全文获取类型
收费全文 | 329篇 |
免费 | 79篇 |
国内免费 | 100篇 |
专业分类
508篇 |
出版年
2024年 | 2篇 |
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 17篇 |
2020年 | 29篇 |
2019年 | 18篇 |
2018年 | 22篇 |
2017年 | 23篇 |
2016年 | 17篇 |
2015年 | 23篇 |
2014年 | 27篇 |
2013年 | 29篇 |
2012年 | 25篇 |
2011年 | 39篇 |
2010年 | 31篇 |
2009年 | 26篇 |
2008年 | 18篇 |
2007年 | 26篇 |
2006年 | 26篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 17篇 |
2002年 | 11篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 2篇 |
排序方式: 共有508条查询结果,搜索用时 8 毫秒
391.
The visual system is remarkably efficient at extracting summary statistics from the environment. Yet at any given time, the environment consists of many groups of objects distributed over space. Thus, the challenge for the visual system is to summarize over multiple groups. The current study investigates the capacity and computational efficiency of ensemble perception, in the context of perceiving mean sizes of multiple spatially intermixed groups of circles. In a series of experiments, participants viewed an array of one to eight sets of circles. Each set contained four circles in the same colors, but with different sizes. Participants estimated the mean size of a probed set. The set that would be probed was either known before onset of the array (pre-cue condition) or afterwards (post-cue condition). By comparing estimation error in the pre-cue and post-cue conditions, we found that participants could reliably estimate mean sizes for approximately two sets (Experiment 1). Importantly, this capacity was robust against attention bias toward individual objects in the sets (Experiment 2). Varying the exposure time to stimulus arrays did not increase the capacity limit, suggesting that ensemble perception could be limited by an internal resource constraint, rather than the speed of information encoding (Experiment 3). Moreover, we found that the visual system could not encode and hold more individual items than ensemble representations (Experiment 4). Taken together, these results suggest that ensemble perception provides an efficient way of information processing but with constraints. 相似文献
392.
脱氧寡核苷酸或肽核酸可与基因双链DNA内的特定序列结合形成三逻DNA,三链DNA结构的形成可以抑制靶基因的转录。三链DNA在治疗肿瘤和病毒感染,降低耐药性,抑制免疫等方面都可以有广泛的应用,三链DNA的提出和发现为基因治疗提供了一个新的方向。 相似文献
393.
本文概述了急诊护理危机管理的含义,分析了当前急诊科护理危机的隐患因素,并进一步探讨危机管理在急诊护理管理中应用时的具体措施.阐述了强化危机管理在现代急诊护理管理中的重要作用,提出应最大限度防范与控制急诊护理危机,全面提高急诊科护理管理水平. 相似文献
394.
395.
对于新产品推出的成功与否, 较早采用者的评论和建议的影响相当巨大, 本研究通过两个实验研究评论效价(正面评论/负面评论)、新产品类型(渐进性新产品/革新性新产品)和调节定向(促进定向/防御定向)对新产品在线评论有用性的影响。实验1设计为2(新产品类型:渐进性新产品/革新性新产品)×2(评论效价:正面/负面)的组间操控设计, 结果表明:相对于渐进性新产品, 负面评论对革新性新产品的有用性更高, 正面评论对渐进性新产品和革新性新产品的有用性差异不显著。实验2设计为2(新产品类型:渐进性新产品/革新性新产品)×2(评论效价:正面/负面)×2(调节定向:促进/防御)的组间操控设计, 结果表明:促进定向的个体认为正负面评论有用性差异不大, 而防御定向的个体认为负面评论有用性显著高于正面评论; 对于促进定向的个体来说, 新产品类型对于评论效价对评论有用性的影响有调节作用, 而对于防御定向的个体来说, 新产品类型的这种调节作用则不存在。 相似文献
396.
采用2×2×2混合实验设计,使用具体和抽象两种不同性质的图形材料对动态和静态两种条件下内隐时间的存在及其特征进行了考察,结果表明:(1)动态条件下被试对抽象图形的位置偏移判断更为准确;(2)测试图形与识记图形之间位置偏移判断的错误率在测试图形与诱导图形内隐运动方向一致的条件下比不一致条件下大;(3)无论实验材料为具体图形还是抽象图形,被试对测试图形和识记图形的位置偏移判断错误率之间不存在差异。研究结果证明了内隐时间的存在,进一步探明了内隐时间具有方向性和认知不可渗透性的特点,并证明了运动范式为研究内隐时间及其特点的有效方法。 相似文献
397.
Dazhi Cheng Qing Xiao Jiaxin Cui Chuansheng Chen Jieying Zeng Qian Chen Xinlin Zhou 《Developmental science》2020,23(4)
Studies have shown that numerosity‐based arithmetic training can promote arithmetic learning in typically developing children as well as children with developmental dyscalculia (DD), but the cognitive mechanism underlying this training effect remains unclear. The main aim of the current study was to examine the role of visual form perception in arithmetic improvement through an 8‐day numerosity training for DD children. Eighty DD children were selected from four Chinese primary schools. They were randomly divided into the intervention and control groups. The intervention group received training on an apple‐collecting game, whereas the control group received an English dictation task. Children's cognitive and arithmetic performances were assessed before and after training. The results showed that the intervention group showed a significant improvement in arithmetic performance, approximate number system (ANS) acuity, and visual form perception, but not in spatial processing and sentence comprehension. The control group showed no significant improvement in any cognitive ability. Mediation analysis further showed that training‐related improvement in arithmetic performance was fully mediated by the improvement in visual form perception. The results suggest that short‐term numerosity training enhances the arithmetic performance of DD children by improving their visual form perception. 相似文献
398.
Na Xiao 《Journal of Consumer Behaviour》2020,19(1):24-35
The researcher of this paper contributes to the literature by identifying nuances among three types of choice settings that are likely to activate choice‐related goals and their implications for product evaluation. First, the research verifies that choice settings can activate choice‐related goals, for example, simplifying a choice. Second, it is proposed and shown that choice settings activate goals, not semantic constructs. Third, this research attempts to shed light on some nuances among different choice settings, which vary in the degree of cognitive effort used to compare alternatives. The results aid in understanding how three different choice settings can activate choice‐related goals. Fourth, the research proposes that goal activation has an implication for product evaluation, offering a new perspective to preference and choice reversal literature. Five experiments were conducted to test the hypotheses. 相似文献
399.
Gail D. Heyman Xiao Pan Ding Genyue Fu Fen Xu Brian J. Compton Kang Lee 《Cognitive Science》2020,44(3):e12824
Starting in early childhood, children are socialized to be honest. However, they are also expected to avoid telling the truth in sensitive situations if doing so could be seen as inappropriate or impolite. Across two studies (total N = 358), the reasoning of 3- to 5-year-old children in such a scenario was investigated by manipulating whether the information in question would be helpful to the recipient. The studies used a reverse rouge paradigm, in which a confederate with a highly salient red mark on her nose asked children whether she looked okay prior to having her picture taken. In Study 1, children tended to tell the truth only if they were able to observe that the mark was temporary and the confederate did not know it was there. In Study 2, children tended to tell the truth only if they were able to observe that the mark could be concealed with makeup. These findings show that for children as young as age 3, decisions about whether to tell the truth are influenced by the likelihood that the information would be helpful to the recipient. 相似文献
400.
为探究分心抑制和关系整合对学前儿童类比推理的影响,实验一先初步探究分心抑制和关系整合对25名3~4岁和26名5~6岁儿童完成含有知觉分心的类比情景任务的影响。其次,揭示知觉分心与关系整合在类比推理中的具体作用模式。实验二先初步探究分心抑制和关系整合对30名3~4岁和28名5~6岁儿童完成含有语义分心的类比情景任务的影响。其次,揭示语义分心与关系整合在类比推理中的具体作用模式。结果表明,抑制控制能显著预测儿童完成各种类型类比推理成绩,工作记忆能显著预测儿童完成含有语义分心的类比推理成绩而不能显著预测含有知觉分心的类比推理成绩。儿童完成类比情景中的分心抑制是在关系整合中完成的,当类比情景中的关系整合没有超过儿童的工作记忆容量时,知觉或语义分心才能造成对儿童类比推理的影响。 相似文献