projective cover

The mapping φ: X——>Y is a covering mapping if φ is an "k-to-1", open, local homeomorphism.

映射:φX——>Y称为覆盖映射,如果φ是k到1的开的局部同胚映射。

Let f be a covering mapping of a compact manifold M without boundary.

设ｆ是紧致不带边流形Ｍ上的覆盖映射，证明了ｆ是拟双曲覆盖映射的充分必要条件是（Ｉ－ｆ＊）为单射且有闭值域。

The fractal dimension of fracture surface was measured directly by using projective covering method and laser triangulation technique.

采用投影覆盖法结合激光三角测试技术 ,直接测定了混凝土断裂表面分维值 。

A projective covering method (PCM) is proposed and used to directly estimate the fractal dimension D ∈[2,3) of fracture surface.

提出了一种新的分形测量方法———投影覆盖法，直接测量断裂表面的多重分形维数Ｄ∈［２，３），并引入粗糙性概率度量表面不规则性。

Based on the fractal theory and the projective covering method,this paper develped a method for measureing roughness coefficeint of overland flow,gully and stream flows directly.

根据分形理论和投影覆盖法的原理,建立了山区河流坡面流、沟道和山溪水流糙率直接测量方法。

In this paper the relations of compact-covering mappings and some families of subsets are investigated in Ponomaxev-systems,and the following results are obtained.

本文讨论了Ponomarev-系中的紧覆盖映射与集族之间的关系,得到如下结果。

In this paper,we give some new characterizations on sn-metrizable spaces,using the concepts of compact-covering mappings,point-star networks and CF families.

本文利用紧覆盖映射、点星网、CF族的概念,给出了sn可度量空间的新刻画。