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   31894篇
  免费   1210篇
  国内免费   14篇
  2020年   347篇
  2019年   370篇
  2018年   559篇
  2017年   526篇
  2016年   595篇
  2015年   402篇
  2014年   546篇
  2013年   2630篇
  2012年   943篇
  2011年   1035篇
  2010年   613篇
  2009年   688篇
  2008年   922篇
  2007年   969篇
  2006年   919篇
  2005年   802篇
  2004年   761篇
  2003年   770篇
  2002年   731篇
  2001年   944篇
  2000年   959篇
  1999年   735篇
  1998年   404篇
  1997年   365篇
  1996年   348篇
  1995年   335篇
  1994年   315篇
  1992年   619篇
  1991年   546篇
  1990年   601篇
  1989年   521篇
  1988年   494篇
  1987年   487篇
  1986年   506篇
  1985年   574篇
  1984年   478篇
  1983年   431篇
  1982年   383篇
  1981年   347篇
  1980年   333篇
  1979年   436篇
  1978年   413篇
  1977年   350篇
  1976年   337篇
  1975年   433篇
  1974年   483篇
  1973年   483篇
  1972年   377篇
  1968年   359篇
  1966年   324篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The purpose of this study was to examine the relationship between learned resourcefulness and two common addictive behaviors, namely, drinking and smoking. Male and female college students (N = 175) completed the Self-Control Schedule (SCS), the Quantity-Frequency-Variability questionnaire, and a smoking history form. Learned resourcefulness was related to self-reported patterns of alcohol consumption; specifically, heavy drinking subjects were lower in learned resourcefulness than were light and moderate drinkers who, in turn, were lower in learned resourcefulness than were infrequent drinkers and abstainers. Learned resourcefulness was only modestly related to smoking, with students who had never smoked evidencing somewhat higher learned resourcefulness than ex-smokers and current smokers. Overall, these data provide correlational support for the notion that learned resourcefulness may protect young adults against substance abuse.  相似文献   
992.
993.
Unification of models for choice between delayed reinforcers.   总被引:2,自引:2,他引:0       下载免费PDF全文
Two models for choice between delayed reinforcers, Fantino's delay-reduction theory and Killeen's incentive theory, are reviewed. Incentive theory is amended to incorporate the effects of arousal on alternate types of behavior that might block the reinforcement of the target behavior. This amended version is shown to differ from the delay-reduction theory in a term that is an exponential in incentive theory and a difference in delay-reduction theory. A power series approximation to the exponential generates a model that is formally identical with delay-reduction theory. Correlations between delay-reduction theory and the amended incentive theory show excellent congruence over a range of experimental conditions. Although the assumptions that gave rise to delay-reduction theory and incentive theory remain different and testable, the models deriving from the theories are unlikely to be discriminable by parametric experimental tests. This congruence of the models is recognized by naming the common model the delayed reinforcement model, which is then compared with other models of choice such as Killeen and Fetterman's (1988) behavioral theory of timing, Mazur's (1984) equivalence rule, and Vaughan's (1985) melioration theory.  相似文献   
994.
Effects of alcohol and extended practice on divided-attention performance   总被引:3,自引:0,他引:3  
The effects of alcohol and extended practice on divided attention were investigated using a visual tracking task and an auditory detection task. Subjects performed the tasks with and without alcohol, under single-task (S) and dual-task (D) conditions, both before and after they had received extended practice under single-task conditions without alcohol. Tracking accuracy improved with practice and was impaired under divided-attention conditions but was not affected by alcohol. Speed of detection was impaired by alcohol, improved by practice, and impaired by divided attention. Extended practice did not reduce the influence of alcohol. The effects of both alcohol and practice on speed of detection were significantly greater under dual-task conditions than under single-task conditions. Analysis of detection-task reaction times in terms of relative divided-attention costs, (D-S)/S, showed no effect of alcohol, but a highly significant reduction in costs with extended practice. It is concluded that (1) alcohol and practice can have quantitatively, but not qualitatively, similar effects on speeded performance, and (2) the effect of alcohol is not influenced by the attentional requirements of the task.  相似文献   
995.
Lucca, Dellantonio, and Riggio (1986) reported large distortions in a tactual analogue of the visual Poggendorff illusion. They also reported large effects in the direction opposite to the visual illusion, which they termed "inversions." However, their evidence for such effects is questionable; they used what we consider to be inappropriate measurement and analysis procedures. In attempting to replicate their experiment, and in conducting four additional experiments, we found no evidence at all for their alleged tactual analogue of the visual Poggendorff effect. Instead, we demonstrated that "inversions" are likely due to the use of a raised stimulus display that causes artifactual mistracking, which is totally unrelated to normal mechanisms of alignment judgment. We also discuss the possible role of intersensory factors in the generation of tactual illusions.  相似文献   
996.
Examination of perceptions of human facial attributes revealed that individual attributes are similarly perceived by males and females. However, patterns of attribute interrelationships differ as a function of gender of the face. Undergraduate students (N = 280) rated pictures of 40 male or female Caucasians on 12 physical attributes (e.g., nose size, face width) and overall attractiveness. The four sets of attribute ratings (defined by rater gender and picture gender) were submitted to principal components analyses, and five-factor solutions were found for each condition (accounting for about 76% of the variance). Comparisons of the four component solutions using confirmatory factor procedures revealed that male and female raters share one factor structure when rating photographs of female faces and another factor structure when rating photographs of male faces. Multiple regression analyses revealed that the patterns of attribute interrelationships were not "perceptual units" in the perception of attractiveness, and that different "rules" are used to assess the attractiveness of male and female stimuli faces. The importance of these results for models of facial attractiveness and interfacial similarity judgements are discussed.  相似文献   
997.
The role of discontinuities in the perception of subjective figures   总被引:2,自引:0,他引:2  
Recently we proposed a theory of visual interpolation (Kellman & Shipley, in press) that addresses a variety of unit formation phenomena, including the perception of partly occluded objects and subjective figures. A basic notion of the theory is that discontinuities in the first derivative of projected edges are the initiating conditions for interpolation of boundaries that are not physically specified. In this paper, we report four experiments in which this claim was tested in the domain of subjective figures. Experiments 1 and 2 demonstrate that discontinuities in the first derivative of the edges of inducing elements have a clear effect on the frequency of report and the perceived clarity of simple subjective figures. Similar effects are found when unfamiliar subjective figures and inducing elements are used (Experiment 3). Experiment 4 rules out the possibility that the discontinuities in the first derivative merely add to the clarity of subjective figures. These experiments suggest that first-order discontinuities play a central role in unit formation.  相似文献   
998.
The role played by attribution of meaning in research involving simulation is examined. Acknowledgement of this role, lacking to date, queries the traditional use of simulation but also opens up interesting research questions.  相似文献   
999.
The cyclic variation in the energy envelope of the speech signal results from the production of speech in syllables. This acoustic property is often identified as a source of information in the perception of syllable attributes, though spectral variation can also provide this information reliably. In the present study of the relative contributions of the energy and spectral envelopes in speech perception, we employed sinusoidal replicas of utterances, which permitted us to examine the roles of these acoustic properties in establishing or maintaining time-varying perceptual coherence. Three experiments were carried out to assess the independent perceptual effects of variation in sinusoidal amplitude and frequency, using sentence-length signals. In Experiment 1, we found that the fine grain of amplitude variation was not necessary for the perception of segmental and suprasegmental linguistic attributes; in Experiment 2, we found that amplitude was nonetheless effective in influencing syllable perception, and that in some circumstances it was crucial to segmental perception; in Experiment 3, we observed that coarse-grain amplitude variation, above all, proved to be extremely important in phonetic perception. We conclude that in perceiving sinusoidal replicas, the perceiver derives much from following the coherent pattern of frequency variation and gross signal energy, but probably derives rather little from tracking the precise details of the energy envelope. These findings encourage the view that the perceiver uses time-varying acoustic properties selectively in understanding speech.  相似文献   
1000.
Measures of illusion magnitude for a real-contour and two subjective-contour Poggendorff figures were obtained from 42 men and 42 women. Although magnitudes of illusion differed as a function of figure type, male-female differences in magnitude of illusion did not vary across figures or judgment orders. Also, correlations among the illusions observed for three types of figures did not differ for men and women. These data are consistent with the view that real- and subjective-contour Poggendorff figures evoke similar processing strategies and that sex differences, when observed, are probably the result of differences in cognitive-judgmental strategy rather than differences in the optical and neural properties of the visual system.  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