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71.
Calculation of K-band position of α, β-unsaturated carbonyl compounds is the key and difficult point in the chapter of Ultraviolet-Visible Absorption Spectroscopy in Introduction to Spectroscopy. In teaching, it is found that students always have various problems in the process of calculating K-band position, so it's hard for students to get the right results. This paper gives a detailed introduction to the calculation method and matters needing attention, where are further illustrated by examples. We will try to help students learn and master the problem of K-band position calculation.  相似文献   
72.
Word embeddings based on a conditional model are commonly used in Natural Language Processing (NLP) tasks to embed the words of a dictionary in a low dimensional linear space. Their computation is based on the maximization of the likelihood of a conditional probability distribution for each word of the dictionary. These distributions form a Riemannian statistical manifold, where word embeddings can be interpreted as vectors in the tangent space of a specific reference measure on the manifold. A novel family of word embeddings, called α-embeddings have been recently introduced as deriving from the geometrical deformation of the simplex of probabilities through a parameter α, using notions from Information Geometry. After introducing the α-embeddings, we show how the deformation of the simplex, controlled by α, provides an extra handle to increase the performances of several intrinsic and extrinsic tasks in NLP. We test the α-embeddings on different tasks with models of increasing complexity, showing that the advantages associated with the use of α-embeddings are present also for models with a large number of parameters. Finally, we show that tuning α allows for higher performances compared to the use of larger models in which additionally a transformation of the embeddings is learned during training, as experimentally verified in attention models.  相似文献   
73.
Protein-protein interaction (PPI) extraction from published scientific literature provides additional support for precision medicine efforts. Meanwhile, knowledge bases (KBs) contain huge amounts of structured information of protein entities and their relations, which can be encoded in entity and relation embeddings to help PPI extraction. However, the prior knowledge of protein-protein pairs must be selectively used so that it is suitable for different contexts. This paper proposes a Knowledge Selection Model (KSM) to fuse the selected prior knowledge and context information for PPI extraction. Firstly, two Transformers encode the context sequence of a protein pair according to each protein embedding, respectively. Then, the two outputs are fed to a mutual attention to capture the important context features towards the protein pair. Next, the context features are used to distill the relation embedding by a knowledge selector. Finally, the selected relation embedding and the context features are concatenated for PPI extraction. Experiments on the BioCreative VI PPI dataset show that KSM achieves a new state-of-the-art performance (38.08 % F1-score) by adding knowledge selection.  相似文献   
74.
对地质分析时使用标准物质的一般原则、容易忽略的问题、贵金属标准物质的选择、过期标准物质的选择、疑难样品“标准物质室”的建立、仪器期间核查标准物质的选择进行了论述。  相似文献   
75.
一种快速的近岸红外目标检测   总被引:1,自引:0,他引:1  
近岸红外目标检测由于背景复杂和实时性的要求,是当前研究的一个难点。基于上下文的视觉注意机制是解决这一难题的有效途径。首先根据近岸红外目标存在于海面这一先验知识,利用灰度、纹理特征及位置关系,分割出海面;其次利用基于相位谱的视觉注意机制定位显著区域;最后综合海面和显著区域位置,便可检测出近岸红外目标。实验证明,这种算法高效、准确,能够满足目标检测阶段的实时性要求。  相似文献   
76.
One of the most rapidly advancing areas of deep learning research aims at creating models that learn to disentangle the latent factors of variation from a data distribution. However, modeling joint probability mass functions is usually prohibitive, which motivates the use of conditional models assuming that some information is given as input. In the domain of numerical cognition, deep learning architectures have successfully demonstrated that approximate numerosity representations can emerge in multi-layer networks that build latent representations of a set of images with a varying number of items. However, existing models have focused on tasks requiring to conditionally estimate numerosity information from a given image. Here, we focus on a set of much more challenging tasks, which require to conditionally generate synthetic images containing a given number of items. We show that attention-based architectures operating at the pixel level can learn to produce well-formed images approximately containing a specific number of items, even when the target numerosity was not present in the training distribution.  相似文献   
77.
王一斌  郑佳  尹诗白 《光子学报》2021,50(3):159-166
针对雾图成像时变化的场景光及去雾过程中不同雾相关信息在处理上的差异性,提出了通道注意网络和模糊划分熵图割的单幅图像去雾算法。以考虑变化场景光的大气散射物理成像模型为基础,首先使用通道注意的编码解码网络来估计透射率,并在编码器最后及解码器起始处添加通道注意模块,以便为编码器提取的不同雾相关特征图分配不同的权重,准确地计算透射率;然后利用所提出的模糊划分熵图割算法将透射率划分为不同场景光覆盖下的近景、中景、远景,此分割策略将考虑空间相关性的图割算法与模糊划分熵的阈值分割算法相结合,解决了单一阈值分割算法产生的区域误分问题;最后估计场景光和大气光,得到去雾图像。实验结果表明,算法在合成雾图及真实雾图上均有较好的去雾效果。与已有的去雾算法相比,本文算法在峰值信噪比及结构相似性上均有提升,单张图像的平均处理时间为3.9 s。  相似文献   
78.
Your attention please: Phenomenal conciousness, that is, how something feels, does not exist for an observer. As science relies on observations, it is not aware of the nature of subjectivity and thus science is not often defined as a collective intelligence. In this Essay, the roles of intelligence and attention are discussed, as well as an analysis of scientific communication and citation, in order to evaluate whether science is a case of collective intelligence.  相似文献   
79.
基于深交所“互动易”平台的机构调研信息和投资者问答数据,以投资者关注为聚焦点,通过剖析机构调研行为-投资者关注-股票流动性的传导路径,检验中国股票市场机构调研行为的示范效应。结论表明,机构调研行为具有强烈的示范效应,能够通过引起其他投资者的关注,促进中短期股票流动性的提高,且机构调研行为越集中,这种示范效应越强。此外,对于信息披露质量较低和机构持股比例较低的公司,机构调研行为更容易引起投资者的关注,示范效应更强。研究结论验证了机构投资者的信息优势性和行为影响力,支持了投资者的信息解读能力,为机构投资者的市场引导作用提供解释依据。  相似文献   
80.
黄传波  金忠 《光子学报》2014,40(7):1025-1030
基于视觉注意模型提取的特征能够反映图像高层语义的新特征,将视觉注意机制引入到图像分析领域能有效地减小语义鸿沟,获得高效的图像检索性能.根据视觉感知的特点,对Itti视觉注意模型进行了改进.采用主分量图表示亮度图,将纹理粗糙度信息融入视觉注意模型,进而提出了一种基于视觉注意空间分布特征的图像检索算法.首先由改进视觉注意模型将图像分解得到38个视觉特征图,然后采用网格平分法提取视觉特征图的空间分布信息,组成特征矢量来多层次地对图像特征进行描述,用于图像检索.实验结果表明,该算法利用基于改进注意力模型方法来提取图像空间分布特征进行图像检索,能获得较高的检索率.  相似文献   
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