Autonomy support in physical education promotes autonomous motivation towards leisure-time physical activity: evidence from a sample of Chinese college students.

Based on the trans-contextual model, two studies aimed to test whether autonomy-supportive physical education (PE) promotes autonomous motivation towards leisure-time physical activity among Chinese college students. Study 1 was conducted in September 2015 and used a cross-sectional design. Participants were students who provided data on perceived autonomy support and motivation for physical activity. Regression analysis was used to analyze the data. Study 2 took place from September to December 2015 and employed an experimental design. Participants were PE teachers and their students. The teachers were randomized to either an intervention or a control group and those in the intervention group received a 3-month long autonomy-supportive intervention program. Their students provided data on motivation. The data were analyzed with repeated measurement analysis of variance. A total of 681 students aged 16-26 years participated in Study 1. Perceived autonomy support predicted autonomous motivation in PE (ß = 0.18, P = 0.001), which in turn predicted autonomous motivation towards leisure-time physical activity (ß = 0.51, P = 0.001). Ten PE teachers (28-53 years) and 258 students (16-26 years) participated in Study 2. Students who were educated by the intervention teachers had significantly stronger autonomous motivation towards leisure-time physical activity than students educated by the control teachers after the intervention, (F = 12.41, P = 0.001). The results suggest that PE may serve as an effective platform to promote an active lifestyle among Chinese college students when teachers provide students with an experience of autonomy.

Sensitivity and uncertainties assessment in radiative forcing due to aerosol optical properties in diverse locations in China.

Aerosol optical properties play an important role in affecting direct aerosol radiative forcing (DARF). However, DARF estimation is still uncertain due to the complexity of aerosol optical properties. Therefore, in this study, the spatiotemporal distributions of aerosol properties and their effects on DARF in China from 2004 to 2020 are investigated using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. The results show that the aerosol optical parameters vary greatly and change with seasonal regularity, which is greatly affected by human activities. The control variable method was employed on aerosol optical properties for better estimation of DARF. Single scattering albedo (SSA) has the greatest effect on DARF, followed by aerosol optical depth (AOD) and the asymmetric factor (ASY) among the seven examined stations in China. The average DARF decreases by 4.2 % when the SSA increases by 0.3 % but increases by 34.7 % when the SSA decreases by 3 % in mainland China. When the AOD changes from -60 to +60 %, DARF changes from -54.7 % to +58.4 %. The variation in DARF is between -3 % and +3 % when the ASY varies from -30 % to +30 %. The instability in DARF resulted from the complicated and volatile nature of aerosol optical properties in the region; the aerosol optical properties are greatly affected by the aerosol types and relative humidity. The results of this study have important reference significance for understanding the variation of DARF and formulating pollution prevention and control policies in the region.