中文摘要：

在覆盖近似空间（U，C）中，基于最小描述定义了一种新的Zoom—in算子，并讨论了其性质。在论域U上，通过复合Zoom-in和Zoom—out算子，得到了具有对偶性的两对近似算子。同样在粒化论域C上，通过复合Zoom—out和Zoom—in算子，也得到了具有对偶性的两对近似算子。

英文摘要：

In the covering approximation space （U,C）, a new zoom-in operator is redefined based on the minimum description and its properties are also discussed. On the universe of discourse U, by combining the Zoom-in and Zoom-out operators, two pairs of approximation operators which have the duality property are obtained. Similarly, on the granulated universe of discourse C, by combining the Zoom-out and Zoom-in operators, the other two pairs of approximation operators which have the duality property are also obtained.