This article discussed about snow temperature variations and their impact on snow cover parameters. Automatic temperature recorders were used to sample at lo-minute intervals at the Tianshan Station for Snow-cover and...This article discussed about snow temperature variations and their impact on snow cover parameters. Automatic temperature recorders were used to sample at lo-minute intervals at the Tianshan Station for Snow-cover and Avalanche Research, Chinese snow temperature Academy of Sciences. lo-layer and the snow cover parameters were measured by the snow property analyzer （Snow Fork） in its Stable period, Interim period and Snow melting period. Results indicate that the amplitude of the diurnal fluctuation in the temperature during Snow melting period is 1.62 times greater than that during Stable period. Time up to the peak temperature at the snow surface lags behind the peak solar radiation by more than 2.5 hours, and lags behind the peak atmospheric temperature by more than 0.2 hours during all three periods. The optimal fitted function of snow temperature profile becomes more complicated from Stable period to Snow melting period. 22 h temperature profiles in Stable period are the optimal fitted by cubic polynomial equation. In Interim period and Snow melting period, temperature profiles are optimal fitted by exponential equation between sunset and sunrise, and by Fourier function when solar radiation is strong. The vertical gradient in the snow temperature reaches its maximum value at the snow surface for three periods. The peak of this maximum value occurs during Stableperiod, and is 4.46 times greater than during Interim period. The absolute value of temperature gradient is lower than 0.1℃ cm-1 for 30 cm beneath snow surface. Snow temperature and temperature gradient in Stable period-Interim period indirectly cause increase （decrease） of snow density mainly by increasing （decreasing） permittivity. While it dramatically increases its water content to change its permittivity and snow density in Snow melting period.展开更多
Under the initiative of“encouraging 300 million people to participate in ice and snow sports”and the guidance of the‘Evidence-based’policy-making process,this study takes the Hierarchical Model of Leisure Constrai...Under the initiative of“encouraging 300 million people to participate in ice and snow sports”and the guidance of the‘Evidence-based’policy-making process,this study takes the Hierarchical Model of Leisure Constraints as the theoretical framework to empirically explore the constraints influencing the participation of residents in Southern China in ice and snow sports.After factor analysis,the constraint dimension of residents’participation was obtained,and the constraints of participants and non-participants were evaluated and compared by Propensity Score Matching(PSM).The results indicate that Chengdu residents have potential interest in and demand for winter sports,and the constraint dimensions are:facilities and services,companions,time,and personal feelings.The predisposition scores of the experimental group and the control group revealed that the constraints on interest,relevant knowledge and skills,and personal feelings of the participating group were significantly lower than those of the non-participating group,while the other constraints were not significant.We suggest that efforts should be made to increase the effective supply according to local conditions in order to reduce structural constraints,and the social attributes should be integrated into ice and snow sports to resolve the inter-personal constraints.展开更多
基金supported by social welfare of Ministry Science and Technology Development of China (Grant No.GYHY200706008)the "Western Light" Project (RCPY200902) of the Chinese Academy of Sciencesthe Oasis Scholar "Doctor" Talent Training Program (0771021) of Xinjiang Institute of Ecology
文摘This article discussed about snow temperature variations and their impact on snow cover parameters. Automatic temperature recorders were used to sample at lo-minute intervals at the Tianshan Station for Snow-cover and Avalanche Research, Chinese snow temperature Academy of Sciences. lo-layer and the snow cover parameters were measured by the snow property analyzer （Snow Fork） in its Stable period, Interim period and Snow melting period. Results indicate that the amplitude of the diurnal fluctuation in the temperature during Snow melting period is 1.62 times greater than that during Stable period. Time up to the peak temperature at the snow surface lags behind the peak solar radiation by more than 2.5 hours, and lags behind the peak atmospheric temperature by more than 0.2 hours during all three periods. The optimal fitted function of snow temperature profile becomes more complicated from Stable period to Snow melting period. 22 h temperature profiles in Stable period are the optimal fitted by cubic polynomial equation. In Interim period and Snow melting period, temperature profiles are optimal fitted by exponential equation between sunset and sunrise, and by Fourier function when solar radiation is strong. The vertical gradient in the snow temperature reaches its maximum value at the snow surface for three periods. The peak of this maximum value occurs during Stableperiod, and is 4.46 times greater than during Interim period. The absolute value of temperature gradient is lower than 0.1℃ cm-1 for 30 cm beneath snow surface. Snow temperature and temperature gradient in Stable period-Interim period indirectly cause increase （decrease） of snow density mainly by increasing （decreasing） permittivity. While it dramatically increases its water content to change its permittivity and snow density in Snow melting period.
基金The National Social Science Foundation of China(17CTY014).
文摘Under the initiative of“encouraging 300 million people to participate in ice and snow sports”and the guidance of the‘Evidence-based’policy-making process,this study takes the Hierarchical Model of Leisure Constraints as the theoretical framework to empirically explore the constraints influencing the participation of residents in Southern China in ice and snow sports.After factor analysis,the constraint dimension of residents’participation was obtained,and the constraints of participants and non-participants were evaluated and compared by Propensity Score Matching(PSM).The results indicate that Chengdu residents have potential interest in and demand for winter sports,and the constraint dimensions are:facilities and services,companions,time,and personal feelings.The predisposition scores of the experimental group and the control group revealed that the constraints on interest,relevant knowledge and skills,and personal feelings of the participating group were significantly lower than those of the non-participating group,while the other constraints were not significant.We suggest that efforts should be made to increase the effective supply according to local conditions in order to reduce structural constraints,and the social attributes should be integrated into ice and snow sports to resolve the inter-personal constraints.
