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   1299篇
  免费   108篇
  国内免费   13篇
电工技术   38篇
综合类   6篇
化学工业   305篇
金属工艺   26篇
机械仪表   65篇
建筑科学   64篇
矿业工程   3篇
能源动力   86篇
轻工业   120篇
水利工程   28篇
石油天然气   24篇
无线电   122篇
一般工业技术   196篇
冶金工业   42篇
原子能技术   13篇
自动化技术   282篇
  2024年   7篇
  2023年   41篇
  2022年   48篇
  2021年   93篇
  2020年   85篇
  2019年   95篇
  2018年   124篇
  2017年   122篇
  2016年   97篇
  2015年   59篇
  2014年   95篇
  2013年   153篇
  2012年   85篇
  2011年   89篇
  2010年   53篇
  2009年   41篇
  2008年   27篇
  2007年   19篇
  2006年   20篇
  2005年   7篇
  2004年   10篇
  2003年   8篇
  2002年   2篇
  2001年   3篇
  2000年   3篇
  1999年   5篇
  1998年   6篇
  1997年   7篇
  1996年   3篇
  1995年   1篇
  1994年   3篇
  1992年   1篇
  1991年   3篇
  1988年   1篇
  1987年   1篇
  1985年   1篇
  1977年   2篇
排序方式: 共有1420条查询结果,搜索用时 0 毫秒
1.
International Journal of Control, Automation and Systems - In this paper, a new controllable simulator is proposed and modeled by which, experimental tests of the aircraft’s models can be...  相似文献   
2.
3.
Neural Computing and Applications - Texture analysis is devised to address the weakness of color-based image segmentation models by considering the statistical and spatial relations among the group...  相似文献   
4.
The Journal of Supercomputing - Data center network virtualization is being considered as a promising technology to provide a performance guarantee for cloud computing applications. One important...  相似文献   
5.
6.
Tumor necrosis factor alpha (TNF-alpha) may play a central role in the disease pathogenesis which occurs as a consequence of chlamydial infection. To investigate the importance of TNF-alpha gene promoter polymorphisms and TNF-alpha levels in tear fluid in scarring trachoma, a large matched-pair case-control study was performed in The Gambia. The -308A allele was present in a higher proportion of patients (28.4%) than controls (18.4%), with an increasing association for homozygotes (chi2 for trend, P = 0.032; allele frequency, 0.163 in patients and 0.099 in controls; chi2, P = 0.025). For the -238A allele, the association was similar but not significant. The disease association was highly significant when the number of either -308A or -238A sites in an individual was considered (P = 0.003). TNF-alpha promoter alleles are tightly linked to some HLA class I and II alleles, but multivariate analysis confirmed that the disease associations were independent of HLA, although a class I allele, A*6802, is also associated with disease. TNF-alpha was more frequently detected in tear samples from patients (27.6%) than from controls (15.9%), increasingly so for higher levels of detectable TNF-alpha (P = 0.015). Among patients, detectable TNF-alpha in tears was highly associated with the presence of ocular chlamydial infection (P < 0.001). The results indicate that TNF-alpha plays a major role in the tissue damage and scarring which occurs as a consequence of Chlamydia trachomatis infection.  相似文献   
7.
安南  张申生  胡涛 《计算机工程》2003,29(6):17-18,26
介绍了Cit-CSP--Cit/E-commerce信息安全保障平台子系统,并阐述了它所提供的消息摘要、块加密、加密(公钥)、签名和MAC等功能和服务。  相似文献   
8.

Shear connectors play a prominent role in the design of steel-concrete composite systems. The behavior of shear connectors is generally determined through conducting push-out tests. However, these tests are costly and require plenty of time. As an alternative approach, soft computing (SC) can be used to eliminate the need for conducting push-out tests. This study aims to investigate the application of artificial intelligence (AI) techniques, as sub-branches of SC methods, in the behavior prediction of an innovative type of C-shaped shear connectors, called Tilted Angle Connectors. For this purpose, several push-out tests are conducted on these connectors and the required data for the AI models are collected. Then, an adaptive neuro-fuzzy inference system (ANFIS) is developed to identify the most influencing parameters on the shear strength of the tilted angle connectors. Totally, six different models are created based on the ANFIS results. Finally, AI techniques such as an artificial neural network (ANN), an extreme learning machine (ELM), and another ANFIS are employed to predict the shear strength of the connectors in each of the six models. The results of the paper show that slip is the most influential factor in the shear strength of tilted connectors and after that, the inclination angle is the most effective one. Moreover, it is deducted that considering only four parameters in the predictive models is enough to have a very accurate prediction. It is also demonstrated that ELM needs less time and it can reach slightly better performance indices than those of ANN and ANFIS.

  相似文献   
9.
Mahdi  M. 《Microsystem Technologies》2021,27(8):2913-2917
Microsystem Technologies - In this paper, we propose a simple design for the heating device with ultra-low power consumption. The device is composed of a micro heater made of Nichrome (20/80)...  相似文献   
10.
In real scheduling problems, some disruptions and unexpected events may occur. These disruptions cause the initial schedule to quickly become infeasible and non-optimal. In this situation, an appropriate rescheduling method should be used. In this paper, a new approach has been proposed to achieve stable and robust schedule despite uncertain processing times and unexpected arrivals of new jobs. This approach is a proactive–reactive method which uses a two-step procedure. In the first step an initial robust solution is produced proactively against uncertain processing times using robust optimization approach. This initial robust solution is more insensitive against the fluctuations of processing times in future. In the next step, when an unexpected disruption occurs, an appropriate reactive method is adopted to deal with this unexpected event. In fact, in the second step, the reactive approach determines the best modified sequence after any unexpected disruption based on the classical objective and performance measures. The robustness measure is implemented in the reactive approach to increase the performance of the real schedule after disruption. Computational results indicate that this method produces better solutions in comparison with four classical heuristic approaches according to effectiveness and performance of solutions.  相似文献   
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