全文获取类型
收费全文 | 2965篇 |
免费 | 203篇 |
出版年
2024年 | 7篇 |
2023年 | 48篇 |
2022年 | 41篇 |
2021年 | 73篇 |
2020年 | 89篇 |
2019年 | 106篇 |
2018年 | 176篇 |
2017年 | 154篇 |
2016年 | 163篇 |
2015年 | 113篇 |
2014年 | 113篇 |
2013年 | 360篇 |
2012年 | 197篇 |
2011年 | 212篇 |
2010年 | 143篇 |
2009年 | 59篇 |
2008年 | 185篇 |
2007年 | 154篇 |
2006年 | 129篇 |
2005年 | 107篇 |
2004年 | 63篇 |
2003年 | 69篇 |
2002年 | 64篇 |
2001年 | 22篇 |
2000年 | 43篇 |
1999年 | 22篇 |
1998年 | 24篇 |
1997年 | 13篇 |
1996年 | 17篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 14篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1973年 | 4篇 |
1968年 | 3篇 |
排序方式: 共有3168条查询结果,搜索用时 31 毫秒
101.
Using 4 samples of adolescents from 3 nations (Australia, Sweden, and the United States), the authors explored whether the gendered nature of the family socialization environment affected young people's level of group-based social egalitarianism. It was hypothesized that the greater the father's influence in the family, the greater the children's level of group-based social anti-egalitarianism. The results were consistent with the authors' expectations. Children from father-headed households had the highest level of group-based social anti-egalitarianism; children from mother-headed households had the lowest level of group-based anti-egalitarianism; and children from dual-parent households were in between. Similarly, children from homes in which the father had the greatest decision-making power tended to exhibit the highest levels of anti-egalitarianism, whereas children from homes in which the mother had the greatest decision-making power displayed the lowest levels of social anti-egalitarianism. Family structure did not interact with either the nationality or gender of the child. 相似文献
102.
103.
Differential effects of emotional arousal in short- and long-term memory in healthy adults 总被引:4,自引:0,他引:4
Quevedo J Sant'Anna MK Madruga M Lovato I de-Paris F Kapczinski F Izquierdo I Cahill L 《Neurobiology of learning and memory》2003,79(2):132-135
Recent studies demonstrated important differences between short- and long-term memory mechanisms. Besides, the emotional component has a crucial role in memory formation. This study was carried out to answer whether there is a differential influence of emotional arousal in short- and long-term memory in healthy adults. Thirty-one healthy volunteers were divided into two major groups. In the first group long-term memory (LTM) was evaluated, with the testing session one week after training. The second group was tested 1h after training, where short-term memory (STM) was evaluated. Each group was divided in to two subgroups. One half of the volunteers was exposed to an emotionally neutral story, and the other half of each group was exposed to a closely matched but more emotionally arousing story. The testing session consisted of a questionary containing 80 questions of multiple choices. The results were evaluated through percentage of correct answers. Results showed that correct answers were increased, in LTM measures, in the subjects that were given the emotional version of the test. In STM measures, no differences were found between the emotional and neutral version. However, the presentation of emotional story caused an emotional reaction in both groups. The lack of effect of emotional arousal in STM suggests that amygdala is not related to STM mechanisms. Further studies using different approaches are needed to elucidate if STM processes are influenced by emotional arousal. 相似文献
104.
Giménez de la Peña A Canto Ortiz JM Fernández Berrocal P Barrett M 《The Spanish journal of psychology》2003,6(1):28-34
Social psychologists have shown a profound interest in intergroup relationships, but there are very few papers focusing on the developmental aspects that explain the psychological mechanisms involved in the construction of group and cultural identity. Our research aims to explore how the self-categorization of Andalusian children evolves. We tried to assess the degree to which they self-identify as Andalusian, Spanish, and European, and how this identification changes with age. We were also interested in the affective evaluation of different groups (French, Italian, English, German, Spanish, Catalonian, and Andalusian) made by Andalusian children. Furthermore, we analyzed the relationship between self-categorization and the evaluation of these groups. Results show that the development of national (autonomous community) identity in these children is influenced by their cognitive development, as well as by the relationships among the regional communities of Spain and the relationships between Spain and other countries. The peculiarity of Andalusians as a group is that they assume both identities: Spanish and Andalusian, from a very early age. In-group favoritism is an extended phenomenon at all ages, and Andalusian children have a negative stereotype of the other Spanish groups and other European communities. 相似文献
105.
Lesion of the ventral periaqueductal gray reduces conditioned fear but does not change freezing induced by stimulation of the dorsal periaqueductal gray 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Learning & memory (Cold Spring Harbor, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Vianna DM Graeff FG Landeira-Fernandez J Brandão ML 《Learning & memory (Cold Spring Harbor, N.Y.)》2001,8(3):164-169
Previously-reported evidence showed that freezing to a context previously associated with footshock is impaired by lesion of the ventral periaqueductal gray (vPAG). It has also been shown that stepwise increase in the intensity of the electrical stimulation of the dorsal periaqueductal gray (dPAG) produces alertness, then freezing, and finally escape. These aversive responses are mimicked by microinjections of GABA receptor antagonists, such as bicuculline, or blockers of the glutamic acid decarboxylase (GAD), such as semicarbazide, into the dPAG. In this work, we examined whether the expression of these defensive responses could be the result of activation of ventral portion of the periaqueductal gray. Sham- or vPAG electrolytic–lesioned rats were implanted with an electrode in the dPAG for the determination of the thresholds of freezing and escape responses. The vPAG electrolytic lesions were behaviorally verified through a context-conditioned fear paradigm. Results indicated that lesion of the vPAG disrupted conditioned freezing response to contextual cues associated with footshocks but did not change the dPAG electrical stimulation for freezing and escape responses. In a second experiment, lesion of the vPAG also did not change the amount of freezing and escape behavior produced by microinjections of semicarbazide into the dPAG. These findings indicate that freezing and escape defensive responses induced by dPAG stimulation do not depend on the integrity of the vPAG. A discussion on different neural circuitries that might underlie different inhibitory and active defensive behavioral patterns that animals display during threatening situations is presented. 相似文献
106.
The nature and extent of young caring in the UK continue to be a feature of a growing number of research programmes motivated by a children and carers' rights philosophy. However, the context in which young caring occurs as a result of parental ill-health or disability can only be fully understood by examining the findings and implications of medical research into parental impairment, and the social movements that have served to re-define the concept of 'disability' in society. This paper examines the arguments put forward by medical researchers, by those proposing a social model of disability and by those who have specifically investigated the conditions and experiences of young carers. It argues that children's caring roles within families where there is parental illness or disability need to be understood not only as a reflection of the nature of the medical condition itself, but as a consequence of complex family, social and economic processes. A 'whole family' approach is proposed, where the needs of children and parents are respected and responded to. 相似文献
107.
Selçuk Özgediz 《Knowledge, Technology, and Policy》1999,11(4):97-113
Investing in research is a long-term, risky proposition. In agriculture, it could take fifteen years or more for a research
finding to show an improvement in a farmer’s field. Yet, research institutions, like other organizations it needs to be evaluated.
For more than twenty years, independent panels of outside experts have evaluated each of the international research centers
that the Consultative Group of International Agricultural Research (CGIAR) supports. This paper examines the evolution of
this review system, outlines the key methodological challenges faced, and draws lessons for others engaged in evaluating research
institutions. It notes that the scope of the CGIAR reviews have been broadened over time in response to users’ concerns. Reviews
now cover four dimensions of performance: research results, quality and relevance of research, vision and strategic directions,
and management efficiency. The methodological challenges faced in measurement, valuation, and attribution are reviewed, along
with practices found to be helpful in addressing these concerns. The paper concludes that the panel approach to institutional
evaluation has served CGIAR’s needs well, and recommends it as an evaluation technique for integrating quantitative and qualitative
dimensions of institutional performance.
His recent work has concentrated on the governance and management of the CGIAR and the individual research centers it supports,
including questions of evaluating management effectiveness. Prior to joining the World Bank in 1979, he was Assistant Professor
of Political Science at Bogazici University (Istanbul) and Senior Research Director of Systems Research Incorporated (Lansing,
Michigan). 相似文献
108.
Sara Jo Nixon 《Psychological science》1999,10(3):181-185
The neurocognitive effects of alcohol have been frequently examined. Studies reveal a wide array of cognitive deficits. Attempts to develop a parsimonious model for these effects have been difficult because of the intra- and intersubject variability. Complicating the development of a model of cognitive deficits in substance abusers is the common practice of polysubstance abuse. The use of theoretical models that focus on the underlying cognitive processes offers flexibility while maintaining sufficient theoretical precision. This article briefly reviews the literature on neurocognitive changes associated with substance abuse as well as the various theoretical models that have been studied. It also provides an overview of recovery of function. Its primary objective is to evaluate cognitive function among alcoholic subtypes, defined by patterns of other drug use. This analysis suggests there are significant differences in neurocognitive function among these subtypes. 相似文献
109.
Propositional knowledge and the enigma of realism 总被引:1,自引:0,他引:1
Murat Baç 《Philosophia》1999,27(1-2):199-223
110.