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101.
Xiong H Zhang Y Chen XW 《IEEE/ACM transactions on computational biology and bioinformatics / IEEE, ACM》2007,4(4):583-595
One important application of gene expression analysis is to classify tissue samples according to their gene expression levels. Gene expression data are typically characterized by high dimensionality and small sample size, which makes the classification task quite challenging. In this paper, we present a data-dependent kernel for microarray data classification. This kernel function is engineered so that the class separability of the training data is maximized. A bootstrapping-based resampling scheme is introduced to reduce the possible training bias. The effectiveness of this adaptive kernel for microarray data classification is illustrated with a k-Nearest Neighbor (KNN) classifier. Our experimental study shows that the data-dependent kernel leads to a significant improvement in the accuracy of KNN classifiers. Furthermore, this kernel-based KNN scheme has been demonstrated to be competitive to, if not better than, more sophisticated classifiers such as Support Vector Machines (SVMs) and the Uncorrelated Linear Discriminant Analysis (ULDA) for classifying gene expression data. 相似文献
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KCNQ potassium channels are activated by changes in transmembrane voltage and play an important role in controlling electrical excitability. Human mutations of KCNQ2 and KCNQ3 potassium channel genes result in reduction or loss of channel activity and cause benign familial neonatal convulsions (BFNCs). Thus, small molecules capable of augmenting KCNQ currents are essential both for understanding the mechanism of channel activity and for developing therapeutics. We performed a high-throughput screen in search for agonistic compounds potentiating KCNQ potassium channels. Here we report identification of a new opener, zinc pyrithione (1), which activates both recombinant and native KCNQ M currents. Interactions with the channel protein cause an increase of single-channel open probability that could fully account for the overall conductance increase. Separate point mutations have been identified that either shift the concentration dependence or affect potentiation efficacy, thereby providing evidence for residues influencing ligand binding and downstream events. Furthermore, zinc pyrithione is capable of rescuing the mutant channels causal to BFNCs. 相似文献
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Zhu Jing Zeng Zhaofu Xiong Mengqing Mo Huaheng Jin Meng Hu Ke 《Sleep and biological rhythms》2022,20(3):421-429
Sleep and Biological Rhythms - The relationship between plasma orexin A (OXA) levels and cognitive function in patients with obstructive sleep apnea (OSA) remains unclear. This study aimed to... 相似文献
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Zhiyong Huang Chenhan Xiong Jianhua Huang Tianxiang Zhao Wei Cao Guoping Du Nan Chen 《Luminescence》2022,37(6):944-952
Inorganic–organic hybrid nanoparticles formed by lanthanide-doped nanostructures and organic ligands have been intensively studied, which could greatly increase their photoluminescence performance as a result of the energy transfer process from organic ligands to Ln3+ ions. However, the photoluminescence intensity and excitation spectral width are still quite limited on coordinating with a single type of organic ligand. In this work, Eu3+-doped LaF3 (LaF3:Eu3+) nanoparticles were prepared using a hydrothermal method, and were then hybridized with benzoic acid and thenoyltrifluoroacetone to form the hybrid nanostructures. After that, the hybrid nanostructures were mixed with 2,2′-azobisisobutyronitrile and methyl methacrylate to prepare the composites. The sample obtained by hybridization and composite doping with 5% Eu3+ exhibited the best photoluminescence performance. The excitation peak width and luminescence intensity of the hybrid nanostructures were significantly increased. The excitation spectral width of the inorganic–organic mixed hybrid nanostructures was particularly enhanced, and covered the whole ultraviolet band region of solar light on Earth. The prepared composites exhibited good optical properties. 相似文献
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In the presence of abscisic acid or environmental stress, activated SnRK2s transiently phosphorylate Raptor1B, a regulatory component of the TOR complex, to inhibit plant growth. To examine such transient interactions between a kinase and its substrate, comprehensive genetic or biochemistry evidence is more conclusive than a single negative co-immunoprecipitation test. 相似文献
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