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   13058篇
  免费   218篇
  国内免费   4篇
电工技术   164篇
综合类   5篇
化学工业   1364篇
金属工艺   345篇
机械仪表   153篇
建筑科学   216篇
矿业工程   8篇
能源动力   172篇
轻工业   503篇
水利工程   24篇
石油天然气   13篇
无线电   548篇
一般工业技术   763篇
冶金工业   160篇
原子能技术   128篇
自动化技术   8714篇
  2024年   8篇
  2023年   38篇
  2022年   181篇
  2021年   213篇
  2020年   98篇
  2019年   113篇
  2018年   150篇
  2017年   136篇
  2016年   189篇
  2015年   111篇
  2014年   373篇
  2013年   461篇
  2012年   1030篇
  2011年   2582篇
  2010年   1308篇
  2009年   1178篇
  2008年   886篇
  2007年   751篇
  2006年   627篇
  2005年   712篇
  2004年   619篇
  2003年   663篇
  2002年   345篇
  2001年   58篇
  2000年   56篇
  1999年   53篇
  1998年   40篇
  1997年   32篇
  1996年   34篇
  1995年   39篇
  1994年   19篇
  1993年   22篇
  1992年   9篇
  1991年   15篇
  1990年   10篇
  1989年   11篇
  1988年   7篇
  1987年   7篇
  1986年   8篇
  1985年   9篇
  1984年   10篇
  1983年   6篇
  1982年   16篇
  1981年   11篇
  1980年   5篇
  1979年   8篇
  1978年   7篇
  1977年   4篇
  1976年   3篇
  1973年   3篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
The patterning of contact holes by selecting out-of-focus image plane (defocus) using attenuated phase shift masks (APSM) has been studied. Defocus is found to enhance the image modulation at low partial coherence for contact holes with negative local average of mask function. Semi-dense holes up to 130 nm in 8% APSM have been printed by 0.5 μm defocus at a partial coherence of 0.31 using KrF scanner with highest numerical aperture of 0.68. However, these holes were closed with in-focus imaging. Defocus is also found to be beneficial for patterning the pitches that have extensive side lobes with in-focus imaging.  相似文献   
2.
This paper assesses the impacts of a GTL plant on the expansion of Brazil's oil refining segment. The GTL plant (50,000 bpd) was sized to start up operations in 2015, producing diesel and naphtha through the indirect route (FT-synthesis). This plant will consume the non-associated natural gas production from the recent discoveries at the Santos Basin (around 419 Bm3), and the associated gas production from the Campos Basin. Both basins are located in the Southeast of Brazil, the most populated, rich and industrialized region of the country. Two different criteria for refinery expansion were simulated in order to meet oil product demand scenarios. Findings show that depending on the refinery expansion criteria considered GTL will play a fundamental hole to meet the oil product demand forecast to Brazil in the next 10 years.  相似文献   
3.
An unexpected experimental finding is reported where the primary morphology developed during polymerization-induced phase separation in a rubber-modified thermoplastic practically disappears at high conversions. This process was evidenced by light scattering (LS) and scanning electron microscopy (SEM) for a particular composition of solutions of polyisobutylene oligomers (PIB) in isobornylmethacrylate (IBoMA), during the free-radical polymerization of the monomer. The primary phase separation produced a dispersion of domains rich in PIB containing significant amounts of the monomer (IBoMA). Polymerization of the monomer in these domains occurred at high overall conversions producing the filling of dispersed domains with a PIBoMA-PIB blend that could not be distinguished from the matrix. Under these conditions the final material had the appearance of a homogeneous blend.  相似文献   
4.
This letter presents a novel approach for organizing computational resources into groups within H.264/AVC motion estimation architectures, leading to reductions of up to 75% in the equivalent gate count with respect to state‐of‐the‐art designs.  相似文献   
5.
6.
7.
This paper proposes a frequency domain algorithm for Wiener model identifications based on exploring the fundamental frequency and harmonics generated by the unknown nonlinearity. The convergence of the algorithm is established in the presence of white noise. No a priori knowledge of the structure of the nonlinearity is required and the linear part can be nonparametric.  相似文献   
8.
Hydrogenated and chlorinated silicon films were used to deposit Schottky barrier solar cells. Photovoltaic characterization, together with the results of electronic transport measurements, led to the conclusion that the presence of chlorine is detrimental to the properties of this kind of device.  相似文献   
9.
Years have lapsed since the inauguration of the first Wireless Application Protocol (WAP) application. One of the main reasons for the lukewarm response so far may be attributed to the lack of a “Killer” application. Many companies and developers have attempted to replicate email services (an Internet Killer appplication) within the WAP realm, but till now, no significant success has been reported. This paper will first discuss on the key functions which are lacking in the present WAP-email service, and which are arguably necessary if a much larger user base is to be attracted to these services. A new system will be proposed which can enable the user to send files residing in a remote personal computer (PC) as attachments to his emails using WAP-enabled mobile devices. The implementation of the system will be presented in details. Issue relating to the connection to various types of email servers and the security of the system will also be addressed in the paper.  相似文献   
10.
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