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   1443320篇
  免费   25641篇
  国内免费   6918篇
电工技术   33939篇
综合类   6361篇
化学工业   267791篇
金属工艺   63369篇
机械仪表   40485篇
建筑科学   45043篇
矿业工程   11241篇
能源动力   50081篇
轻工业   105833篇
水利工程   14408篇
石油天然气   37241篇
武器工业   129篇
无线电   194306篇
一般工业技术   274410篇
冶金工业   130937篇
原子能技术   33703篇
自动化技术   166602篇
  2021年   15458篇
  2020年   11723篇
  2019年   14505篇
  2018年   13996篇
  2017年   13231篇
  2016年   20410篇
  2015年   17125篇
  2014年   28506篇
  2013年   87423篇
  2012年   33646篇
  2011年   44824篇
  2010年   40800篇
  2009年   49552篇
  2008年   42334篇
  2007年   39221篇
  2006年   43414篇
  2005年   37670篇
  2004年   40306篇
  2003年   40353篇
  2002年   39651篇
  2001年   36079篇
  2000年   34765篇
  1999年   33176篇
  1998年   33984篇
  1997年   32732篇
  1996年   31255篇
  1995年   28440篇
  1994年   26989篇
  1993年   26732篇
  1992年   25728篇
  1991年   22726篇
  1990年   23154篇
  1989年   22179篇
  1988年   20729篇
  1987年   19067篇
  1986年   18414篇
  1985年   21796篇
  1984年   22188篇
  1983年   20111篇
  1982年   19117篇
  1981年   19160篇
  1980年   17753篇
  1979年   18442篇
  1978年   17669篇
  1977年   17054篇
  1976年   17534篇
  1975年   15922篇
  1974年   15493篇
  1973年   15550篇
  1972年   13039篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
This paper presents part of the work ComEd and Quanta Technology have performed to quantify the locational and temporal value of DER to avoid distribution grid upgrade investments. It focuses on the formulation of a robust and efficient algorithm for DER optimal dispatch on a distribution feeder to mitigate the violation of current and voltage limits using the allocated cost of capacity and locational marginal value of real and reactive DER injection/withdrawal.  相似文献   
2.
3.
In this paper, we present a novel memory access reduction scheme (MARS) for two-dimension fast cosine transform (2-D FCT). It targets programmable DSPs with high memory-access latency. It reduces the number of memory accesses by: 1) reducing the number of weighting factors and 2) combining butterflies in vector-radix 2-D FCT pruning diagram from two stages to one stage with an efficient structure. Hardware platform based on general purpose processor is used to verify the effectiveness of the proposed method for vector-radix 2-D FCT pruning implementation. Experimental results validate the benefits of the proposed method with reduced memory access, less clock cycle and fewer memory space compared with the conventional implementation.  相似文献   
4.
5.
6.
One specific class of non-linear evolution equations, known as the Tzitzéica-type equations, has received great attention from a group of researchers involved in non-linear science. In this article, new exact solutions of the Tzitzéica-type equations arising in non-linear optics, including the Tzitzéica, Dodd–Bullough–Mikhailov and Tzitzéica–Dodd–Bullough equations, are obtained using the expa function method. The integration technique actually suggests a useful and reliable method to extract new exact solutions of a wide range of non-linear evolution equations.  相似文献   
7.
ABSTRACT

Bacteriocin is a proteinaceous biomolecule produced by bacteria (both Gram-positive and Gram-negative) that exhibits antimicrobial activity against closely related species, and food-borne pathogens. It has recently gained importance and attracted the attention of several researchers looking to produce it from various substrates and bacterial strains. This ushers in a new era of food preservation where the use of bacteriocin in food products will be an alternative to chemical preservatives, and heat treatment which are understood to cause unwanted side effects, and reduce sensory and nutritional quality. However, this new market depends on the success of novel downstream separation schemes from various types of crude feedstocks which are both effective and economic. This review focuses on the downstream separation of bacteriocin from various sources using both conventional and novel techniques. Finally, recommendations for future interesting areas of research that need to be pursued are highlighted.  相似文献   
8.
9.
This study aimed to evaluate the physicochemical characteristics and sensory attributes of beef burgers with the addition of pea fibre as a partial substitute of meat or fat. Three formulations were prepared: control (CON) – similar to the commercial formulation; fibre/less meat (FLM)—5% meat reduction and addition of 1% pea fibre; fibre/less fat (FLF)—7% fat reduction and addition of 1% pea fibre. Non-significant differences were obtained for pH, colour parameters (L* and b*), texture profile, cooking loss and size reduction among formulations. Moreover, sensory analysis with consumers of beef burgers did not indicate differences among the formulations for all the analysed attributes. Therefore, pea fibre is a promising partial replacer for meat and fat in beef burgers due to the preservation of technological parameters and sensory acceptance.  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