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   60331篇
  免费   1629篇
  国内免费   16篇
  2020年   394篇
  2019年   455篇
  2018年   3942篇
  2017年   3288篇
  2016年   2843篇
  2015年   710篇
  2014年   677篇
  2013年   2839篇
  2012年   1690篇
  2011年   3420篇
  2010年   3126篇
  2009年   2097篇
  2008年   2649篇
  2007年   3109篇
  2006年   917篇
  2005年   1076篇
  2004年   985篇
  2003年   853篇
  2002年   801篇
  2001年   1333篇
  2000年   1304篇
  1999年   944篇
  1998年   453篇
  1997年   381篇
  1992年   887篇
  1991年   819篇
  1990年   849篇
  1989年   728篇
  1988年   734篇
  1987年   704篇
  1986年   734篇
  1985年   817篇
  1984年   628篇
  1983年   576篇
  1982年   394篇
  1981年   394篇
  1979年   716篇
  1978年   450篇
  1977年   435篇
  1976年   437篇
  1975年   598篇
  1974年   687篇
  1973年   729篇
  1972年   627篇
  1971年   585篇
  1970年   580篇
  1969年   566篇
  1968年   752篇
  1967年   666篇
  1966年   593篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
An electronic apparatus using infrared beams for monitoring the movements of individual bees under dark conditions is described. The searching behavior of workers in an arena was monitored over 2-h periods. Mean ambulatory velocity for one bee over a distance of 100 mm was 45.6±1.51 mm/sec (n=45). Thigmokinesis and temporal activity patterns are illustrated.  相似文献   
45.
46.
47.
Previous work on children's intuitive knowledge about the natural world has documented their difficulty in acquiring an overarching concept of biological life that includes plants as well as humans and non‐human animals. It has also suggested that the acquisition of fundamental biological concepts like alive and die may be influenced by the language used to describe them, as evidenced by differences between English‐ and Indonesian‐speaking children's performance in tasks involving these concepts. Here, we examine one particularly important source of linguistic information available to children during this acquisition process: everyday conversations with their parents. We take a cross‐linguistic approach in analysing the evidence available to English‐ and Indonesian‐speaking children as they acquire meanings for words corresponding to the concepts alive and die . Our analysis illustrates that young children acquiring English and Indonesian are faced with distinct problems, but that parental input in both languages does little to support the acquisition of broad, inclusive biological concepts.  相似文献   
48.
This paper examines college students' attributions about suicide as a function of gender and context (athletic vs. relationship failure). Results indicated that male athletes who suicided were considered more emotionally well-adjusted compared to males who suicided because of a relationship failure and all females. Male and female athletes who suicided were seen as more competent and less distressed compared to those who suffered a failed relationship. Females were also seen as more distressed compared to males. These results are discussed in terms of a positive bias toward athletes in our society as well as gender stereotypes. Implications of these findings as well as methodological limitations are discussed.  相似文献   
49.
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