum grew well on raw (unheated) substrate containing a minimal amount of water and produced as much phytase as on heated substrate. About half of the phytic acid in soybean meal and cottonseed meal was hydrolyzed by treatment withA. ficuum phytase. 相似文献
70.
Morphological changes of sensory CGRP-immunoreactive and sympathetic nerves in peripheral tissues following chronic denervation 总被引:2,自引:0,他引:2
The morphological relationship between sensory and sympathetic nerves was studied in tissues of the eye and the oral cavity following chronic sympathetic or sensory denervation. Immunoreactivities for calcitonin gene-related peptide (CGRP) and tyrosine hydroxylase (TH) were used as indexes to assess the changes of the two nerve populations after denervation. Following surgical sympathectomy, a marked increase of CGRP-containing fibres was seen in all tissues studied, while TH-imunoreactive fibres were totally depleated. Conversely, after capsaicin treatment, an increase of TH-immunoreactive nerves was found in the same tissues, concomitant with a sharp decrease of CGRP-immunoreactive nerves. These changes were particularly evident in iridial stroma and around blood vessels in all tissue, where sensory and sympathetic nerves have a closely overlapping distribution pattern. The altered proportion of sensory peptide- and catecholamine-containing nerves following sympathetic and sensory denervation suggest that there is a reciprocal trophic influence between the two nerve subsets, possibly with the intervention of neurotrophic substances such as nerve growth factor. These results indicate a close interaction between sensory peptidergic and sympathetic nervous systems in peripheral organs. 相似文献