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91.
Abstract

This study aimed to produce age- and sex-specific physical fitness reference data for Portuguese youth; to report the prevalence of youth in the healthy zone of physical fitness according to the FITNESSGRAM® criteria; to verify the agreement between the Portuguese physical fitness percentiles and the FITNESSGRAM® healthy zones. In 2008, 22,048 Portuguese children and adolescents (10–18 years) were evaluated. Physical fitness (curl-ups, push-ups, 20-m shuttle run and modified-back-saver-sit-and-reach tests) was evaluated using the FITNESSGRAM® Test Battery 8.0. Smoothed percentile curves were estimated using Cole’s LMS method. Boys consistently outperformed girls in every physical fitness test, except for the modified-back-saver-sit-and-reach tests. In both sexes and for all physical fitness tests, higher percentile values were observed at older ages. The 50th percentile of all physical fitness tests had the highest accuracy to discriminate between under healthy zone and healthy zone of the FITNESSGRAM®. Portuguese schools and physical education teachers may considerer the 50th percentile for age and sex or the FITNESSGRAM® criteria for classifying participants in the healthy zone as acceptable cut-offs, above which youth should be considered fit. These reference values can be used as normative data and for baseline values for subsequent surveillance of the physical fitness of Portuguese youth.  相似文献   
92.
Abstract

This study aimed to investigate the direct and indirect associations between perceived environmental characteristics and psychosocial factors and physical activity levels in adolescents from Northeast Brazil. The sample was composed of 2,361 adolescents aged 14–19 years (56.6% female). Physical activity was measured using a questionnaire and environmental (perceived environmental characteristics) and psychosocial (self-efficacy, social support from parents and friends for physical activity) factors with previously validated scales. Perceived environmental characteristics were not directly associated with the levels of physical activity, but exhibited significant indirect associations, mediated by self-efficacy in males. Self-efficacy and social support were positively and directly associated with physical activity levels, and part of the associations between social support and physical activity was mediated by self-efficacy. Perception of self-efficacy and social support, important factors associated with physical activity levels in adolescents, should be the target of interventions aimed at increasing physical activity. Favorable environments for physical activity also need to be considered, since they have a positive influence on the self-efficacy of adolescents.  相似文献   
93.
Abstract

The aims of the this prospective study were to analyse physical activity (PA) engagement during the first and second trimesters, considering the different guidelines published on PA, to document the individual characteristics associated with the accomplishment of these guidelines and to examine pregnant women’s perceived barriers to leisure PA, using a socioecological framework. A sample of 133 pregnant women in two stages – at 10–12 weeks’ gestation (T1) and 20–22 weeks’ gestation (T2) – were evaluated. PA was assessed by accelerometry during the T1 and T2 evaluation stages. Socio-demographic characteristics, lifestyle factors and barriers to leisure PA were assessed via questionnaire. A large proportion of women (ranging from 32% to 96%) did not reach the levels of PA recommended by the guidelines. There were no significant differences between T1 and T2 with regard to compliance with PA recommendations. A decrease in PA levels from T1 to T2 was noted for all recommendations. No associations were found between participants’ characteristics and adherence to the recommendations in T1 and T2. No significant differences were found in barriers to leisure PA between T1 and T2. The most commonly reported barriers to leisure PA were intrapersonal, not health related. Our results indicate that there were no differences between trimesters regarding compliance of PA recommendations, and perceived barriers were similar in both trimesters.  相似文献   
94.

In this article we analyse the interaction between a high school chemistry teacher and her students from two different classes, emphasizing how emotions, affects and feelings contributed to, or obstructed, the dynamic of interactions. The data come from an ethnographic research approach and include videotapes of the lessons, interviews and field notes. Using the distinction introduced by Damasio between primary and secondary emotions, and between emotions and feelings, we describe how the background feelings emerged in different ways in the two classrooms. In class B, the relationships were constructed in a friendly way from the very beginning. The positive emotions that contributed to raising positive background feelings occurred in a high number and frequency. In class A, the picture was completely different, with a higher number and frequency of negative emotions. Thus, emotions and background feelings that were constructed differently in each classroom were at the heart of the different outcomes in terms of attitudes towards chemistry that arose in the two classrooms. In the paper, we also discuss the implication of this kind of analysis for science teaching generally.  相似文献   
95.
Australian, Iranian and Portuguese university students (n?=?967) completed the University Students Depression Inventory (USDI) in English, Persian and Portuguese languages, respectively. A series of MANOVA analyses were used to examine differences in depression symptoms as an effect of the country and demographic variables. Interactions were also examined. The results indicated that country, gender and year level had some impact on the depressive symptoms of the university students. Australian students were more depressed than the Iranian and Portuguese students, while Iranian students were more depressed than the Portuguese students. Sub-scales of USDI – Lethargy, Motivation and Cognitive/Emotional – were also used to compare the depressive symptoms of students. The Australian female students reported a significantly higher level of lethargy than their male counterparts. Similarly, the first-year male students from Iran were significantly more lethargic than the first-year Iranian female students. Iranian and Portuguese male students, compared to the female students of these countries, experienced a lower level of motivation. The Australian and Iranian students, compared to the Portuguese students, reported a significantly higher level of cognitive and affective symptoms. The scores on the Cognitive/Emotional sub-scale increased with the year level. Differences among students' depression are described and implications discussed.  相似文献   
96.
Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52–59.01) Tg C yr−1, which is ∼30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios.  相似文献   
97.
Cardiorespiratory fitness (CRF) is associated with health benefits in children, improving cardiac morphology, cardiovascular disease risk factors, and biological outcomes. This study aimed to examine the substitution effects of displaying a fixed duration of sedentary time with a fixed duration of physical activity (PA) at different intensities on children’s CRF. A total of 315 children (136 boys) were assessed (age: 10.6 ± 0.6 years old). Outcomes at baseline and follow-up (16-months) were CRF determined using a maximal cycle test and sedentary time and PA measured with accelerometers. Data were analysed by isotemporal substitution analyses estimating the effect of reallocating 30 min/day of sedentary time by light (LPA), moderate (MPA) and vigorous physical activity (VPA) on CRF. VPA was positively and significantly associated with CRF cross-sectional (β = 0.026, < 0.001) and prospectively (β = 0.010, < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, < 0.001) and prospectively (β = 0.303, < 0.05) associated with CRF. Conversely, relocating 30-minutes of sedentary time into 30 minutes of LPA and MPA was not associated with CRF. These results suggest that reallocating an equal amount of time from sedentary into VPA is cross-sectional and prospectively associated with a favourable CRF.  相似文献   
98.
99.
Methodologies for engineering learning and teaching (MELT) approach aims to enhance the attractiveness of education through science, technology, engineering and mathematics (STEM) among young people, while promoting awareness of future careers in these areas. To this end, students’ expectations are considered within university programmes, aiming to an increased engagement in STEM careers. To accomplish these goals, a new and integrated approach (MELT) is presented, involving the main stakeholders in both scientific education and society. An education framework is presented, providing guidelines for an improved collaborative approach to STEM education in the future. Results from the pilot implementation of MELT are presented, from a small-scale education parliament prototype. From these initial stage and results, it is seen that there is a need for a proper alignment of expectations from all involved stakeholders, concerning the engineering education towards society’s demands.  相似文献   
100.
In the wake of new federal and state mandates,community colleges are faced with demands to provideaccountability reports on student outcomes. With the useof the Employment Development Department Unemployment Insurance (EDD-UI) wage record data, along withthe California Community Colleges Chancellor's OfficeManagement Information System administrative database,this study sought to investigate the extent to which completing an associate degree andvocational certificate impacts the postcollege earningsof students. Based on information from 700,564 studentsfrom California community colleges during the 1992-93 academic year, the findings suggest thatstudents' gains from first year out of college to thirdyear out will differ by age group. Among economicallydisadvantaged students, a strong positive relationship exists between educational attainment andpostcollege gains. An important finding among vocationalstudents is that as women complete more education, theearnings gap closes between men and women. Finally, this study raises several policy implicationsand presents suggestions for future research.  相似文献   
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