首页 | 官方网站   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   44163篇
  免费   2199篇
  国内免费   57篇
工业技术   46419篇
  2024年   85篇
  2023年   390篇
  2022年   835篇
  2021年   1308篇
  2020年   955篇
  2019年   1068篇
  2018年   1569篇
  2017年   1563篇
  2016年   1684篇
  2015年   1329篇
  2014年   1655篇
  2013年   3296篇
  2012年   2594篇
  2011年   2788篇
  2010年   2171篇
  2009年   2046篇
  2008年   1945篇
  2007年   1706篇
  2006年   1295篇
  2005年   1134篇
  2004年   1049篇
  2003年   959篇
  2002年   846篇
  2001年   613篇
  2000年   573篇
  1999年   640篇
  1998年   2813篇
  1997年   1797篇
  1996年   1215篇
  1995年   669篇
  1994年   554篇
  1993年   556篇
  1992年   187篇
  1991年   177篇
  1990年   133篇
  1989年   156篇
  1988年   158篇
  1987年   147篇
  1986年   116篇
  1985年   152篇
  1984年   114篇
  1983年   79篇
  1982年   89篇
  1981年   106篇
  1980年   109篇
  1979年   56篇
  1977年   187篇
  1976年   373篇
  1975年   57篇
  1973年   61篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
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   
7.
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   
8.
9.
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-23

京公网安备 11010802026262号