全文获取类型
收费全文 | 23178篇 |
免费 | 179篇 |
专业分类
23357篇 |
出版年
2023年 | 18篇 |
2022年 | 33篇 |
2021年 | 42篇 |
2020年 | 61篇 |
2019年 | 95篇 |
2018年 | 3549篇 |
2017年 | 2910篇 |
2016年 | 2324篇 |
2015年 | 283篇 |
2014年 | 173篇 |
2013年 | 484篇 |
2012年 | 707篇 |
2011年 | 2516篇 |
2010年 | 2598篇 |
2009年 | 1555篇 |
2008年 | 1811篇 |
2007年 | 2257篇 |
2006年 | 133篇 |
2005年 | 320篇 |
2004年 | 256篇 |
2003年 | 194篇 |
2002年 | 147篇 |
2001年 | 64篇 |
2000年 | 91篇 |
1999年 | 64篇 |
1998年 | 68篇 |
1997年 | 56篇 |
1996年 | 46篇 |
1995年 | 20篇 |
1994年 | 20篇 |
1993年 | 28篇 |
1992年 | 33篇 |
1991年 | 20篇 |
1990年 | 20篇 |
1989年 | 27篇 |
1988年 | 13篇 |
1987年 | 21篇 |
1986年 | 20篇 |
1985年 | 27篇 |
1984年 | 22篇 |
1983年 | 21篇 |
1982年 | 30篇 |
1981年 | 25篇 |
1980年 | 15篇 |
1979年 | 17篇 |
1978年 | 15篇 |
1977年 | 15篇 |
1976年 | 19篇 |
1974年 | 11篇 |
1973年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Previous publications emanating from the Colorado Adoption Project have reported significant relationships between parental general cognitive ability (g) and infant Bayley MDI scores. The present study compared infant Bayley factor scores representing separable dimensions of infant cognition with parental general and specific cognitive abilities for 182 adoptive families and 164 nonadoptive families. Parent/offspring correlations between 12-month Bayley factors and parental cognitive abilities suggest only minimal relationships for both parental g and specific abilities. At 24 months, more parent/offspring resemblance was present; moreover, Bayley factors that were related to parental cognition tended to be related to parental g, not to specific abilities. The finding of significant parent/offspring relationships at 24 months between biological parents and their adopted-away infants, as well as between nonadoptive parents and their infants, suggests some genetic continuity from infancy to adulthood. 相似文献
22.
Two hundred and sixty three young adult college students responded to openended questions assessing their specific intentions, motives, and plans for having children. The most commonly stated motives for childbearing reflected a strong interest in establishing an identity and social network. Financial, marital, and emotional stability were identified as important factors influencing the timing of parenthood. Several significant sex differences were found for both motives and the timing of parenthood. These findings are discussed in terms of changing social norms regarding parenthood and changing sex role expectations.Portions of this research were presented at the Eastern Regional Psychological Association Convention in New York, April 1986. This research was funded by a grant from Trenton State College, Committee for Faculty and Institutional Research and Sabbatical Leave. 相似文献
23.
Homosexuals, bisexuals, and heterosexuals were compared on self-reported love preferences and ideals. In general, the three groups tended to agree on ideal characteristics of love objects, love relationships, and love related beliefs. Nevertheless, the groups differed significantly on preferences and beliefs related to love-object sex, residential proximity, ethnic background, physical intimacy, freedom from feelings of jealousy, sexual fidelity, emotional intimacy, and the importance of religious or legal acknowledgment.An early version of this paper was presented at the Annual Meeting of the National Council on Family Relations, in San Francisco, October 1984, Journal Series No. 2973 of the Hawaii Institute of Tropical Agriculture and Human Resources. 相似文献
24.
Comparing visual field asymmetries for bilaterally presented words and corresponding line drawings, we found an RVF advantage for words and no visual field asymmetry for line drawings. We suggested that the RVF advantage previously obtained by Young, Bion, and Ellis (Brain and Language, 11, 54–65, 1980) for bilaterally presented line drawings may have resulted from a forced order of report procedure, noting that the RVF advantage was greater on trials on which subjects were forced to report in the nonpreferred right-to-left order. Young and Ellis (Brain and Language, 20, 166–171, 1983) attempt to discredit this claim and maintain their hypothesis that the RVF advantage for line drawings is attributable to better temporary storage of these stimuli by the left than the right hemisphere. In the present article, we present in greater detail our arguments for the effects of forced order of report on the perception of bilaterally presented stimuli and refute Young and Ellis's ibid. criticisms of this proposal. 相似文献
25.
An experiment was conducted aimed first at establishing the reliability and validity of a measure of individual differences in sleeping schedules. Two samples of subjects completed a questionnaire concerning their sleeping behavior which was scored according to the diurnal or nocturnal pattern of their responses. The scores were then used to classify subjects as morning people or evening people. Both the internal reliability and cross-time reliability of the scale were assessed and found to be high. In addition, three indices of construct validity, obtained 4 months after the administration of the scale, supported its validity. In a second part of the experiment, subjects classified as either morning or evening people rated themselves on a set of behavioral and personality dimensions. Another sample of subjects indicated their perceptions of morning people and evening people in general, along the same dimensions. It was found that subjects did have strong beliefs about personality and behavioral differences between morning people and evening people. However, the self-perceptions of the actual morning and evening people did not differ, thereby casting doubt on the validity of popular stereotypic perceptions about the two groups. 相似文献
26.
27.
Code-switching occurs regularly in the input to bilingual children. Yet, the effect of code-switched input on language development is unclear. To test whether word learning would be affected by code-switching, Spanish–English bilingual children (N = 45, 19 boys, MeanAge = 5.05 years; ethnicity: 37 Hispanic/Latino, six Non-Hispanic/Latino, two unreported) were taught English-like novel words in two conditions. In the English-only condition, definitions for novel words were provided entirely in English. In the code-switch condition, definitions for novel words were provided in English and Spanish, incorporating code-switches. Children required fewer exposures to retain novel words in the code-switch than the English-only condition and this effect was not moderated by children's language ability or exposure to code-switching, suggesting that code-switched input does not pose word-learning risks to bilingual children, including children with lower levels of language ability. 相似文献
28.
Hans Wallach Karl Josef Frey Katharine Anne Bode 《Attention, perception & psychophysics》1972,11(1):110-116
In previous work by the senior authors, brief adaptation to glasses that changed the accommodation and convergence with which objects were seen resulted in large alterations in size perception. Here, two further effects of such adaptation are reported: alterations in stereoscopic depth perception and a change when distance is represented by a response of S’s arm. We believe that the three effects are manifestations of one primary effect, an alteration of the relation between accommodation and convergence on the one hand and the distance they represent in the nervous system (registered distance) on the other. This view was supported by the results of two experiments, each of which demonstrated that the alterations in stereoscopic depth perception could be obtained after adaptation periods which had provided no opportunity to use stereoscopic vision, and that the adaptation effect was larger for depth perception than for size perception when it was obtained under the same conditions; the latter finding was expected if both effects resulted from the same change in registered distance. In three of the five experiments here reported, the variety of cues that could represent veridical distance during the adaptation period was limited. In one condition of adaptation, only the pattern of growth of the retinal images of objects that S approached and the kinesthetic cues for S’s locomotion served as cues to veridical distance. In two other conditions S remained immobile. In one of these, only the perspective distortion in the projection of the scene that S viewed mediated veridical distance, and in the other one familiar objects of normal size were successively illuminated in an otherwise totally dark field, conditions from which opportunities to use stereoscopic vision were again absent. After exposure to each of these adaptation conditions, adaptive changes in perceived size and larger ones in perceived stereoscopic depth were obtained. Because we found that familiar size may serve as the sole indicator of veridical distance in an adaptation process, we concluded that it can function as a perceptual as distinguished from an inferential cue to distance. 相似文献
29.
Daily food intake in rats was temporarily reduced by the introduction of an activity wheel and temporarily increased by the subsequent removal of the wheel. When this outcome is coupled with the positive relation between food deprivation and running—and food deprivation is seen as a loss of eating rather than as a physiological state—there is the suggestion that the total behavior output of the organism may be regulated as such. Specifically, when the rat is deprived of a behavior that recurrently comprises a large part of its total daily activity, an increase may occur in some other behavior. 相似文献
30.