Suchergebnisse

With data from the New Brunswick School Climate Study (N = 6,883 students from 147 schools), this study examined individual differences in and school effects on health outcomes of students. Results of hierarchical linear modeling showed that females reported experiencing more physical health problems, eating less healthy food, and doing fewer exercises than males. Students of high socioeconomic status (SES) reported eating more healthy food and doing more exercises than students of low SES. Native students reported experiencing more physical health problems and eating less healthy food than nonnative students. Students of single parents reported eating more healthy food and exercising more than students of both parents. Schools showed effects on health outcomes over and above the effects of students. Students in schools with high SES and positive disciplinary climate reported fewer physical and mental health problems. Students in large schools reported less healthy food intake and fewer physical exercises.

The purpose of this study was to examine differences in the rate at which males and females acquired mathematical skills during secondary grades and to determine the relationship between their rates of growth and student- arid school-level characteristics. Based on data from the Longitudinal Study of American Youth (LSAY), a three-level hierarchical linear model (HLM) indicated that males and females acquired mathematical skills at the same rate. The variation in scores among students increased over time, and students maintained their initial position in the distribution. This fan-spread phenomenon among students was more pronounced in basic skills and knowledge than in problem-solving. Schools were more homogeneous in female rate of growth than in male rate of growth. The variation in scores among schools enlarged over time, and schools maintained their initial position in the distribution. This fan-spread phenomenon among schools was more pronounced in basic skills and knowledge than in problem-solving. Policy implications and suggestions for future research are provided. ; Le but de cette recherche était d'étudier les différences dans le rythme auquel les adolescents et les adolescentes ont acquis des habiletés en mathématiques pendant leurs années au secondaire et d'établir le rapport entre leur taux de croissance et des caractéristiques liées aux individus d'une part et à l'école d'autre part. D'après les données du Longitudinal Study of American Youth (LSAY), un modèle linéaire à trois niveaux (HLM) a indiqué que les filles et les garçons acquéraient des habiletés en mathématiques au même rythme. La variation dans les résultats s'est accrue avec le temps et les élèves ont maintenu leur position relative dans la distribution. Ce phénomène d'éventail chez les élèves était plus prononcé pour les habiletés et les connaissances de base que pour la capacité de résolution de problèmes. Les écoles présentaient des profils plus homogènes pour le taux d'assimilation des habiletés chez les filles que chez les garçons. La variation dans les résultats par école s'est accrue avec les temps et les écoles ont maintenu leur position relative dans la distribution. Ce phénomène d'éventail parmi les écoles était plus prononcé pour les habiletés et les connaissances de base que pour la capacité de résolution de problèmes. On présente des implications en ce qui concerne la politique et des suggestions pour la recherche à l'avenir.

China&rsquo ; s rapid urbanization has caused dramatically increasing energy consumption in the district heating systems of the building sector in the Jing-Jin-Ji urban agglomeration, and this change has led to enormous air pollution issues in this region. However, the drivers and the sustainable development process of the district heating system of the building sector have not been investigated to understand the management of energy conservation and emissions reduction in the Jing-Jin-Ji urban agglomeration. This study investigates the drivers of the district heating energy consumption of the building sector (DHEB) in the Jing-Jin-Ji urban agglomeration between 2004 and 2016 by developing a decomposition framework. The decoupling status between the DHEB and gross domestic product (GDP) is then analyzed based on the Tapio decoupling index. The results show that a weak decoupling effect is mainly found between the DHEB and GDP in the Jing-Jin-Ji urban agglomeration from 2004 to 2016. The increase in the DHEB in 2004-2016 is largely driven by the growth of the district heating area and population, while the heating energy intensity negatively contributes to the increase. Significant differences in the effects of the share of the energy mix and share of heat production technology were found between subregions in response to government policy, which impacted levels in Beijing, Tianjin, and Hebei in decreasing order.

The rapid growth of energy consumption in commercial building operations has hindered the pace of carbon emission reduction in the building sector in China. This study used historical data to model the carbon emissions of commercial building operations, the LASSO regression was applied to estimate the model results, and the whale optimization algorithm was used to optimize the nonlinear parameter. The key findings show the following: (1) The major driving forces of carbon emissions from commercial buildings in China were found to be the population size and energy intensity of carbon emissions, and their elastic coefficients were 0.6346 and 0.2487, respectively. (2) The peak emissions of the commercial building sector were 1264.81 MtCO2, and the peak year was estimated to be 2030. Overall, this study analyzed the historical emission reduction levels and prospective peaks of carbon emissions from China's commercial buildings from a new perspective. The research results are helpful for governments and decision makers to formulate effective emission reduction policies and can also provide references for the low-carbon development of other countries and regions.

With an educational issue that has caught the attention of many countries in the world (study load), a population of 8th graders from a typical Chinese metropolitan city (40,536 from 118 schools), and an advanced statistical strategy (multilevel piecewise regression), we examined whether there was a turning point in terms of the effects of study load on science achievement. We did identify a turning point for each and every measure of study load. For weekday learning on science achievement, we identified a turning point of 22.50 hr for the effects of in-school learning, 7.50 hr for the effects of homework, and 12 hr for the effects of after-school learning. For weekend learning on science achievement, we identified a turning point of 1.50 hr for the effects of in-school learning, 5 hr for the effects of homework, and 1 hr for the effects of after-school learning. In each case, the difference in effects before and after the turning point was statistically significant, indicating that the effects of study load on science achievement were nonlinear. All of these turning points offered important implications for science education.