The average concentration of H2S in Changqing oil Field is higher than 100mg/m3,which is much higher than the demand of “Operational Site Harm Factor Occupation Contact Limiting Value” (GBZ2-2002). Taking this factor into consideration, the experiment aimed at reducing H2S concentration in crude oil gatering and transferring systems by using the denitrifying bacteria. The experiment has two parts: First sulphat reduction process and then denitrification inhibit process. Therefore, two UASB reactors are used in a series to achieve these two processes. The first UASB reactor are mainly used to create SRB bacteria and H2S gas .After the first UASB reactor successfully starting, sodium nitrite are added in the second UASB to achieve denitrification inhibit process. The experiment showed that after the first UASB reactor start, the S2- can achieve 120mg/L and SO42- concentration is about 200 mg/L. So the Sulfate conversion rate can achieve 75%. Then, when the second UASB reactor started successfully, the S2- concentration sharply droped into 20 mg/L and SO42- concentration increased to 400mg/L, the sulphat reduction can achieve 83%. Also, advanced research showed that both SO42-concentration ratio and ORP value can contribute to restraining the SRB bacteria.Finally，through DGGE technology,many kinds of bacteria take into this process, for example pseudomonas aeruginosa. The results of this experiment has a great value to refrain the concentration of H2S in oil fields.

This paper establishes correlation analysis model to calculate the profile of trees and the distribution of leaves, and estimate mass of leaves. The establishment of the proposed model makes an in-depth analysis of sample data and determines the interrelationship of all relevant factor which make it easy to operate and applicable to all types of trees. If there are sufficient types of trees, more factors can be considered to make the model more accurate.

The mineral processing experimental research was carried out on the hematite bearing characteristics of low grade, fine grain,complex composition. The results showed that using the technological flowsheet of “stage grinding- low intensity magnetic separation”, the iron concentrate with recovery of 36.56% and grade of 65.85% Fe can be obtained. And the iron concentrate with recovery of 17.23% and grade of 63.53% Fe can be obtained by “stage grinding-HIMS process-reverse flotation” process. The final iron concentrate with TFe grade of 65.10%,yield of 19.19% and total iron recovery of 53.79% from the raw ores with TFe grade of 23.41％ was obtained, with the first stage grinding size being 55% -0.074mm and the second stage,93% -0.074mm.