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   850篇
  免费   38篇
  国内免费   1篇
  2024年   3篇
  2023年   11篇
  2022年   17篇
  2021年   15篇
  2020年   24篇
  2019年   25篇
  2018年   36篇
  2017年   36篇
  2016年   48篇
  2015年   34篇
  2014年   28篇
  2013年   118篇
  2012年   62篇
  2011年   62篇
  2010年   26篇
  2009年   25篇
  2008年   52篇
  2007年   40篇
  2006年   28篇
  2005年   25篇
  2004年   28篇
  2003年   22篇
  2002年   20篇
  2001年   11篇
  2000年   17篇
  1999年   16篇
  1998年   6篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1993年   2篇
  1991年   2篇
  1989年   3篇
  1987年   5篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1981年   7篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   2篇
  1973年   2篇
  1972年   1篇
  1970年   2篇
  1968年   1篇
  1966年   1篇
排序方式: 共有889条查询结果,搜索用时 15 毫秒
21.
We used the take‐the‐best heuristic to develop a model to forecast the popular two‐party vote shares in U.S. presidential elections. The model draws upon information about how voters expect the candidates to deal with the most important issue facing the country. We used cross‐validation to calculate a total of 1000 out‐of‐sample forecasts, one for each of the last 100 days of the ten U.S. presidential elections from 1972 to 2008. Ninety‐seven per cent of forecasts correctly predicted the winner of the popular vote. The model forecasts were competitive compared to forecasts from methods that incorporate substantially more information (e.g., econometric models and the Iowa Electronic Markets). The purpose of the model is to provide fast advice on which issues candidates should stress in their campaign. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
22.
We investigated people's ability to decide how much time to spend on the task at hand. To make such decisions well, one must take into account, among other things, the cost of failing and how one's task performance changes as a function of time. We first investigated timing decisions when the underlying task was perceptual. Decisions were highly efficient and suggested that people can make good use of perceptual knowledge and abstract reward information. Previous studies have found that perceptual decisions are generally optimal, but that cognitive decisions are generally suboptimal--a perception-cognition gap. Does a similar gap exist for timing decisions? We compared timing decisions for a perceptual task with timing decisions for more cognitive tasks. Performance was highly similar across the tasks, which suggests that knowledge can be acquired, and used to make timing decisions, in an equally efficient way regardless of whether that knowledge is derived through perceptual or cognitive experience.  相似文献   
23.
Deficits in executive functioning and working memory associated with frontal lobe dysfunction are prominent in depression and work-related long-term sick leave (LTSL). This study used functional magnetic resonance imaging (fMRI) to investigate potential differences in brain activation patterns in these conditions. In addition, the function of the hypothalamic-pituitary-adrenal (HPA) axis was examined and compared between groups. Since there is a clear overrepresentation of women in these diagnostic groups, and to ensure a more homogenous sample population, only women were included. To examine the neural correlates of relevant cognitive processes in patients on sick leave >90 days due to work-related LTSL, recently diagnosed patients with major depression Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV criteria, untreated), and healthy controls (n?=?10, each group), a 2-back working memory task and a visual long-term memory task were administered during fMRI scanning. HPA axis functioning was investigated using a diurnal curve of saliva cortisol and a dexamethasone suppression test. Task performance was comparable among the three groups. Multivariate image analysis revealed that both memory tasks engaged a similar brain network in all three groups, including the prefrontal and parietal cortex. During the 2-back task, LTSL patients had significant frontal hypoactivation compared to controls and patients with depression. Saliva cortisol measurements showed a flattening of the diurnal rythmicity in LTSL patients compared to patients with depression and healthy contols. Taken together, these findings indicate that work stress-related LTSL and major depression are dissociable in terms of frontal activation and diurnal cortisol rhythmicity.  相似文献   
24.
Little is known about positive development across the transition from adolescence to young adulthood. The purpose of this paper was to use longitudinal data from a large community sample, the Australian Temperament Project, to investigate prospective associations between positive development at age 19?C20?years and changes in social, health, and behavioral outcomes at 23?C24?years. Data from 890 young adults (61.7% women) were analyzed using path analysis. Emotional health, physical well-being, friendship quality, reduced antisocial behavior, and positive development in young adulthood were predicted by higher levels of positive development in late adolescence, after controlling for baseline levels of respective outcomes, gender, and family socioeconomic status. Parent relationship quality and alcohol use were not significantly predicted. Based on these findings, interventions promoting positive development during adolescence should be investigated as a potential means of yielding positive social, health, and behavioral consequences well into young adulthood.  相似文献   
25.
A substantial amount of research shows that social exclusion is a threat to mental health. In the research reported here, we tested the hypothesis that the presence of a companion animal can serve as a buffer against these adverse effects. In a controlled laboratory experiment, we found that only socially excluded participants who did not work in the presence of a dog reported lower mental well-being compared with socially excluded participants who performed in the presence of a dog and participants who were not socially excluded. The theoretical and practical implications of these findings are discussed.  相似文献   
26.
Intervention programs for treating adiposity which focus on dietary change and physical exercise often do not lead to the desired long-term reduction in weight. This article reports on the effectiveness of M.O.B.I.L.I.S., a standardized theory-driven intervention program. Participants are taught cognitive-behavioral strategies of goal setting, action planning, barrier management, and self-monitoring. Persons with obesity (N=316) responded to a public advertisement to participate in the intervention program (IG) or comparison group (CG; quasi-experimental design). Assessments were conducted at four time points, with the last assessment being conducted two years after baseline. At the 24-month follow-up, the IG showed weight loss of 5.57%, whereas the CG lost 1.12% of their weight (t1-t4, p < .01). The results yielded significant interaction terms (group x time), indicating that the intervention had a substantial effect on food choice and level of physical exercise (p < .01). The IG showed significantly enhanced self-efficacy, stronger goal intentions, and more detailed implementation intentions than the CG at follow-ups. The intervention program has the potential to evoke enduring changes in the cognitions we hypothesized to be responsible for inducing obese adults to begin and continue regular exercise and healthy eating behavior, resulting in substantial weight loss.  相似文献   
27.
After making a preliminary decision, a balanced search for information that is consistent and inconsistent with one's decision is associated with effective decision making. However, whereas searching for information that is inconsistent with one's preliminary preference arouses the aversive motivational state of cognitive dissonance, evokes negative emotions, and threatens the self, preference‐consistent information reduces dissonance, evokes positive emotions, and has positive implications for the self. Thus, searching for information in a balanced way requires the willingness to face the negative implications of searching for preference‐inconsistent (relative to preference‐consistent) information. Social exclusion has been shown to be associated with impulsive, undercontrolled behavior. Therefore, we expected socially excluded (relative to included or control) participants to be less willing to confront oneself with the unappealing qualities of preference‐inconsistent information and more willing to seek for the appealing qualities of preference‐consistent information. This hypothesis was supported in two studies, with the use of different manipulations of social exclusion. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
28.
The picture-word interference paradigm is a prominent tool for studying lexical retrieval during speech production. When participants name the pictures, interference from semantically related distractor words has regularly been shown. By contrast, when participants categorize the pictures, facilitation from semantically related distractors has typically been found. In the extant studies, however, differences in the task instructions (naming vs. categorizing) were confounded with the response level: While responses in naming were typically located at the basic level (e.g., "dog"), responses were located at the superordinate level in categorization (e.g., "animal"). The present study avoided this confound by having participants respond at the basic level in both naming and categorization, using the same pictures, distractors, and verbal responses. Our findings confirm the polarity reversal of the semantic effects--that is, semantic interference in naming, and semantic facilitation in categorization. These findings show that the polarity reversal of the semantic effect is indeed due to the different tasks and is not an artifact of the different response levels used in previous studies. Implications for current models of language production are discussed.  相似文献   
29.
The objective of this study was to investigate the link between the Eysenck Personality Questionnaire (EPQ) scores and depressive symptomatology with reasoning performance induced by a task including valid and invalid Aristotelian syllogisms. The EPQ and the Zung Depressive Scale (ZDS) were completed by 48 healthy subjects (27 male, 21 female) aged 33.5 ± 9.0 years. Additionally, the subjects engaged into two reasoning tasks (valid vs. invalid syllogisms). Analysis showed that the judgment of invalid syllogisms is a more difficult task than of valid judgments (65.1% vs. 74.6% of correct judgments respectively, p < 0.01). In both conditions, the subjects’ degree of confidence is significantly higher when they make a correct judgment than when they make an incorrect judgment (83.8 ± 11.2 vs. 75.3 ± 17.3, p < 0.01). Subjects with extraversion as measured by EPQ and high sexual desire as rated by the relative ZDS subscale are more prone to make incorrect judgments in the valid syllogisms, while, at the same time, they are more confident in their responses. The effects of extraversion/introversion and sexual desire on the outcome measures of the valid condition are not commutative but additive. These findings indicate that extraversion/introversion and sexual desire variations may have a detrimental effect in the reasoning performance.  相似文献   
30.
Training science views itself as an integrated and applied science, developing practical measures founded on scientific method. Therefore, it demands consideration of a wide spectrum of approaches and methods. Especially in the field of competitive sports, research questions are usually located in complex environments, so that mainly field studies are drawn upon to obtain broad external validity. Here, the interrelations between different variables or variable sets are mostly of a nonlinear character. In these cases, methods like neural networks, e.g., the pattern recognizing methods of Self-Organizing Kohonen Feature Maps or similar instruments to identify interactions might be successfully applied to analyze data. Following on from a classification of data analysis methods in training-science research, the aim of the contribution is to give examples of varied sports in which network approaches can be effectually used in training science. First, two examples are given in which neural networks are employed for pattern recognition. While one investigation deals with the detection of sporting talent in swimming, the other is located in game sports research, identifying tactical patterns in team handball. The third and last example shows how an artificial neural network can be used to predict competitive performance in swimming.  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