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   409篇
  免费   42篇
  2022年   3篇
  2021年   7篇
  2020年   8篇
  2019年   15篇
  2018年   19篇
  2017年   16篇
  2016年   17篇
  2015年   27篇
  2014年   17篇
  2013年   68篇
  2012年   25篇
  2011年   28篇
  2010年   13篇
  2009年   12篇
  2008年   25篇
  2007年   19篇
  2006年   18篇
  2005年   8篇
  2004年   11篇
  2003年   6篇
  2002年   14篇
  2001年   5篇
  2000年   3篇
  1999年   4篇
  1996年   4篇
  1995年   2篇
  1994年   3篇
  1992年   1篇
  1991年   5篇
  1990年   1篇
  1989年   1篇
  1986年   2篇
  1982年   2篇
  1981年   2篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1974年   5篇
  1973年   1篇
  1972年   5篇
  1971年   4篇
  1970年   1篇
  1969年   2篇
  1968年   3篇
  1967年   1篇
  1966年   1篇
  1964年   5篇
  1961年   1篇
  1960年   2篇
  1950年   1篇
排序方式: 共有451条查询结果,搜索用时 15 毫秒
281.
The objective was to compare the effects of two types of written material for insomnia in a randomized trial with follow-up after three months. Insomniacs were recruited through newspaper advertisements to a web-based survey with validated questionnaires about sleep, anxiety, depression, and use of sleep medications. A self-help book focusing on cognitive behavioral therapy for insomnia was compared to standard sleep hygiene advice; 77 and 78 participants were randomized to self-help book or sleep hygiene advice, respectively. The response rate was 81.9%. The self-help book gave significantly better scores on the sleep questionnaires compared to sleep hygiene advice. The proportion using sleep medications was reduced in the self-help book group, whereas it was increased in the sleep hygiene group. Compared to pre-treatment, the self-help book improved scores on the sleep (effect sizes 0.61-0.62) and depression (effect size 0.18) scales, whereas the sleep hygiene advice improved scores on some sleep scales (effect sizes 0.24-0.28), but worsened another (effect size -0.36). In addition, sleep hygiene advice increased the number of days per week where they took sleep medications (effect size -0.50). To conclude, in this randomized controlled trial, the self-help book improved sleep and reduced the proportion using sleep medications compared to sleep hygiene advice. The self-help book is an efficient low-threshold intervention, which is cheap and easily available for patients suffering from insomnia. Sleep hygiene advice also improved sleep at follow-up, but increased sleep medication use. Thus, caution is warranted when sleep hygiene advice are given as a single treatment.  相似文献   
282.
The effect of emotional stimulus content on working memory performance has been investigated with conflicting results, as both emotion-dependent facilitation and impairments are reported in the literature. To clarify this issue, 52 adult participants performed a modified visual 2-back task with highly arousing positive stimuli (sexual scenes), highly arousing negative stimuli (violent death) and low-arousal neutral stimuli. Emotional stimulus processing was found to facilitate task performance relative to that of neutral stimuli, both in regards to response accuracy and reaction times. No emotion-dependent differences in false-alarm rates were found. These results indicate that emotional information can have a facilitating effect on working memory maintenance and processing of information.  相似文献   
283.
In two studies, the influence of key emotional and motivational factors on performance in different achievement goal-type situations is examined. In study 1, based on 314 sixth-graders, two types of goal situations were induced; performance and mastery. The goals were examined with respect to important antecedents (e.g., motive dispositions) and several consequences (e.g., performance, satisfaction, pleasant affect, worry, and emotionality). The results showed that the motive to achieve success (M s) produced positive affects, satisfaction, and increased performance, whereas the motive to avoid failure (M f) produced worries and performance reduction. In study 2, based on 331 sixth-graders, three types of goal situations were induced; performance–approach, performance–avoidance, and mastery goals. The findings revealed that the most important single factors positively related to performance were M s and mastery–goal situation. In addition, high M s pupils performed better under mastery condition than under performance condition. Finally, avoidance-goal situation accentuate the negative effects of high M f on performance.  相似文献   
284.
A major problem in learning from instructional animations is that the complex perceptual and cognitive processing exceeds the learner's limited processing capacities. Although attention cueing might help learners in focusing on essential parts of an animation, previous studies have shown that it does not necessarily improve learning performance. This study investigated whether generating self‐explanations while studying a cued or an uncued animation might engage learners in cognitive activities necessary for learning. It was hypothesized that learning from a cued animation that reduces working memory load associated with searching for specific elements might be improved by generating self‐explanations, whereas self‐explaining with an uncued animation would have no positive effect on learning. The results confirmed the hypothesized interaction between cueing and self‐explaining. They suggest that self‐explanation enhances learning if visual cues are used to structure and highlight the essential parts of an animation. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
285.
Children of ages 3 to 4.5 years (N = 107; 45 boys, 62 girls) were studied twice, 6 months apart, to examine whether the cortisol rise in child care at Time 1 (T1) was associated with (a) changes in anxious, vigilant behavior from T1 to Time 2 (T2) and (b) higher internalizing symptoms at T2. Controlling for measures of home environment and child care quality at T1, as well as for cortisol activity at T2, we obtained results indicating that behavioral inhibition moderated the associations between the rise in cortisol at T1 and child outcomes at T2 (i.e., anxious, vigilant behavior and internalizing symptoms). For both outcomes, the rise in cortisol at T1 became more positively predictive at increasing levels of behavioral inhibition. Specifically, at higher levels of behavioral inhibition, children with larger T1 cortisol increases expressed more internalizing symptoms than did children at lower levels of behavioral inhibition; in contrast, for those with low cortisol activity at T1, children with higher levels of inhibition expressed fewer internalizing symptoms than did children at lower levels of inhibition. In addition, children with higher levels of behavioral inhibition and lower cortisol activity at T1 exhibited reductions in anxious, vigilant behavior from T1 to T2, whereas at lower levels of behavioral inhibition, variations in the T1 cortisol rise bore no relation to changes in this behavior. These results suggest that the rise in cortisol at child care may have differential predictive value as a function of behaviorally inhibited temperament.  相似文献   
286.
Myhr AI  Myskja BK 《Nanoethics》2011,5(1):73-86
Nanoparticles have multifaceted advantages in drug administration as vaccine delivery and hence hold promises for improving protection of farmed fish against diseases caused by pathogens. However, there are concerns that the benefits associated with distribution of nanoparticles may also be accompanied with risks to the environment and health. The complexity of the natural and social systems involved implies that the information acquired in quantified risk assessments may be inadequate for evidence-based decisions. One controversial strategy for dealing with this kind of uncertainty is the precautionary principle. A few years ago, an UNESCO expert group suggested a new approach for implementation of the principle. Here we compare the UNESCO principle with earlier versions and explore the advantages and disadvantages by employing the UNESCO version to the use of PLGA nanoparticles for delivery of vaccines in aquaculture. Finally, we discuss whether a combined scientific and ethical analysis that involves the concept of responsibility will enable approaches that can provide a supplement to the precautionary principle as basis for decision-making in areas of scientific uncertainty, such as the application of nanoparticles in the vaccination of farmed fish.  相似文献   
287.
This paper reports on the role of personality as an antecedent of proactive behaviour at work in the form of whistleblowing. In the interest of triangulation, two studies were used, along with two personality measures. The results of Study 1, conducted among 503 municipality employees, show that the NEO Five‐Factor Inventory dimensions of extraversion and agreeableness are significantly associated with whistleblowing, with odds ratios of 1.13 and 0.91, respectively. The result from Study 2, conducted among a representative sample of employees, shows that the circumplex of interpersonal problems dimension domineering was significantly associated with whistleblowing, with an odds ratio of 1.66. The results suggest that personality, in the form of high extraversion and dominance and low agreeableness, do play a role as antecedents of whistleblowing.  相似文献   
288.
289.
Bariatric surgery is effective on short- and medium-term weight loss, reduction of comorbidities, and overall mortality. A large and increasing portion of the population is eligible for bariatric surgery, which increases instant health care costs. A review of the literature identifies a series of ethical challenges: unjust distribution of bariatric surgery, autonomy and informed consent, classification of obesity and selecting assessment endpoints, prejudice among health professionals, intervention in people's life-world, and medicalization of appearance. Bariatric surgery is particularly interesting because it uses surgical methods to modify healthy organs, is not curative, but offers symptoms relief for a condition that it is considered to result from lack of self-control and is subject to significant prejudice. Taking the reviewed ethical issues into account is important when meeting persons eligible for bariatric surgery, as well as in the assessment of and decision making on surgery for obesity.  相似文献   
290.
The main goal of the present research was to demonstrate the interaction between category and causal induction in causal model learning. We used a two-phase learning procedure in which learners were presented with learning input referring to two interconnected causal relations forming a causal chain (Experiment 1) or a common-cause model (Experiments 2a, b). One of the three events (i.e., the intermediate event of the chain, or the common cause) was presented as a set of uncategorized exemplars. Although participants were not provided with any feedback about category labels, they tended to induce categories in the first phase that maximized the predictability of their causes or effects. In the second causal learning phase, participants had the choice between transferring the newly learned categories from the first phase at the cost of suboptimal predictions, or they could induce a new set of optimally predictive categories for the second causal relation, but at the cost of proliferating different category schemes for the same set of events. It turned out that in all three experiments learners tended to transfer the categories entailed by the first causal relation to the second causal relation.  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