全文获取类型
收费全文 | 688篇 |
免费 | 75篇 |
国内免费 | 200篇 |
专业分类
963篇 |
出版年
2024年 | 5篇 |
2023年 | 12篇 |
2022年 | 28篇 |
2021年 | 23篇 |
2020年 | 31篇 |
2019年 | 27篇 |
2018年 | 23篇 |
2017年 | 33篇 |
2016年 | 22篇 |
2015年 | 18篇 |
2014年 | 24篇 |
2013年 | 61篇 |
2012年 | 38篇 |
2011年 | 54篇 |
2010年 | 50篇 |
2009年 | 48篇 |
2008年 | 38篇 |
2007年 | 70篇 |
2006年 | 76篇 |
2005年 | 51篇 |
2004年 | 46篇 |
2003年 | 38篇 |
2002年 | 36篇 |
2001年 | 15篇 |
2000年 | 21篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 6篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 1篇 |
排序方式: 共有963条查询结果,搜索用时 15 毫秒
21.
22.
23.
用微机化的伪随机点立体图对发生器产生静态和动态随机点立体图对(RDS),显示在左右两个示波器上。RDS图形中的元素密度可以改变。具有正常立体视的10名被试通过立体镜观察这些图形,测量双眼融合能产生完整立体图形感知所需最小的元素密度,即密度容限。 设计了三个实验用以检测改变RDS图形的空间参数对密度客限的影响。第一个实验,在静、动态RDS图形下,改变视差图形面积;第二个实验,改变视差图形的形状;第三个实验,改变视差图形的周长。 实验结果表明,双眼深度感知要求一定的元素密度容限,视差图形的大小和形状对密度容限有一定程度的影响。静态和动态RDS图形的密度容限也不相同。 本文利用RDS的整体立体感知特性和空间频率通道理论对实验结果进行了讨论。 相似文献
24.
The recent H1N1 pandemic influenza stimulated numerous studies into the attitudes and intentions about the H1N1 vaccine. However, no study has investigated prospective predictors of vaccination behaviour. We conducted a two-wave longitudinal study among residents in four U.S. cities during the course of the H1N1 outbreak, using Internet surveys to assess demographic, cognitive and emotional predictors of H1N1 vaccination behaviour. Surveys were conducted at two time points, before (Time 1) and after (Time 2) the H1N1 vaccine was widely available to the public. Results show that Time 2 vaccination rates, but not Time 1 vaccination intentions, tracked H1N1 prevalence across the four cities. Receipt of seasonal influenza vaccine in the previous year, worry, compliance with recommended interventions, household size and education assessed at Time 1 were significant prospective predictors of vaccination behaviour. Perception of the H1N1 vaccine, social influence and prioritised vaccine recipient status assessed at Time 2 also predicted vaccination behaviour. Critically, worry about H1N1 mediated the effects of both objective risk (prevalence at the city level) and perceived risk on vaccination behaviour. These results suggest that H1N1 vaccination behaviour appropriately reflected objective risk across regions, and worry acted as the mechanism by which vaccination behaviour followed objective risk. 相似文献
25.
26.
This article introduces a simple survey method to distinguish between two types of variables that affect happiness—type A, which exerts an absolute effect on happiness, and type B, which affects happiness only through social context. The authors validate the method by comparing its findings with the findings of a theoretically superior but less practical experimental method, and use the method to identify the AB nature of a variety of naturally-occurring variables among both college students and people with work experience. We conclude by discussing the limitation of this method as well as its potential to inform policymakers about where to invest resources in order to improve people’s happiness over time. 相似文献
27.
The event-related brain potential (ERP) technique was used to investigate the neural mechanism of non-target language processing in Chinese-English bilinguals. Participants were presented with a mixed list of Chinese and English words and required to make conceptual decisions for words in one language and ignore words in the other non-target language. Regardless of whether the nontarget word was in Chinese or English, the ERPs they elicited were modulated by word frequency, suggesting that their meaning had been accessed. The N400 peak was delayed in the English as the non-target language condition, probably because participants were less proficient in English. The results suggest that the non-target language can be processed during conceptual tasks with participants' proficiency in this language being a critical factor. 相似文献
28.
Research has documented that children and adolescents with attention-deficit/hyperactivity disorder (ADHD) are at increased
risk of substance use problems. Few studies, however, have focused on early-onset substance use. This study therefore investigated
how the two symptom dimensions of ADHD (hyperactivity/impulsivity and inattention) are associated with early-onset substance
use, the role of persistent ADHD for the association, and to what extent the association is influenced by genetic and environmental
factors. Twins (1,480 pairs) in the Swedish Twin Study of Child and Adolescent Development were followed from childhood to
adolescence. ADHD symptoms were measured at age 8–9 and age 13–14 via parent-report, whereas substance use was assessed at
age 13–14 via self-report. Results revealed that hyperactive/impulsive symptoms predicted early-onset “sometimes” tobacco
use (adjusted odds ratios, 1.12, for one symptom count), controlling for inattentive symptoms and conduct problem behaviors.
There is no independent effect of inattentive symptoms on early-onset substance use. Children with persistent hyperactivity/impulsivity
(defined as scoring above the 75th percentile at both time points) had a pronounced risk of both early-onset tobacco and alcohol
use (adjusted odds ratios from 1.86 to 3.35, compared to the reference group). The associations between hyperactivity/impulsivity
and early-onset substance use were primarily influenced by genetic factors. Our results indicated that hyperactivity/impulsivity,
but not inattention, is an important early predictor for early-onset substance use, and a shared genetic susceptibility is
suggested to explain this association. 相似文献
29.
This study determined the working memory (WM) components (executive, phonological loop, and visual–spatial sketchpad) that best predicted mathematical word problem-solving accuracy of elementary school children in Grades 2, 3, and 4 (N = 310). A battery of tests was administered to assess problem-solving accuracy, problem-solving processes, WM, reading, and math calculation. Structural equation modeling analyses indicated that (a) all three WM components significantly predicted problem-solving accuracy, (b) reading skills and calculation proficiency mediated the predictive effects of the central executive system and the phonological loop on solution accuracy, and (c) academic mediators failed to moderate the relationship between the visual–spatial sketchpad and solution accuracy. The results support the notion that all components of WM play a major role in predicting problem-solving accuracy, but basic skills acquired in specific academic domains (reading and math) can compensate for some of the influence of WM on children’s mathematical word problem solving. 相似文献
30.
Correction to: Trends of Positive Youth Development Publications (1995–2020): A Scientometric Review
Qi Shaojie Hua Fengrui Zhou Zheng Shek Daniel T. L. 《Applied research in quality of life》2022,17(1):447-448
Applied Research in Quality of Life - A Correction to this paper has been published: https://doi.org/10.1007/s11482-020-09905-3 相似文献