Impact of background characteristics on students evaluation of teacher s teaching;

This paper expounds the background characteristic of vanadium element and the relationship of its distribution law with the medium composition of subsurface water,the redox environment and the acid base degree.

According to the studying results of national tasking key problems of science and technology,the relation between the forming of the background feature and distribution law of Ni element in groundwater at the middle lower reaches of Yangtze River and the composition of the aquiferous medium in groundwater and condition of runoff,acidity-alkalinity in groundwater is demonstrated in this paper.