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   67963篇
  免费   3570篇
  国内免费   98篇
电工技术   574篇
综合类   100篇
化学工业   13072篇
金属工艺   1282篇
机械仪表   1421篇
建筑科学   2100篇
矿业工程   147篇
能源动力   1488篇
轻工业   10439篇
水利工程   687篇
石油天然气   323篇
武器工业   5篇
无线电   3564篇
一般工业技术   11620篇
冶金工业   15393篇
原子能技术   313篇
自动化技术   9103篇
  2024年   127篇
  2023年   619篇
  2022年   734篇
  2021年   1669篇
  2020年   1389篇
  2019年   1432篇
  2018年   2637篇
  2017年   2622篇
  2016年   2678篇
  2015年   1997篇
  2014年   2502篇
  2013年   5029篇
  2012年   4074篇
  2011年   3782篇
  2010年   3030篇
  2009年   2739篇
  2008年   2980篇
  2007年   2634篇
  2006年   1932篇
  2005年   1566篇
  2004年   1489篇
  2003年   1391篇
  2002年   1283篇
  2001年   911篇
  2000年   818篇
  1999年   975篇
  1998年   4989篇
  1997年   3110篇
  1996年   1991篇
  1995年   1154篇
  1994年   946篇
  1993年   958篇
  1992年   316篇
  1991年   314篇
  1990年   307篇
  1989年   280篇
  1988年   291篇
  1987年   243篇
  1986年   252篇
  1985年   283篇
  1984年   248篇
  1983年   168篇
  1982年   200篇
  1981年   231篇
  1980年   216篇
  1979年   161篇
  1978年   151篇
  1977年   305篇
  1976年   626篇
  1975年   126篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
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   
2.
3.
4.
5.
6.
7.
8.
9.
ABSTRACT

In this paper, we review some algebraic control system. Precisely, linear and bilinear systems on Euclidean spaces and invariant and linear systems on Lie groups. The fourth classes of systems have a common issue: to any class, there exists an associated subgroup. From this object, we survey the controllability property. Especially, from those coming from our contribution to the theory.  相似文献   
10.
Context: The administration of pharmabiotics is a promising alternative to antimicrobial drugs for the treatment and/or prevention of female urogenital infections.

Objective: To design pharmabiotic formulations including bioactive ingredients of microbial origin combined with non-microbial substances and then to evaluate the stability of the combinations during freeze-drying and storage.

Materials and methods: Different formulations including Lactobacillus gasseri CRL 1263, Lactobacillus salivarius CRL 1328, salivaricin CRL 1328 (a bacteriocin) and non-microbial compounds (lactose, inulin and ascorbic acid) were assayed, and the ingredients were freeze-dried together or separately. The formulations were stored in gelatin capsules at 4?°C for 360?d.

Results: The viability of lactobacilli was affected to different extents depending on the strains and on the formulations assayed. L. salivarius and ascorbic acid were successfully combined only after the freeze-drying process. Salivaricin activity was not detected in formulations containing L. gasseri. However, when combined with ascorbic acid, lactose, inulin or L. salivarius, the bacteriocin maintained its activity for 360?d. The selected microorganisms proved to be compatible for their inclusion in multi-strain formulations together with lactose, inulin and ascorbic acid. Salivaricin could be included only in a L. salivarius CRL 1328 single-strain formulation together with non-microbial substances.

Conclusions: This study provides new insights into the design of urogenital pharmabiotics combining beneficial lactobacilli, salivaricin CRL 1328 and compounds with different functionalities.  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