空心圆柱内的稳态热传导。边界条件：左边界为给定温度，右边界为对流，上边界为绝热，下边界为给定热流。整个计算区域内都有源项。 求：该区域中的温度分布。 -Steady-state within the hollow cylinder heat transfer. Boundary conditions: the left margin for a given temperature, the right boundary for the convection, the boundary i