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   46509篇
  免费   1187篇
  国内免费   12篇
  47708篇
  2021年   274篇
  2020年   393篇
  2019年   421篇
  2018年   3951篇
  2017年   3322篇
  2016年   2809篇
  2015年   677篇
  2014年   635篇
  2013年   2563篇
  2012年   1568篇
  2011年   3294篇
  2010年   3016篇
  2009年   1903篇
  2008年   2462篇
  2007年   2876篇
  2006年   736篇
  2005年   779篇
  2004年   706篇
  2003年   629篇
  2002年   597篇
  2001年   818篇
  2000年   820篇
  1999年   594篇
  1998年   269篇
  1997年   235篇
  1996年   240篇
  1992年   462篇
  1991年   459篇
  1990年   453篇
  1989年   413篇
  1988年   434篇
  1987年   385篇
  1986年   397篇
  1985年   401篇
  1984年   314篇
  1983年   280篇
  1981年   211篇
  1979年   356篇
  1978年   255篇
  1977年   216篇
  1975年   282篇
  1974年   361篇
  1973年   367篇
  1972年   292篇
  1971年   289篇
  1970年   282篇
  1969年   256篇
  1968年   358篇
  1967年   311篇
  1966年   295篇
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
241.
To test the generality, across modality and across species, of a bidirectional effect of photic stimulation in infant rats found in previous experiments, two experiments examined the effects on heart rate (HR) of onset and offset of auditory stimulation in rats and of photic stimulation in guinea pigs. Experiment 1 demonstrated a unidirectional, decelerative response in rats 17 and 21 days of age to the onset and offset of a 1-kHz tone, at both low (80 dB) and high (100 dB) intensity levels and at 14 days to the onset of the high-intensity tone. Experiment 2 demonstrated that infant guinea pigs, which unlike infant rats are precocial and not nocturnal, responded to the offset but not to the onset of light, and that this response was decelerative. These results indicated a lack of generality of the bidirectional HR effect, and were discussed in terms of the orienting/defensive reflex distinction.  相似文献   
242.
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   
243.
244.
This article reports the results of 629 subjects in three experiments designed to replicate and extend the phenomenon of vicarious verbal conditioning. Experiment I replicated the finding that subjects who responded most to vicarious verbal conditioning were aware of the contingency involved. Experiment II attempted to examine the effects of prior history with the verbal reinforcer on vicarious verbal conditioning by providing seven groups of subjects with varying classic conditioning histories prior to vicarious verbal conditioning. The null results associated with this experiment were hypothesized to be due to the fact that the vicarious verbal conditioning took place in a language laboratory where the subjects could hear but not see the model. Experiment III replicated Experiment II in a live group context as was done in Experiment I. The results showed a) that vicarious verbal conditioning was again found to take place, b) that associating the verbal reinforcer with a tone or tone plus money via forward classic conditioning potentiated the effects of the verbal reinforcer, c) that backward classic conditioning did not potentiate the reinforcer, d) nor did either of two sensitization procedures potentiate the effects of the verbal reinforcer. Both aware and unaware subjects evidenced vicarious verbal conditioning.  相似文献   
245.
Sternheim and Boynton’s (1966) continuous judgmental color-naming technique was used to assess the elemental nature of achromatic colors. Results from three subjects indicate that the names “black” and “white” are necessary and sufficient to describe achromatic test lights associated with the name “gray.” On the basis of the criteria that establishes a color as elemental, black and white were confirmed as elemental, whereas gray was not. These findings support the assumption of various opponent processing models that there are only two elemental achromatic sensations. In addition, the results support Hering’s (1920) view that black and white differ from the paired-chromatic opponent colors in that they are not mutually exclusive.  相似文献   
246.
Carroll JB  Andrusko D 《America》1985,152(21):450-453
  相似文献   
247.
248.
B Wood 《Family process》1985,24(4):487-507
The purpose of this research was to develop logical and empirically valid conceptual tools for investigating relationships between family patterns of interconnectedness and psychosocial functioning of children in the family. The family systems concept of boundary was analyzed into two component concepts: Proximity (interpersonal boundaries) and generational Hierarchy (subsystem boundaries). These concepts were operationalized as dimensions, and eight families were assessed by means of interaction coding, interview, and Kinetic Family Drawing to yield empirical verification of these dimensions. Findings indicated that Proximity and Hierarchy are reliable, valid, and independent dimensions of family interconnectedness. Weak generational Hierarchy was associated with increased levels of psychological dysfunction for both identified patients and their siblings. High Proximity was similarly associated with psychological dysfunction, but only for identified patients. The hypothesis that enmeshment is a composite pattern of high Proximity and weak Hierarchy was disconfirmed. Suggestions for future research include systemic analysis of deviation-counteracting and -amplifying relationships between patterns of Proximity and Hierarchy, on the one hand, and psychosocial dysfunction, on the other.  相似文献   
249.
This study, the first of three designed to investigate different age groups' knowledge of developmental norms of children, focused on older adolescent female university students. Data were collected from 280 midwestern university students through a questionnaire consisting of 16 items focusing on physical and social development of children from birth to three years of age. Results showed that knowledge of normal development was both over- and underestimated regardless of age of student or year in school. These findings are discussed within the context of the importance of knowledge of developmental norms for future parents.  相似文献   
250.
Forty-four preschool children ranging from three to five years of age received a series of stones in which the protagonists experience happiness, sadness, or fear These protagonists were portrayed as either similar or dissimilar to the child, and the situations depicted were either familiar or unfamiliar to him/her as well The children's task was to infer the emotions experienced by the protagonists Results indicate that children were more accurate in judging the emotions of similar target persons than they were for dissimilar ones Familiarity with the situation, on the other hand, had no effect on accuracy Children were more accurate in identifying happiness and sadness than they were in judging fear, and age was positively related to judgmental accuracy for the former two but not for the latter These results help to resolve the controversy arising from earlier studies of empathy development which failed to disentangle the similarity and familiarity dimensions  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