全文获取类型
收费全文 | 21716篇 |
免费 | 98篇 |
国内免费 | 4篇 |
出版年
2023年 | 18篇 |
2022年 | 22篇 |
2021年 | 21篇 |
2020年 | 30篇 |
2019年 | 42篇 |
2018年 | 3530篇 |
2017年 | 2855篇 |
2016年 | 2299篇 |
2015年 | 225篇 |
2014年 | 114篇 |
2013年 | 234篇 |
2012年 | 633篇 |
2011年 | 2421篇 |
2010年 | 2557篇 |
2009年 | 1510篇 |
2008年 | 1734篇 |
2007年 | 2222篇 |
2006年 | 78篇 |
2005年 | 248篇 |
2004年 | 209篇 |
2003年 | 159篇 |
2002年 | 102篇 |
2001年 | 55篇 |
2000年 | 81篇 |
1999年 | 38篇 |
1998年 | 42篇 |
1997年 | 33篇 |
1996年 | 20篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 15篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1973年 | 9篇 |
1971年 | 8篇 |
1970年 | 10篇 |
1968年 | 7篇 |
1967年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
Numerous previous investigators have explained species differences in spatial memory performance in terms of differences
in foraging ecology. In three experiments we attempted to extend these findings by examining the extent to which the spatial
memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their
prey (ants and termites). This is a species and a foraging situation that have not been examined in this way before. Echidnas
were better able to learn to avoid a previously rewarding location (to "win-shift") than to learn to return to a previously
rewarding location (to "win-stay"), at short retention intervals, but were unable to learn either of these strategies at retention
intervals of 90 min. The short retention interval results support the ecological hypothesis, but the long retention interval
results do not.
Electronic Publication 相似文献
112.
Little is known about how a prey species' cognitive limitations might shape a predator's prey-capture strategy. A specific
hypothesis is investigated: predators take advantage of times when the prey's attention is focussed on its own prey. Portia fimbriata, an araneophagic jumping spider (Salticidae) from Queensland, is shown in a series of 11 experiments to exploit opportunistically
a situation in which a web-building spider on which it preys, Zosis genicularis (Uloboridae), is preoccupied with wrapping up its own prey. Experimental evidence supports three conclusions: (1) while relying
on optical cues alone, P. fimbriata perceives when Z. genicularis is wrapping up prey; (2) when busy wrapping up prey, the responsiveness of Z. genicularis to cues from potential predators is diminished; and (3) P. fimbriata moves primarily during intervals when Z. genicularis is busy wrapping up prey. P. fimbriata's strategy is effective partly because the wrapping behaviour of Z. genicularis masks the web signals generated by the advancing P. fimbriata's footsteps and also because, while wrapping, Z. genicularis' attention is diverted away from predator-revealing cues.
Electronic Publication 相似文献
113.
Current theoretical thinking about dual processes in recognition relies heavily on the measurement operations embodied within the process dissociation procedure. We critically evaluate the ability of this procedure to support this theoretical enterprise. We show that there are alternative processes that would produce a rough invariance in familiarity (a key prediction of the dual-processing approach) and that the process dissociation procedure does not have the power to differentiate between these alternative possibilities. We also show that attempts to relate parameters estimated by the process dissociation procedure to subjective reports (remember-know judgments) cannot differentiate between alternative dual-processing models and that there are problems with some of the historical evidence and with obtaining converging evidence. Our conclusion is that more specific theories incorporating ideas about representation and process are required. 相似文献
114.
The Role of Families and Care Givers as Risk and Protective Factors in Preventing Youth Violence 总被引:3,自引:0,他引:3
This paper reviews research which discusses the risk and protective functions that families and other caregivers provide in influencing the development of aggressive behavior in youth. Currently, there is an emphasis on providing violence prevention programs in the school environment, typically with little parental or caregiver involvement. By enhancing the role of families and caregivers in youth violence prevention programs, we assert that an unique opportunity exists to both address specific risk factors for violence while enhancing the protective features of the family. Relatedly, the risk literature on youth violence indicates that the most influential risk factors (i.e., the family, community, and peers) have their principle impact on youth aggression outside the school. We suggest a shift in the focus of violence prevention programming that is more inclusive of families as both a risk and protective agent. In support of this position, relevant theory and reviews of exemplary family-involved programs are offered. Challenges to involving youth caregivers are identified and recommendations for overcoming those challenges suggested. Last, recommendations for future research and public policy in the prevention of youth violence are offered. 相似文献
115.
116.
Robert E. Lee Kathleen Burns Jager Jason B. Whiting Catherine T. Kwantes 《Contemporary Family Therapy》2000,22(1):81-90
Confirmatory factor analysis and regression analyses of the Beavers Interactional Scales did not appear to support the model offered by its developers, namely, several specified family attributes contributing respectively to two global factors of Family Competence and Family Style. Moreover, regression analysis indicated that only three of 12 items predicted raters' assessments of Global Family Health, and one of seven items predicted Global Family Style. Individuals interested in the family dynamic centripetal/centrifugal might best think of that as a unitary entity and rate it accordingly. 相似文献
117.
118.
Deane-Peter Baker 《International Journal for Philosophy of Religion》2005,57(2):77-103
Alvin Plantingas Warranted Christian Belief is without questionone of the central texts of the Reformed epistemology movement. Critiques of Plantingas defence have been both multiple and varied. As varied as these responses are, however, it is my contention that many of them amount to the same thing. It is the purpose of this paper to offer an overview of the main lines of attack that have been directed as Plantingas project, and thereafter to show how many, if not most, of these objections can be understood as versions or aspects of the same criticism, what I call the Inadequacy Thesis. 相似文献
119.
Postural stability and hand preference as constraints on one-handed catching performance in children
Angelakopoulos GT Davids K Bennett SJ Tsorbatzoudis H Grouios G 《Journal of motor behavior》2005,37(5):377-385
Effects of postural state and hand preference as constraints on 1-handed catching performance were investigated in different ability groups of children aged 9-10 years. On the basis of pretest data, the authors classified 48 participants into groups of good, intermediate, and poor catchers (n = 16 in each) and asked them to perform 1-handed catches with their preferred and nonpreferred hands while standing and sitting. The good catchers' performance was not affected by the imposed postural constraints but did improve when they used the preferred hand. A similar effect of hand preference was evident in the intermediate and poor catchers, but there was also an effect of postural constraint. Independent of hand preference, intermediate catchers' performance while seated improved significantly compared with that during standing. For poor catchers, there was an interaction between hand preference and posture; significant improvement was evident only when they used the preferred hand in the sitting condition. The finding that manipulation of posture and hand preference affected performance outcomes indicates that perceptual skill is not the only influence on catching performance in children. Manipulation of those key constraints may facilitate the acquisition of catching skill, but more research is needed to determine the permanence of those effects. 相似文献
120.
The authors of this essay suggest that the field of bioethics and Christian theology have a great deal to offer to each other. The authors first argue that representatives from both fields must first make sure that they fully and correctly represent their respective position. In other words, scientists, ethicists, and theologians alike must make sure that they present their fields and not use their knowledge merely for personal gain at the stake of misguiding people. Once this is established, the authors then proceed to show the intimate relationship between Christianity and medicine that has existed throughout the ages. It is a call for a continuation of such a relationship that the authors suggest between bioethics and theology. Through an integration of bioethics and Christian theology, both scientists/physicians and theologians are able to gain greater insight into the human person—a focus in both fields. 相似文献