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991.
干旱胁迫对大豆生长的影响及抗旱性评价方法与指标筛选   总被引:1,自引:0,他引:1  
2014-2015年在年降雨量不足40 mm的敦煌市,设干旱和正常灌水两个处理,通过测定12份大豆品种的8个形态指标(株高、主茎节数、有效分枝数、单株荚数、单株粒数、单株粒重、单株生物量和百粒重)及小区产量,采用改进抗旱指数法及权重隶属函数值D对其进行抗旱性评价,并筛选出3份不同抗旱类型的大豆品种进行生理指标测定,验证该方法和指标。结果显示,与灌水处理(CK)相比较,干旱胁迫下的8个形态指标及产量,2014年除有效分枝数及百粒重差异不显著外,其余考察性状均达到了极显著差异,2015年所有考察表型性状均达到极显著差异;两年权重隶属函数法评价结果显著相关,小区产量与两年两种评价方法极显著相关;两种处理下,中度抗旱(中黄24)、弱抗旱品种(WDD00172)的SOD活性、POD活性、CAT活性、丙二醛含量、可溶性糖含量差异极显著,且与权重隶属函数值D显著相关,而强抗旱品种(晋豆21号)中SOD活性、POD活性、脯氨酸含量差异不显著,且6个生理指标与权重隶属函数值D均不相关。因此,权重隶属函数法和小区产量可作为大豆抗旱性评价单一可靠的方法与指标。  相似文献   
992.
993.
目的:从产品开发角度分析免疫细胞治疗类药物的发展现状和未来趋势。方法:检索科睿唯安(Clarivate Analytics)的Cortellis数据库的数据,利用定量分析法和对比分析法对检索结果进行分析。结果:目前已有2种免疫细胞治疗类药物上市,1种免疫细胞治疗类药物处于预注册阶段,4种药物处于临床Ⅲ期,同时大量处于临床Ⅱ/Ⅰ期药物显示未来市场上将有更多免疫细胞治疗类药物。产品交易方面,目前在免疫细胞治疗类药物的商业交易也趋向频繁。通过列举分析目前已发生的交易金额前十的交易,发现其中药物开发及商业化许可是最主要的交易模式。结论:目前免疫细胞治疗类药物市场尚处于起步阶段,但随着未来技术的不断发展改进,相信未来有更多的药物进入商用市场,为癌症及其他疾病的治疗提供新的契机。  相似文献   
994.
Metal organic frameworks (MOFs) are considered as promising candidates for supercapacitors because of high specific area and potential redox sites. However, their shuffled orientations and low conductivity nature lead to severely‐degraded performance. Designing an accessibly‐manipulated and efficient method to address those issues is of outmost significance for MOF application in supercapacitors. It is the common way that MOFs scarify themselves as templates or precursors to prepare target products. But to reversely think it, using target products to prepare MOF could be the way to unlock the bottleneck of MOFs' performance in supercapacitors. Herein, a novel strategy using Co(OH)2 as both the template and precursor to fabricate vertically‐oriented MOF electrode is proposed. The electrode shows a double high specific capacitance of 1044 Fg?1 and excellent rate capability compared to MOF in powder form. An asymmetric supercapacitor was also fabricated, which delivers a maximum energy density of 28.5 W h kg?1 at a power density of 1500 W kg?1, and the maximum of 24000 W kg?1 can be obtained with a remaining energy density of 13.3 W h kg?1. Therefore, the proposed strategy paves the way to unlock the inherent advantages of MOFs and also inspires for advanced MOF synthesis with optimum performance.  相似文献   
995.
Lipid metabolites play an important role in understanding the stress physiology of Pyropia haitanensis, and can be used to facilitate development of stress‐resistant Pyropia cultivars. Therefore, in this study ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC‐Q‐TOF‐MS) and gas chromatography–mass spectrometry (GC–MS) based metabolomics approaches were developed to screen the responses of lipid metabolites such as phospholipids, glycolipids, fatty acids and volatile organic compounds (VOCs) to different heat shock times. A total of 26 potential lipid biomarkers including Lyso‐monogalactosyldiacylglycerol (Lyso‐MGDG), Lyso‐digalactosyldiacylglycerol (Lyso‐DGDG), sulfoquinovosylmonoacylglycerols (SQMG), sulfoquinovosyldiacylglycerol (SQDG), diacylglyceryltrimethylhomoserine (DGTS), triacylglycerol (TAG), Lyso‐phosphatidicacid (Lyso‐PA), Lyso‐phosphatidylcholine (Lyso‐PC), Lyso‐phosphatidylethanolamine (Lyso‐PE), Lyso‐phosphatidylglycerol (Lyso‐PG), phosphatidylglycerol (PG), phosphatidylinositol (PI), and phosphatidylinositol phosphate (PIP) were identified, most of which responded to high temperature by reducing or increasing levels after stimulation for 1 h or 6 h. After times longer than 6 h, the levels of most lipids gradually recovered to the control group levels. Moreover, the balance of lipids and fatty acids transformation was disrupted. Overall, 11 total fatty acids (TFAs), 13 free fatty acids (FFAs) and 29 VOCs were identified during 0–72 h of high temperature stress. The FFAs, especially polyunsaturated C 20 fatty acids and VOCs, showed opposing change trends, indicating the transformation between C 20 fatty acids and VOCs. Overall, this study provides important insights into the metabolic variations of P. haitanensis under different heat shock time and the relationship between the conversion of lipids, fatty acids, and VOCs. The information provided herein will facilitate efficient development and improvement of Pyropia quality by producing cultivars resistant to high temperature.  相似文献   
996.
The process of initiation of host invasion and survival of some foliar phytopathogenic fungi in the absence of external nutrients on host leaf surfaces remains obscure. Here, we demonstrate that gluconeogenesis plays an important role in the process and nutrient‐starvation adaptation before the pathogen host invasion. Deletion of phosphoenolpyruvate c arboxyk inase gene BcPCK1 in gluconeogenesis in Botrytis cinerea, the causative agent of grey mould, resulted in the failure of the ΔBcpck1 mutant conidia to germinate on hard and hydrophobic surface and penetrate host cells in the absence of glucose, reduction in conidiation and slow conidium germination in a nutrient‐rich medium. The wild‐type and ΔBcpck1 conidia germinate similarly in the presence of glucose (higher concentration) as the sole carbon source. Conidial glucose‐content should reach a threshold level to initiate germination and host penetration. Infection structure formation by the mutants displayed a glucose‐dependent fashion, which corresponded to the mutant virulence reduction. Exogenous glucose or complementation of BcPCK1 completely rescued all the developmental and virulence defects of the mutants. Our findings demonstrate that BcPCK1 plays a crucial role in B. cinerea pathogenic growth and virulence, and provide new insights into gluconeogenesis mediating pathogenesis of plant fungal pathogens via initiation of conidial germination and host penetration.  相似文献   
997.
The use of toxin to attack neighbours and immunity proteins to protect against toxin has been observed in bacterial conflicts, including kin discrimination. Here, we report a novel nuclease‐toxin and its immunity protein function in the colony‐merger incompatibility, a kind of bacterial kin discrimination, in Myxococcus xanthus DK1622. The MXAN_0049 gene was determined to be a genetic determinant for colony‐merger incompatibility, and the incompatibility could be eliminated by deletion of the upstream co‐transcribed MXAN_0050 gene. We demonstrated that the MXAN_0050 protein was a nuclease, and MXAN_0049 protein was able to bind to MXAN_0050 to block nuclease activity in vitro. Expression of MXAN_0050 in Escherichia coli inhibited cellular growth, and the inhibition effect could be recovered by co‐expression of MXAN_0049. We found that deletion of the PAAR‐encoding gene (MXAN_0044) or the type VI secretion system led to the colony‐merger and co‐existence with the ΔMXAN_0049 mutant, suggesting that they were associated with colony‐merger incompatibility. Homologues of the nuclease‐toxin and cognate immunity pair are widely distributed in bacteria. We propose a simplified model to explain the kin discrimination mechanism mediated by the nuclease‐toxin and immunity protein.© 2018 Society for Applied Microbiology and John Wiley & Sons Ltd  相似文献   
998.
999.
1000.
Viruses can infect host plants to cause severe diseases and substantial agricultural loss, while plants have evolved RNA interference (RNAi) strategy to defend against viral infection. Despite enormous efforts, only a few host proteins in RNAi pathway were shown to mediate antiviral defense, including RNA-dependent RNA polymerase 1 (RDR1), RDR6, DICER-LIKE 2 (DCL2) and DCL4. In this study, we carried out a genetic screen for antiviral factors of RNAi pathway in Arabidopsis rdr6 background via inoculation with a 2b-deficient Cucumber Mosaic Virus (CMV-Δ2b). We identified a mutant susceptible to CMV-Δ2b, referred to as enhancer of rdr6 (enor) 3-1 rdr6, and found that ENOR3 encodes a functionally unknown protein with high homology to the mammalian Non Imprinted in Prader-Willi/Angelman (NIPA) magnesium transporters. ENOR3 inhibits accumulation of CMV-Δ2b and acts additively with RDR1, RDR6, DCL2 and DCL4 in antiviral defense. These results uncover that ENOR3 is a key component in antiviral RNAi pathway, and provide new insights into antiviral immunity.  相似文献   
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