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   448685篇
  免费   7979篇
  国内免费   1404篇
电工技术   7889篇
综合类   348篇
化学工业   71494篇
金属工艺   17137篇
机械仪表   14463篇
建筑科学   9925篇
矿业工程   2245篇
能源动力   12499篇
轻工业   36821篇
水利工程   4682篇
石油天然气   8083篇
武器工业   22篇
无线电   51275篇
一般工业技术   90401篇
冶金工业   81990篇
原子能技术   9339篇
自动化技术   39455篇
  2022年   3755篇
  2021年   5679篇
  2020年   4023篇
  2019年   4978篇
  2018年   8226篇
  2017年   8171篇
  2016年   8793篇
  2015年   5794篇
  2014年   8979篇
  2013年   23548篇
  2012年   14272篇
  2011年   18109篇
  2010年   14334篇
  2009年   15731篇
  2008年   16073篇
  2007年   15641篇
  2006年   13770篇
  2005年   12195篇
  2004年   11530篇
  2003年   11301篇
  2002年   10664篇
  2001年   10296篇
  2000年   9655篇
  1999年   10060篇
  1998年   26236篇
  1997年   18110篇
  1996年   13736篇
  1995年   10121篇
  1994年   8856篇
  1993年   8927篇
  1992年   6309篇
  1991年   5935篇
  1990年   5858篇
  1989年   5499篇
  1988年   5232篇
  1987年   4577篇
  1986年   4455篇
  1985年   4984篇
  1984年   4571篇
  1983年   4115篇
  1982年   3798篇
  1981年   3899篇
  1980年   3593篇
  1979年   3437篇
  1978年   3435篇
  1977年   4020篇
  1976年   5413篇
  1975年   2912篇
  1974年   2720篇
  1973年   2802篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
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   
2.
3.
In this study, amaranth flour was used as an ingredient to prepare gluten-free cookies. The production process and attributes of amaranth cookies were characterised, and the potential use of amaranth flour as a functional ingredient was analysed. Cookies exhibited a non-uniform reddish brown colour and a cookie factor ratio of 4.5 ± 0.6. Storage studies indicated that after 3 weeks at room temperature cookies presented slight variations in the texture. Simulated gastrointestinal digestion of this product was able to release peptides capable of exerting potential antithrombotic and antihypertensive activities, IC50 values of 0.22 ± 0.04 and 0.23 ± 0.03 mg mL−1 protein, respectively. This work demonstrates for the first time that food made with amaranth flour exerts potential antithrombotic and antihypertensive activity. In conclusion, these amaranth cookies could be an alternative way of incorporating potentially health beneficial products for people who choose a conscious diet, including coeliac or vegan consumers.  相似文献   
4.
5.
6.
7.
8.
9.
10.
Lobster krill (Munida genus) represents an under‐valued crustacean frequently caught on European fishing banks. In this work, its sensory, microbiological and biochemical qualities were evaluated during chilled storage. Additionally, the effects of a prestorage antimelanosic treatment consisting of soaking in sodium metabisulphite (SMB) solutions at two different concentrations (0.25% and 0.75%) were also studied. SMB prestorage treatment provided lobster specimens that still exhibited acceptable sensory quality after 10 days of storage, while control specimens were unacceptable at that time. SMB treatment also resulted in a significant (P < 0.05) inhibition of microbial growth, mainly of Enterobacteriaceae, psychrotrophes and proteolytic bacteria. Low lipid oxidation levels were observed for all batches; however, a significantly higher (P < 0.05) retention of polyunsaturated fatty acids was found in SMB‐treated lobster, especially in the 0.75% SMB batch. The results presented here open the way to the potential commercialisation of currently under‐utilised lobster krill as a chilled product.  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