本文运用OLS方法揭示区域信息化与电子商务的数量相关性,然后建立动力学因果回路模型,从区域信息化是电子商务赖以生存的必要基础......

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The development and application of vertical-cavity surface-emitting lasers (VCSELs) are summarized in this paper. The em......

调查了上海闵行区的高等植物和鸟类.共发现有高等植物114科,337属,556种(包括亚种、变种),鸟类4目,12科,2亚科,17属,25种.探讨了调......

The geometries, bondings, and vibrational frequencies of C2nH (n=3-9) and C2n-1N(n=3-9) were investigated by means of de......

滇池等部分云南高原淡水湖泊由于人为污染,长期处于重度或中度富营养化状态,水体富营养化的显著特点是藻类过量增长而发生水华。近......