全文获取类型
收费全文 | 2767篇 |
免费 | 125篇 |
国内免费 | 1篇 |
出版年
2023年 | 17篇 |
2022年 | 15篇 |
2021年 | 29篇 |
2020年 | 43篇 |
2019年 | 55篇 |
2018年 | 73篇 |
2017年 | 80篇 |
2016年 | 114篇 |
2015年 | 57篇 |
2014年 | 89篇 |
2013年 | 333篇 |
2012年 | 142篇 |
2011年 | 146篇 |
2010年 | 89篇 |
2009年 | 82篇 |
2008年 | 131篇 |
2007年 | 113篇 |
2006年 | 112篇 |
2005年 | 87篇 |
2004年 | 99篇 |
2003年 | 90篇 |
2002年 | 62篇 |
2001年 | 63篇 |
2000年 | 54篇 |
1999年 | 42篇 |
1998年 | 40篇 |
1997年 | 38篇 |
1996年 | 35篇 |
1995年 | 41篇 |
1994年 | 27篇 |
1993年 | 31篇 |
1992年 | 37篇 |
1991年 | 27篇 |
1990年 | 32篇 |
1989年 | 20篇 |
1988年 | 32篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 22篇 |
1984年 | 23篇 |
1983年 | 17篇 |
1982年 | 23篇 |
1981年 | 11篇 |
1979年 | 20篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1974年 | 17篇 |
1972年 | 13篇 |
1970年 | 11篇 |
1968年 | 11篇 |
排序方式: 共有2893条查询结果,搜索用时 15 毫秒
291.
B. Van de Moortèle § T. Epicier J. L. Soubeyroux J. M. Pelletier 《Philosophical Magazine Letters》2013,93(4):245-256
The devitrification process of Zr46.75Ti8.25Cu7.5Ni10Be27.5 metallic glass during annealing in the supercooled liquid region has been studied by conventional, high-resolution and analytical transmission electron microscopy (TEM). Two kinds of particle appear during devitrification: quasicrystals and crystalline precipitates. Nanoanalysis with energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy reveal that quasicrystals are Be free, while the crystallites have the ZrBe2 hexagonal structure. These experiments confirm the key role of Be during devitrification. They also indicate that quasicrystals can form in the system Zr–Ti–Cu–Ni (without Be), as further evidenced by direct synthesis and an in situ neutron diffraction investigation, according to the chemical composition deduced from the TEM analysis. 相似文献
292.
Human sensitivity for social cues is exquisite, as illustrated by the ease with which simplified point-light movements invoke social and emotional responses. Compared to faces, these biological motion stimuli only recently started to be used to explore questions regarding social cognition and anxiety. We presented human point-light walkers that could be perceived as facing towards or facing away from the observer, and tested whether participants with high social anxiety would perceive these bistable stimuli differently, because this type of stimuli has particular relevance for them. The results showed that observers with high social anxiety tended to see walkers as facing away more frequently than those with low social anxiety. This may mean that high socially anxious observers are biased towards the more positive perceptual alternative because they are motivated to protect themselves against threatening social experiences, but we also explore alternative explanations. The findings are in line with the evidence for a positivity bias in perception, also called wishful seeing, but in contrast with the attentional negativity bias often found in social anxiety. We discuss reasons for this divergence and possible limitations of the current study. 相似文献
293.
Bev Killian Mary Van der Riet Angela Hough Vivien O'Neill Thabisile Zondi 《Journal of Psychology in Africa》2013,23(3):403-412
This study explores the notion of children's agency in situations of extreme adversity. The child participants (n=117) live in the midst of the HIV/AIDS pandemic; extreme poverty; and systemic educational malfunction. Four focus group interviews were conducted with the children to explore their experiences of potential barriers to education. The findings indicated that contextual factors had a profoundly negative impact on the children, with their agentive capacity being severely compromised through their exposure to multiple, complex layers of risk. There was very little evidence to suggest that children retain any sense of their own agency in such adversity. This has implications for their resilience and for the development of policy and intervention strategies that may meet these children's needs. 相似文献
294.
Deployment may lead the soldiers to dichotomise their profession and their family life, resulting in unwanted effects on family or career. Effects on reintegration and functioning within family are considered. Reunions may be characterized by perceived negative reception and consequences could spill over to children as parents attempt to equivocate their differences. Risks exist for fragmentation of the family system or divorce. Social support may serve to buffer families with members on deployment. 相似文献
295.
Gregory R. Peterson Michael Spezio James A. Van Slyke Kevin Reimer Warren Brown 《Theology & Science》2013,11(2):139-161
This paper argues that consideration of moral exemplars may provide a means for integrating insights across philosophical ethics, theological ethics, and the scientific study of moral cognition. Key to this endeavor is an understanding of the relation of cognition and emotion in ethical decision-making, a relation that is usually understood to be oppositional but which in proper circumstances may be understood to be quite the opposite. Indeed, a distinctive feature of moral exemplarity may consist in the ability to properly integrate the emotions into the moral life, and reference to and imitation of exemplars may involve a referencing and imitating of the emotions of the exemplar. 相似文献
296.
ABSTRACTThis article responds to calls for conceptual clarification in the media effects domain by providing a definition for attitudinal cultivation effects. Our definition contains 5 core characteristics: the (a) linear effects of (b) repeated media exposure on (c) the evaluation as given by memory associations (d) strengthened by and (e) valenced in line with those media messages. We reason that, when accepting this definition, the cultivation hypothesis predicts effects of repeated media use on evaluations to primarily occur at the level of gut evaluations given by automatically activated memory associations. Corroborating this logic for the effects of alcohol use portrayals in television fiction, we find the relationship between fiction exposure and self-reported alcohol use evaluations to be (a) moderated by speed of expressing those evaluations and (b) mediated by responses to self-reports tapping into gut feelings. The implications of these findings for future media effects studies are discussed. 相似文献
297.
Martijn Schouteden Katrijn Van Deun Sven Pattyn Iven Van Mechelen 《Behavior research methods》2013,45(3):822-833
Often data are collected that consist of different blocks that all contain information about the same entities (e.g., items, persons, or situations). In order to unveil both information that is common to all data blocks and information that is distinctive for one or a few of them, an integrated analysis of the whole of all data blocks may be most useful. Interesting classes of methods for such an approach are simultaneous-component and multigroup factor analysis methods. These methods yield dimensions underlying the data at hand. Unfortunately, however, in the results from such analyses, common and distinctive types of information are mixed up. This article proposes a novel method to disentangle the two kinds of information, by making use of the rotational freedom of component and factor models. We illustrate this method with data from a cross-cultural study of emotions. 相似文献
298.
Wim Van den Noortgate José Antonio López-López Fulgencio Marín-Martínez Julio Sánchez-Meca 《Behavior research methods》2013,45(2):576-594
Although dependence in effect sizes is ubiquitous, commonly used meta-analytic methods assume independent effect sizes. We describe and illustrate three-level extensions of a mixed effects meta-analytic model that accounts for various sources of dependence within and across studies, because multilevel extensions of meta-analytic models still are not well known. We also present a three-level model for the common case where, within studies, multiple effect sizes are calculated using the same sample. Whereas this approach is relatively simple and does not require imputing values for the unknown sampling covariances, it has hardly been used, and its performance has not been empirically investigated. Therefore, we set up a simulation study, showing that also in this situation, a three-level approach yields valid results: Estimates of the treatment effects and the corresponding standard errors are unbiased. 相似文献
299.
Susan A. Yoon Karen Elinich Joyce Wang Christopher Steinmeier Jacqueline G. Van Schooneveld 《Visitor Studies》2013,16(2):157-170
ABSTRACT This study investigated the effects of using digital augmentation to enhance an exhibit device to influence conceptual understanding about a science topic in a science museum setting. In particular, the study considered how students in Grades 6–8 engaged with the device that was available in both augmented and nonaugmented (control) conditions. Results show increased cognitive (critical thinking) skills when the digital augmentation was present that we hypothesize led to increased conceptual gains. We illustrate how this research contributes to three important areas of need identified in informal science literature: the need for evidence of conceptual and cognitive gains; the need for understanding how digital platforms improve the learning experience; and the need to demonstrate how designed interactive devices may impact higher order skills such as critical thinking and theorizing. 相似文献
300.