1. Assume that a flat plate is put horizontally in a rarefied gas. In case that the surface of the plate has non-uniform temperature distribution, a flow from a low temperature region to a high temperature region along the surface is induced under a certain condition. This flow is called as thermal creep flow. Explain the mechanism why such a flow is induced.

2. A superposition of diffuse scattering and lobular scattering fits well with many experimental results. Explain this scattering mode!.

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A 0- Gas- Thermal creep flow" Low Temp. C 0(2) B High Temp.