全文获取类型
收费全文 | 10012篇 |
免费 | 2502篇 |
国内免费 | 1653篇 |
专业分类
电工技术 | 473篇 |
综合类 | 1185篇 |
化学工业 | 62篇 |
金属工艺 | 121篇 |
机械仪表 | 711篇 |
建筑科学 | 105篇 |
矿业工程 | 75篇 |
能源动力 | 45篇 |
轻工业 | 193篇 |
水利工程 | 72篇 |
石油天然气 | 70篇 |
武器工业 | 69篇 |
无线电 | 1910篇 |
一般工业技术 | 591篇 |
冶金工业 | 62篇 |
原子能技术 | 17篇 |
自动化技术 | 8406篇 |
出版年
2024年 | 107篇 |
2023年 | 285篇 |
2022年 | 449篇 |
2021年 | 490篇 |
2020年 | 515篇 |
2019年 | 356篇 |
2018年 | 306篇 |
2017年 | 392篇 |
2016年 | 445篇 |
2015年 | 488篇 |
2014年 | 671篇 |
2013年 | 619篇 |
2012年 | 852篇 |
2011年 | 899篇 |
2010年 | 794篇 |
2009年 | 784篇 |
2008年 | 825篇 |
2007年 | 858篇 |
2006年 | 711篇 |
2005年 | 672篇 |
2004年 | 556篇 |
2003年 | 457篇 |
2002年 | 328篇 |
2001年 | 259篇 |
2000年 | 197篇 |
1999年 | 150篇 |
1998年 | 145篇 |
1997年 | 101篇 |
1996年 | 90篇 |
1995年 | 84篇 |
1994年 | 55篇 |
1993年 | 43篇 |
1992年 | 43篇 |
1991年 | 41篇 |
1990年 | 13篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 15篇 |
1984年 | 7篇 |
1983年 | 12篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Cluster analysis in industrial market segmentation through artificial neural network 总被引:6,自引:0,他引:6
Market segmentation has commonly applied cluster analysis. This study intends to make the comparison of conventional two-stage method with proposed two-stage method through the simulated data. The proposed two-stage method is the combination of self-organizing feature maps and K-means method. The simulation results show that the proposed scheme is better than the conventional two-stage method based on the rate of misclassification. 相似文献
22.
23.
A Novel Segmentation and Feedback Model for Resolving Contention in Optical Burst Switching 总被引:2,自引:0,他引:2
A novel segmentation and feedback model (SFM) applied to resolve contention is proposed. Simulation and performance analyses show that the SFM effectively avoids contentions in optical burst switching (OBS). The long delay time of deflection routing and the immature technology of wavelength converters and optical buffers are not deployed in the SFM. The SFM does not only realize fast switching but also allows preemption by higher priority bursts. 相似文献
24.
曲线的透视不变性分割在基于二次曲线的三维重建中非常重要。首先给出了连续曲线零曲率点和角点的提取法,在数字图像中曲经是不连续的,曲率的变化受噪声的干扰很大。在这种情况下为了检测出零曲率点和角点,对曲线采用了高斯滤波然后再提到零曲率点和角点。实验证明这种方法效果优于直接求曲率法。 相似文献
25.
26.
Gu Junzhong 《计算机科学技术学报》1993,8(4):3-20
In object-oriented database systems(OOBSs),the traditional transaction models are no longer suitable because of the difference between the object-oriented data model(OODM)and the conventional data models(e.g.relational data model).In this paper,transction models for advanced database applications are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed instead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a metho.Each transaction(even subtransactions)keeps relative ACID(Atomicity,Consistency,Isolation,Durability)properties,therefore the special problems appearing in OOBSs such as“long transactions”,“visibility of inconsistent database state”can be solved. 相似文献
27.
In this work we present a snake based approach for the segmentation of images of computerized tomography (CT) scans. We introduce a new term for the internal energy and another one for external energy which solve common problems associated with classical snakes in this type of images. A simplified minimizing method is also presented. 相似文献
28.
Gabriel Tsechpenakis Dimitris Metaxas Carol Neidle 《Computer Vision and Image Understanding》2006,104(2-3):140
We present a data-driven dynamic coupling between discrete and continuous methods for tracking objects of high dofs, which overcomes the limitations of previous techniques. In our approach, two trackers work in parallel, and the coupling between them is based on the tracking error. We use a model-based continuous method to achieve accurate results and, in cases of failure, we re-initialize the model using our discrete tracker. This method maintains the accuracy of a more tightly coupled system, while increasing its efficiency. At any given frame, our discrete tracker uses the current and several previous frames to search into a database for the best matching solution. For improved robustness, object configuration sequences, rather than single configurations, are stored in the database. We apply our framework to the problem of 3D hand tracking from image sequences and the discrimination between fingerspelling and continuous signs in American Sign Language. 相似文献
29.
30.