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排序方式: 共有3501条查询结果,搜索用时 15 毫秒
51.
Chun-Xia Dou Zhi-Sheng Duan Xing-Bei Jia Pei-Feng Niu 《International Journal of Control, Automation and Systems》2011,9(3):478-488
This study introduces delay independent decentralized guaranteed cost control design method based on two controller structures
for nonlinear uncertain interconnected large scale systems with time delays. First, a set of equivalent Takagi-Sugeno (T-S)
fuzzy models are extended to represent the systems. Then a decentralized state-feedback guaranteed cost performance controller
is proposed for the fuzzy systems. Based on delay independent Lyapunov functional approach, some sufficient conditions for
the existence of the controller can be cast into the feasible problem of LMIs irrespective of the sizes of the time delays
so that the system can be asymptotically stabilized for all considered uncertainties whose sizes are not larger than their
bounds. Finally, the minimizing approach is proposed to search the suboptimal upper bound value of guaranteed cost function.
Moreover, the corresponding conditions are extended into the generalized dynamic output-feedback close-loop system. Finally,
the better control performances of the proposed methods are shown by the simulation examples. 相似文献
52.
Szu‐Han Chen Ming‐Dou Ker Tzu‐Ming Wang 《Journal of the Society for Information Display》2011,19(8):539-546
Abstract— A digital time‐modulation pixel memory circuit on glass substrate has been designed and verified for a 3‐μm low‐temperature polysilicon (LTPS) technology. From the experimental results, the proposed circuit can generate 4‐bit digital codes and the corresponding inversion data with a time‐modulation technique. While the liquid‐crystal‐display (LCD) panel operates in the still mode, which means the same image is displayed on the panel, a data driver for an LCD panel is not required to provide the image data of the frame by the proposed pixel memory circuit. This pixel memory circuit can store the frame data and generate its corresponding inversion data to refresh a static image without activating the data driver circuit. Therefore, the power consumption of a data driver can be reduced in the LCD panel. 相似文献
53.
Consider a rooted tree T of arbitrary maximum degree d representing a collection of n web pages connected via a set of links, all reachable from a source home page represented by the root of T. Each web page i carries a probability p
i
representative of the frequency with which it is visited. By adding hotlinks—shortcuts from a node to one of its descendents—we
wish to minimize the expected number of steps l needed to visit pages from the home page, expressed as a function of the entropy H(p) of the access probabilities p. This paper introduces several new strategies for effectively assigning hotlinks in a tree. For assigning exactly one hotlink
per node, our method guarantees an upper bound on l of 1.141H(p)+1 if d>2 and 1.08H(p)+2/3 if d=2. We also present the first efficient general methods for assigning at most k hotlinks per node in trees of arbitrary maximum degree, achieving bounds on l of at most
\frac2H(p)log(k+1)+1\frac{2H(p)}{\log(k+1)}+1
and
\fracH(p)log(k+d)-logd+1\frac{H(p)}{\log(k+d)-\log d}+1
, respectively. All our methods are strong, i.e., they provide the same guarantees on all subtrees after the assignment. We also present an algorithm implementing these
methods in O(nlog n) time, an improvement over the previous O(n
2) time algorithms. Finally we prove a Ω(nlog n) lower bound on the running time of any strong method that guarantee an average access time strictly better than 2H(p). 相似文献
54.
针对实际采样环境中存在的各种干扰,以及交通数据的非平稳特性,在交通数据小波变换特性分析的基础上,提出基于小波分析的交通数据自适应消噪算法:对交通数据进行小波分解,然后对高频系数的自相关函数进行白噪声检验,从而确定小波分解的层数和阈值。采用实际检测交通流数据,对算法的有效性进行了验证分析。 相似文献
55.
56.
Cloud computing has rendered its ever-increasing advantages in flexible service provisions, which attracts the attentions from large-scale enterprise applications to small-scale smart uses. For example, more and more multimedia services are moving towards cloud to better accommodate people’s daily uses on various smart devices that support cloud, some of which are similar or equivalent in their functionality (e.g., more than 1,000 video services that share similar “video-play” functionality are present in APP Store). In this situation, it is necessary to discriminate these functional-equivalent multimedia services, based on their Quality of Service (QoS) information. However, due to the abundant information of multimedia content, dozens of QoS criteria are often needed to evaluate a multimedia service, which places a heavy burden on users’ multimedia service selection. Besides, the QoS criteria of multimedia services are usually not independent, but correlated, which cannot be accommodated very well by the traditional selection methods, e.g., traditional simple weighting methods. In view of these challenges, we put forward a multimedia service selection method based on weighted Principal Component Analysis (PCA), i.e., Weighted PCA-based Multimedia Service Selection Method (W_PCA_MSSM). The advantage of our proposal is two-fold. First, weighted PCA could reduce the number of QoS criteria for evaluation, by which the service selection process is simplified. Second, PCA could eliminate the correlations between different QoS criteria, which may bring a more accurate service selection result. Finally, the feasibility of W_PCA_MSSM is validated, by a set of experiments deployed on real-world service quality set QWS Dataset. 相似文献
57.
目的 哈希是大规模图像检索的有效方法。为提高检索精度,哈希码应保留语义信息。图像之间越相似,其哈希码也应越接近。现有方法首先提取描述图像整体的特征,然后生成哈希码。这种方法不能精确地描述图像包含的多个目标,限制了多标签图像检索的精度。为此提出一种基于卷积神经网络和目标提取的哈希生成方法。方法 首先提取图像中可能包含目标的一系列区域,然后用深度卷积神经网络提取每个区域的特征并进行融合,通过生成一组特征来刻画图像中的每个目标,最后再产生整幅图像的哈希码。采用Triplet Loss的训练方法,使得哈希码尽可能保留语义信息。结果 在VOC2012、Flickr25K和NUSWIDE数据集上进行多标签图像检索。在NDCG(normalized discounted cumulative gain)性能指标上,当返回图像数量为 1 000时,对于VOC2012,本文方法相对于DSRH(deep semantic ranking hashing)方法提高24个百分点,相对于ITQ-CCA(iterative quantization-canonical correlation analysis)方法能提高36个百分点;对于Flickr25,本文方法比DSRH方法能提高2个左右的百分点;对于NUSWIDE,本文方法相对于DSRH方法能提高4个左右的百分点。对于平均检索准确度,本文方法在NUSWIDE和Flickr25上能提高25个百分点。根据多项评价指标可以看出,本文方法能以更细粒度来精确地描述图像,显著提高了多标签图像检索的性能。结论 本文新的特征学习模型,对图像进行细粒度特征编码是一种可行的方法,能够有效提高数据集的检索性能。 相似文献
58.
温度测量与控制在工业、农业、国防等行业有着广泛的应用.由于利用单片机技术的温度测控可靠性高、价格低廉而被广泛采用.本文对电阻炉的数字控制电路进行了分析和设计. 相似文献
59.
文章采用MATLAB5 .2 /SIMULINK建立模糊直接转矩控制系统的仿真模型 ,介绍了用SIMULINK软件进行封装、S函数设计及用模糊工具箱设计模糊控制器的方法 ,并通过仿真结果验证了此模型的正确性 相似文献
60.
用XML表示和发布图文混合信息 总被引:4,自引:0,他引:4
可扩展标识语言XML以其合理的数据组织结构和可扩展的特性,广泛适合于表示各类复杂的数据形式。利用XML表示和发布图文混合信息具有很重要的实际价值。基于实例介绍了使用XML表示和发布图文混合信息内容的方法和过程。 相似文献