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   1478819篇
  免费   25847篇
  国内免费   7016篇
电工技术   34312篇
综合类   6510篇
化学工业   269488篇
金属工艺   63788篇
机械仪表   41973篇
建筑科学   45528篇
矿业工程   11419篇
能源动力   50170篇
轻工业   109930篇
水利工程   14802篇
石油天然气   37512篇
武器工业   186篇
无线电   195814篇
一般工业技术   280169篇
冶金工业   148018篇
原子能技术   33885篇
自动化技术   168178篇
  2021年   15505篇
  2020年   11804篇
  2019年   14557篇
  2018年   15347篇
  2017年   14677篇
  2016年   21027篇
  2015年   17270篇
  2014年   28609篇
  2013年   87586篇
  2012年   34680篇
  2011年   46756篇
  2010年   41880篇
  2009年   50358篇
  2008年   43793篇
  2007年   40798篇
  2006年   44160篇
  2005年   38712篇
  2004年   40969篇
  2003年   40955篇
  2002年   40063篇
  2001年   36827篇
  2000年   35343篇
  1999年   34115篇
  1998年   40018篇
  1997年   36239篇
  1996年   33435篇
  1995年   29677篇
  1994年   27974篇
  1993年   27816篇
  1992年   26066篇
  1991年   23096篇
  1990年   23404篇
  1989年   22414篇
  1988年   20957篇
  1987年   19302篇
  1986年   18684篇
  1985年   21991篇
  1984年   22284篇
  1983年   20248篇
  1982年   19200篇
  1981年   19270篇
  1980年   17849篇
  1979年   18479篇
  1978年   17699篇
  1977年   17187篇
  1976年   17735篇
  1975年   15965篇
  1974年   15539篇
  1973年   15589篇
  1972年   13040篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
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   
33.
34.
Metallurgical and Materials Transactions A - The influence of the chemical composition on the crystallization process, amorphous phase formation, and the anticorrosion properties of Al-Zr-Ni-Fe-Y...  相似文献   
35.
Powder Metallurgy and Metal Ceramics - The infiltration of aluminum melts into porous metal skeletons produced by powder metallurgy methods, including 3D printing, under a pressure gradient was...  相似文献   
36.
37.
38.
Here we report some recent biophysical issues on the preparation of solute-filled lipid vesicles and their relevance to the construction of “synthetic cells.” First, we introduce the “semi-synthetic minimal cells” as the liposome-based cell-like systems, which contain a minimal number of biomolecules required to display simple and complex biological functions. Next, we focus on recent aspects related to the construction of synthetic cells. Emphasis is given to the interplay between the methods of synthetic cell preparation and the physics of solute encapsulation. We briefly introduce the notion of structural and compositional “diversity” in synthetic cell populations.  相似文献   
39.
40.
Pinhão seed is an unconventional source of starch and the pines grow up in native forests of southern Latin America. In this study, pinhão starch was adjusted at 15, 20 and 25% moisture content and heated to 100, 110 and 120 °C for 1 h. A decrease in λ max (starch/iodine complex) was observed as a result of increase in temperature and moisture content of HMT. The ratio of crystalline to amorphous phase in pinhão starch was determined via Fourier transform infra red by taking 1045/1022 band ratio. A decrease in crystallinity occurred as a result of HMT. Polarised light microscopy indicated a loss of birefringence of starch granules under 120 °C at 25% moisture content. Granule size distribution was further confirmed via scanning electron microscopy which showed the HMT effects. These results increased the understanding on molecular and structural properties of HMT pinhão starch and broadened its food and nonfood industrial applications.  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