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This paper introduces a steam-foam drive profile modification technology for heavy oil development in Block Qi40 based on an in-depth study of the characteristics of heavy oil reservoir and cross flow characteristics of injected steam in Block Qi40 of Liaohe Oilfield. The performance evaluation was carried out indoors for foaming agents. Influencing factors affecting profile modification and foam injection mode selection are studied. The results show that the CX-4 foaming agent system has excellent foaming properties and foam stability at 300°C. The plugging pressure difference of core can be increased by more than 15 times at 240°C. When a 0.5 PV foaming agent system is injected, the oil displacement efficiency can reach more than 68%. The optimal concentration of the foaming agent is 0.5% and the change of resistance factor is the largest in the range of oil saturation between 15 and 20%. Foam has better plugging ability in high permeability and large pores. Furthermore, after field application effect analysis, it confirms that the steam-foam profile modification technology has an obvious effect on enhancing oil recovery.

The effects of the first four statistical moments defining the statistical characteristic of elastic modulus on the probabilistic foundation settlement are investigated in this study. By combining the Hermite probability model and spectral representation method, a method to simulate nonGaussian homogenous fields based on the first four statistical moments is proposed. Linear elastic finite element models are employed to study the total settlement and the differential settlement of a shallow foundation. Probabilistic measurements of total-differential settlement obtained by the Monte Carlo simulations are presented. For the cases considered, the effects of skewness and kurtosis defining the probabilistic characteristic of elastic modulus on the total-differential settlement of a probabilistic foundation are illustrated. The computed results show that the value of skewness has a more significant effect on the probabilistic foundation settlement than kurtosis, and the case with the smallest skewness is observed as the most critical one. Key words: random field, spectral representation method, soil variability, foundation settlement, differential settlement, Monte Carlo. Les effets des quatre premiers moments statistiques definissant la caracteristique statistique du module d'elasticite sur le tassement probabiliste des fondations sont etudies dans cette etude. En combinant le modele de probabilite de Hermite et la methode de representation spectrale, une methode de simulation du champ homogene non gaussien basee sur les quatre premiers moments statistiques est proposee. Des modeles elastiques lineaires par elements finis sont utilises pour etudier le tassement total et le tassement differentiel d'une fondation peu profonde. Les mesures probabilistes du tassement totaldifferentiel obtenues par les simulations de Monte Carlo sont presentees. Pour les cas consideres, les effets de l'asymetrie et de l'aplatissement definissant la caracteristique probabiliste du module d'elasticite sur le tassement total-differentiel d'une fondation probabiliste sont illustres. Les resultats calcules montrent que la valeur de l'asymetrie a un effet plus important sur le tassement probabiliste des fondations que l'aplatissement, et le cas de la plus petite asymetrie est considere comme le plus critique. [Traduit par la Redaction] Mots-cles : champ aleatoire, methode de representation spectrale, variabilite du sol, tassement des fondations, tassement differentiel, Monte Carlo., 1. Introduction Soil properties always exhibit considerable spatial variation because soils are always formed in different physical and chemical conditions. This spatial variation brings uncertainties in the estimation of soil [...]

Objective To investigate the change of the total number and density of cholinergic neurons in dentate gyrus (DG) of hippocampus of 8-month-old APP/PS1 mice after fluoxetine (FLX) intervention and analyze whether the improvement of cognitive function is related to the change of the number of cholinergic neurons after FLX intervention. Methods Twenty 8-month-old female APP/PS1 mice were randomly divided into control group and intervention group. The mice in the control group and the intervention group were given 8 weeks of normal saline and the same amount of FLX by intraperitoneal injection, Then, Morris water maze test was used to test the learning and memory ability of the mice. The total number and density of the cholinergic neurons in the DG were calculated using stereological methods. The cholinergic-related neurotransmitters were determined by enzyme-linked immunosorbent assay. Results The results of Morris water maze test showed that the escape latency of the intervention group was significantly shorter than that of the control group (P < 0.05). The results of stereological findings showed that FLX significantly increased the total number and density of cholinergic neurons in the DG of hippocampus of 8-month-old APP/PS1 mice (P < 0.01); The results of enzyme linked immunosorbent assay showed that FLX statistically increased the level of acetylcholine (ACh) in the hippocampus of APP/PS1 mice (P < 0.01). Conclusion The change of the total number of cholinergic neurons in the DG of hippocampus and the level of ACh in the hippocampus may be related to the behavioral changes of 8-month-old APP/PS1 mice after FLX intervention.