全文获取类型
收费全文 | 50847篇 |
免费 | 1960篇 |
国内免费 | 28篇 |
专业分类
52835篇 |
出版年
2020年 | 476篇 |
2019年 | 642篇 |
2018年 | 893篇 |
2017年 | 958篇 |
2016年 | 960篇 |
2015年 | 721篇 |
2014年 | 799篇 |
2013年 | 4013篇 |
2012年 | 1408篇 |
2011年 | 1544篇 |
2010年 | 975篇 |
2009年 | 956篇 |
2008年 | 1324篇 |
2007年 | 1310篇 |
2006年 | 1190篇 |
2005年 | 1042篇 |
2004年 | 962篇 |
2003年 | 1007篇 |
2002年 | 976篇 |
2001年 | 1798篇 |
2000年 | 1746篇 |
1999年 | 1272篇 |
1998年 | 562篇 |
1997年 | 476篇 |
1996年 | 488篇 |
1992年 | 1077篇 |
1991年 | 1044篇 |
1990年 | 996篇 |
1989年 | 939篇 |
1988年 | 929篇 |
1987年 | 892篇 |
1986年 | 870篇 |
1985年 | 941篇 |
1984年 | 742篇 |
1983年 | 615篇 |
1981年 | 478篇 |
1979年 | 769篇 |
1978年 | 563篇 |
1977年 | 509篇 |
1976年 | 486篇 |
1975年 | 652篇 |
1974年 | 737篇 |
1973年 | 793篇 |
1972年 | 639篇 |
1971年 | 579篇 |
1970年 | 553篇 |
1969年 | 549篇 |
1968年 | 691篇 |
1967年 | 617篇 |
1966年 | 638篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
The effects of tobacco smoking on responses to electrical stimulation were studied according to a Method of Limits (ML) threshold analysis and a Sensory Decision Theory (SDT) analysis. For the ML procedure, Detection Threshold (DT), Pain Threshold (PT) and Tolerance Level (TL) measures were obtained. For the SDT procedure, nonparametric estimates of capacity to discriminate between stimulus intensities (P(A)) and response criterion (B) were calculated. There was no main effect of tobacco smoking on responses to electrical stimulation. Males had consistently higher ML thresholds than females in both the NS and S condition. Males also tended to increase in DT and PT after smoking. From a comparison between the effects of smoking on ML and SDT measures it was suggested that PT is related mainly to sensory factors and TL to response factors. 相似文献
952.
In many classification problems, one often possesses external and/or internal information concerning the objects or units to be analyzed which makes it appropriate to impose constraints on the set of allowable classifications and their characteristics. CONCLUS, or CONstrained CLUStering, is a new methodology devised to perform constrained classification in either an overlapping or nonoverlapping (hierarchical or nonhierarchial) manner. This paper initially reviews the related classification literature. A discussion of the use of constraints in clustering problems is then presented. The CONCLUS model and algorithm are described in detail, as well as their flexibility for use in various applications. Monte Carlo results are presented for two synthetic data sets with appropriate discussion of the resulting implications. An illustration of CONCLUS is presented with respect to a sales territory design problem where the objects classified are various Forbes-500 companies. Finally, the discussion section highlights the main contribution of the paper and offers some areas for future research.We wish to thank C. Mallows and J. D. Carroll for some helpful technical discussion and L. Clark and D. Art for their valuable computer assistance. We also wish to thank H. Pollak, R. Gnanadesikan, and J. Kettenring for their thorough reviews of a previous draft of this paper. Finally, we acknowledge helpful comments of the editor and two anonymous reviewers. 相似文献
953.
S. D. Reicher 《European journal of social psychology》1984,14(1):1-21
The paper contains a detailed study of the St. Pauls' riots of April 1980. Particular attention is paid to the limits of participation in the event and the limits of crowd action. It is argued that these limits show clear social form and cannot be explained in terms of the individualistic theories that dominate crowd psychology. Instead a model of crowd behaviour based on the social identity model is advanced to account for the observations. It is concluded that crowd behaviour is more sophisticated and creative than hitherto allowed and that the neglect of this field should be remedied. 相似文献
954.
S. Wiegersma 《Memory & cognition》1984,12(2):190-194
The question of whether repetition avoidance in sequential response production depends on the phonetic or the semantic encoding of previous responses was investigated by varying the acoustic and semantic similarity among the response alternatives. The results indicated that acoustic similarity affected repetition avoidance with six alternative words and a production rate of one per second, but not with four alternative letters and a rate of one per 2 sac. Semantic similarity between words was also studied, and was not seen to affect repetition avoidance. Results were explained by means of a model in which comparisons between a memory set of admissible responses and a memory set of recent responses are made at a phonetic level of response representation. 相似文献
955.
Sarah B. Woods Angela Hiefner Patricia N. E. Roberson Nida Zahra Elizabeth Mayfield Arnold Victoria Udezi 《Family process》2023,62(1):230-253
African Americans are at significantly greater risk of hypertension and worse cardiovascular outcomes than other racialized groups, yet hypertension intervention effects remain limited. Thus, it is necessary to understand the potential mechanisms whereby interventions may be more effectively targeted to improve health. Supported by prior research evidence and guided by the Biobehavioral Family Model, this study examined associations between family relationship quality, psychological wellbeing, and self-management behaviors for African Americans with hypertension. Data were pooled from three Midlife Development in the U.S. projects, resulting in a sample of 317 African Americans (63.4% female, Mage = 53.32) with self-reported high blood pressure in the past 12 months. We tested four cross-sectional multiple mediator models, with depressed mood and environmental mastery mediating associations between family strain and exercise, smoking, problematic alcohol use, and stress-eating. Environmental mastery mediated the association between greater family strain and decreased odds of achieving recommended exercise levels; greater odds of reporting problematic alcohol use; and greater stress-eating. Though family strain was associated with depressed mood in each model, this variable did not serve as an indirect pathway to self-management behaviors. Family strain, and the potential pathway identified via environmental mastery, may be a meaningful predictor of disease self-management for African Americans with hypertension. Longitudinal studies are needed to examine directionality and to support intervention trials for improving self-management and hypertension outcomes. 相似文献
956.
957.
Janet H. Hsiao Antoni B. Chan 《British journal of psychology (London, England : 1953)》2023,114(Z1):17-20
Multiple factors have been proposed to contribute to the other-race effect in face recognition, including perceptual expertise and social-cognitive accounts. Here, we propose to understand the effect and its contributing factors from the perspectives of learning mechanisms that involve joint learning of visual attention strategies and internal representations for faces, which can be modulated by quality of contact with other-race individuals including emotional and motivational factors. Computational simulations of this process will enhance our understanding of interactions among factors and help resolve inconsistent results in the literature. In particular, since learning is driven by task demands, visual attention effects observed in different face-processing tasks, such as passive viewing or recognition, are likely to be task specific (although may be associated) and should be examined and compared separately. When examining visual attention strategies, the use of more data-driven and comprehensive eye movement measures, taking both spatial–temporal pattern and consistency of eye movements into account, can lead to novel discoveries in other-race face processing. The proposed framework and analysis methods may be applied to other tasks of real-life significance such as face emotion recognition, further enhancing our understanding of the relationship between learning and visual cognition. 相似文献
958.
Fanny Lalot Dominic Abrams Maria S. Heering Jacinta Babaian Hilal Ozkececi Linus Peitz Kaya Davies Hayon Jo Broadwood 《Political psychology》2023,44(5):983-1011
We test the hypothesis that COVID-19 vaccine hesitancy is attributable to distrustful complacency—an interactive combination of low concern and low trust. Across two studies, 9,695 respondents from different parts of Britain reported their level of concern about COVID-19, trust in the UK government, and intention to accept or refuse the vaccine. Multilevel regression analysis, controlling for geographic area and relevant demographics, confirmed the predicted interactive effect of concern and trust. Across studies, respondents with both low trust and low concern were 10%–22% more vaccine hesitant than respondents with either high trust or high concern, and 26%–29% more hesitant than respondents with both high trust and high concern. Results hold equally among White, Black, and Muslim respondents, consistent with the view that regardless of mean-level differences, a common process underlies vaccine hesitancy, underlining the importance of tackling distrustful complacency both generally and specifically among unvaccinated individuals and populations. 相似文献
959.
To illustrate the view that a speaker can have a partial understanding of a concept, Burge uses the example of Leibniz’s and Newton’s understanding of the concept of derivative. In a recent article, Sheldon Smith criticizes this example and maintains that Newton’s and Leibniz’s use of their derivative symbols does not univocally determine their references. The present article aims at challenging Smith’s analysis. It first shows that Smith misconstrues Burge’s position. It second suggests that the philosophical lessons one should draw from the practice of the historians of philosophy are more ambivalent than what Smith thinks.
相似文献960.
Sara Suzuki Taina B. Quiles Elena Maker Castro 《Journal of community & applied social psychology》2023,33(2):406-424
Critical action—behaviours aimed at dismantling systems of oppression—must be examined within youths' racialized experiences and should incorporate cultural and sociohistorical factors. We considered an expansive list of items capturing youth behaviours to create a novel four-factor (service, community change, expression, and care) measure of critical action for Asian and Hispanic/Latinx youth. Multiple distinct profiles of critical action were identified within both racial-ethnic groups, and associations between the profiles and sociodemographic and contextual support variables were explored. Gender differences in the type of critical action were found in both racial-ethnic groups, pointing to the potential influence of gender roles on critical action among these populations. Differences in critical action patterns were also found between those born in the U.S. versus those born outside the U.S.; access to critical action may differ within racial-ethnic groups depending on birthplace and associated nuances in familial and cultural contexts. This paper demonstrated a need for attending to variation between and within groups in the study of critical action in order to effectively support racialized youth's coping within and resistance against systems of oppression. 相似文献