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   1603707篇
  免费   37138篇
  国内免费   12851篇
电工技术   42164篇
技术理论   9篇
综合类   14901篇
化学工业   289349篇
金属工艺   70519篇
机械仪表   50053篇
建筑科学   54693篇
矿业工程   14670篇
能源动力   53330篇
轻工业   117858篇
水利工程   17396篇
石油天然气   43331篇
武器工业   1183篇
无线电   209543篇
一般工业技术   294779篇
冶金工业   159675篇
原子能技术   35591篇
自动化技术   184652篇
  2022年   14273篇
  2021年   20953篇
  2020年   15830篇
  2019年   17762篇
  2018年   19772篇
  2017年   19641篇
  2016年   24935篇
  2015年   22072篇
  2014年   34394篇
  2013年   94512篇
  2012年   42822篇
  2011年   55811篇
  2010年   49692篇
  2009年   58016篇
  2008年   51055篇
  2007年   47858篇
  2006年   49952篇
  2005年   44182篇
  2004年   44731篇
  2003年   44571篇
  2002年   43699篇
  2001年   40037篇
  2000年   37981篇
  1999年   36613篇
  1998年   43606篇
  1997年   38798篇
  1996年   35459篇
  1995年   31270篇
  1994年   29218篇
  1993年   28762篇
  1992年   26546篇
  1991年   23479篇
  1990年   23720篇
  1989年   22795篇
  1988年   21149篇
  1987年   19388篇
  1986年   18725篇
  1985年   22047篇
  1984年   22239篇
  1983年   20199篇
  1982年   19221篇
  1981年   19315篇
  1980年   17961篇
  1979年   18458篇
  1978年   17664篇
  1977年   17374篇
  1976年   18065篇
  1975年   15934篇
  1974年   15440篇
  1973年   15529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.
4.
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   
5.
6.
7.
Qin  Yi  Tao  Xianping  Huang  Yu    Jian 《World Wide Web》2019,22(1):1-37
World Wide Web - Rule mechanism has been widely used in many areas, such as databases, artificial intelligent and pervasive computing. In a rule mechanism, rule activation decides which rules are...  相似文献   
8.
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   
9.
10.
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   
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