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   481643篇
  免费   8609篇
  国内免费   2617篇
电工技术   9091篇
技术理论   5篇
综合类   1356篇
化学工业   74946篇
金属工艺   17863篇
机械仪表   13982篇
建筑科学   12655篇
矿业工程   2178篇
能源动力   12015篇
轻工业   50496篇
水利工程   4761篇
石油天然气   7691篇
武器工业   250篇
无线电   55979篇
一般工业技术   88779篇
冶金工业   89739篇
原子能技术   8303篇
自动化技术   42780篇
  2021年   4178篇
  2020年   3085篇
  2019年   3765篇
  2018年   5940篇
  2017年   5925篇
  2016年   6487篇
  2015年   4983篇
  2014年   7958篇
  2013年   22383篇
  2012年   13753篇
  2011年   18616篇
  2010年   14692篇
  2009年   16061篇
  2008年   17181篇
  2007年   17266篇
  2006年   15484篇
  2005年   13720篇
  2004年   12749篇
  2003年   12292篇
  2002年   11821篇
  2001年   12153篇
  2000年   11180篇
  1999年   11669篇
  1998年   27404篇
  1997年   19637篇
  1996年   14916篇
  1995年   11266篇
  1994年   10083篇
  1993年   9854篇
  1992年   7290篇
  1991年   6919篇
  1990年   6852篇
  1989年   6604篇
  1988年   6326篇
  1987年   5259篇
  1986年   5177篇
  1985年   6139篇
  1984年   5732篇
  1983年   5274篇
  1982年   4738篇
  1981年   5010篇
  1980年   4568篇
  1979年   4625篇
  1978年   4377篇
  1977年   4830篇
  1976年   6230篇
  1975年   3811篇
  1974年   3603篇
  1973年   3680篇
  1972年   3013篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
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   
2.
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   
3.
4.
5.
6.
7.
8.
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   
9.
The viability and β‐galactosidase activity of four Lactobacillus strains in milk drink containing gums during 28 days of refrigerated storage at 4 °C were assessed. The population of Lactobacillus rhamnosus GGB101 and Lactobacillus rhamnosus GGB103 were maintained, whereas the population of Lactobacillus reuteri DSM20016 and Lactobacillus reuteri SD2112 significantly decreased. The recommended level of 6 log CFU g?1 was exceeded for all tested trains throughout storage. The highest viable number of Lactobacillus rhamnosus GGB103 (8.76 ± 0.03 log CFU mL?1) was obtained in the product containing carrageenan–maltodextrin. The addition of guar–locust bean–carrageenan led to 20‐fold increase in the level of β‐galactosidase activity for L. rhamnosus GGB101 (1208 ± 2.12 Miller units mL?1) compared to the control (61 ± 2.83 Miller units mL?1). Our results suggested that gums could be added to milk to improve viability and enhance β‐galactosidase activity of Lactobacillus.  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