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   5304篇
  免费   246篇
  国内免费   1篇
  2024年   4篇
  2023年   47篇
  2022年   79篇
  2021年   164篇
  2020年   144篇
  2019年   153篇
  2018年   185篇
  2017年   184篇
  2016年   235篇
  2015年   340篇
  2014年   319篇
  2013年   430篇
  2012年   432篇
  2011年   394篇
  2010年   263篇
  2009年   197篇
  2008年   309篇
  2007年   265篇
  2006年   258篇
  2005年   207篇
  2004年   211篇
  2003年   163篇
  2002年   136篇
  2001年   40篇
  2000年   35篇
  1999年   40篇
  1998年   32篇
  1997年   21篇
  1996年   27篇
  1995年   11篇
  1994年   13篇
  1993年   16篇
  1992年   18篇
  1991年   12篇
  1990年   6篇
  1989年   14篇
  1988年   6篇
  1987年   4篇
  1986年   7篇
  1985年   7篇
  1984年   19篇
  1983年   11篇
  1982年   12篇
  1981年   4篇
  1980年   9篇
  1979年   9篇
  1978年   7篇
  1975年   4篇
  1974年   4篇
  1964年   4篇
排序方式: 共有5551条查询结果,搜索用时 343 毫秒
61.
62.
Most rabies vaccines are based on inactivated virus, which production process demands a high level of biosafety structures. In the past decades, recombinant rabies virus glycoprotein (RVGP) produced in several expression systems has been extensively studied to be used as an alternative vaccine. The immunogenic characteristics of this protein depend on its correct conformation, which is present only after the correct post-translational modifications, typically performed by animal cells. The main challenge of using this protein as a vaccine candidate is to keep its trimeric conformation after the purification process. We describe here a new immunoaffinity chromatography method using a monoclonal antibody for RVGP Site II for purification of recombinant rabies virus glycoprotein expressed on the membrane of Drosophila melanogaster S2 cells. RVGP recovery achieved at least 93%, and characterization analysis showed that the main antigenic proprieties were preserved after purification.  相似文献   
63.
64.
International Journal of Primatology - The hormone dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are the most abundant circulating steroids in human and some nonhuman primates, and...  相似文献   
65.
Environmental Biology of Fishes - This study evaluated how the plasma steroid hormones testosterone (T) and 17β-estradiol (E2) are related to follicular development in regenerating females of...  相似文献   
66.
Journal of Plant Growth Regulation - The rising demand for agricultural commodities in developing countries has put increasing pressure on land resources for higher yields, with associated growth...  相似文献   
67.

Salicylic acid (SA) is a plant hormone that stimulates the growth and metabolism of plants, also acting as an abiotic elicitor. This study aimed to evaluate the effect of SA on leaf production, leaf area and synthesis of secondary compounds in yarrow plants. The experiments were conducted under field conditions in two consecutive years and f-received SA foliar applications (T1-control; T2-1.0 mmol L−1 applications at 20, 60 and 100 days after planting (DAP) and T3-1.0 mmol L−1 applications at 100 DAP during 3 days). The exogenous application of SA resulted in increases in leaf area (total and specific), number of leaves and leaf mass ratio of yarrow plants, polyphenolic compounds, phenylalanine ammonia-lyase and chalcone synthase enzymes and the antioxidant activity of the plant extract. The HPLC–DAD–MS/MS analysis of phenolic compounds revealed increases in the amounts of quinic acid and rutin. The results of this research lead us to affirm that SA exerted both the hormonal effect on number of leaves and leaf area, and also acted as eliciting substance.

  相似文献   
68.
Journal of Insect Behavior - Control of the sugarcane borers, Diatraea saccharalis and Diatraea impersonatella (= D. flavipennella) (Lepidoptera: Crambidae), in Brazil, is based on mass release of...  相似文献   
69.
70.
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