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   4086篇
  免费   90篇
  国内免费   15篇
电工技术   54篇
综合类   8篇
化学工业   639篇
金属工艺   119篇
机械仪表   104篇
建筑科学   46篇
矿业工程   15篇
能源动力   176篇
轻工业   181篇
水利工程   30篇
石油天然气   7篇
无线电   551篇
一般工业技术   831篇
冶金工业   1063篇
原子能技术   28篇
自动化技术   339篇
  2024年   10篇
  2023年   41篇
  2022年   67篇
  2021年   156篇
  2020年   80篇
  2019年   84篇
  2018年   121篇
  2017年   85篇
  2016年   101篇
  2015年   73篇
  2014年   110篇
  2013年   208篇
  2012年   130篇
  2011年   182篇
  2010年   144篇
  2009年   154篇
  2008年   141篇
  2007年   110篇
  2006年   111篇
  2005年   86篇
  2004年   64篇
  2003年   69篇
  2002年   57篇
  2001年   61篇
  2000年   65篇
  1999年   78篇
  1998年   349篇
  1997年   177篇
  1996年   131篇
  1995年   100篇
  1994年   98篇
  1993年   96篇
  1992年   61篇
  1991年   68篇
  1990年   59篇
  1989年   39篇
  1988年   36篇
  1987年   43篇
  1986年   38篇
  1985年   33篇
  1984年   31篇
  1983年   20篇
  1982年   28篇
  1981年   15篇
  1980年   27篇
  1979年   21篇
  1978年   10篇
  1977年   28篇
  1976年   56篇
  1973年   8篇
排序方式: 共有4191条查询结果,搜索用时 78 毫秒
1.
Wireless Networks - In Wireless Sensor Networks (WSNs), where power consumption is a huge concern, the improvement of the network’s lifetime is an area of constant study and innovation. The...  相似文献   
2.
Analog Integrated Circuits and Signal Processing - As the 5G era beckons in the world of communication and information technology, there is a surge in demand for battery-operated, mobile wireless...  相似文献   
3.
Multimedia Tools and Applications - Gastrointestinal stromal tumor is one of the critical tumors that doctors do not suggest to get frequent endoscopy, so there is a need for a diagnosis system...  相似文献   
4.
In the present work, two types of shear thickening fluids have been synthesized by using neat and aminosilane functionalized silica nanoparticles and their viscosity curves have been obtained by the rheometer. Based on the values of peak viscosity of synthesized shear thickening fluids, the surface functionalized nanosilica based shear thickening fluid has been chosen as a best candidate due to the high viscosity for impregnation into the neat Kevlar of different layers viz. four (04) and eight (08) layers for velocity impact study. The experimental investigations reveal high energy absorption of shear thickening fluid impregnated Kevlar as compared to the neat Kevlar. The maximum energy absorption 62 J is achieved corresponding to the initial velocity 154 m∙s−1 for 08 layers shear thickening fluid impregnated Kevlar specimen. The data have also been analytically determined and validated with the experimental data. The experimental data have good agreement with the analytical data within the accuracy of around 15 to 20%. The present findings can have significant inferences towards the fabrication of shear thickening fluids using nanomaterials for numerous applications such as soft armors, dampers, nanofinishing and so forth.  相似文献   
5.
Wireless Personal Communications - The ongoing technological developments have totally transformed the lives of human beings. With the emergence of the smart era and the smart city concept, a few...  相似文献   
6.
The demand for food production has been constantly increasing due to rising population. In developed countries, for example, the emergence of regional production of old grains that are rarely utilized, along with the production of commonly consumed grains, has gained importance in recent years. These grains, known collectively as ancient or heirloom grains, have offered both farmers and consumers novel ways of cultivation and products with interesting taste, characteristics and nutritional value. Among the 30 000 plant species known, only five cereals currently provide more than 50% of the world's energy intake – bread wheat (Triticum aestivum), rice (Oryza sativa), sorghum (Sorghum bicolor), millets (Panicum sp.) and maize (Zea mays). The excessive utilization of these selected species has a great potential to cause genetic losses and difficulty in bridging future agricultural demands. Teff (Eragrostis tef), an ancient grain extensively cultivated in countries like Eritrea and Ethiopia, provides promising alternatives for new food uses since its nutritional value is significantly higher than most others cereal grains. The absence of gluten allows flexibility in food utilization since it can be directly substituted to gluten-containing products. The grain also offers an excellent balance of essential amino acids and minerals, which can fulfil the recommended daily intake and eliminates the need for fortification and enrichment. This review provides a general overview of the physical properties and nutritional composition of teff grains related to processing and applications in the food and feed industries. The current status of teff utilization, as well as the challenges in production and commercialization, and future opportunities is presented and discussed.  相似文献   
7.
8.
9.
10.
Multimedia Tools and Applications - Rapid advancement in technology has led to the use of biometric authentication in every field. In particular, from the past few years, iris recognition systems...  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