全文获取类型
收费全文 | 17565篇 |
免费 | 3132篇 |
国内免费 | 1257篇 |
专业分类
电工技术 | 7654篇 |
技术理论 | 3篇 |
综合类 | 1457篇 |
化学工业 | 390篇 |
金属工艺 | 181篇 |
机械仪表 | 666篇 |
建筑科学 | 1080篇 |
矿业工程 | 225篇 |
能源动力 | 804篇 |
轻工业 | 195篇 |
水利工程 | 429篇 |
石油天然气 | 234篇 |
武器工业 | 136篇 |
无线电 | 2506篇 |
一般工业技术 | 1052篇 |
冶金工业 | 128篇 |
原子能技术 | 106篇 |
自动化技术 | 4708篇 |
出版年
2024年 | 120篇 |
2023年 | 381篇 |
2022年 | 675篇 |
2021年 | 909篇 |
2020年 | 961篇 |
2019年 | 689篇 |
2018年 | 642篇 |
2017年 | 820篇 |
2016年 | 829篇 |
2015年 | 964篇 |
2014年 | 1738篇 |
2013年 | 1263篇 |
2012年 | 1780篇 |
2011年 | 1729篇 |
2010年 | 1262篇 |
2009年 | 1156篇 |
2008年 | 1084篇 |
2007年 | 1236篇 |
2006年 | 936篇 |
2005年 | 732篇 |
2004年 | 529篇 |
2003年 | 375篇 |
2002年 | 242篇 |
2001年 | 197篇 |
2000年 | 172篇 |
1999年 | 137篇 |
1998年 | 97篇 |
1997年 | 76篇 |
1996年 | 53篇 |
1995年 | 51篇 |
1994年 | 31篇 |
1993年 | 22篇 |
1992年 | 9篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1988年 | 17篇 |
1987年 | 7篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1959年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
地理空间信息网格调度技术,要比传统的高性能计算中的调度技术复杂,原因是如果将全部网格资源作为一个应用程序的调度和执行目标,必将导致通信延迟、成本昂贵、执行低效等。为此,综合考虑应用程序特性、机器特性等,研究设计了地理空间信息网格高性能调度技术中的应用程序调度模型,包括地理空间信息网格应用程序分析;资源特性分析;应用程序分解;性能预测;资源调度;机器选择;任务映射;任务调度;任务调度器和调度器管理模块。以实现为不同的应用程序匹配不同的计算资源,提高计算资源的利用率和应用程序的执行效率。 相似文献
2.
3.
A method constructinq C~1 Piecewise quintic polynomial over a triangular grid to interpo-late function values and partial derivatives at vertices is presented in this paper.The set of precise poly-nomials of this method is discussed. 相似文献
4.
AutoCAD 下非结构网格自动生成 总被引:1,自引:1,他引:0
在AutoCAD环境下,从背景网格生成和数据结构两方面对推进阵面法进行修正。采用修理后的方法,使得在流场、泥沙输移和床面冲淤数值计算的前处理过程中无须精心预设内部控制点而只需给边界一个尺度,就能自动生成适应任意复杂边界的非结构网格,从而提高网格生成、优化的效率和通用性。 相似文献
5.
Dongchang Sun Liyong Tong 《International journal for numerical methods in engineering》2004,60(11):1911-1932
A novel finite element model is presented for static and dynamic analysis of composite plates integrated with a laminated piezoelectric layer, a host laminated composite plate and an adhesive layer between them. A new adhesive element is developed which includes both peel and shear effects in the adhesive layer based on first‐order shear deformation plate theory. The thin adhesive layer between the piezoelectric layer and the host plate is modelled by assuming that it carries constant shear and peel strains throughout its thickness. In addition, a weighted static shape control scheme for finding the optimal voltage distribution for static shape control is given. By selecting different weighting matrices, a variety of items such as displacements, slopes, curvatures, strains and even generalized forces, can be included in finding the optimal actuating voltage for static shape control. The present model is validated by comparing with those results available in the literature. The numerical results show that the weighted linear least method can give a satisfactory voltage distribution to best match the desired shape. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
6.
CAO Wei-feng WANG Wen-boBeijing University of Posts Telecommunications Beijing P.R. China 《中国邮电高校学报(英文版)》2005,12(4)
1IntroductionCurrently,smart antenna technology can greatly en-hance system performance and i mprove the system ca-pacity so that it has been considered as a keytechnologyinthe third generation wireless communicationsystems .The researches on channel model , beamforming algo-rithms and receive algorithms have been widely carriedout and a great many of proposition have beensubmittedtothe 3th Generation Project Partner (3GPP) . Fromthe viewpoint of link-level and system-level research,many asp… 相似文献
7.
Gert van der Horn Johan H. Huijsing 《Analog Integrated Circuits and Signal Processing》1997,14(3):207-222
In many applications electronic sensors are used toimprove performance and reliability of measurement systems. Suchsensors should provide a correct transfer from the physical signalto be measured to the electrical output signal. One importantstep to achieve this, is to calibrate each sensor by applyingdifferent reference input signals and adjusting the sensor transferaccordingly. Besides expensive reference equipment the calibrationprocess takes much time and attention per individual sensor,which means a considerable increase in sensor production costs.By including at the sensor or sensor interface chip a programmablecalibration facility the calibration of such smart sensors caneasily be automated and can be executed for a batch of sensorsat a time, thus minimizing the calibration time and costs. Thispaper presents a calibration method and options for integrationin the smart sensor concept, in hardware as well as in software.An advantage of the proposed method is that it does not needa large matrix of calibration data, which needs to be storedin a look-up table or converted into a correction formula, butinstead it uses a step-by-step approach to correct the sensortransfer at each calibration measurement until the error is sufficientlysmall. 相似文献
8.
9.
Amanda LaCoste Karen M. Schaich David Zumbrunnen Kit L. Yam 《Packaging Technology and Science》2005,18(2):77-87
Researchers from Rutgers University and Clemson University have collaborated to develop a concept of using smart blending to generate functional packaging films for the controlled release of active compounds such as antimicrobials, antioxidants and flavour compounds to extend the shelf‐life of food. In this paper, literature results are reviewed to justify the significance of controlled release packaging (CRP) and the research gaps for further development are identified. A major research gap is the lack of packaging materials that can provide the release of active compounds at rates suitable for a wide range of food packaging applications. Smart blending is a promising technology for bridging this research gap. To fully realize the potentials of smart blending, a systematic approach for developing CRP using smart blending is also presented. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
10.