The article uses the method of regression statistics to obtain the regression formula of iron fluid nodule ratio Q and compacted graphite ratio R, through rare earth magnesium treatment. At the same time it has given ...The article uses the method of regression statistics to obtain the regression formula of iron fluid nodule ratio Q and compacted graphite ratio R, through rare earth magnesium treatment. At the same time it has given thejudging figure of Q and R, considering oxygen activity and temperature. When using oxygen activity to judgenodule ratio and compacted graphite ratio of the ironfluid treated by rare earth magnesium alloy, its limit value changes with the change of temperature.展开更多
Taken fractal dimension, compact ratio, urban centroid and urban principal axis as the urban spatial characteristic indices, Tianjin city＇s urban area is investigated in the last 26 years in a quantitative perspectiv...Taken fractal dimension, compact ratio, urban centroid and urban principal axis as the urban spatial characteristic indices, Tianjin city＇s urban area is investigated in the last 26 years in a quantitative perspective, and its traits and changes during different periods are also analyzed. It is clear that these indices can not only scientifically and explicitly assess the urban morphology, urban direction and its changes and trends, but also uncover long-term effects of economy and urban planning on urban morphology.展开更多
文摘The article uses the method of regression statistics to obtain the regression formula of iron fluid nodule ratio Q and compacted graphite ratio R, through rare earth magnesium treatment. At the same time it has given thejudging figure of Q and R, considering oxygen activity and temperature. When using oxygen activity to judgenodule ratio and compacted graphite ratio of the ironfluid treated by rare earth magnesium alloy, its limit value changes with the change of temperature.
基金National Basic Research Program of China (973 Program), No.2002CB412507
文摘Taken fractal dimension, compact ratio, urban centroid and urban principal axis as the urban spatial characteristic indices, Tianjin city＇s urban area is investigated in the last 26 years in a quantitative perspective, and its traits and changes during different periods are also analyzed. It is clear that these indices can not only scientifically and explicitly assess the urban morphology, urban direction and its changes and trends, but also uncover long-term effects of economy and urban planning on urban morphology.
