The genetic relationships between microenvironment of the Late Paleozoic peat-forming swamp and the sulfur contents of coal in North China have been studied by
The Tarim River is a typical inland river in arid area without runoff yield of itself, and water resources are all supplied by its headstreams. The method of ti
In this paper the ionosonde data from 16 stations all over the world were used to analyze the morphological features of occurrence rate of spread-F, i.e. their