Some special properties of upper and low approximation operations based on the fine covering are studied.
本文从拓扑学的角度,利用邻域系重新定义了广义粗集近似集的概念,并分析了这些近似集概念之间的差异;证明了在加细覆盖条件下,上、下近似集运算存在一些特别性质;给出了加细覆盖下近似集运算的公理化构造条件。
a hard outer covering or skin on food.
食物硬的外层覆盖物或外皮。
The hard outer covering or integument of certain plants and animals, such as lichens and crustaceans.
甲壳某些植物或动物的硬的外层覆盖物或包裹物，如地衣和甲壳纲动物
t covered by an epidermis
整株覆盖着一层外皮
A natural outer covering, such as the fur of an animal;an integument.
覆盖物自然的外部覆被，例如动物毛皮；覆盖物
The outermost layer of cells covering the leaves and young parts of a plant.
外胚层覆盖于植物叶面和萌芽之上的最外一层细胞
To remove a cloak or cover from.
脱去外套或揭开覆盖物
an outer covering or casing.
外面的覆盖物或包装。
Material overlying a useful mineral deposit.
覆盖层，超覆层覆盖在有价值的矿石沉积物之上的物质
To cover with a thin protective layer.
覆盖以薄的保护层覆盖
To cover or surround with mulch.
覆盖用覆盖层覆盖或包围
A coating or an incrustation of filth or refuse.
污垢污物或垃圾的覆盖层或凝结物
A coating, as of syrup, applied to food
冻胶层浇在食物表面的覆盖物（如糖浆）
having a coating; covered with an outer layer or film; often used in combination.
有被覆的；覆盖有外层或薄膜的；常用于结合式。
a covering that protects the outside of a building.
保护建筑外表的一种覆盖层。
apply a thin coating of paint, metal, etc., to.
用涂料，金属等的稀少外层覆盖。
The membranous outer covering of an organ or a blood vessel.
外膜器官或血管的膜状外表覆盖物
Lacking outer covering such as scales, fur, feathers, or a shell.
外部无遮盖的缺乏外部覆盖物，如鳞、皮、毛或壳
cover sth with a layer of different material
在某物上覆盖一层另一种材料
