全文获取类型
收费全文 | 15390篇 |
免费 | 607篇 |
国内免费 | 4篇 |
专业分类
16001篇 |
出版年
2021年 | 87篇 |
2020年 | 167篇 |
2019年 | 217篇 |
2018年 | 306篇 |
2017年 | 318篇 |
2016年 | 323篇 |
2015年 | 248篇 |
2014年 | 316篇 |
2013年 | 1777篇 |
2012年 | 554篇 |
2011年 | 584篇 |
2010年 | 379篇 |
2009年 | 381篇 |
2008年 | 564篇 |
2007年 | 537篇 |
2006年 | 517篇 |
2005年 | 524篇 |
2004年 | 536篇 |
2003年 | 501篇 |
2002年 | 535篇 |
2001年 | 262篇 |
2000年 | 220篇 |
1999年 | 246篇 |
1998年 | 263篇 |
1997年 | 237篇 |
1996年 | 222篇 |
1995年 | 223篇 |
1994年 | 211篇 |
1993年 | 226篇 |
1992年 | 214篇 |
1991年 | 172篇 |
1990年 | 180篇 |
1989年 | 164篇 |
1988年 | 151篇 |
1987年 | 166篇 |
1986年 | 148篇 |
1985年 | 194篇 |
1984年 | 217篇 |
1983年 | 233篇 |
1982年 | 231篇 |
1981年 | 202篇 |
1980年 | 170篇 |
1979年 | 151篇 |
1978年 | 202篇 |
1977年 | 176篇 |
1976年 | 177篇 |
1975年 | 156篇 |
1974年 | 177篇 |
1973年 | 122篇 |
1972年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
41.
Processing resources and age differences in working memory 总被引:1,自引:0,他引:1
This study investigated the performance of young and old subjects on a modified version of the working memory task developed by Baddeley and Hitch (1974). Subjects were required to verify a set of sentences of varying complexity while they repeated aloud zero, two, or four words. The older subjects took longer to verify the sentences, especially when the sentences were grammatically complex, but the effect of concurrent memory load on verification latency was the same in both groups. These results cast doubt on the notion that there is an age-related decline in one general pool of processing resources. They also suggest that older people have greater difficulty with the active processing aspects, rather than with the passive holding aspects, of working memory tasks. 相似文献
42.
Maternal depression and its relationship to life stress,perceptions of child behavior problems,parenting behaviors,and child conduct problems 总被引:3,自引:0,他引:3
This study examined the relationship of reported maternal depression to prior and current life stressors, and to mother perceptions of child adjustment, parenting behaviors, and child conduct problems. Forty-six depressed mothers and 49 nondepressed mothers and their clinic-referred children (aged 3-8 years) participated. Depressed mothers were more critical than nondepressed mothers, but the behavior of children of depressed and nondepressed mothers showed no significant differences. Depressed mothers were more likely to have experience child abuse, spouse abuse, or more negative life events than nondepressed mothers. Maternal reports of stress related to mother characteristics and to negative life events were the most potent variables discriminating depressed from nondepressed mother families. 相似文献
43.
44.
The purpose of the present study was to determine whether the sex role orientations of male and female collegiate athletes were more similar in team sports than in individual sports. It was predicted that females in masculine-oriented team sports (basketball and volleyball) would exhibit sex role orientations more similar to those of their male counterparts than would females in individual sports (track/field and swimming). To test this notion the S. L. Bem (The Measurement of Psychological Androgyny, Journal of Consulting and Clinical Psychology, 1974, 42, 155–167) Sex Role Inventory was administered to 381 athletes from 37 National Collegiate Athletic Association institutions. The median-split procedure (S. L. Bem, On the Utility of Alternative Procedures for Assessing Psychology Androgyny, Journal of Consulting and Clinical Psychology, 1977, 45, 196–205) was used to classify subjects as masculine, feminine, androgynous, or undifferentiated. Separate Gender × Sex Role Orientation chi square tests were performed on the frequency data of team and individual sport athletes. The results indicated no significant differences in the sex role orientations of male and female team sport performers, with the greatest proportion (66%) having a masculine (33%) or androgynous (33%) orientation. For individual sports there was a significant difference in the sex role orientations of males and females. The highest proportion of females were classified as feminine (37%) and the lowest proportion were classified as masculine (11%). Individual sport males were somewhat evenly distributed among the four sex role orientation categories, with the highest proportion classified as undifferentiated (36%). It was concluded that sex role orientation of elite female athletes may be associated with the male appropriateness of the sport in which they participate. 相似文献
45.
46.
John Woods 《Argumentation》1988,2(4):419-424
Mackenzie, this journal, this issue, convincingly shows that in certain dialogue games (commitment games) there are procedural restrictions similar to those that I impose on rationality idealizations. But, whereas my rationality analysis is set in the context of belief games, commitment games do not postulate beliefs. Is this significant? I suggest that mackenzie thinks that it is. There follow discussions of Psychologism and Behaviourism. 相似文献
47.
John Polich Maung Aung Donald J. Dalessio 《Integrative psychological & behavioral science》1988,23(1):35-40
Experiment 1 elicited the P1, N1, P2, and N2 components of the long latency auditory evoked potential (AEP) using a 1000 Hz tone presented at 30, 50, or 70 dB SPL and 1-, 3-, or 5- second inter-stimulus intervals to assess the relative effects of the combination of these variables on component amplitude and latency. Four blocks of 16 tone presentations each were recorded from each subject to determine if changes in the AEP would occur because of short-term habituation. Both stimulus factors interacted significantly in a systematic fashion for the amplitude measures, with increases in latency also associated with increases in intensity and inter-stimulus interval. Only minor changes across the four trial blocks for either the amplitude or latency measures were observed over the various stimulus presentation conditions. Experiment 2 employed the same tone stimulus presented at 50 dB SPL and a 3-second inter-stimulus interval. Eight blocks of 64 trials were recorded from each subject on each day for four days to investigate long-term habituation effects. No substantial changes in any of the component amplitudes or latencies were obtained across the 32 trial blocks. It was concluded that intensity and inter-stimulus interval interact to determine AEP amplitude as well as latency values and that the constituent components do not change appreciably with repeated stimulus presentations, even after several days. 相似文献
48.
Thirty children and 5 adults participated in two experiments designed to compare visual processing in normal and reading disabled children. The children were aged 8, 10, and 12 years. In Experiment 1, subjects were asked to detect the temporal order of two briefly presented stimuli. In Experiment 2, subjects sorted cards containing bracket stimuli that did or did not produce perceptual grouping effects. Poor readers required more time to make accurate temporal order judgments and showed stronger perceptual grouping effects. For both good and poor readers, the amount of time necessary to make a correct temporal order judgment decreased, and perceptual grouping effects became weaker with age. However, the magnitude of the difference between the groups did not lessen with age. These results suggest that there are visual processing differences between good and poor readers that do not appear to correct by age 12. 相似文献
49.
John Pais 《Studia Logica》1992,51(2):279-316
The properties of belief revision operators are known to have an informal semantics which relates them to the axioms of conditional logic. The purpose of this paper is to make this connection precise via the model theory of conditional logic. A semantics for conditional logic is presented, which is expressed in terms of algebraic models constructed ultimately out of revision operators. In addition, it is shown that each algebraic model determines both a revision operator and a logic, that are related by virtue of the stable Ramsey test.The author is grateful for a correction and several other valuable suggestions of two anonymous referees. This work was supported by the McDonnell Douglas Independent Research and Development program. 相似文献
50.
We introduce two new belief revision axioms: partial monotonicity and consequence correctness. We show that partial monotonicity is consistent with but independent of the full set of axioms for a Gärdenfors belief revision sytem. In contrast to the Gärdenfors inconsistency results for certain monotonicity principles, we use partial monotonicity to inform a consistent formalization of the Ramsey test within a belief revision system extended by a conditional operator. We take this to be a technical dissolution of the well-known Gärdenfors dilemma.In addition, we present the consequential correctness axiom as a new measure of minimal revision in terms of the deductive core of a proposition whose support we wish to excise. We survey several syntactic and semantic belief revision systems and evaluate them according to both the Gärdenfors axioms and our new axioms. Furthermore, our algebraic characterization of semantic revision systems provides a useful technical device for analysis and comparison, which we illustrate with several new proofs.Finally, we have a new inconsistency result, which is dual to the Gärdenfors inconsistency results. Any elementary belief revision system that is consequentially correct must violate the Gärdenfors axiom of strong boundedness (K*8), which we characterize as yet another monotonicity condition.This work was supported by the McDonnell Douglas Independent Research and Development program. 相似文献