首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2637篇
  免费   198篇
  国内免费   3篇
  2024年   4篇
  2023年   44篇
  2022年   43篇
  2021年   57篇
  2020年   94篇
  2019年   123篇
  2018年   134篇
  2017年   172篇
  2016年   159篇
  2015年   107篇
  2014年   116篇
  2013年   307篇
  2012年   156篇
  2011年   146篇
  2010年   95篇
  2009年   79篇
  2008年   127篇
  2007年   123篇
  2006年   130篇
  2005年   84篇
  2004年   75篇
  2003年   67篇
  2002年   50篇
  2001年   38篇
  2000年   19篇
  1999年   28篇
  1998年   8篇
  1997年   15篇
  1996年   18篇
  1995年   19篇
  1994年   20篇
  1993年   16篇
  1992年   13篇
  1991年   7篇
  1990年   13篇
  1989年   9篇
  1988年   8篇
  1987年   9篇
  1986年   13篇
  1985年   7篇
  1984年   6篇
  1983年   5篇
  1981年   9篇
  1980年   6篇
  1979年   5篇
  1977年   4篇
  1976年   7篇
  1975年   4篇
  1974年   6篇
  1967年   4篇
排序方式: 共有2838条查询结果,搜索用时 15 毫秒
211.
The recent exceptional migratory surge has put huge pressure on many countries of the developed world. The Member States of the European Union are still striving to find a sustainable solution to the ongoing massive asylum crisis, with hundreds of thousands of people fleeing from wars, authoritarian regimes, and poverty in the Middle East and North Africa. Really, the recent asylum crisis is essentially a policy asylum crisis, which places under pressure a limited number of Member States. The research provides a diagnosis of what went wrong, by highlighting the weakness of mechanisms for implementing the principle of solidarity and fair sharing of responsibility. To overcome some drawbacks of the European asylum system, the research suggests a novel and constructive solution, which could promote common values and interests in a viable way. Due to its geographic location and expertise, Italy could play a central role in supporting the EU asylum system, by facilitating substantial cooperation and policy integration.  相似文献   
212.
During the execution of a cognitive task, the brain maintains contextual information to guide behavior and achieve desired goals. The AX-Continuous Performance Task is used to study proactive versus reactive cognitive control. Young adults tend to behave proactively in standard testing conditions. However, it remains unclear how interindividual variability (e.g., in cognitive and motivational factors) may drive people into more reactive or proactive control under the same task demands. We investigated the use of control strategies in a large population of healthy young adults. We computed the proactive behavioral index and consequently divided participants into proactive, reactive, and intermediate groups. We found that reactive participants were generally slower, presented lower context sensitivity, and larger response variability. Pupillary changes and blink rate index cognitive effort allocation. We measured, concomitantly to the task, the pupil size and frequency of blinks associated with the cue maintenance and response intervals. During the cue period, nonfrequent, nontarget cues led to increased pupil dilation and number of blinks in all participants. During the response interval, we found more errors and increased pupil dilation to the probe when all participants had to overcome a response bias generated by the frequent cue. Only reactive participants showed larger response-related pupil when they had to overcome a response bias related to the frequent probe. Contrary to expectations, groups did not differ in ocular measures in the cue period. In conclusion, interindividual differences in cognitive control between healthy adults can be mapped onto different patterns of effort allocation indexed by the pupil.  相似文献   
213.
Behavioural variant frontotemporal dementia (bvFTD) is a form of frontotemporal degeneration characterized by early changes in personality, emotional blunting, and/or loss of empathy. Recent research has highlighted that these features may be at least partially explained by impairments in the theory of mind (ToM; i.e., the ability to understand and predict other people’s behaviour by attributing independent mental states to them). The aim of this randomized, double-blind, placebo-controlled study was to test the hypothesis that transcranial direct current stimulation (tDCS) over the medial frontal cortex (MFC) selectively enhances communicative intention processing, a specific ToM ability. Using a single-session online design, we administered a ToM task that measures the ability to represent other people’s private and communicative intentions during active or sham tDCS to 16 bvFTD patients. To assess the impact of dementia on performance on the ToM task, we included 16 age-matched healthy volunteers who were asked to perform the entire experimental ToM task. BvFTD is characterized by an impairment in the comprehension of both communicative and private intentions relative to a healthy control group and by a disproportional impairment in communicative intention compared with private intention processing. Significant and selective accuracy improvement in the comprehension of communicative intentions after active stimulation was observed in patients with bvFTD. This is the first study that analyses ToM ability in patients with bvFTD using tDCS stimulation. Our findings could potentially contribute to the development of an effective, noninvasive brain stimulation treatment of ToM impairments in patients with bvFTD.  相似文献   
214.
Humans possess an invaluable ability of self-expression that extends into visual, literary, musical, and many other fields of creation. More than any other profession, artists are in close contact with this subdomain of creativity. Probably one of the most intriguing aspects of creativity is its negative correlation with the availability of monetary reward. The aim of this study was to investigate the reactivity of the dopaminergic reward system in artists and nonartist controls using the desire-reason-dilemma (DRD) paradigm, which allows separate evaluation of reactivity to the acceptance and rejection of rewards. Using fMRI, blood-oxygen-level-dependent (BOLD) responses were measured in key regions of the reward system, namely the ventral striatum (VS), the ventral tegmental area (VTA), and the anterior ventral prefrontal cortex (AVPFC). In contrast to controls, artists presented significantly weaker VS activation in reward acceptance. Additionally, they showed stronger suppression of the VS by the AVPFC in reward rejection. No other differences in demographic or behavioral data were evidenced. These results support the existence of characteristic neural traits in artists, who display reduced reactions to monetary reward acceptance and increased reactions to monetary reward rejection.  相似文献   
215.
Reflective functioning (RF) is a measure of mentalization—the capacity to think about one’s own and others’ thoughts and feelings and to understand the connections between mental states and behaviors. Previous research indicates a decline in marital quality across the transition to parenthood, and some studies have found that parents are less happy than non-parents. Thus, researchers have called for research into possible moderators of these patterns. RF may help couples navigate this transition by more easily taking each other’s (and the infant’s) perspective and understanding each other’s behaviors. Much of the research on RF has focused on mothering behavior; research has not yet examined associations between RF and other family interactions. We examined associations between RF and marital and coparenting quality for both wives and husbands. Reflective functioning was coded from Adult Attachment Interviews conducted during pregnancy. We assessed marital quality at 3.5 months, and coparenting quality at 13 months, after the birth of the target child. Wives’ higher RF was associated with higher levels of positive—and lower levels of negative—marital and coparenting interactions. Wives who were better able to reflect on their early experiences with their parents were involved in marital interactions that were more positive and supportive and less conflicted and undermining. Husbands’ RF did not predict marital or coparenting quality. These findings highlight the importance of reflective functioning in understanding family functioning.  相似文献   
216.
Background and Objectives: Diminished heart rate variability has been found to be associated with high anxiety symptomatology. Since adolescence is the period of onset for many anxiety disorders, this study aimed to determine sex- and anxiety-related differences in heart rate variability and complexity in adolescents.

Methods: We created four groups according to sex and anxiety symptomatology: high-anxiety girls (n?=?24) and boys (n?=?25), and low-anxiety girls (n?=?22) and boys (n?=?24) and recorded their cardiac function while they performed regular school activities. A series of two-way (sex and anxiety) MANOVAs were performed on time domain variability, frequency domain variability, and non-linear complexity.

Results: We obtained no multivariate interaction effects between sex and anxiety, but highly anxious participants had lower heart rate variability than the low-anxiety group. Regarding sex, girls showed lower heart rate variability and complexity than boys.

Conclusions: The results suggest that adolescent girls have a less flexible cardiac system that could be a marker of the girls’ vulnerability to developing anxiety disorders.  相似文献   
217.
In this article, we assume an interdisciplinary approach to the study of why and how people transpose political considerations to their lifestyles. Our aims are threefold: to understand the meanings and perceptions of people engaged in lifestyle politics and collective action; to examine the motives guiding individual change; and to explore the linkage processes between lifestyle politics and collective action. Identity process theory is considered as a lens to examine the processes and the motives of identity via a thematic analysis of 22 interviews. This study combined interviews with people seeking social change through their lifestyles with interviews with members of action groups and social movements. We found that each participant's identity is guided by identity motives such as distinctiveness, continuity, and psychological coherence. Besides, lifestyle politics is evaluated as an effective way to bring about social change, depending on the individual experience of perceived power to bring about change through collective action. Overall, lifestyle politics states the way in which the participants decided to live, to construct their identities, and to represent their beliefs about the right thing to do. Lifestyle politics complements collective action as a strategy to increase the potential of bringing about social change. The implications of this research are discussed in relation to the importance of understanding the processes of identity and lifestyle change in the context of social, environmental, and political change.  相似文献   
218.
This paper investigates the interpretation that Italian-speaking children and adults assign to negative sentences with disjunction and negative sentences with conjunction. The aim of the study was to determine whether children and adults assign the same interpretation to these types of sentences. The Semantic Subset Principle (SSP) (Crain et al., in: Clifton, Frazer, Rayner (eds) Perspective on sentence processing, Lawrence Erlbaum, Hillside, 1994) predicts that children’s initial scope assignment should correspond to the interpretation that makes sentences true in the narrowest range of circumstances, even when this is not the interpretation assigned by adults. This prediction was borne out in previous studies in Japanese, Mandarin and Turkish. As predicted by the SSP, the findings of the present study indicate that Italian-speaking children and adults assign the same interpretation to negative sentences with conjunction (conjunction takes scope over negation). By contrast, the study revealed that some children differed from adults in the interpretation they assigned to negative sentences with disjunction. Adults interpreted disjunction as taking scope over negation, whereas children were divided into two groups: one group interpreted disjunction as taking scope over negation as adults did; another group interpreted negation as taking scope over disjunction, as predicted by the SSP. To explain the findings, we propose that Italian-speaking children initially differ from adults as dictated by the SSP, but children converge on the adult grammar earlier than children acquiring other languages due to the negative concord status of Italian, including the application of negative concord to sentences with disjunction.  相似文献   
219.

Background/Objectives

This paper aimed to validate the Spanish version of scores of the Visual Analogue Scale for Anxiety-Revised (VAA-R) in child population, and to verify the existence of anxiety profiles and to relate them to school refusal.

Method

The sample was made up of 911 Spanish students between 8 and 12 years old (M = 9.61, SD = 1.23). The measures used were the VAA-R and the School Refusal Assessment Scale-Revised for Children (SRAS-R-C).

Results

Confirmatory factorial analysis supported the three-dimensional VAA-R structure: Anticipatory Anxiety (AA), School-based performance Anxiety (SA) and Generalized Anxiety (GA). The VAA-R has an adequate reliability and structural invariance across sex and age. No latent mean differences were found across sex, but did occur through age in AA and GA factors. Cluster analysis identified four child anxiety profiles: High Anxiety, High Anxiety School-type, Low Anxiety, and Moderate Anxiety, which differed significantly in all dimensions of school refusal.

Conclusions

These findings may be useful for the assessment and treatment of anxious symptoms originated at school.  相似文献   
220.
The Mapuche practice of weaving has occupied a transcendental role for this community in its system of symbolic representation. These textiles involve different elements of cultural identity for the community, for the wearers of the garments and, most of all, for their creators. This article analyzes the creation context in which the Mapuche textile tradition brings into tension different aspects of cultural identity and innovation within the construction of cultural memory. It examines two principal scenarios that arose from ethnographic work: 1) selection of materials; 2) preparation and fabrication. The findings show that, in both scenarios, the new rules emerging from religious and commercial concerns in the present-day context of these weavers are linked with the diverse positions taken by each woman. We discuss how these new rules are associated with different processes of cultural identity in this group of Mapuche women.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号