Collapsible loess is prone to self weight collapse after soaking. The strength of loess will be greatly reduced, and it will threaten the safe operation of buried pipelines along the way. In order to study the stability of buried pipelines in collapsible loess regions, the displacements, stresses and strains of different pipe outer diameters and wall thicknesses during collapsing were analyzed based on the finite element method. The limit length that the buried pipeline could withstand in the loess disaster under certain conditions was obtained by the eigenvalue buckling theory. The results show that: increasing the outer diameter and wall thickness of the pipeline and reducing the buried depth of the pipeline in the loess can effectively reduce the displacement of the pipeline in the collapsible loess; and increasing the outer diameter and wall thickness of the pipeline can also effectively avoid the phenomenon that the local stress of the pipeline is too high; the maximum stress and strain of the pipeline occur at the center of the collapsing zone and the fixed ends on both sides; according to the buckling eigenvalue theory, the ultimate length of the collapsible area of the pipeline is about 65 m when the soil mass has self weight collapsible, and increasing the outer diameter and wall thickness of the pipeline can enhance the buckling resistance of buried pipelines when self weight collapse after soaking.

In order to achieve the emulsification viscosity reduction of heavy oil in Huanxiling oil production plant of Liaohe oilfield, the emulsifier solution with the mass fraction of 30%, emulsifying temperature of 50 ℃, emulsifying time of 1 h, stirring speed of 200 r/min, stirring time of 5 min, under the shear rate of 16.9 s－1, the effect of single emulsifier and compounding emulsifier on the stability and viscosity⁃reducing rate of emulsion is investigated. The results show that the optimal compounding mode of the compounding emulsifier is as follow: 0.7% OP⁃12 and 0.8% sodium oleate; the best compound emulsifier and heavy oil could form a stable emulsion, and the viscosity can be reduced from 1 020.9 mPa•s to 72.0 mPa•s, and the viscosity reduction rate reachs 92.95%. The emulsion with the best compound emulsifier and heavy oil has better stability than the single agent OP⁃12 and heavy oil emulsion.

According to the principle of atomizing corona discharge, a cooking fume purifier was made, and the volt-ampere characteristic curve of atomization condition and non-atomization condition, purification efficiency and discharge current were studied. The results showed that the discharge current of atomizing corona discharge was higher than the non atomizing corona discharge current, either positive or negative corona discharge; it was not conducive to the purification of earthed negative corona discharge cooking fume purification weather the flow too large or too small; cooking fume purifier efficiency were decreased with the increase of wind speed under both condition; the efficiency and the discharge current of atomizing corona discharge cooking fume purifier was almost unchanged with the increase of application time, while both of them decrease under the non-atomizing corona.