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   2028篇
  免费   167篇
  国内免费   1篇
  2021年   30篇
  2019年   20篇
  2018年   21篇
  2017年   22篇
  2016年   50篇
  2015年   84篇
  2014年   82篇
  2013年   110篇
  2012年   115篇
  2011年   102篇
  2010年   81篇
  2009年   72篇
  2008年   94篇
  2007年   90篇
  2006年   80篇
  2005年   74篇
  2004年   77篇
  2003年   79篇
  2002年   66篇
  2001年   45篇
  2000年   30篇
  1999年   40篇
  1998年   24篇
  1997年   30篇
  1996年   21篇
  1995年   13篇
  1994年   20篇
  1993年   24篇
  1992年   22篇
  1991年   34篇
  1990年   28篇
  1989年   30篇
  1988年   22篇
  1987年   34篇
  1986年   35篇
  1985年   28篇
  1984年   18篇
  1983年   13篇
  1982年   20篇
  1981年   14篇
  1980年   13篇
  1979年   13篇
  1978年   15篇
  1977年   17篇
  1976年   19篇
  1974年   23篇
  1971年   21篇
  1970年   18篇
  1969年   15篇
  1966年   13篇
排序方式: 共有2196条查询结果,搜索用时 265 毫秒
81.
82.
Quantitative data were collected on the behaviour of four social groupings of captive common marmost monkeys. The observational study covered a period of eight months in 1973 during which time, data were intermittently collected on marking, self and social grooming, three categories of social play, together with some few additional data on close physical proximity and social contact referred to as ‘huddling.’ Each social group was observed for a total of 180-ten-min. observation sessions; one family group of monkeys was further observed individually for 100-ten-min. sessions.  相似文献   
83.
84.
Two kinds of TBG polymorphism are described in human, one found in deglycosylated TBG from individual blood donors, the other is a genetically determined polymorphism. TBG from plasma samples from a patient with toxic goiter, not autoimmune, (p)TBG, from the patient's mother (m)TBG and from individual donors (n)TBG, were labeled with [125I]T4 or [125I]T3 and submitted to isoelectric focusing (IEF), followed by autoradiography. Three faint [125I]T4 radiolabeled bands were detectable in (p)TBG while four strong [125I]T4 radiolabeled bands were detectable in (m)TBG and (n)TBG), respectively. IEF of the [125I]T3 incubated serum samples resulted in no detectable isoelectric radiolabeled band for (p)TBG while a normal pattern was found in (m)TBG and in (n)TBG, respectively. These data suggest a new intraindividual not linked to sexual chromosome X polymorphism characterized by a loss in hormone binding.  相似文献   
85.
86.
87.
88.
89.
Anomalous molecular weights to proteases in gel chromatography   总被引:4,自引:0,他引:4  
Attention is drawn to the fact that, in comparison to those values derived from sedimentation equilibrium experiments, gel chromatographic methods give anomalously low molecular weights for a variety of proteases. This appears to be particularly true for extracellular proteases of broad specificity produced by bacteria and fungi.  相似文献   
90.
With the goal of understanding how nervous systems produce activity and respond to the environment, neuroscientists turn to model systems that exhibit the activity of interest and are accessible and amenable to experimental methods. The stomatogastric nervous system (STNS) of the American lobster (Homarus americanus; also know was the Atlantic or Maine lobster) has been established as a model system for studying rhythm generating networks and neuromodulation of networks. The STNS consists of 3 anterior ganglia (2 commissural ganglia and an oesophageal ganglion), containing modulatory neurons that project centrally to the stomatogastric ganglion (STG). The STG contains approximately 30 neurons that comprise two central pattern generating networks, the pyloric and gastric networks that underlie feeding behaviors in crustaceans1,2. While it is possible to study this system in vivo3, the STNS continues to produce its rhythmic activity when isolated in vitro. Physical isolation of the STNS in a dish allows for easy access to the somata in the ganglia for intracellular electrophysiological recordings and to the nerves of the STNS for extracellular recordings. Isolating the STNS is a two-part process. The first part, dissecting the stomach from the animal, is described in an accompanying video article4. In this video article, fine dissection techniques are used to isolate the STNS from the stomach. This procedure results in a nervous system preparation that is available for electrophysiological recordings.  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