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   413篇
  免费   115篇
  国内免费   117篇
  645篇
  2023年   8篇
  2022年   12篇
  2021年   9篇
  2020年   32篇
  2019年   17篇
  2018年   44篇
  2017年   20篇
  2016年   22篇
  2015年   25篇
  2014年   27篇
  2013年   53篇
  2012年   33篇
  2011年   26篇
  2010年   18篇
  2009年   28篇
  2008年   21篇
  2007年   17篇
  2006年   24篇
  2005年   24篇
  2004年   17篇
  2003年   23篇
  2002年   23篇
  2001年   18篇
  2000年   11篇
  1999年   11篇
  1998年   10篇
  1997年   6篇
  1996年   6篇
  1995年   4篇
  1994年   6篇
  1993年   7篇
  1992年   1篇
  1991年   1篇
  1990年   3篇
  1989年   2篇
  1988年   1篇
  1987年   5篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   2篇
  1982年   1篇
  1981年   1篇
  1980年   2篇
  1979年   4篇
  1978年   3篇
  1977年   6篇
  1976年   3篇
  1975年   3篇
排序方式: 共有645条查询结果,搜索用时 15 毫秒
151.
We investigate computational properties of propositional logics for dynamical systems. First, we consider logics for dynamic topological systems (W.f), fi, where W is a topological space and f a homeomorphism on W. The logics come with ‘modal’ operators interpreted by the topological closure and interior, and temporal operators interpreted along the orbits {w, f(w), f2 (w), ˙˙˙} of points w ε W. We show that for various classes of topological spaces the resulting logics are not recursively enumerable (and so not recursively axiomatisable). This gives a ‘negative’ solution to a conjecture of Kremer and Mints. Second, we consider logics for dynamical systems (W, f), where W is a metric space and f and isometric function. The operators for topological interior/closure are replaced by distance operators of the form ‘everywhere/somewhere in the ball of radius a, ‘for a ε Q +. In contrast to the topological case, the resulting logic turns out to be decidable, but not in time bounded by any elementary function.  相似文献   
152.
文章主要介绍了语义启动的过程及其脑机制的研究进展。启动效应是内隐记忆的研究焦点,而语义启动是通过刺激的语义特征来研究启动效应的。语义启动的脑机制研究一般是通过脑损伤、脑成像和ERPs等方法实现的。研究表明,大脑的广泛区域都参与着语义启动过程,尤其是脑前区和大脑的左半球。  相似文献   
153.
How are appropriate combinations of forelimb muscles selected during reach-to-grasp movements in the presence of neuromotor redundancy and important task-related constraints? The authors tested whether grasp type or target location preferentially influence the selection and synergistic coupling between forelimb muscles during reach-to-grasp movements. Factor analysis applied to 14–20 forelimb electromyograms recorded from monkeys performing reach-to-grasp tasks revealed 4–6 muscle components that showed transport/preshape- or grasp-related features. Weighting coefficients of transport/preshape-related components demonstrated strongest similarities for reaches that shared the same grasp type rather than the same target location. Scaling coefficients of transport/preshape- and grasp-related components showed invariant temporal coupling. Thus, grasp type influenced strongly both transport/preshape- and grasp-related muscle components, giving rise to grasp-based functional coupling between forelimb muscles.  相似文献   
154.
In everyday decision making, people often face decisions with outcomes that differ on multiple dimensions. The trade‐off in preferences between magnitude, temporal proximity, and probability of an outcome is a fundamental concern in the decision‐making literature. Yet, their joint effects on behavior in an experience‐based decision‐making task are understudied. Two experiments examined the relative influences of the magnitude and probability of an outcome when both were increasing over a 10‐second delay. A first‐person shooter video game was adapted for this purpose. Experiment 1 showed that participants waited longer to ensure a higher probability of the outcome than to ensure a greater magnitude when experienced separately and together. Experiment 2 provided a precise method of comparing their relative control on waiting by having each increase at different rates. Both experiments revealed a stronger influence of increasing probability than increasing magnitude. The results were more consistent with hyperbolic discounting of probability than with cumulative prospect theory's decision weight function. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
155.
大学生现在将来的自我时间比较研究   总被引:1,自引:0,他引:1  
使用大学生自我概念问卷对200名西南大学在校大二学生实施问卷调查,了解大学生现在与将来自我时间比较的特点。研究结果表明:大学生在自我时间比较中对将来自我的评价显著高于对现在自我的评价;近期将来和远期将来的自我提升除在交际品质维度上有显著差异外,在其他维度上均无显著差异;在重要品质上的自我提升高于在不重要品质上的自我提升,但差异不显著。  相似文献   
156.
Lucchiari, C. & Pravettoni, G. (2010). Feedback related brain activity in a gambling task: A temporal analysis of EEG correlates. Scandinavian Journal of Psychology 51, 449–454. The pattern of neural correlates of feedback processing has been the subject of a number of studies, using both neuroimaging and electrophysiological recordings. A complex functional network was found to be activated after a choice in order to process a feedback and sustain an adaptive behavior. However, many aspects of this network are still unclear and further research is needed to better understand this process. We conducted an EEG study using a simple gambling task. Twenty three subjects participated to the study. We analyzed both EEG power spectrum and ERP components evoked by presentation of a feedback signal (money gain or loss) during a simple gambling task. Our data confirmed that a negative ERP component is present about 270 ms after feedback, particularly relevant following a choice with negative outcome. Furthermore, the theta and delta oscillatory activity seem to be correlated to a dynamic decision‐making process within specific cortical networks. In particular, theta activity showed a valence dependent development between 150 and 350 ms post‐feedback onset. Differently from previous studies (Cohen, Elger & Ranganath, 2007; Marco‐Pallares, Cucurell, Cunillera et al., 2008), we did not find any valence effect in beta range. However, our data are consistent with Christie and Tata (2009) , probably due to the nature of the gambling task used in both studies. In conclusion, our data, in line with some prior findings showed that the feedback related response is correlated to a complex pattern of cortical activation probably mediated by theta and delta activity.  相似文献   
157.
基于以往对自我透视和价值偏好的研究,本研究提出自我差异是引发价值偏好出现分离的原因之一。两项研究对这一假设进行了检验。结果发现:相对于害怕的可能自我,大学生在期望可能自我上体验到更大的差异;在可能自我差异激活后,理想主义价值在个体的价值系统中占据主导地位,而在当前自我差异激活后,实用主义价值占据主导地位;当下目标和当前自我同时启动时,与当下目标未启动时,两组个体对价值偏好无显著差异。  相似文献   
158.
多感觉整合的时间再校准   总被引:1,自引:0,他引:1  
跨通道刺激的时间同步性是多感觉整合的必要条件, 但是由于刺激物理传导与神经传导的差异, 它们在时间上并非完全匹配。时间再校准指大脑能够适应跨通道刺激间很短的时间延迟的现象, 反映了多感觉整合在时间维度上的可塑性, 表现为适应相继呈现的跨通道刺激后, 主观同时点向时间延迟方向的偏移。本文主要介绍了时间再校准的通道效应与潜在机制, 其初始加工阶段, 它与刺激内容加工的关系及主要的影响因素。今后的研究应当进一步探索时间再校准能否发生于早期加工阶段, 检验其认知过程是否具有双向性, 探讨空间选择性注意的作用, 并结合神经机制的研究, 从综合的视角进行更完善的理论建构。  相似文献   
159.
大脑前扣带回皮层与执行功能   总被引:9,自引:2,他引:9  
回顾了近期有关大脑前扣带回皮层(ACC)参与执行功能的研究资料。结果显示,ACC可以对正在进行的目标定向行为实施在线监控,在出现反应冲突或错误时提供信号,以便能及时调整与分配注意资源,因此可能是一个行为规划与执行的高级调控结构。这两年来的新发现提示,ACC的执行监控作用可能是基于动机与奖赏期待做出的对“意志行动”的整合性控制,并可能具有对行动结果的情绪评价意义。  相似文献   
160.
The first step in reasoning about actions and change involves reasoning about how the world would evolve if a certain action is executed in a certain state. Most research on this assumes the evolution to be only a single step and focus on formulating the transition function that defines changes between states due to actions. In this paper we consider cases where the evolution is more than just a single change between one state and another. This is manifested when the execution of an action may trigger execution of other actions, or when multiple agents act on the environment following certain strategies.  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