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   4429篇
  免费   192篇
  国内免费   1篇
  2022年   23篇
  2021年   30篇
  2020年   70篇
  2019年   59篇
  2018年   98篇
  2017年   120篇
  2016年   170篇
  2015年   74篇
  2014年   117篇
  2013年   573篇
  2012年   169篇
  2011年   194篇
  2010年   101篇
  2009年   144篇
  2008年   183篇
  2007年   182篇
  2006年   199篇
  2005年   120篇
  2004年   163篇
  2003年   145篇
  2002年   146篇
  2001年   72篇
  2000年   66篇
  1999年   63篇
  1998年   70篇
  1997年   64篇
  1996年   59篇
  1995年   55篇
  1994年   74篇
  1993年   51篇
  1992年   43篇
  1991年   40篇
  1990年   34篇
  1989年   41篇
  1988年   42篇
  1987年   47篇
  1986年   34篇
  1985年   51篇
  1984年   48篇
  1983年   37篇
  1982年   61篇
  1981年   45篇
  1980年   37篇
  1979年   35篇
  1978年   48篇
  1977年   50篇
  1976年   50篇
  1975年   46篇
  1974年   35篇
  1973年   27篇
排序方式: 共有4622条查询结果,搜索用时 296 毫秒
821.
822.
Automation is being used extensively in aviation, particularly in the aircrafts themselves. The airline industry benefits from automation because it often increases efficiency and performance. To date, automation research has focused largely on operator trust and reliance, while largely ignoring the role of affect and trust in shaping the attitudes of the novice consumer. In two studies, we found that participants rated a human pilot more favorably than an auto-pilot. However, attitudes toward the automated pilot were more favorable in a high priced compared to a low priced ticket condition, indicating that participants used price to infer quality. In Study 2, inducing positive affect increased ratings of an automated pilot. Path analyses provided additional evidence that perceptions of automation are largely influenced by feelings.  相似文献   
823.
Recent assessments have shown that capuchin monkeys, like chimpanzees and other Old World primate species, are sensitive to quantitative differences between sets of visible stimuli. In the present study, we examined capuchins’ performance in a more sophisticated quantity judgment task that required the ability to form representations of food quantities while viewing the quantities only one piece at a time. In three experiments, we presented monkeys with the choice between two sets of discrete homogeneous food items and allowed the monkeys to consume the set of their choice. In Experiments 1 and 2, monkeys compared an entirely visible food set to a second set, presented item-by-item into an opaque container. All monkeys exhibited high accuracy in choosing the larger set, even when the entirely visible set was presented last, preventing the use of one-to-one item correspondence to compare quantities. In Experiment 3, monkeys compared two sets that were each presented item-by-item into opaque containers, but at different rates to control for temporal cues. Some monkeys performed well in this experiment, though others exhibited near-chance performance, suggesting that this species’ ability to form representations of food quantities may be limited compared to previously tested species such as chimpanzees. Overall, these findings support the analog magnitude model of quantity representation as an explanation for capuchin monkeys’ quantification of sequentially presented food items.
Theodore A. EvansEmail:
  相似文献   
824.
Despite a widespread familiarity with the often compelling urge to yawn after perceiving someone else yawn, an understanding of the neural mechanism underlying contagious yawning remains incomplete. In the present auditory fMRI study, listeners used a 4-point scale to indicate how much they felt like yawning following the presentation of a yawn, breath, or scrambled yawn sound. Not only were yawn sounds given significantly higher ratings, a trait positively correlated with each individual’s empathy measure, but relative to control stimuli, random effects analyses revealed enhanced hemodynamic activity in the right posterior inferior frontal gyrus (pIFG) in response to hearing yawns. Moreover, pIFG activity was greatest for yawn stimuli associated with high as opposed to low yawn ratings and for control sounds associated with equally high yawn ratings. These results support a relationship between contagious yawning and empathy and provide evidence for pIFG involvement in contagious yawning. A supplemental figure for this study may be downloaded from http://cabn.psychonomic-journals.org/content/supplemental.  相似文献   
825.
826.
In the present study, we examined whether preparing motor responses under different emotional conditions alters motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation delivered to the motor cortex. Analyses revealed three findings: (1) Reaction times were expedited during exposure to unpleasant images, as compared with pleasant and neutral images; (2) force amplitude was greater during exposure to unpleasant images, as compared with pleasant and neutral images; and (3) MEPs were larger while participants viewed unpleasant images, as compared with neutral images. Hence, coupling the preparation of motor responses with the viewing of emotional images led to arousal-driven changes in corticospinal motor tract excitability, whereas movement speed and force production varied as a function of emotional valence. These findings demonstrate that the effects of emotion on the motor system manifest at varying sensitivity levels across behavioral and neurophysiological measures. Moreover, they validate the action readiness component of emotional experience by demonstrating that emotional states influence the execution of future movements but, alone, do not lead to overt movement.  相似文献   
827.
Although there are many well-known forms of visual cues specifying absolute and relative distance, little is known about how visual space perception develops at small temporal scales. How much time does the visual system require to extract the information in the various absolute and relative distance cues? In this article, we describe a system that may be used to address this issue by presenting brief exposures of real, three-dimensional scenes, followed by a masking stimulus. The system is composed of an electronic shutter (a liquid crystal smart window) for exposing the stimulus scene, and a liquid crystal projector coupled with an electromechanical shutter for presenting the masking stimulus. This system can be used in both full- and reduced-cue viewing conditions, under monocular and binocular viewing, and at distances limited only by the testing space. We describe a configuration that may be used for studying the microgenesis of visual space perception in the context of visually directed walking.  相似文献   
828.
Insects, birds, and mammals have been shown capable of encoding spatial information in memory using multiple strategies or frames of reference simultaneously. These strategies include orientation to a goal-specific cue or beacon, to the position of the goal in an array of local landmarks, or to its position in the array of distant landmarks, also known as the global frame of reference. From previous experiments, it appears that birds and mammals that scatter hoard rely primarily on a global frame of reference, but this generalization depends on evidence from only a few species. Here we examined spatial memory in a previously unstudied scatter hoarder, the southern flying squirrel. We dissociated the relative weighting of three potential spatial strategies (beacon, global, or relative array strategy) with three probe tests: transposition of beacon and the rotation or the expansion of the array. The squirrels’ choices were consistent with a spatial averaging strategy, where they chose the location dictated by at least two of the three strategies, rather than using a single preferred frame of reference. This adaptive and flexible heuristic has not been previously described in animal orientation studies, yet it may be a common solution to the universal problem of encoding and recalling spatial locations in an ephemeral physical landscape.  相似文献   
829.
Evidence from intervention studies, quantitative genetic and molecular genetic studies suggests that genetic, and to a lesser extent, shared environmental influences are important to the development of reading and related cognitive skills. The Northeast‐Northwest Collaborative Adoption Projects (N2CAP) is a sample of 241 adoptive families, containing 354 children and their adoptive parents. Negative parent outcome × child age interactions significantly predicted child outcomes, suggesting that shared environmental influences related to parent–offspring resemblance, although modest, are most salient in younger children. Additional analyses suggested that identified measures of the family environment largely accounted for these parent–offspring correlations. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
830.
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