全文获取类型
收费全文 | 178858篇 |
免费 | 7978篇 |
国内免费 | 156篇 |
专业分类
186992篇 |
出版年
2020年 | 2787篇 |
2019年 | 3433篇 |
2018年 | 3506篇 |
2017年 | 3963篇 |
2016年 | 4599篇 |
2015年 | 3916篇 |
2014年 | 4797篇 |
2013年 | 23425篇 |
2012年 | 4630篇 |
2011年 | 3684篇 |
2010年 | 3861篇 |
2009年 | 4753篇 |
2008年 | 3902篇 |
2007年 | 3435篇 |
2006年 | 4037篇 |
2005年 | 4040篇 |
2004年 | 3520篇 |
2003年 | 3145篇 |
2002年 | 2954篇 |
2001年 | 3551篇 |
2000年 | 3391篇 |
1999年 | 3306篇 |
1998年 | 2839篇 |
1997年 | 2669篇 |
1996年 | 2598篇 |
1995年 | 2429篇 |
1994年 | 2392篇 |
1993年 | 2356篇 |
1992年 | 2809篇 |
1991年 | 2647篇 |
1990年 | 2524篇 |
1989年 | 2389篇 |
1988年 | 2350篇 |
1987年 | 2387篇 |
1986年 | 2372篇 |
1985年 | 2636篇 |
1984年 | 2639篇 |
1983年 | 2419篇 |
1982年 | 2403篇 |
1981年 | 2381篇 |
1980年 | 2198篇 |
1979年 | 2368篇 |
1978年 | 2240篇 |
1977年 | 2196篇 |
1976年 | 2018篇 |
1975年 | 2168篇 |
1974年 | 2247篇 |
1973年 | 2157篇 |
1972年 | 1737篇 |
1971年 | 1665篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
912.
Observers classified sine-wave and square-wave gratings on the basis of fundamental frequency (Are the bars wide or narrow?) or on the basis of higher harmonic frequencies (Are the bars sharp or fuzzy?). Stimuli were presented in either the left (LVF) or right (RVF) visual field. When the classification was made on the basis of the fundamental frequencies (1 or 3 c/deg), there was a LVF/right hemisphere advantage. However, when the classification was on the basis of a sharp/fuzzy distinction which involved searching for the higher harmonic frequencies, then a RVF/left hemisphere advantage was found. 相似文献
913.
The purpose of the present study was to determine if there were differences in hemispheric lateralization during the experience of emotions and if those differences were related to personality style. College-age adult subjects selected for high positive and negative affectivity on Tellegen's Multidimensional Personality Questionnaire (MPQ; Tellegen, 1982) viewed video stimuli selected for their emotionally evocative nature and rated the intensity of the emotions they experienced. The ongoing electroencephalogram (EEG) was recorded while they watched the video clips. Analyses of the EEG data revealed that there were differences in regional activation during the emotional video clips, especially for those stimuli selected to elicit either happy or disgust emotions. These results support the hypothesis that the right hemisphere is specialized for the experience of certain negative affects, whereas the left hemisphere is specialized for the experience of certain positive affects. The findings also indicated some support for the theory that individual differences in personality style are related to differing levels of hemispheric arousal. 相似文献
914.
Laird S. Cermak Mieke Verfaellie Marie Sweeney Larry L. Jacoby 《Brain and cognition》1992,20(2):367-377
To examine the relative contribution of fluency and recollection to the word completion performance of amnesics, we administered a task in which patients were told specifically not to utilize previously presented words during stem completion (an Exclusion condition). This condition was contrasted with a standard word completion task in which patients were encouraged simply to complete the stem with the first word that came to mind (an Inclusion condition). Since the exclusion condition necessitated controlled respecification of the initial presentation, it was hypothesized that amnesics would be less able than controls to exclude study list items. Consistent with this hypothesis, the results indicated that the amnesics' performance, unlike that of the alcoholic controls, did not significantly differ as a function of task condition. To examine whether amnesics' conscious recollection could be enhanced, Experiment 2 presented the study list five times. The amnesics now were able to exclude a significant number of items from the study list; however, they still did so considerably less frequently than alcoholic controls. For the alcoholic controls, increasing the number of study trials had little additional effect on their exclusion performance, but it significantly enhanced their inclusion performance. Taken together, these findings suggest that for control subjects, word completion performance is likely mediated by a combination of fluency and recollection, while for amnesic patients, performance is almost exclusively based on the fluency with which an item comes to mind. 相似文献
915.
In a group of male and female subjects we studied the VEPs related to the solution of a lexical decision task presented in the Left and Right Hemispaces with respect to the Central position in order to explore the electrophysiological correlates of the performance asymmetries obtained when overt spatial attention is directed to the Left or Right Hemispace. When stimuli were presented in the Left Hemispace a significant asymmetry was observed between the two hemispheres of the negative activity around 280 msec in the occipital-parietal areas. Moreover a general increase in the Central and Frontal areas of both the hemispheres was observed. In this paper we discuss why these effects can be considered to be the cause of the costs on accuracy observed in the male subjects. The differences obtained with the female group are discussed in relation to the observed modification on the negative activity around 400 msec with stimuli in the Left Hemispace. These findings give some suggestions about the interaction of structural and attentional mechanisms in the brain during the solution of a lateralized cognitive task. 相似文献
916.
Patterns of coping with cancer. 总被引:12,自引:0,他引:12
We identified five patterns of coping in a sample of 603 cancer patients: "seeking or using social support," "focusing on the positive," "distancing," "cognitive escape-avoidance," and "behavioral escape-avoidance." Relationships of these coping patterns to sociodemographic characteristics, medical factors, stress appraisals, psychotherapeutic experience, and emotional distress were tested using correlational and regression techniques. Type of cancer, time since diagnosis, and whether a person was currently in treatment had few or no relationships to coping. The specific cancer-related problem (e.g., pain, fear of future) was also not associated with how individuals coped. Perceptions of its stressfulness, however, were related to significantly more coping through social support and more of both forms of escape-avoidance. Coping through social support, focusing on the positive, and distancing was associated with less emotional distress, whereas using cognitive and behavioral escape-avoidance was associated with more emotional distress. Implications of the results for understanding coping processes and intervention with cancer patients are discussed. 相似文献
917.
H Intraub R S Bender J A Mangels 《Journal of experimental psychology. Learning, memory, and cognition》1992,18(1):180-191
Ss tend to remember close-up photographs as having had extended boundaries (Intraub & Richardson, 1989). Three alternate explanations were tested: object completion, distortion toward a perceptual schema, and normalization toward a prototypic view. In three experiments, 55-130 undergraduates viewed 16 close-up, prototypic, or wide-angle views of objects for 15 s each. Immediately or 48 hr later, they rated test pictures on a 5-point scale as "same", "closer up", or "father away." Results ruled out object completion because boundary extension occurred when the picture contained no incomplete objects. Immediate tests supported the perceptual schema hypothesis because all unidirectional distortions involved boundary extension. Delayed tests were more suggestive of a memory schema effect because wide-angle pictures yielded boundary restriction. A two-component model of picture processing is proposed. 相似文献
918.
Anterior cerebral asymmetry and the nature of emotion. 总被引:14,自引:0,他引:14
R J Davidson 《Brain and cognition》1992,20(1):125-151
This article presents an overview of the author's recent electrophysiological studies of anterior cerebral asymmetries related to emotion and affective style. A theoretical account is provided of the role of the two hemispheres in emotional processing. This account assigns a major role in approach- and withdrawal-related behavior to the left and right frontal and anterior temporal regions of two hemispheres, respectively. Individual differences in approach- and withdrawal-related emotional reactivity and temperament are associated with stable differences in baseline measures of activation asymmetry in these anterior regions. Phasic state changes in emotion result in shifts in anterior activation asymmetry which are superimposed upon these stable baseline differences. Future directions for research in this area are discussed. 相似文献
919.
920.