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   76篇
  免费   1篇
林业   46篇
农学   1篇
  12篇
综合类   9篇
农作物   1篇
畜牧兽医   1篇
植物保护   7篇
  2020年   3篇
  2015年   1篇
  2014年   4篇
  2013年   2篇
  2012年   2篇
  2011年   3篇
  2008年   4篇
  2007年   3篇
  2006年   1篇
  2005年   1篇
  2004年   1篇
  2003年   1篇
  2002年   2篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1997年   2篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1988年   1篇
  1968年   1篇
  1950年   2篇
  1948年   2篇
  1938年   1篇
  1935年   1篇
  1931年   1篇
  1930年   1篇
  1929年   4篇
  1925年   3篇
  1924年   1篇
  1921年   3篇
  1917年   4篇
  1916年   1篇
  1915年   2篇
  1914年   2篇
  1913年   9篇
  1912年   1篇
排序方式: 共有77条查询结果,搜索用时 20 毫秒
1.
2.
Background: Nitrogen losses is an economic problem for wheat production and a high risk to the environment. Therefore, improved N fertilizer management is a key to increasing the N efficiency and minimizing N losses. To increase N efficiency, enhanced fertilizers such as urea combined with urease inhibitor can be used. Aims: The aim of present study was to evaluate the effects of different N forms on grain storage protein subunits in winter wheat and to examine whether the observed changes correlate with parameters of baking quality. Methods: The investigation was performed over two consecutive years at two locations in Germany. Protein subunits were analyzed by SDS‐PAGE. Results: Protein concentrations were similarly increased after fertilization with ammonium nitrate and urea + urease inhibitor. Analysis of the individual storage protein fractions indicated that both fertilizers specifically enhanced ω‐gliadins and HMW glutenins, but the effect was more pronounced in the ammonium nitrate treatment. Application of urea + urease inhibitor had greater influence on the protein composition and resulted in higher specific baking volume as well as the best fresh keeping ability, in comparison with urea treatment. Conclusion: Considering that the urea + urease inhibitor treatment resulted in almost comparable improvements of NUE and baking quality, with the additional benefit of reduced N losses in combination with easy handling, urea + urease inhibitor can be recommended as a viable alternative to both urea alone and ammonium nitrate treatments. This opens up an opportunity for the reduction of N loss in wheat production when use of urea is preferred.  相似文献   
3.
4.
5.
6.
Newly synthesized compounds were examined in screening tests with the pea aphid, Acyrthosiphon pisum (Harris) for juvenilizing effects. usign the spray-residue method. Two derivatives of 2-(4-hydroxvbenzyl)eyclohexanone bearing a carbamate or an ether group were found to be the most active inhibitors of development and reproduction. Tests with the hop aphid, Phorodon humuli (Schrank) of insecticide-susceptible and multi-resistant biotypes and with the green peach aphid, Myzus persicae (Sulzer) confirmed their biological activity. Cross-resistance between conventional insecticides and juvenoids was not indicated. The formation of supernumerary larvae, where retention of larval cauda and corresponding larval characters were observed and reproduction was entirely suppressed, was recognized as the critical result of the juvenilizing effect. The production of viable progeny was not affected in those aphids which survived treatment and developed normal adult external genitalia.  相似文献   
7.
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