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For the purpose of grain re®nement, development of the microstructure of coarse grain, high purity aluminium during cold asymmetric rolling has been studied by electron backscatter pattern (EBSP) analysis, as well as optical and transmission electron microscopy, and compared with that developed during conventional rolling. In 91 . 3% asymmetrically rolled sheet, new ®ne equiaxed grains with an average size of y2 mm are evolved almost uniformly throughout the thickness. On the other hand, in conventionally rolled sheet, the coarse ®brous structure is predominant. A change of grain boundary misorientation distribution with an increase in reduction shows that the fraction of sub-boundaries below 10³ decreases linearly, and that of the high angle boundaries above 15³ increases linearly. The ®ne grain evolution during asymmetric rolling seems to result from the development of sub-boundaries into high angle boundaries promoted by a simultaneous action of two deformation modes, namely compression and additional shear deformation. Fine grains evolved during asymmetric rolling are stable at temperatures below 423 K. Annealing at temperatures above 473 K results in remarkable grain growth.MST/4466

As one of the most vulnerable sectors exposed to the COVID-19 pandemic, transport sectors have been severely affected. However, the shocks and impact mechanisms of infectious diseases on transport sectors are not fully understood. This paper employs a multi-sectoral computable general equilibrium model of China, CHINAGEM, with highly disaggregated transport sectors to examine the impacts of the COVID-19 pandemic on China’s transport sectors and reveal the impact mechanisms of the pandemic shocks with the decomposition analysis approach. This study suggests that, first, multiple shocks of the COVID-19 pandemic to transport sectors are specified, including the supply-side shocks that raised the protective cost and reduced the production efficiency of transport sectors, and the demand-side shocks that reduced the demand of households and production sectors for transportation. Second, the outputs of all transport sectors in China have been severely affected by the COVID-19 pandemic, and passenger transport sectors have larger output decreases than freight transport sectors. While the outputs of freight transport sectors are expected to decline by 1.03–2.85%, the outputs of passenger transport sectors would decline by 3.08–11.44%. Third, with the decomposition analysis, the impacts of various exogenous shocks are quite different, while the changes in the output of different transport sectors are dominated by different exogenous shocks. Lastly, while the supply-side shocks of the pandemic would drive output decline in railway, waterway, and aviation transport sectors, the demand-side shocks would drive so in the road, pipeline, and other transport sectors. Moreover, the COVID-19 pandemic has negative impacts on the output of most non-transport sectors and the macro-economy in China. Three policy implications are recommended to mitigate the damages caused by the COVID-19 pandemic to the transport sectors.