Based on the data observed,it was found that: 1) summer precipitation displayed a decreasing trend from east to west in the intermediate altitude with a rate of approximately 80 mm·(100 km-1);2) the zone of maximum precipitation lay between 4 500 to 4 700 m a.

To apply this method in low-pressure gas fields and gas wells, dynamic simulation method was firstly adopted to analyze how to generate big temperature drop through small pressure difference.

There were three topics discussed in the dissertation, which were the degrading of xylan enzymatic hydrolysate residues at a higher temperature, the separation of the xylooligosaccharides by chromatography and the proliferation, use rules to xylo-oligosaccharides and metabolizing mechanism of Bifidobacterium odolescentis, etc.