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   64篇
  免费   2篇
系统科学   2篇
现状及发展   30篇
研究方法   13篇
综合类   20篇
自然研究   1篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   1篇
  2014年   2篇
  2013年   1篇
  2012年   3篇
  2011年   2篇
  2010年   2篇
  2008年   2篇
  2007年   2篇
  2006年   4篇
  2005年   2篇
  2004年   2篇
  2001年   2篇
  2000年   6篇
  1999年   3篇
  1996年   1篇
  1989年   3篇
  1988年   1篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
  1975年   2篇
  1974年   2篇
  1973年   4篇
  1967年   2篇
  1965年   1篇
  1963年   3篇
排序方式: 共有66条查询结果,搜索用时 31 毫秒
41.
42.
Cataclysmic variables (classical novae and dwarf novae) are binary star systems in which a red dwarf transfers hydrogen-rich matter, by way of an accretion disk, to its white dwarf companion. In dwarf novae, an instability is believed to episodically dump much of the accretion disk onto the white dwarf. The liberation of gravitational potential energy then brightens these systems by up to 100-fold every few weeks or months. Thermonuclear-powered eruptions thousands of times more luminous occur in classical novae, accompanied by significant mass ejection and formation of clearly visible shells from the ejected material. Theory predicts that the white dwarfs in all dwarf novae must eventually accrete enough mass to undergo classical nova eruptions. Here we report a shell, an order of magnitude more extended than those detected around many classical novae, surrounding the prototypical dwarf nova Z Camelopardalis. The derived shell mass matches that of classical novae, and is inconsistent with the mass expected from a dwarf nova wind or a planetary nebula. The shell observationally links the prototypical dwarf nova Z Camelopardalis with an ancient nova eruption and the classical nova process.  相似文献   
43.
Zusammenfassung In der Kopfniere des TeleostiersAnabes testudineus wurde eine besonders hohe Peroxidase-Aktivität nachgewiesen, insbesondere deren Iodid-Oxydation zu Tri-Iodid.  相似文献   
44.
45.
46.
The C-reactive proteins (CRP) from both rat and Limulus were found to bind mercury (Hg) in both in vivo and in vitro conditions. CRP has high-affinity binding sites for Hg as evidenced by the loss of free sulfhydryl groups, arrested mobility in polyacrylamide gel electrophoresis, and the consumption of CRP in the serum after Hg administration. The binding was tight as it could not be inhibited either by the addition of cysteine or EDTA. By using a direct titration method it was shown that binding of Hg to CRP was saturable at a molar ratio of Hg/CRP = 13.11. The possibility that CRP may act as a scavenger for Hg is discussed.  相似文献   
47.
48.
Summary The C-reactive proteins (CRP) from both rat andLimulus were found to bind mercury (Hg) in both in vivo and in vitro conditions. CRP has high-affinity binding sites for Hg as evidenced by the loss of free sulfhydryl groups, arrested mobility in polyacrylamide gel electrophoresis, and the consumption of CRP in the serum after Hg administration. The binding was tight as it could not be inhibited either by the addition of cysteine or EDTA. By using a direct titration method it was shown that binding of Hg to CRP was saturable at a molar ratio of Hg/CRP=13.11. The possibility that CRP may act as a scavenger for Hg is discussed.  相似文献   
49.
Summary Restraint-induced stress potentiated morphine catalepsy in rats. This potentiation was partially antagonized by pharmacologic treatments decreasing central serotonin, acetylcholine, prostaglandins and by naloxone. Selective increase in central dopamine also inhibited the potentiation.Acknowledgments. SKB is an ECFMG Senior Faculty Fellow from the Department of Pharmacology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India. Partial research support by the Dakota State Aerie Fraternal Order of Eagles is gratefully acknowledged.  相似文献   
50.
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