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991.
北京农科城驱动产业融合发展实践与成效分析   总被引:1,自引:0,他引:1  
产业融合是产业经济发展中的一种新范式,本文作者基于产业融合理论,构建农业产业融合发展驱动模型,并以北京农科城驱动产业融合发展实践为例,剖析农业产业融合发展的路径与成效。研究发现北京农科城建设有效驱动了农业产业融合发展,具体实践具有代表性,对我国农业产业融合发展具有借鉴作用。  相似文献   
992.
以猕猴桃叶斑病典型症状叶片为试材,采用组织分离法分离、纯化并结合回接试验确定病原菌,结合形态学和分子生物学对病原菌进行鉴定,并通过不同培养条件对该病原菌的生物学特性进行探究,以期为该病害发生规律的探究和综合防治措施的制定提供参考依据.结果 表明:引起猕猴桃叶斑病致病病原为可可毛色二孢菌(L.theobromae);该病原菌在10~35℃内均能生长,最适温度为28℃,最适pH为5,光照条件为连续光照,适宜的碳、氮源分别为可溶性淀粉和酵母膏.  相似文献   
993.
概述了核桃坚果果皮结构及硬壳发育过程,归纳了核桃坚果硬壳发育的主要内部影响因素和外界影响因素,提出了目前在核桃坚果硬壳发育研究方面所存在的问题,并对今后的研究做出了展望。  相似文献   
994.
近海水质非线性时间序列通常由于采集范围大、时间间隔长带有一定震荡性和模糊性,这使得对其进行分析与预测有一定的难度。本研究中以某近海水质指标磷酸盐(PO3-4-P)、硝酸盐(NO-3-N)、亚硝酸盐(NO-2-N)、铵盐(TNH+4-N)和硅酸盐(Si O2-3-Si)所形成的5种时间序列为例,采用逼近细分模式导出的细分外推法和多参考加权数据的模糊预测法对近海水质时序预测进行了比较分析,并通过图形与误差计算比较了两种方法的异同。结果表明:采用细分外推法预测序列在整体形状上能更好地逼近初始时序,而模糊预测法在整体逼近精度上占有优势。本研究中提出的预测比较方法可为同类问题的预测与模型选取提供参考依据。  相似文献   
995.
为了建立适合于南方红豆杉(Taxus chinensis var.mairei)种群遗传多样性分析的SSR-PCR扩增体系,在单因素试验确定各因素浓度范围的基础上,采用正交试验设计,对影响南方红豆杉SSR-PCR扩增的主要因素浓度进行了筛选。结果表明,南方红豆杉SSR-PCR最佳反应扩增体系为:20μL反应体系中含有1.50mmol/L Mg2++0.2 mmol/L d NTP+0.5U Taq DNA聚合酶+0.3μmol/L引物+75 ng DNA模板。  相似文献   
996.
The effects of the severity and timing of leaf removal(LR) on the amino acids of Sauvignon Blanc grapes and wines were studied during the 2017 growing season. High-performance liquid chromatography(HPLC) was used to analyze the amino acids profiles of grape berries and wines. The basal leaves were removed at three time points(40, 56 and 72 days after flowering, named LR40, LR56 and LR72, respectively) at two severity levels(one at which the first, third, and fifth basal leaves of each shoot were removed(50% level); and another at which the first six basal leaves were removed(100% level)). The results showed that leaf removal had little impact on total soluble solids(°Brix), titratable acidity, pH or berry weight. The LR72-50% treated grapes had higher berry weight, titratable acidity and °Brix than those of the other treatments. The highest concentrations of total amino acids and of total amino acids except proline were detected in LR72-50% treated grapes(2 952.58 and 2 764.36 mg L~(-1), respectively); the lowest were detected in LR72-100% treated grapes(2 172.82 and 2 038.71 mg L~(-1), respectively). LR72-50% treatment significantly promoted the synthesis of aspartic acid, serine, arginine, alanine, aminobutyric acid and proline at both severity levels for grapes, the concentrations of all of these amino acids were increased relative to the control concentrations. The LR72-50%, LR40-100% and LR72-100% treated wines had higher total amino acids concentrations and higher concentrations of some individual amino acids, such as arginine, alanine and serine, than did the control wines. Of all the amino acids studied, glycine, tyrosine, cysteine, methionine and lysine were not significantly influenced by the timing or severity basal defoliation in grapes and wines. The present study reveals the effects of the timing and severity of leaf removal on the amino acids profiles of grapes and wines.  相似文献   
997.
Cadmium (Cd) intake is harmful to human health and Cd contamination in rice grains represents a severe threat to those consuming rice as a staple food. Knockout of Cd transporters is a promising strategy to reduce Cd accumulation in rice grains. OsNRAMP5 is the major transporter for Cd and manganese (Mn) uptake in rice. Nevertheless, it is uncertain whether knockout of OsNRAMP5 is applicable to produce low Cd rice without affecting plant growth and grain yield. In this study, we adopted CRISPR/Cas9-based gene editing technology to knock out OsNRAMP5 in two japonica varieties. We generated three independent transgene-free osnramp5 mutants and investigated the effect of osnramp5 mutations on Cd accumulation and plant growth. Hydroponic experiments showed that plant growth and chlorophyll content were significantly reduced in osnramp5 mutants at low Mn conditions, and this defective growth in the mutants could be fully rescued by supply of high levels of Mn. Cd and Mn accumulation in both roots and shoots was markedly reduced in the mutants compared to that in wild-type plants. In paddy field experiments, although Cd in flag leaves and grains was greatly reduced in osnramp5 mutants, some agronomic traits including plant height, seed setting rate, and grain number per panicle were affected in the mutants, which ultimately caused a mild reduction in grain yield. The reduced plant growth in the mutants can be attributed to a marked decrease in Mn accumulation. Our results reveal that the manipulation of OsNRAMP5 should be treated with caution: When assessing the applicability of osnramp5 mutants, soil pH and soil water content in paddy fields need to be taken into consideration, since they might affect the levels of available Mn in the soil and consequently determine the effect of the mutation on grain yield.  相似文献   
998.
目的:分析探讨开放性实验的现状及存在的问题,旨在提高体育院校开放性实验教学质量,培养综合素质高与专业能力强的有用人才。方法:运用资料分析法对广州体育学院十年来积累的开放性实验教学资料进行研究。结果:(1)开放性实验形成了比较有效的教学模式;(2)历年参加开放性实验的学生人数占当年在校生人数比例非常高;(3)开放性实验科目内容丰富,以验证性实验为主,兼顾综合性和设计性实验;(4)开放性实验教学效果比较满意,教学质量较高。(5)改进开放性实验教学方式、构建独立的实验教学体系等措施可以有效解决体育类大学生参加开放性实验存在的一些问题。结论:体育类大学生参加开放性实验能够有效地巩固所学理论知识,促进专业水平的发展,培养独立分析问题及解决问题的能力。  相似文献   
999.
AIM: In podocytes, autophagy occurs at a high basal level and dysregulated autophagy is associa-ted with a variety of podocytopathies. This paper is to investigate the role of autophagy in sublytic C5b-9-induced podocyte injury. METHODS: Sublytic complement C5b-9 stimulation was used as an in vitro model. Autophagosomes were confirmed using monodansylcadaverine (MDC) staining. Immunoblotting was used to measure the change of autophagy-related markers. Cellular morphological changes were observed by Wright-Giemsa staining. Immunofluorescence staining and confocal microscopy were used to detect the expression and distribution of nephrin. The cell viability was assessed by methylthiazol tetrazolium (MTT) assay. The cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/PI staining. RESULTS: For ensuring sublytic complement injury, the maximal amounts of anti-podocyte antiserum and 160×-diluted normal human serum were used without inducing cell lysis (defined as >5% LDH release). Sublytic C5b-9 promoted autophagy of podocytes in vitro. The proautophagic effect of sublytic C5b-9 manifested in the form of accumulated MDC-labeled vesicles and enhanced the expression of LC3-Ⅱ. Autophagy inhibitor 3-methyladenosine (3-MA) promoted sublytic C5b-9-induced podocyte morphological abnormalities. Compared with the sublytic C5b-9-injured podocytes, 3-MA exposure further decreased the expression of nephrin. 3-MA enhanced sublytic C5b-9-induced podocyte apoptosis. CONCLUSION: Sublytic C5b-9 attack induces autophagy, which may play a protective role against complement-mediated podocyte injury.  相似文献   
1000.
随着环境的恶化和资源的匮乏,非生物胁迫已成为制约植物生长和发育的重要因素,严重影响农作物的产量和农产品的品质。泛素/26S蛋白酶体途径(ubiquitin/26Sproteasome pathway,UPP)通过特异性地降解泛素化修饰的蛋白质,介导了植物生长发育的诸多方面,并在植物应对非生物胁迫过程中起关键的调控作用。该文主要概述了泛素/26S蛋白酶体途径及其调控植物响应非生物胁迫机制的研究进展。  相似文献   
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