全文获取类型
收费全文 | 960篇 |
免费 | 168篇 |
国内免费 | 102篇 |
专业分类
电工技术 | 59篇 |
综合类 | 31篇 |
化学工业 | 103篇 |
金属工艺 | 70篇 |
机械仪表 | 24篇 |
建筑科学 | 31篇 |
矿业工程 | 14篇 |
能源动力 | 25篇 |
轻工业 | 29篇 |
水利工程 | 13篇 |
石油天然气 | 30篇 |
武器工业 | 3篇 |
无线电 | 143篇 |
一般工业技术 | 83篇 |
冶金工业 | 18篇 |
原子能技术 | 9篇 |
自动化技术 | 545篇 |
出版年
2024年 | 22篇 |
2023年 | 52篇 |
2022年 | 84篇 |
2021年 | 76篇 |
2020年 | 77篇 |
2019年 | 77篇 |
2018年 | 54篇 |
2017年 | 52篇 |
2016年 | 48篇 |
2015年 | 48篇 |
2014年 | 62篇 |
2013年 | 69篇 |
2012年 | 70篇 |
2011年 | 55篇 |
2010年 | 39篇 |
2009年 | 50篇 |
2008年 | 44篇 |
2007年 | 63篇 |
2006年 | 52篇 |
2005年 | 35篇 |
2004年 | 24篇 |
2003年 | 22篇 |
2002年 | 10篇 |
2001年 | 13篇 |
2000年 | 5篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有1230条查询结果,搜索用时 15 毫秒
81.
Changes in land surface temperatures and NDVI values over Europe between 1982 and 1999 总被引:2,自引:0,他引:2
We used land surface temperature (LST) algorithms and NDVI values to estimate changes in vegetation in the European continent between 1982 and 1999 from the Pathfinder AVHRR Land (PAL) dataset. These two parameters are monitored through HANTS (Harmonic ANalysis of Time Series) software, which allows the simultaneous observation of mean value, first harmonic amplitude and phase behaviors in the same image. These results for each complete year of data show the effect of volcanic aerosols and orbital drift on PAL data. Comparison of time series of HANTS cloud-free time series with the original time series for various land cover proves that this software is useful for LST analysis, although primarily designed for NDVI applications. Comparison of yearly averages of HANTS LST over the whole Europe with air temperature confirms the validity of the results. Maps of the evolution for both parameters between periods 1982/1986 and 1995/1999 have been elaborated: NDVI data show the well confirmed trend of increase over Europe (up to 0.1 in NDVI), Southern Europe seeing a decrease in NDVI (− 0.02). LST averages stay stable or slightly decrease (up to − 1.5 K) over the whole continent, except for southern areas for which the increase is up to 2.5 K. These results evidence that arid and semi-arid areas of Southern Europe have become more arid, the rest of Europe seeing an increase in its wood land proportion, while seasonal amplitude in Northern Europe has decreased. 相似文献
82.
101复合松醇油浮选辉钼矿的试验研究 总被引:3,自引:0,他引:3
通过小型试验及工业试验,对101复合松醇油浮选辉钼矿的性能进行了研究.结果表明:该药剂用于浮选辉钼矿,不仅能提高回收率,而且能很高钼精矿质量. 相似文献
83.
84.
85.
86.
ADSP-TS101 is a high performance DSP with good properties of parallel processing and high speed. According to the real-time processing requirements of underwater acoustic communication algorithms, a real-time parallel processing system with multi-channel synchronous sample, which is composed of multiple ADSP-TS101s, is designed and carried out. For the hardware design, field programmable gate array (FPGA) logical control is adopted for the design of multi-channel synchronous sample module and cluster/data flow associated pin connection mode is adopted for multiprocessing parallel processing configuration respectively: And the software is optimized by two kinds of communication ways: broadcast writing way through shared bus and point-to-point way through link ports. Through the whole system installation, connective debugging, and experiments in a lake, the results show that the real-time parallel processing system has good stability and real-time processing capability and meets the technical design requirements of real-time processing. 相似文献
87.
Alexandros Andre Chaaraoui Pau Climent-Pérez Francisco Flórez-Revuelta 《Pattern recognition letters》2013
In this paper, a human action recognition method is presented in which pose representation is based on the contour points of the human silhouette and actions are learned by making use of sequences of multi-view key poses. Our contribution is twofold. Firstly, our approach achieves state-of-the-art success rates without compromising the speed of the recognition process and therefore showing suitability for online recognition and real-time scenarios. Secondly, dissimilarities among different actors performing the same action are handled by taking into account variations in shape (shifting the test data to the known domain of key poses) and speed (considering inconsistent time scales in the classification). Experimental results on the publicly available Weizmann, MuHAVi and IXMAS datasets return high and stable success rates, achieving, to the best of our knowledge, the best rate so far on the MuHAVi Novel Actor test. 相似文献
88.
Carmelo Cassisi Alfredo Ferro Rosalba Giugno Giuseppe Pigola Alfredo Pulvirenti 《Information Systems》2013
Clustering is a widely used unsupervised data mining technique. It allows to identify structures in collections of objects by grouping them into classes, named clusters, in such a way that similarity of objects within any cluster is maximized and similarity of objects belonging to different clusters is minimized. In density-based clustering, a cluster is defined as a connected dense component and grows in the direction driven by the density. The basic structure of density-based clustering presents some common drawbacks: (i) parameters have to be set; (ii) the behavior of the algorithm is sensitive to the density of the starting object; and (iii) adjacent clusters of different densities could not be properly identified. In this paper, we address all the above problems. Our method, based on the concept of space stratification, efficiently identifies the different densities in the dataset and, accordingly, ranks the objects of the original space. Next, it exploits such a knowledge by projecting the original data into a space with one more dimension. It performs a density based clustering taking into account the reverse-nearest-neighbor of the objects. Our method also reduces the number of input parameters by giving a guideline to set them in a suitable way. Experimental results indicate that our algorithm is able to deal with clusters of different densities and outperforms the most popular algorithms DBSCAN and OPTICS in all the standard benchmark datasets. 相似文献
89.
90.