全文获取类型
收费全文 | 3127篇 |
免费 | 174篇 |
专业分类
3301篇 |
出版年
2023年 | 39篇 |
2022年 | 65篇 |
2021年 | 89篇 |
2020年 | 124篇 |
2019年 | 99篇 |
2018年 | 183篇 |
2017年 | 180篇 |
2016年 | 159篇 |
2015年 | 92篇 |
2014年 | 115篇 |
2013年 | 413篇 |
2012年 | 236篇 |
2011年 | 230篇 |
2010年 | 139篇 |
2009年 | 75篇 |
2008年 | 189篇 |
2007年 | 140篇 |
2006年 | 120篇 |
2005年 | 67篇 |
2004年 | 60篇 |
2003年 | 72篇 |
2002年 | 46篇 |
2001年 | 26篇 |
2000年 | 36篇 |
1999年 | 21篇 |
1998年 | 19篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1994年 | 12篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 18篇 |
1990年 | 9篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1981年 | 8篇 |
1980年 | 8篇 |
1978年 | 6篇 |
1974年 | 6篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1968年 | 9篇 |
1967年 | 6篇 |
1966年 | 8篇 |
1965年 | 8篇 |
排序方式: 共有3301条查询结果,搜索用时 7 毫秒
71.
72.
Josef Broek 《Journal of the history of the behavioral sciences》1986,22(3):299-300
73.
74.
75.
76.
This work analyzed the effects of unrealistic optimism in the interaction between the emotional valence of future events, the perception of control over these events, and the person with whom one compares oneself. It was hypothesized that, if the person of comparison is judged as very competent, a pessimistic bias should be produced. Likelihood of four different types of events (positive and controllable, positive and uncontrollable, negative and controllable, and negative and uncontrollable) were rated by 133 university students (22 men and 111 women) for themselves, for an average student, for their best friend, and for a bright friend. A pessimistic bias was observed on the relative likelihood of the events when the comparison was made between oneself and a competent and bright friend, when events were perceived as controllable, especially positive ones. Not enough is known, however, to provide meaningful interpretation at present; that must await further data and theoretical development. 相似文献
77.
Gutiérrez G. de Guzmán I. P. Martínez J. Ojeda-Aciego M. Valverde A. 《Studia Logica》2002,72(1):85-112
The tree-based data structure of -tree for propositional formulas is introduced in an improved and optimised form. The -trees allow a compact representation for negation normal forms as well as for a number of reduction strategies in order to consider only those occurrences of literals which are relevant for the satisfiability of the input formula. These reduction strategies are divided into two subsets (meaning- and satisfiability-preserving transformations) and can be used to decrease the size of a negation normal form A at (at most) quadratic cost. The reduction strategies are aimed at decreasing the number of required branchings and, therefore, these strategies allow to limit the size of the search space for the SAT problem. 相似文献
78.
Petr Hájek 《Studia Logica》2002,71(2):149-164
79.
The positive effect of postlearning sleep on memory consolidation as well as the relationship between sleep-related memory processes and the hippocampal formation are increasingly clarified topics in neurobiology. However, the possibility of a stable relationship between waking mnemonic performance and sleep-dependent hippocampal electric activity is unexplored. Here we report a correlative analysis between sleep-dependent parahippocampal-hippocampal (pHip-Hip) electric activity recorded by foramen ovale (FO) electrodes and different types of memory performances in epileptic patients. Psychological testing was performed days or weeks before electrophysiological recordings. The relative spectral power of the slow activity (below 1.25 Hz) during deep non-REM (NREM) sleep at the right pHip-Hip region correlated positively with the visual memory performance according to Rey-Osterrieth Complex Figure Test (ROCFT). Along the posterior-anterior direction of the hippocampal formation a linear increasing of correlations was observed. The relative power of the activity below 1.25 Hz at the left pHip-Hip during phasic REM sleep correlated positively with verbal learning performance and mnemonic retention values according to ROCFT. It is concluded that the pHip-Hip structures' capacity of producing high amplitude and synchronized slow (< 1 Hz) oscillation during deep NREM sleep is related to the functional power of these structures. We hypothesize that the asymmetric (side-specific) propagation of ponto-geniculo-occipital (PGO) activity to the pHip-Hip region is related to the memory correlates of phasic REM sleep. 相似文献
80.
Attending, ignoring, and repetition: on the relation between negative priming and inhibition of return 总被引:8,自引:0,他引:8
A series of spatial localization experiments is reported that addresses the relation between negative priming and inhibition of return. The results of Experiment 1 demonstrate that slowed responses to repeated location stimuli can be obscured by repetition priming effects involving stimulus dimensions other than spatial location. The results of Experiments 2, 3A, and 3B demonstrate that these repetition priming effects may occur only when participants are required to respond to the prime display. Together, these results suggest that differences between attended and ignored repetition effects in selective attention studies of spatial localization do not provide a basis for distinguishing between spatial negative priming and inhibition of return. 相似文献