On the basis of the emission data of the industrial sulphur dioxide (SO_2) and observed climate fields over East Asia, the distribution of anthropogenic sulfate aerosol(SO_4~2-) with seasonal variation in the troposph...On the basis of the emission data of the industrial sulphur dioxide (SO_2) and observed climate fields over East Asia, the distribution of anthropogenic sulfate aerosol(SO_4~2-) with seasonal variation in the troposphere is simulated and analyzed by a regional sulfur transport model, and the direct radiative effects of SO_4~2- under different weather conditions are also calculated using the discrete ordinate method. The results show that the concentration of SO_4~2- has significant seasonal and spatial variations resulting from the effects of SO_2 emission source and precipitation and wind fields. Both the concentration of SO_2 and its radiative forcing have the largest values in October and the lowest in July. SO_4~2- causes the decrease of the radiation flux absorbed by earth-atmosphere and the cooling of air temperature by scattering more solar radiation back into space. Besides, the radiative and climatic effects of SO_4~2- are related to the types and height and optical thickness, etc., of the clouds.展开更多
Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking t...Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking the effect of coupling of flexural and axial action into consideration. The linear vertical equation is obtained by omitting the nonlinear term, and the pseudo excitation method(PEM). Taking the self-anchored concrete suspension bridge over Lanqi Songhua river for an example, the expected peak responses of main beam, towers and cables are calculated. And the seismic spatial effects on vertical seismic response of self-anchored suspension bridges are discussed.展开更多
文摘On the basis of the emission data of the industrial sulphur dioxide (SO_2) and observed climate fields over East Asia, the distribution of anthropogenic sulfate aerosol(SO_4~2-) with seasonal variation in the troposphere is simulated and analyzed by a regional sulfur transport model, and the direct radiative effects of SO_4~2- under different weather conditions are also calculated using the discrete ordinate method. The results show that the concentration of SO_4~2- has significant seasonal and spatial variations resulting from the effects of SO_2 emission source and precipitation and wind fields. Both the concentration of SO_2 and its radiative forcing have the largest values in October and the lowest in July. SO_4~2- causes the decrease of the radiation flux absorbed by earth-atmosphere and the cooling of air temperature by scattering more solar radiation back into space. Besides, the radiative and climatic effects of SO_4~2- are related to the types and height and optical thickness, etc., of the clouds.
文摘Based on the variational prineiple of incomplete generalized potential energy with large deflection, the vertical nonlinear vibrational differential equation of self-anchored suspension bridge is presented by taking the effect of coupling of flexural and axial action into consideration. The linear vertical equation is obtained by omitting the nonlinear term, and the pseudo excitation method(PEM). Taking the self-anchored concrete suspension bridge over Lanqi Songhua river for an example, the expected peak responses of main beam, towers and cables are calculated. And the seismic spatial effects on vertical seismic response of self-anchored suspension bridges are discussed.
