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   89697篇
  免费   3598篇
  国内免费   54篇
  93349篇
  2020年   1003篇
  2019年   1232篇
  2018年   1737篇
  2017年   1815篇
  2016年   1856篇
  2015年   1291篇
  2014年   1559篇
  2013年   7550篇
  2012年   2727篇
  2011年   3063篇
  2010年   1871篇
  2009年   1831篇
  2008年   2698篇
  2007年   2602篇
  2006年   2302篇
  2005年   2062篇
  2004年   1967篇
  2003年   1895篇
  2002年   1889篇
  2001年   2997篇
  2000年   2906篇
  1999年   2117篇
  1998年   1090篇
  1997年   943篇
  1996年   844篇
  1995年   844篇
  1994年   835篇
  1993年   838篇
  1992年   1785篇
  1991年   1705篇
  1990年   1657篇
  1989年   1540篇
  1988年   1471篇
  1987年   1458篇
  1986年   1432篇
  1985年   1544篇
  1984年   1213篇
  1983年   1022篇
  1979年   1185篇
  1978年   907篇
  1975年   1070篇
  1974年   1152篇
  1973年   1147篇
  1972年   1019篇
  1971年   881篇
  1970年   807篇
  1969年   875篇
  1968年   1029篇
  1967年   942篇
  1966年   941篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
931.
Counseling prisoners involves multiple ethical and therapeutic choices and risks. Prison environments emphasize external control and security. Thus, work in such settings challenges the role of the counselor as a facilitator of client responsibility for independent decision making.  相似文献   
932.
933.
Food-deprived Drosophila melanogaster extend their proboscises following sucrose stimulation of the front tarsi (the proboscis extension reflex). Médioni and Vaysse (1975) reported that the inhibition of this response can be conditioned over trials if such proboscis extensions are punished by applying an aversive stimulus to the foreleg tarsi. In this study, Médioni and Vaysse's basic observations of conditioning were replicated, with a different strain of flies and a modified conditioning apparatus.  相似文献   
934.
Two adult male chimpanzees reached through a hole in the wall of their home cage and, by tracking the images of their hands and of an otherwise hidden target object in a mirror or closed-circuit television picture, moved their hands in whichever direction was necessary to make contact with the target object. They discriminated between live video images and tapes and performed effectively when the target objects were presented in novel locations and when the video picture was presented at random in different orientations. There was thus no consistent relation between the location of images on the monitor and the location of their real-world counterparts. Comparable performances in monkeys and nonprimates seem unlikely.  相似文献   
935.
Bornstein’s hypothesis that there is a loss of color discrimination in tropical areas was not supported in earlier research in the Cook Islands. Using a more sensitive color vision test (the Farnsworth-Munsell 100-Hue Test), a loss of color discrimination in the red-purple and blue-green regions of the spectrum was found. The lack of sex differences in this color discrimination loss supports a physiological rather than a genetic explanation of the observed decrement.  相似文献   
936.
937.
938.
939.
Five- and 7-month-old infants were tested for sensitivity to the depth cue of shading. Infants were presented with two displays: a surface in which a convexity and a concavity were molded and a photograph in which shading specified a convexity and a concavity. Each display was presented under both monocular and binocular viewing conditions. Reaching was observed as the dependent measure. Infants in both age groups reached preferentially for the actual convexity in both the monocular and binocular viewing conditions. In the monocular photograph condition, the 7-month-olds reached preferentially for the apparent convexity specified by shading, indicating that they perceived it to be an actual convexity. These infants showed no significant reaching preference in the binocular photograph condition. This finding rules out interpretations of the infants’ reaching not based on perceived depth. The results therefore suggest that the 7-month-olds perceived depth from shading. The 5-month-olds showed no significant reaching preferences when viewing the photograph; thus, they showed no evidence of depth perception from shading. These findings are consistent with the results of a number of studies that have investigated infants’ sensitivity to pictorial depth cues. Together, these studies suggest that the ability to perceive depth from pictorial cues may first develop between 5 and 7 months of age.  相似文献   
940.
Forty-eight American children, 12 popular and 12 rejected children from Grades 3 and 6, were paired with same-sex friends and nonfriends on an interactive task. Children were videotaped and their interactions judged for the amount and type of attention each child in the dyad gave to each other and the conversation. Main dependent measures included mutual engagements, acknowledgement of the partner, getting the attention of the partner, attention to the conversation, and social impact of the utterances. Both rejected and popular children attended to the conversation and the partner, but rejected children appeared to overattend in several ways. The interactions of rejected children and their matches involved more mutual engagements, conversational initiators, facilitators, terminators, and nonverbal attention-getting devices. Sex and developmental effects were also found.  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