世界500强的产业分布规律

世界 5 0 0强的产业分布及其特征 ,反映了全球经济的发展轨迹和结构调整的步伐 :过去的基础性工业企业已逐渐丧失传统领地 ,信息产业已成为全球经济发展的支柱行业。美、日、欧等发达国家的大企业在世界 5 0 0强中占据了绝对优势 ,中国上榜企业数稳中有增。

福建河川径流年内不均匀系数分布规律的研究

福建河川径流年内不均匀系数分布规律的研究陈祥官（福建师范大学地理研究所）福建省河川径流的主要特点是：径流丰富而年内分配不匀。径流丰富可以用年径流量多少生米来表示，但年内分配不匀情况到目前为止，主要是以多年平均季（或月）径流量占多年平均年径流量的百分数...

Spatial distribution rules and affecting factors of BIF in Anshan-Benxi area

A detailed investigation on 3D spatial distribution rules of Banded Iron-bearing Formation(BIF) with methods of gravity-magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the Anshan-Benxi area.Three dimension spatial distribution types of BIF are concluded as hook-like,tabularlike and "W"-like.BIF was mainly developed in three types of space including(1) the syncline cores,(2)cover coverage area,and(3) the deeper buried area where the range of tectonic uplift is small.The influences of tectonism,magmatic intrusion and uplift-erosion on the spatial distribution shapes of BIF are clarified.