首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   58080篇
  免费   19550篇
  国内免费   99篇
电工技术   3001篇
综合类   431篇
化学工业   22138篇
金属工艺   711篇
机械仪表   1951篇
建筑科学   2754篇
矿业工程   203篇
能源动力   1869篇
轻工业   7599篇
水利工程   513篇
石油天然气   297篇
武器工业   19篇
无线电   9614篇
一般工业技术   17165篇
冶金工业   1068篇
原子能技术   52篇
自动化技术   8344篇
  2024年   11篇
  2023年   17篇
  2022年   41篇
  2021年   425篇
  2020年   2838篇
  2019年   5495篇
  2018年   4975篇
  2017年   5498篇
  2016年   5361篇
  2015年   5182篇
  2014年   5204篇
  2013年   5530篇
  2012年   4653篇
  2011年   4324篇
  2010年   3540篇
  2009年   3123篇
  2008年   3107篇
  2007年   2945篇
  2006年   2772篇
  2005年   2301篇
  2004年   2082篇
  2003年   2001篇
  2002年   1936篇
  2001年   1651篇
  2000年   1462篇
  1999年   858篇
  1998年   95篇
  1997年   84篇
  1996年   52篇
  1995年   53篇
  1994年   29篇
  1993年   16篇
  1992年   17篇
  1991年   12篇
  1990年   7篇
  1989年   6篇
  1988年   7篇
  1986年   8篇
  1984年   2篇
  1982年   2篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1965年   1篇
  1963年   1篇
  1957年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
This paper considers a novel distributed iterative learning consensus control algorithm based on neural networks for the control of heterogeneous nonlinear multiagent systems. The system's unknown nonlinear function is approximated by suitable neural networks; the approximation error is countered by a robust term in the control. Two types of control algorithms, both of which utilize distributed learning laws, are provided to achieve consensus. In the provided control algorithms, the desired reference is considered to be an unknown factor and then estimated using the associated learning laws. The consensus convergence is proven by the composite energy function method. A numerical simulation is ultimately presented to demonstrate the efficacy of the proposed control schemes.  相似文献   
43.
44.
45.
This paper introduces two novel nonlinear stochastic attitude estimators developed on the Special Orthogonal Group with the tracking error of the normalized Euclidean distance meeting predefined transient and steady‐state characteristics. The tracking error is confined to initially start within a predetermined large set such that the transient performance is guaranteed to obey dynamically reducing boundaries and decrease smoothly and asymptotically to the origin in probability from almost any initial condition. The proposed estimators produce accurate attitude estimates with remarkable convergence properties using measurements obtained from low‐cost inertial measurement units. The estimators proposed in continuous form are complemented by their discrete versions for the implementation purposes. The simulation results illustrate the effectiveness and robustness of the proposed estimators against uncertain measurements and large initialization error, whether in continuous or discrete form.  相似文献   
46.
In this study, we have proposed an automated classification approach to identify meaningful patterns in wind field data. Utilizing an extensive simulated wind database, we have demonstrated that the proposed approach can identify low‐level jets, near‐uniform profiles, and other patterns in a reliable manner. We have studied the dependence of these wind profile patterns on locations (eg, offshore vs onshore), seasons, and diurnal cycles. Furthermore, we have found that the probability distributions of some of the patterns depend on the underlying planetary boundary layer schemes in a significant way. The future potential of the proposed approach in wind resource assessment and, more generally, in mesoscale model parameterization improvement is touched upon in this paper.  相似文献   
47.
48.
Consumer studies and market reports show an increase in consumption of ready‐to‐eat (RTE) foods. Although conventional processing technologies can in most cases produce safe products, they can also lead to the degradation of nutritional compounds and negatively affect quality characteristics. Consumers strongly prefer food that is minimally processed with the maximum amount of health‐promoting substances. Novel processing technologies as pre‐ or post‐treatment decontamination methods or as substitutes of conventional technologies have the potential to produce foods that are safe, rich in nutrient content and with superior organoleptic properties. Combining novel with conventional processes can eliminate potential drawbacks of novel technologies. This review examines available scientific information and critically evaluates the suitability and efficiency of various novel thermal and nonthermal technologies in terms of microbial safety, quality as well as nutrient content on the production of RTE meals, meats and pumpable products.  相似文献   
49.
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号