全文获取类型
收费全文 | 33305篇 |
免费 | 1403篇 |
国内免费 | 18篇 |
专业分类
34726篇 |
出版年
2020年 | 376篇 |
2019年 | 425篇 |
2018年 | 573篇 |
2017年 | 678篇 |
2016年 | 649篇 |
2015年 | 489篇 |
2014年 | 553篇 |
2013年 | 2764篇 |
2012年 | 898篇 |
2011年 | 988篇 |
2010年 | 680篇 |
2009年 | 683篇 |
2008年 | 909篇 |
2007年 | 846篇 |
2006年 | 804篇 |
2005年 | 664篇 |
2004年 | 612篇 |
2003年 | 661篇 |
2002年 | 596篇 |
2001年 | 1204篇 |
2000年 | 1176篇 |
1999年 | 857篇 |
1998年 | 381篇 |
1996年 | 331篇 |
1995年 | 335篇 |
1994年 | 328篇 |
1993年 | 322篇 |
1992年 | 753篇 |
1991年 | 739篇 |
1990年 | 688篇 |
1989年 | 633篇 |
1988年 | 604篇 |
1987年 | 601篇 |
1986年 | 566篇 |
1985年 | 613篇 |
1984年 | 483篇 |
1983年 | 375篇 |
1981年 | 319篇 |
1979年 | 487篇 |
1978年 | 378篇 |
1977年 | 368篇 |
1975年 | 424篇 |
1974年 | 428篇 |
1973年 | 488篇 |
1972年 | 390篇 |
1971年 | 329篇 |
1969年 | 335篇 |
1968年 | 386篇 |
1967年 | 345篇 |
1966年 | 393篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
Three experiments tested the hypothesis that people can execute focused searches of semantic cases when answering questions about complex facts, such as “the teacher watered the peas, the corn, and the lettuce with the hose.” In Experiment 1, answer time varied mainly with the number of concepts in the relevant or focused case, supporting the hypothesis. Experiment 2 indicated that the irrelevant case undergoes some processing. Experiment 3 confirmed that search in Experiments 1 and 2 focused on semantic cases rather than on taxonomic categories. It is proposed that focused memory search has a high probability of retrieving the relevant case and a low probability of retrieving the irrelevant case. In the latter event, the irrelevant concepts receive full processing. 相似文献
112.
The development of the understanding of affective meaning in music was investigated. Subjects aged 4, 5, 6, and 19 assigned verbal labels to musical segments previously determined by adults to be representative of one of four affects (happy, sad, angry, afraid). Analysis of correct interpretations and errors revealed a pattern of interactions among age, sex, and affect indicating that the ability to verbalize an understanding of affective meaning in music consistent with that of adult subjects is present during the preschool years. Age-related similarities in performance, as well as differences favoring both younger and older subjects, were observed and were discussed in relation to recent research in, and theories of, affective development and communication.The authors thank H. Julia Hannay, Edward Kemery, Shiela MacDonald, and Robert McGrath for their assistance in this research. The conceptual inspiration of Joseph Intrieri is gratefully acknowledged. We also thank Leslie Brody, Robin Hornik, and several anonymous reviewers for their comments on an earlier draft of the paper. Portions of this research were presented at the Southeastern Conference on Human Development, Baltimore, April 1982. 相似文献
113.
114.
A pediatric auditory version of the Stroop procedure was developed and administered to 48 normal children from 3 to 6 years of age. Our purpose was to define the developmental course characterizing interaction between auditory and semantic speech dimensions in young children. The procedure was a reaction time (RT) task that required children to respond as quickly and as accurately as possible to words spoken by a male or a female voice. Children were instructed to ignore what was said and to push the "Mommy" button if Mommy was talking or the "Daddy" button if Daddy was talking. Performance was obtained for words with neutral, congruent, and conflicting semantic content. Preschool children manifested processing dependencies that were similar to those observed in adults on the visual Stroop procedure. Conflict between semantic and auditory dimensions significantly increased RT and congruence between the two dimensions significantly decreased RT relative to the neutral condition. The pattern of results indicated that the meaning of words was processed automatically in the normal children. The magnitude of the Stroop effect reflected developmental change with increasing age. 相似文献
115.
116.
Studies of psychosocial influences on coronary artery atherogenesis in cynomolgus monkeys 总被引:1,自引:0,他引:1
The cynomolgus macaque provides a suitable primate model for studying how psychosocial factors contribute to coronary artery atherogenesis. Important interactions with diet, sex, and behaviorally elicited cardiovascular reactivity are described. 相似文献
117.
Despite widespread popular belief in the activation of recurrent lesions in genital herpes simplex virus (HSV) by psychosocial stress, little empirical evidence supports that contention. This study retrospectively examined the role of stress in activation of HSV lesions as mediated by social support. Participants were 59 volunteers who had self-reported culture-positive genital HSV for at least 10 months. Measures of stress proneness (State-Trait Anxiety Inventory; STAI-Trait), recent stressful events (Schedule of Recent Events; SRE), and subjective appraisal of stress (global self-rating) were administered along with measures of general social support and herpes-specific social support. When retrospective reports of HSV symptoms were examined using a multiple-regression approach, duration of disease and amount of herpes-specific social support were found to be significant moderators of the relation between stress and number of HSV recurrences in the preceding 12 months. When duration of disease was short (less than 4 years), stress (SRE) and number of recurrences were positively associated; when disease duration was longer, there was no relationship. Similarly, at low levels of herpes-specific social support, a positive relation between stress (SRE) and number of recurrences was found. However, at higher levels of herpes-specific social support, no association was found. No relation was found between stress proneness (STAI-Trait) and HSV symptoms. However, subjective appraisal (global rating) of stress in the preceding 12 months was positively and significantly correlated with reported number of recurrences. Results are discussed in terms of their clinical implications. 相似文献
118.
Smoking, caffeine, and stress: effects on blood pressure and heart rate in male and female college students 总被引:2,自引:0,他引:2
This study examined the independent and joint effects of cigarette smoking and caffeine consumption on blood pressure (BP) and heart rate (HR) reactions to stress in male and female college students. Following an initial physiological baseline, participants received one of four experimental treatments (paced smoking, caffeine, smoking plus caffeine, or neither) and had BP and HR measured before, during, and after two stressful tasks. The results revealed that, compared with the control condition, caffeine ingestion enhanced the magnitude of stress-induced systolic BP and HR reactions. Smoking combined additively with stress, and the joint effect of smoking and caffeine was no greater than either taken alone. Males and females were generally similar in their BP and HR responses to smoking, caffeine, and stress. Inconsistencies with previous research and possible physiological mechanisms underlying the observed effects are discussed. 相似文献
119.
120.