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   2184篇
  免费   89篇
  国内免费   26篇
电工技术   64篇
化学工业   456篇
金属工艺   49篇
机械仪表   68篇
建筑科学   36篇
矿业工程   1篇
能源动力   142篇
轻工业   121篇
水利工程   13篇
石油天然气   20篇
无线电   295篇
一般工业技术   475篇
冶金工业   154篇
原子能技术   28篇
自动化技术   377篇
  2024年   5篇
  2023年   28篇
  2022年   93篇
  2021年   82篇
  2020年   83篇
  2019年   60篇
  2018年   109篇
  2017年   81篇
  2016年   63篇
  2015年   49篇
  2014年   92篇
  2013年   176篇
  2012年   106篇
  2011年   132篇
  2010年   96篇
  2009年   99篇
  2008年   99篇
  2007年   82篇
  2006年   57篇
  2005年   63篇
  2004年   57篇
  2003年   27篇
  2002年   42篇
  2001年   32篇
  2000年   17篇
  1999年   27篇
  1998年   56篇
  1997年   55篇
  1996年   18篇
  1995年   19篇
  1994年   24篇
  1993年   19篇
  1992年   15篇
  1991年   15篇
  1990年   14篇
  1989年   14篇
  1988年   18篇
  1987年   16篇
  1986年   8篇
  1985年   26篇
  1984年   13篇
  1983年   8篇
  1982年   15篇
  1981年   22篇
  1980年   11篇
  1979年   8篇
  1978年   7篇
  1977年   8篇
  1976年   6篇
  1973年   5篇
排序方式: 共有2299条查询结果,搜索用时 15 毫秒
1.
Telecommunication Systems - Energy saving in User Equipment (UE) is one of the important issues for limited sources of power in the device. It is critical for the UE to maximize its energy...  相似文献   
2.
Wireless Personal Communications - Recently, the theory of effective rate has attracted much attention, since it can take the delay aspect into account when performing channel capacity analysis. In...  相似文献   
3.
4.
Neural Processing Letters - Part of Speech (POS) tagging is a sequential labelling task and one of the core applications of Natural Language Processing. It has been a challenging problem for the...  相似文献   
5.
We investigate the challenges of building an end-to-end cloud pipeline for real-time intelligent visual inspection system for use in automotive manufacturing. Current methods of visual detection in automotive assembly are highly labor intensive, and thus prone to errors. An automated process is sought that can operate within the real-time constraints of the assembly line and can reduce errors. Components of the cloud pipeline include capture of a large set of high-definition images from a camera setup at the assembly location, transfer and storage of the images as needed, execution of object detection, and notification to a human operator when a fault is detected. The end-to-end execution must complete within a fixed time frame before the next car arrives in the assembly line. In this article, we report the design, development, and experimental evaluation of the tradeoffs of performance, accuracy, and scalability for a cloud system.  相似文献   
6.
One-third of all proteins are estimated to require metals for structural stability and/or catalytic activity. Desthiobiotin probes containing metal binding groups can be used to capture metalloproteins with exposed active-site metals under mild conditions so as to prevent changes in metallation state. The proof-of-concept was demonstrated with carbonic anhydrase (CA), an open active site, Zn2+-containing protein. CA was targeted by using sulfonamide derivatives. Linkers of various lengths and structures were screened to determine the optimal structure for capture of the native protein. The optimized probes could selectively pull down CA from red blood cell lysate and other protein mixtures. Pull-down of differently metallated CAs was also investigated.  相似文献   
7.
In the recent sub-20 nm technology node, the process variability issues have become a major problem for scaling of MOS devices. We present a design for a strained Si/SiGe FinFET on an insulator using a 3D TCAD simulator. The impact of metal gate work function variability (WFV) on electrical parameters is studied. Such impact of WFV for different mole fractions (x) of the SiGe layer in a strained SOI-FinFET with varying grain size is presented. The results show that as the mole fraction is increased, the variability in threshold voltage (σVT) and off current (σIoff) is decreased; while, the variability of on-current (σIon) is increased. A notable observation is the distribution of electrical parameters approaches a normal distribution for smaller grain sizes.  相似文献   
8.
The UV-Visible absorption spectra of virgin and gamma irradiated (20–800 kGy) CR-39 polymer have been deduced by using Shimadzu Double beam Double Monochromator UV-Visible Spectrophotometer (UV-2550). The existence of the peaks, their shifting and broadening as a result of gamma irradiation has been discussed. Finally the indirect and direct band gap in virgin and gamma irradiated CR-39 has been determined. The values of indirect band gap have been found to be lower than the corresponding values of direct band gap.  相似文献   
9.
Analytical model for the transconductance, cut off frequency, transit time and fringing capacitance of LDD MOSFETs is presented with a simple approach. The analysis is carried out considering the LDD device as a conventional MOSFET with a series resistance [Z.-H. Liu et al., Threshold voltage model for submicrometer MOSFETs. IEEE Trans Electron Devices 1993; ED-40: 86–94] and a simple closed form expressions for cut off frequency and transit time is obtained. The total gate capacitance, i.e. the geometric and fringing capacitance, is calculated for both LDD and non-LDD devices and lower fringing capacitance is reported in LDD devices. Lower cut-off frequencies and higher transit time are reported in LDD devices for the same channel length.  相似文献   
10.
长25-29井在完井阶段通井过程中发生粘附卡钻事故,在处理卡钻过程中又发生卡套铣筒、井漏、溢流等事故及复杂情况。通过对井下情况的认真分析,采取先堵漏后循环再解卡的处理方案,顺利地解除了该次卡钻事故,大大地减少了经济损失。  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