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   331篇
  免费   16篇
教育   264篇
科学研究   7篇
各国文化   3篇
体育   28篇
信息传播   45篇
  2024年   1篇
  2023年   3篇
  2022年   4篇
  2021年   8篇
  2020年   26篇
  2019年   23篇
  2018年   30篇
  2017年   47篇
  2016年   24篇
  2015年   18篇
  2014年   18篇
  2013年   65篇
  2012年   7篇
  2011年   2篇
  2010年   6篇
  2009年   6篇
  2008年   6篇
  2007年   5篇
  2006年   3篇
  2005年   5篇
  2003年   6篇
  2002年   3篇
  2001年   7篇
  2000年   2篇
  1997年   1篇
  1996年   2篇
  1994年   1篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1988年   1篇
  1984年   3篇
  1983年   1篇
  1980年   2篇
  1978年   1篇
  1973年   2篇
  1971年   1篇
  1969年   1篇
  1955年   1篇
  1935年   1篇
排序方式: 共有347条查询结果,搜索用时 31 毫秒
1.
2.
Genetics Home Reference is a free, online resource created and maintained by the National Library of Medicine. It is designed to provide genetic information to a wide variety of audiences, particularly the general public. The site consists of original information and links to other curated resources.  相似文献   
3.
Oh and LaRose (2016) contended that problem severity and channel publicness shape support seekers’ goals, time spent composing messages, and the sophistication of those messages. The current study seeks to replicate and extend Oh and LaRose’s study to produce a more accurate understanding of the factors that influence the sophistication of support-seeking messages online. Support seekers’ goals varied according to the severity of a stressor and the publicness of a channel, and the amount of time people spent composing a message influenced its sophistication. We extend the original study by examining associations that were not initially tested. Time spent composing messages mediated the influence of problem severity on the quality of people’s messages, and this effect was moderated by channel publicness.  相似文献   
4.
Abstract

Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340?kcal?d?1 and 452?kcal?d?1 needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300?kcal?d?1 during the first, second and third trimester, normal weight women an increase of 0, 350 and 500?kcal?d?1 and obese women an increase of 0, 450 and 350?kcal?day?1. The recommendations for carbohydrate and protein intake are 175?g?d?1 and 0.88–1.1?g?kgBM?d?1, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8–11.3?kg and obese women 5.0–9.1?kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5–16.0?kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.  相似文献   
5.
High turnover rates of early care and education teachers reduce the quality of education; unsatisfied teachers, suffering from stress or emotional exhaustion, are less equipped to promote children’s development and more likely to leave the classroom. We used data from a national survey of US early childhood educators (n?=?1129) to examine associations between teachers’ working conditions, well-being, and motivation with professional commitment and turnover intentions to move, leave, or remain. Multiple regression analyses revealed that more intrinsically motivated teachers were more likely to report intentions to move over leave, emotionally exhausted teachers were more likely to report intentions to leave, and lower teacher-reported working conditions predicted intentions to move or leave the field over staying. The results suggest that teachers’ well-being and perceived working conditions relate with their intentions to remain at their job or within the field and to their commitment to the profession.  相似文献   
6.
Children tend to extend object names on the basis of sameness of shape, rather than size, color, or material-a tendency that has been dubbed the "shape bias." Is the shape bias the result of well-learned associations between words and objects? Or does it exist because of a general belief that shape is a good indicator of object category membership? The present three studies addressed this debate by exploring whether the shape bias is specific to naming. In Study 1, 3-year-olds showed the shape bias both when asked to extend a novel name and when asked to select an object of the same kind as a target object. Study 2 found the same shape bias when children were asked to generalize properties relevant to category membership. Study 3 replicated the findings from Study 1 with 2-year-olds. These findings suggest that the shape bias derives from children's beliefs about object kinds and is not the product of associative learning.  相似文献   
7.
8.
Multistage, ultra-endurance events in hot, humid conditions necessitate thermal adaptation, often achieved through short term heat acclimation (STHA), to improve performance by reducing thermoregulatory strain and perceptions of heat stress. This study investigated the physiological, perceptual and immunological responses to STHA prior to the Marathon des Sables. Eight athletes (age 42 ± 4 years and body mass 81.9 ± 15.0 kg) completed 4 days of controlled hyperthermia STHA (60 min·day?1, 45°C and 30% relative humidity). Pre, during and post sessions, physiological and perceptual measures were recorded. Immunological measures were recorded pre-post sessions 1 and 4. STHA improved thermal comfort (P = 0.02), sensation (P = 0.03) and perceived exertion (P = 0.04). A dissociated relationship between perceptual fatigue and Tre was evident after STHA, with reductions in perceived Physical (P = 0.04) and General (P = 0.04) fatigue. Exercising Tre and HR did not change (P > 0.05) however, sweat rate increased 14% (P = 0.02). No changes were found in white blood cell counts or content (P > 0.05). Four days of STHA facilitates effective perceptual adaptations, without compromising immune status prior to an ultra-endurance race in heat stress. A greater physiological strain is required to confer optimal physiological adaptations.  相似文献   
9.
10.
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