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   2040篇
  免费   103篇
  国内免费   2篇
电工技术   29篇
综合类   1篇
化学工业   560篇
金属工艺   48篇
机械仪表   38篇
建筑科学   65篇
矿业工程   2篇
能源动力   44篇
轻工业   194篇
水利工程   4篇
石油天然气   18篇
无线电   137篇
一般工业技术   392篇
冶金工业   254篇
原子能技术   17篇
自动化技术   342篇
  2024年   4篇
  2023年   23篇
  2022年   61篇
  2021年   77篇
  2020年   34篇
  2019年   37篇
  2018年   68篇
  2017年   59篇
  2016年   82篇
  2015年   50篇
  2014年   74篇
  2013年   143篇
  2012年   127篇
  2011年   154篇
  2010年   83篇
  2009年   119篇
  2008年   109篇
  2007年   102篇
  2006年   81篇
  2005年   51篇
  2004年   56篇
  2003年   53篇
  2002年   41篇
  2001年   29篇
  2000年   30篇
  1999年   23篇
  1998年   44篇
  1997年   30篇
  1996年   39篇
  1995年   24篇
  1994年   25篇
  1993年   13篇
  1992年   16篇
  1991年   9篇
  1990年   14篇
  1989年   14篇
  1988年   9篇
  1987年   15篇
  1986年   8篇
  1985年   17篇
  1984年   10篇
  1983年   17篇
  1982年   8篇
  1981年   8篇
  1979年   7篇
  1978年   5篇
  1977年   11篇
  1976年   12篇
  1975年   4篇
  1973年   5篇
排序方式: 共有2145条查询结果,搜索用时 15 毫秒
11.
Identification of the reasons for failures of process plant machines is the first step in obtaining increased reliability. Weibull analysis of the service life obtained from maintenance records requires a minimum of only five incidents and provides an insight into the failure mechanism. Two examples are given where Weibull analysis of maintenance records helped identify the cause of failure and was instrumental in achieving enhanced reliability of process plant machines.  相似文献   
12.
The case of a child who presented with severe rhabdomyolysis associated with renal failure after a viper bite is reported. Rhabdomyolysis is a serious complication resulting from systemic envenomation and is uncommon after viper bites in Europe. It may be due to oedema, myotoxic agents and haemorrhagic factors and may be responsible for two types of potentially fatal complications, i.e. acute renal failure and hyperkalaemia. The present case highlights the need to investigate routinely for rhabdomyolysis after viper bites. Antivenom therapy is recommended as soon as signs of envenomation are present, without waiting for the onset of complications.  相似文献   
13.
We present a multimodal document alignment framework, which highlights existing alignment relationships between documents that are discussed and recorded during multimedia events such as meetings. These relationships that should help indexing the archives of these events are detected using various techniques from natural language processing and information retrieval. The main alignment strategies studied are based on thematic, quotation and reference relationships. At the analysis level, the alignment framework was applied at several levels of granularity of documents, requiring specific document segmentation techniques. Our framework that is language independent was evaluated on corpora in French and English, including meetings and scientific presentations. The satisfactory evaluation results obtained at several stages show the importance of our approach in bridging the gap between meeting documents, independently from the language and domain. They highlight also the utility of the multimodal alignment in advanced applications, e.g. multimedia document browsing, content-based / temporal-based searching, etc.  相似文献   
14.
Boolean functions that have constant degree polynomial representation over a fixed finite ring form a natural and strict subclass of the complexity class ACC0. They are also precisely the functions computable efficiently by programs over fixed and finite nilpotent groups. This class is not known to be learnable in any reasonable learning model. In this paper, we provide a deterministic polynomial time algorithm for learning Boolean functions represented by polynomials of constant degree over arbitrary finite rings from membership queries, with the additional constraint that each variable in the target polynomial appears in a constant number of monomials. Our algorithm extends to superconstant but low degree polynomials and still runs in quasipolynomial time.  相似文献   
15.
Vapor-liquid equilibrium compositions have been measured for the argon-methane system at 115.2°, 123.4° and 137.1°K, by means of a forced-recirculation apparatus. A modified Redlich-Kwong equation of state with the incorporation of a binary interaction constant has been successfully employed to represent the data. Liquid activity coefficients have been evaluated and correlated.  相似文献   
16.
An efficient, reliable and easily programmed method for solving systems of equilibrium stage separation devices is described. The method is an extension of an algorithm developed by Ishii and Otto(9) for single columns. It solves all equations simultaneously, takes advantage of the basic tridiagonal matrix form form of the linearized steady state equations and can handle configurations which include distillation columns, absorbers and reboiled absorbers. The solution for a thermally coupled distillation system is presented.  相似文献   
17.
Denis  R.  Madhubala  P. 《Multimedia Tools and Applications》2021,80(14):21165-21202
Multimedia Tools and Applications - The exponential rise in the development of cloud computing environments in the healthcare field, the protection and confidentiality of the medical records become...  相似文献   
18.
Language Resources and Evaluation - This report presents a corpus of articulations recorded with Schlieren photography, a recording technique to visualize aeroflow dynamics for two purposes. First,...  相似文献   
19.
Low cycle fatigue behaviour of a steel 55NiCrMoV7 under tour tempered conditions is reported. One special type of total swain controlled isothermal cyclic deformation tests were performed in the temperature range 20℃ to 600℃ for the steel tempered 2h at 350℃, 460℃, 560℃ and 600℃. The influence of temperature on cyclic behaviour was investigated. Generally, the cyclic stress response shows an initial exponential softening for the first few cycles, followed by a gradual softening without cyclic softening saturatioo. At 10^-2 strain rate, σmax.Δσ/2 decrease with the test tumperature for all hardness levels. They decrease linearly with tempering temperature when testing temperature is lower than that of tempering, but rest nearly constant when test temperature is equal to or exceed tempering temperature of steel. Cyclic softening intensity increases with testing temperature from 300℃ to 600℃, but the maximal softening intensity occurs at room tumpemture. The strain rate influences notably the cyclic behavioor when T≥50℃, The time dependence of cyclic behaviour is closely related to test temperature and the tempering history of the steel.  相似文献   
20.
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