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   365篇
  免费   13篇
  378篇
  2023年   4篇
  2022年   6篇
  2021年   16篇
  2020年   8篇
  2019年   19篇
  2018年   18篇
  2017年   7篇
  2016年   15篇
  2015年   32篇
  2014年   34篇
  2013年   21篇
  2012年   26篇
  2011年   17篇
  2010年   9篇
  2009年   14篇
  2008年   20篇
  2007年   15篇
  2006年   8篇
  2005年   6篇
  2004年   11篇
  2003年   10篇
  2002年   4篇
  2001年   8篇
  1999年   4篇
  1998年   2篇
  1993年   2篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   3篇
  1982年   1篇
  1981年   1篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1973年   3篇
  1972年   2篇
  1971年   1篇
  1970年   4篇
  1969年   3篇
  1966年   2篇
  1965年   1篇
  1963年   1篇
  1956年   1篇
排序方式: 共有378条查询结果,搜索用时 8 毫秒
371.
Little is known about the early response of roots to desiccation. Young growing root hairs of Arabidopsis thaliana , Vigna unguiculata and Phaseolus vulgaris were used to study the early response of roots to desiccation since they behave like sensors that are able to perceive environmental signals. In control conditions, root hairs were polarized around −120 mV and displayed inward rectifying K+ currents. When submitted to short-term desiccation, root hairs stopped their tip growth and their membrane became depolarized. Under these conditions, the K+ influx carried by the inward rectifying K+ channels was not maintained and instead slow deactivating anion channels were recorded. The inhibition of K+ influx and the large anion efflux due to the activation of slow anion currents could participate in the inhibition of tip growth.  相似文献   
372.
Criconemella anastomoides, described and illustrated herein, is characterized by the presence of regular anastomosis on the body, two zig zag lateral lines, stylet knobs sloping posteriorly, short stylet, and short body length.  相似文献   
373.
One-year-old seeds of chickpea (Cicer arietinum L. cv. C-235) lost about 23 % germinability and leaked larger quantities of N, P, K, saccharides and proteins into the soaking medium in the first 48 h, as compared with fresh seeds. The protein content in stored seeds decreased more than in fresh seeds, as the soaking progressed.  相似文献   
374.

Background  

Helical membrane proteins (HMPs) play a crucial role in diverse cellular processes, yet it still remains extremely difficult to determine their structures by experimental techniques. Given this situation, it is highly desirable to develop sequence-based computational methods for predicting structural characteristics of HMPs.  相似文献   
375.
376.
377.
378.
Ceratapion basicorne (Coleoptera: Apionidae) is a prospective biological control agent of yellow starthistle (Centaurea solstitialis, Asteraceae: Cardueae), which is an important invasive alien weed in the western United States. Previous studies have shown that it is possible for this insect to oviposit on and complete development on safflower (Carthamus tinctorius) under no-choice laboratory conditions; however, it has never been reported as a pest of safflower. Field experiments were conducted at three sites in eastern Turkey during 3 years to evaluate the risk of attack on safflower by this insect in its native range. At two sites where C. basicorne was the only apionid observed, no safflower plants were attacked despite high attack rates on yellow starthistle test plants (48–98% of plants infested). At a third site, where C. basicorne and three other species in the same genus; C. scalptum, C. orientale, and C. onopordi were present, 8–26% of safflower plants were infested, but none of the insects reared from safflower during 3 years were C. basicorne. Other authors have reported rearing C. basicorne from field-collected plants of only Ce. solstitialis, Ce. cyanus, Ce. depressa, and Cnicus benedictus. Our results indicate that C. basicorne does not attack safflower under field conditions and that its introduction would not pose a risk to this crop.  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