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   57326篇
  免费   2030篇
  国内免费   19篇
  2018年   876篇
  2017年   870篇
  2016年   946篇
  2015年   666篇
  2014年   819篇
  2013年   5068篇
  2012年   1471篇
  2011年   1570篇
  2010年   987篇
  2009年   940篇
  2008年   1423篇
  2007年   1320篇
  2006年   1230篇
  2005年   1057篇
  2004年   1041篇
  2003年   1022篇
  2002年   1041篇
  2001年   1786篇
  2000年   1741篇
  1999年   1342篇
  1998年   629篇
  1996年   673篇
  1995年   621篇
  1994年   628篇
  1993年   623篇
  1992年   1291篇
  1991年   1158篇
  1990年   1187篇
  1989年   1073篇
  1988年   1064篇
  1987年   1043篇
  1986年   1041篇
  1985年   1058篇
  1984年   887篇
  1983年   760篇
  1982年   599篇
  1981年   605篇
  1979年   920篇
  1978年   683篇
  1976年   600篇
  1975年   846篇
  1974年   851篇
  1973年   896篇
  1972年   825篇
  1971年   748篇
  1970年   669篇
  1969年   712篇
  1968年   850篇
  1967年   731篇
  1966年   730篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
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   
53.
54.
A time-sharing paradigm was used to study potential interference effects of concurrent successive-auditory/vocal, successive-visual/motor, simultaneous-auditory/vocal, and simultaneous-visual/motor tasks on right- and left-handed manual-motor behaviors of differential levels of difficulty. Participants were selected from each of three developmental levels from 9 through 20 years of age. Results suggested that processing style (i.e., successive or simultaneous) interacts with modality (i.e., auditory/vocal or visual/motor) in terms of lateralized interference effects; however, potential effects due to age level were obfuscated by differential concurrent-task difficulties.  相似文献   
55.
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   
56.
Extensive empirical evidence confirms a depressed entitlement effect wherein women pay themselves less than men for comparable work and believe the allocation fair. The present study tests the hypothesis that status subordination linked to being female underlies at least some of this effect. A 2 × 3 design crossed 180 undergraduates' gender with a control condition, which successfully established the depressed entitlement effect, and two experimental conditions. In one, women's status was enhanced through legitimation of women's task abilities; in the other, both women's and men's status was enhanced by adding educational credentials relevant to task ability. Follow-up analyses of the significant interaction revealed that the gap in self-pay demonstrated in the control condition disappeared when women's status was enhanced such that higher-status women's self-pay equaled that of men and exceeded that of control women. Although these findings confirm that status plays a role in producing depressed entitlement in self-pay, ancillary analyses of participants' perceptions point to the persistence of shifting standards and men's resistance to status threats.  相似文献   
57.
58.
59.
Rats' lever presses on a retractable lever earned brief presentations of discriminative stimuli signalling periods in which responding on an alternative lever was either non-reinforced (extinction) or reinforced on a random ratio schedule. The predictions of two theoretical accounts of this behaviour were tested by studying the effects of omitting either the stimulus signalling the reinforced or that signalling the non-reinforced schedule component. Under these conditions rats' behaviour is determined by the conditioned, affective properties of the stimuli rather than by their purely informational properties.  相似文献   
60.
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