To solve the differential equations, we divide the sphere into two parts: inner part - a sphere with small radius and outer part - a spherical shell.
在微分方程求解过程中，把整个球体分成两部分：内部是球心附近的一个小球，外部为一球壳。
The adoption of the tool in the structure for working inner sphere is easy in manufacture, working as well as radius adjustment, and high in working accuracy.
采用此种结构的刀具加工内球面，易于制做、加工半径易于调整、加工精度高。
The adoption of the tool in the structure for working inner sphere is easy in manufacture, working as well as radius adjustment, and high in working accuracy.
采用此种结构的刀具加工内球面，易于制做、加工半径易于调整、加工精度高。
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