全文获取类型
收费全文 | 4132篇 |
免费 | 225篇 |
国内免费 | 85篇 |
出版年
2024年 | 8篇 |
2023年 | 51篇 |
2022年 | 75篇 |
2021年 | 105篇 |
2020年 | 122篇 |
2019年 | 156篇 |
2018年 | 192篇 |
2017年 | 204篇 |
2016年 | 160篇 |
2015年 | 128篇 |
2014年 | 136篇 |
2013年 | 501篇 |
2012年 | 304篇 |
2011年 | 312篇 |
2010年 | 225篇 |
2009年 | 122篇 |
2008年 | 275篇 |
2007年 | 210篇 |
2006年 | 202篇 |
2005年 | 137篇 |
2004年 | 126篇 |
2003年 | 84篇 |
2002年 | 75篇 |
2001年 | 43篇 |
2000年 | 52篇 |
1999年 | 39篇 |
1998年 | 32篇 |
1997年 | 17篇 |
1996年 | 20篇 |
1995年 | 19篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 20篇 |
1991年 | 14篇 |
1990年 | 14篇 |
1989年 | 19篇 |
1988年 | 12篇 |
1987年 | 16篇 |
1986年 | 11篇 |
1985年 | 13篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1979年 | 10篇 |
1974年 | 8篇 |
1973年 | 9篇 |
1972年 | 7篇 |
1971年 | 10篇 |
1968年 | 15篇 |
1965年 | 7篇 |
排序方式: 共有4442条查询结果,搜索用时 281 毫秒
161.
Recent research with cotton-top tamarin monkeys has revealed language discrimination abilities similar to those found in human
infants, demonstrating that these perceptual abilities are not unique to humans but are also present in non-human primates.
Specifically, tamarins could discriminate forward but not backward sentences of Dutch from Japanese, using both natural and
synthesized utterances. The present study was designed as a conceptual replication of the work on tamarins. Results show that
rats trained in a discrimination learning task readily discriminate forward, but not backward sentences of Dutch from Japanese;
the results are particularly robust for synthetic utterances, a pattern that shows greater parallels with newborns than with
tamarins. Our results extend the claims made in the research with tamarins that the capacity to discriminate languages from
different rhythmic classes depends on general perceptual abilities that evolved at least as far back as the rodents.
Electronic Publication 相似文献
162.
Theories of reasoned action and planned behavior as models of condom use: a meta-analysis 总被引:39,自引:0,他引:39
To examine how well the theories of reasoned action and planned behavior predict condom use, the authors synthesized 96 data sets (N = 22,594) containing associations between the models' key variables. Consistent with the theory of reasoned action's predictions, (a) condom use was related to intentions (weighted mean r. = .45), (b) intentions were based on attitudes (r. = .58) and subjective norms (r. = .39), and (c) attitudes were associated with behavioral beliefs (r. = .56) and norms were associated with normative beliefs (r. = .46). Consistent with the theory of planned behavior's predictions, perceived behavioral control was related to condom use intentions (r. = .45) and condom use (r. = .25), but in contrast to the theory, it did not contribute significantly to condom use. The strength of these associations, however, was influenced by the consideration of past behavior. Implications of these results for HIV prevention efforts are discussed. 相似文献
163.
The recognition potential: An ERP index of lexical access 总被引:6,自引:0,他引:6
Recognition potential (RP) is a brain electrical response that appears when a subject views recognizable images of words. However, it has yet to be determined whether the processes reflected by RP are related to orthographic or to semantic analysis. This study aimed to resolve this question by studying the RP evoked by orthographically correct stimuli that were devoid of meaning. Results showed RP not only to this type of stimuli, but also to others achieving lower levels in the reading process. Strikingly, however, the RP amplitude significantly differed in parallel with the levels of the reading processes attained by the stimuli, the amplitude of the RP progressively increasing as the level approached the semantic one, which showed the highest amplitude. These results not only confirm the replicability of RP, but also its promise of potential usefulness in the study and assessment of language perception. 相似文献
164.
Prism Adaptation and Aftereffect: Specifying the Properties of a Procedural Memory System 总被引:4,自引:1,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)
Prism adaptation, a form of procedural learning, is a phenomenon in which the motor system adapts to new visuospatial coordinates imposed by prisms that displace the visual field. Once the prisms are withdrawn, the degree and strength of the adaptation can be measured by the spatial deviation of the motor actions in the direction opposite to the visual displacement imposed by the prisms, a phenomenon known as aftereffect. This study was designed to define the variables that affect the acquisition and retention of the aftereffect. Subjects were required to throw balls to a target in front of them before, during, and after lateral displacement of the visual field with prismatic spectacles. The diopters of the prisms and the number of throws were varied among different groups of subjects. The results show that the adaptation process is dependent on the number of interactions between the visual and motor system, and not on the time spent wearing the prisms. The results also show that the magnitude of the aftereffect is highly correlated with the magnitude of the adaptation, regardless of the diopters of the prisms or the number of throws. Finally, the results suggest that persistence of the aftereffect depends on the number of throws after the adaptation is complete. On the basis of these results, we propose that the system underlying this kind of learning stores at least two different parameters, the contents (measured as the magnitude of displacement) and the persistence (measured as the number of throws to return to the baseline) of the learned information. 相似文献
165.
When birds raised by another species become adults, they (if they are non-brood-parasitic species) usually attempt to mate
with birds of their foster species rather than with birds of their own species, a phenomenon called sexual imprinting. Avian
brood parasites lay their eggs in nests of other species (the hosts) that rear the young, but the problem of sexual imprinting
among brood parasites has generally been neglected, and brood parasites have been considered as an exception among birds.
Here, we show, with data from field observations and field experiments, firstly, that adult great spotted cuckoos Clamator glandarius sometimes maintain contact with both older nestling and fledgling cuckoos. Adult cuckoos visited parasitized nests during
the last days of the nestling period (5 observations) and, when parasitic chicks left the nest, adult cuckoos maintained contact
with the young (14 observations). Adults and fledgling cuckoos communicated vocally (5 observations), and an adult great spotted
cuckoo even fed a parasite fledgling in two cases. Secondly, when experimentally cross-fostered in nests of magpie Pica pica hosts outside the parasite breeding range (thus avoiding visual and acoustic communication with adult cuckoos), young cuckoos
did not learn to recognize their own species when only one cuckoo chick was introduced per nest, but they learnt to recognize
conspecifics when two cuckoos were reared together. This means that young great spotted cuckoos apparently must learn to recognize
conspecifics, that is, recognition is not innate. Social interactions between adult brood parasites and young have also been
reported in other brood parasites; thus, brood parasites are probably not an exception to the general phenomenon of imprinting,
and young brood parasites may need to be imprinted on conspecifics, although more studies on other brood parasite species
are needed to confirm this.
Received: 7 January 1999 / Accepted after revision: 27 February 1999 相似文献
166.
This study was aimed at the examination of ‘mental construction’ in paradise fish by interactive learning, which is suggested
as an alternative hypothesis for backward or second-order conditioning. Avoidance of goldfish was established in paradise
fish by presenting a harmless goldfish (a novel stimulus) after an aversive event (mild electric shocks) in the dark compartment
of a shuttle tank. It was found that this avoidance depended on context pre-exposure. Experiment 1 was designed to study the
effect of mild shocks on shuttling activity in a familiar context. Experiment 2 aimed at establishing fear-conditioning to
the goldfish in a higher-order conditioning paradigm. In the course of training, unpaired stimuli were presented in the dark
compartment of the shuttle tank in such a manner that the presentation of mild shocks (20 mA) preceded the encounter with
a harmless fish (goldfish). Experiment 3 demonstrated the role of context pre-exposure in interactive learning. Results indicate
that (1) while 60 mA shocks resulted in avoidance of the dark compartment, the 20 mA mild shocks affected exploratory behaviour;
(2) after pre-exposure to the training environment, paradise fish avoided the dark compartment containing goldfish provided
that subjects had previously encountered mild, explorative shocks there; (3) this conditioned fear, a ‘mental construction’
of a potential danger, was proved to be transferable to another context and was consequently aimed specifically at the goldfish,
a living being, rather than the training context; (4) the pre-exposure to the shuttle tank was an important part of this training
procedure, that is, only subjects habituated to the shuttle tank avoided the goldfish. Results are discussed in the framework
of the Interactive Learning Hypothesis, which has been developed as an ethological approach to a higher-order conditioning
paradigm.
Received: 15 January 1999 / Accepted after revision: 18 August 1999 相似文献
167.
The authors tested an attribution-affect model of schizophrenic relapse attending to the role of families' positive affect (warmth) and negative affect (criticism). Coders listened to interviews of 40 family members taken from C. E. Vaughn, K. S. Synder, S. Jones, W. B. Freeman, and I. R. Falloon (1984) and rated their attributions of controllability for the symptoms and behaviors of their relatives with schizophrenia. For family members not designated as emotionally overinvolved, perceptions that their ill relatives' symptoms and behaviors were under the patients' control were related to family members' warmth and criticism and to patients' clinical outcomes. Of the affective reactions, only criticism predicted outcome. In addition, patients' use of street drugs was related to attributions, criticism, and outcome. Together these findings suggest that families' attributions and criticism are important in understanding the relationship between family factors and course of illness. 相似文献
168.
Francisco Flores 《国际科学哲学研究》1999,13(2):123-134
In this paper I draw on Einstein's distinction between “principle” and “constructive” theories to isolate two levels of physical theory that can be found in both classical and (special) relativistic physics. I then argue that when we focus on theoretical explanations in physics, i.e. explanations of physical laws, the two leading views on explanation, Salmon's “bottom‐up” view and Kitcher's “top‐down” view, accurately describe theoretical explanations for a given level of theory. I arrive at this conclusion through an analysis of explanations of mass—energy equivalence in special relativity. 相似文献
169.
17 subjects diagnosed with schizophrenia and having auditory hallucinations in their case history were compared with 15 control subjects in an experiment on perceptual restoration. A tone pattern was presented, then interrupted by noise, under conditions such that the tone pattern could be heard as going on continuously (restoration). A series of 16 stimuli with a distractor of varying amplitude (noise) were presented. Healthy controls reliably reported restoration in Presentations 9 and 10. Four schizophrenics reported no restoration at all. Three of them reported restoration earlier than controls, and four others reported it later than controls and continued to report the phenomenon after a point at which no healthy controls did. Six other presented an irregular pattern of response to the phenomenon. The results are discussed with respect to the neurophysiological functioning of the auditory pathway and schizophrenic symptoms. 相似文献
170.