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   933篇
  免费   51篇
  2022年   3篇
  2021年   10篇
  2020年   2篇
  2019年   8篇
  2018年   9篇
  2017年   9篇
  2016年   21篇
  2015年   19篇
  2014年   29篇
  2013年   73篇
  2012年   77篇
  2011年   53篇
  2010年   38篇
  2009年   42篇
  2008年   55篇
  2007年   55篇
  2006年   57篇
  2005年   61篇
  2004年   45篇
  2003年   50篇
  2002年   60篇
  2001年   12篇
  2000年   7篇
  1999年   10篇
  1998年   9篇
  1997年   12篇
  1996年   16篇
  1995年   14篇
  1994年   11篇
  1993年   6篇
  1992年   13篇
  1991年   8篇
  1990年   6篇
  1989年   4篇
  1988年   6篇
  1987年   4篇
  1986年   6篇
  1985年   11篇
  1984年   8篇
  1983年   3篇
  1982年   6篇
  1981年   4篇
  1980年   3篇
  1979年   2篇
  1978年   2篇
  1977年   7篇
  1976年   5篇
  1974年   6篇
  1973年   2篇
  1972年   2篇
排序方式: 共有984条查询结果,搜索用时 312 毫秒
1.
2.
3.
Nine bacterial strains growing on inulin as the sole carbon and energy source were isolated from soil samples by enrichment culture on a mineral medium. Four of the strains were thermophilic and belong to the genus Bacillus. The thermophilic strains synthesized a β-fructosidase that was active on both inulin and sucrose. The presence of inulin in the culture medium is necessary for enzyme synthesis. Most of the activity on inulin was recovered in the culture medium, and the enzyme was synthesized during cell growth.  相似文献   
4.
5.
6.
Magnesium and Manganese Content of Halophilic Bacteria   总被引:1,自引:0,他引:1       下载免费PDF全文
Magnesium and manganese contents were measured by atomic absorption spectrophotometry in bacteria of several halophilic levels, in Vibrio costicola, a moderately halophilic eubacterium growing in 1 M NaCl, Halobacterium volcanii, a halophilic archaebacterium growing in 2.5 M NaCl, Halobacterium cutirubrum, an extremely halophilic archaebacterium growing in 4 M NaCl, and Escherichia coli, a nonhalophilic eubacterium growing in 0.17 M NaCl. Magnesium and manganese contents varied with the growth phase, being maximal at the early log phase. Magnesium and manganese molalities in cell water were shown to increase with the halophilic character of the logarithmically growing bacteria, from 30 mmol of Mg per kg of cell water and 0.37 mmol of Mn per kg of cell water for E. coli to 102 mmol of Mg per kg of cell water and 1.6 mmol of Mn per kg of cell water for H. cutirubrum. The intracellular concentrations of manganese were determined independently by a radioactive tracer technique in V. costicola and H. volcanii. The values obtained by 54Mn loading represented about 70% of the values obtained by atomic absorption. The increase of magnesium and manganese contents associated with the halophilic character of the bacteria suggests that manganese and magnesium play a role in haloadaptation.  相似文献   
7.
Summary 74 Basidiomycetes have been tested for ligninolytic capability on (14C)lignin-labelled wheat straw. Fifteen strains were selected and rested more accurately for ligninolytic activity and the capacity to degrade wheat straw. The asymptote, inflexion point and degradation rate were determined using a model approach. The fungi exhibited very different responses with respect to lignin biodegradation: high asymptote for Pleurotus ostreatus (77%), low inflexion points for Sporotrichum pulverulentum Nov. (6.1 days) and Pycnoporus spp. (2.7 to 4.7 days) with high and slow degradation rates, respectively (0.91% and 0.45% of 14CO2 release/day). Degradation values for (14C)whole-labelled wheat straw exhibited less variation. Finally, the strains Pleurotus ostreatus, Dichomitus squalens and Bjerkandera adusta showed the highest selectivity of lignin removal.  相似文献   
8.
The formerly unknown microspheric form of Raadshoovenia salentina (Papetti and Tedeschi) and the new genus Cyclopseudedomia (type-species Cyclopseudedomia smouti n.g., n.sp.) are described from limestones of Campanian-Maastrichtian age from Gavrovo-Tripolitza zone in Greece. The new genus is distinguished from others of the sub-family RhapydionininaeKeijzer emend. Hamaoui and Fourcade by its almost entirely evolute test made of chambers tending to a cyclical stage (rapidly reached in the microspheric form).  相似文献   
9.
10.
We have studied 11 cases of acute human trichinosis; five of these patients were treated with thiabendazole. We have reviewed the laboratory data for these patients and described their course. This study has failed to show any definite effect of thiabendazole on the course of human trichinosis at the doses used. However, thiabendazole may have decreased the infectivity of the larvae which were embedded in the muscles of our patients.  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