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11.
混沌识别是对非线性时间序列进行混沌预测的前提。针对时间序列风速确定性与随机性相结合的复杂非线性特征,研究了不同的混沌识别方法,并对风速时间序列进行混沌特征识别。应用随机噪声、周期运动及经典混沌系统的时间序列对所选方法进行可靠性验证。对美国国家风能研究中心M2测风塔实测时间序列风速数据进行非线性混沌特征识别。结果表明:风速时间序列具有明显的混沌特征;各风速时间序列表现出不同程度的混沌特征;各混沌识别方法对风速时间序列混沌特征的表达形式不同,互为补充,相互验证。 相似文献
12.
交通信号灯识别包括检测和状态识别,在智能交通系统中发挥重要作用。基于YOLOv3算法提出了一种交通信号灯检测与状态识别模型。针对交通信号灯相较于交通场景中其他目标具有尺度小的特性进行了算法的设计:降低骨干网络的下采样倍率以增加小尺度目标的特征描述能力;通过增大特征图的尺度来改进多尺度特征融合;引入广义交并比作为检测任务的损失函数来改进目标边界框的回归效果。同时,根据交通信号灯本身的特性,使用颜色和形状约束的方法对信号灯进行状态识别和类别验证。最后在公开的Bosch交通信号灯数据集上和实际的城区道路进行了实验验证。实验结果表明,所提出的算法能够提升交通信号灯识别的精度和召回率,识别准确率可以达到90%左右。 相似文献
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In sport sceneries, automatically recognizing human actions is a useful technique that can be popularly applied in may domains, such as human body tracking and athlete behavior analysis Most state-of-the-art deep architectures have achieved competitive performance in recognizing human action. However, it is still a challenging task due to the unavoidable occlusion, camera angle changes, and varied human posture. In this paper, we propose a novel deep multimodal feature fusion algorithm for human action recognition. The key technique is a multi-model feature fusion scheme. More specifically, we fuse visual feature, skeleton posture, probability maps and audio signal into a hybrid feature, which is utilized to represent human action. Then these feature channels are optimally combined using a deep model, wherein the weights of multiple feature channels can be predicted intelligently. Finally, the optimally fused feature are fed into a multi-class SVM for conducting human action recognition. Extensive comparative results and parameter analysis have shown the effectiveness of our proposed method. 相似文献
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ABSTRACTFeature selection is an important task to improve the classifier’s accuracy and to decrease the problem size. A number of methodologies have been presented for feature selection problems using metaheuristic algorithms. In this paper, an improved self-adaptive inertia weight particle swarm optimisation with local search and combined with C4.5 classifiers for feature selection algorithm is proposed. In this proposed algorithm, the gradient base local search with its capacity of helping to explore the feature space and an improved self-adaptive inertia weight particle swarm optimisation with its ability to converge a best global solution in the search space. Experimental results have verified that the SIW-APSO-LS performed well compared with other state of art feature selection techniques on a suit of 16 standard data sets. 相似文献
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为探究环境因素对毒气扩散危害程度的影响,通过对比有限空间内外环境差异,了解气体在有限空间内受力情况,并以传统高斯烟羽模型为基础,考虑扩散气体与有限空间边界碰撞产生的反射作用,建立了适用于有限空间气体扩散的改进高斯烟羽模型。深度剖析有限空间气体扩散环境,挖掘气体扩散主要关联因子,构建风速、地表粗糙度对有限空间气体扩散的影响函数;参照有限空间环境特征,分别设置3种不同风速与2种不同地表粗糙度,推求6种不同环境条件下气体扩散面积,阐明风速与地表粗糙度对有限空间气体扩散的影响程度。结果表明:在单一风速条件下,风速越高,地表粗糙度越低,洞室内H2S气体滞留时间越短,洞室内气体的扩散面积越小;风速越低,地表粗糙度越高,洞室内气体的扩散面积越大。 相似文献
18.
《矿业科学技术学报(英文版)》2019,29(3):343-355
Since 2009, the Mine Safety and Health Administration(MSHA) has required mines to install refuge alternatives(RAs) in underground coal mines. One of the biggest concerns with occupied RAs is the possible severity of the resulting thermal environment. In 30 CFR 7.504, the maximum allowable apparent temperature(AT) for an occupied RA is specified as 35 °C(95 °F). Manufacturers must conduct heat/humidity tests to demonstrate that their RAs meet the 35 °C(95 °F) AT limit. For these tests, heat input devices are used to input the metabolic heat of actual miners. A wide variety of test methods, sensors, and heat input devices could be used when conducting such tests. Since 2012, the National Institute for Occupational Safety and Health(NIOSH) has conducted over thirty 96-hour heat/humidity tests on four different RAs. This paper discusses the test equipment and procedures used during these investigations. This information is useful for RA manufacturers conducting RA heat/humidity tests, for other researchers investigating RA heat/humidity buildup, and for those who need to assess the thermal environment of any confined space where people may be trapped or are seeking refuge. 相似文献
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Atsushi Tsujita Masashi Ohchi Takayuki Wakimoto 《Electrical Engineering in Japan》2019,208(1-2):17-26
We have been studying on estimating distribution of permittivity between measurement electrodes using capacitance and electric potential. Two arc electrodes were separated by long distance and there electrodes were surrounded by additional electrodes respectively. In past research work, we carried out numerical electric analysis for calculating the capacitance and electric potential using Finite Element Method (FEM) and compared with experimental and numerical results. The capacitance values were almost agreed with experimental and numerical results. However, the electric potential values were different between experimental and numerical results in conventional studies. In this paper, we proposed an equivalent circuit including the stray capacity and measurement method for capacitance, the electric potential in space between long distance electrodes was estimated. 相似文献