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91.
高速非达西流动时元素硫沉积模型研究 总被引:3,自引:2,他引:1
元素硫沉积是含硫气藏开发过程中广泛存在而又必须解决的难题之一。高含硫气藏一旦投入开发,地层压力会逐步下降,使得元素硫溶解度下降而沉积下来,沉积的元素硫会堵塞地层孔隙,降低渗流通道,影响气井产能。考虑了高含硫气体在近井地带作高速非达西流动,建立了硫的沉积模型,并利用该模型对实际气藏进行预测和对比研究,再通过实例计算发现,硫非瞬时平衡沉积比瞬时平衡沉积对地层的伤害更严重,高速非达西流动沉积比达西流动时对地层伤害更严重,认为在开发高含硫气藏时,必须合理选择开发速度,有效防止元素硫沉积。 相似文献
92.
93.
This paper evaluated the capacity of SPOT VEGETATION time-series to monitor herbaceous fuel moisture content (FMC) in order to improve fire risk assessment in the savanna ecosystem of Kruger National Park in South Africa. In situ herbaceous FMC data were used to assess the Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), Vegetation Dryness Index (VDI), Improved VDI (IVDI), and Accumulated Relative NDVI Decrement (ARND) during the dry season. The effect of increasing amounts of dead vegetation on the monitoring capacity of derived indices was studied by sampling mixed live and dead FMC. The IVDI was proposed as an improvement of the VDI to monitor herbaceous FMC during the dry season. The IVDI is derived by replacing NDVI with the integrated Relative Vegetation Index (iRVI), as an approximation of yearly herbaceous biomass, when analyzing the 2-dimensional space with NDWI. It was shown that the iRVI offered more information than the NDVI in combination with NDWI to monitor FMC. The VDI and IVDI exhibited a significant relation to FMC with R2 of 0.25 and 0.73, respectively. The NDWI, however, correlated best with FMC (R2 = 0.75), while the correlation of ARND and FMC was weaker (R2 = 0.60) than that found for NDVI, NDWI, and IVDI. The use of in situ herbaceous FMC consequently indicated that NDWI is appropriate as spatio-temporal information source of herbaceous FMC variation which can be used to optimize fire risk and behavior assessment for fire management in savanna ecosystems. 相似文献
94.
95.
Effect of Y2O3 Content on Microstructure of Gradient Bioceramic Composite Coating Produced by Wide-Band Laser Cladding 总被引:2,自引:0,他引:2
Hydroxyapatite (HA) ,a kind of bioactive materi-al , has wide application prospect in hard tissue re-placemen and repairment due to its si milar chemicalcomposition and crystallographic structure to that ofbone mineral[1 ,2]. Since HA has lowstrength (50 … 相似文献
96.
In this study, the extent of the smear zone and the reduction of permeability and water content within the smear zone were investigated using a large-scale consolidometer. The installation of vertical drains by means of a mandrel causes significant disturbance of the subsoil surrounding the mandrel, resulting in a smear zone. The extent of the smear zone for Moruya clay (New South Wales, Australia) was estimated on the basis of normalized permeability and the reduction of water content by taking undisturbed samples (horizontally and vertically) at different locations. This study reveals that a significant reduction in water content and horizontal permeability takes place towards the drain, whereas the variation in the vertical permeability is negligible. The smear zone for Moruya clay was found to be 2.5 times the equivalent radius of the mandrel with the horizontal permeability varying from 1.09 to 1.64, an average of 1.34 times smaller than that of the undisturbed zone. Finally, a correlation between the permeability decrease and water content reduction within smear zone is proposed. 相似文献
97.
鄂北地区气测现场解释评价研究 总被引:2,自引:1,他引:1
鄂尔多斯盆地鄂北地区现场气测录井由于受多种因素影响,解释符合率相对较低。针对这一问题,在探讨影响气测录井显示因素、识别气测异常的基础上,分析了消除影响因素的途径和校正公式,建立了随钻全烃与全脱全烃的关系式,论述了地面和地层含气量计算方法。在初步评价气显示性质条件下,经统计分析得出了应用4参数——峰面积、校正全烃值、全烃计算值和地层含气量加权分值的解释评价标准,为鄂北地区气测录井解释评价和产能的初步预测探索了一种新模式,不但解决了鄂北地区气测解释符合率低的问题,而且对于深入开展气测录井参数与油气解释评价研究具有一定的参考意义。 相似文献
98.
Kofi E. Aidoo Richard F. Tester Janet E. Morrison & David MacFarlane 《International Journal of Food Science & Technology》1996,31(5):433-438
Composition and microbiological contamination was measured in samples of pre-packed dates purchased from a number of stores and retail outlets in Greater Glasgow. The sugar content of dried pitted dates was c . 74%, about 10% more than reported on those packs where nutritional information was given. Potentially pathogenic bacteria like Escherichia coli, Staphylococcus aureus and Bacillus cereus were identified in some of the samples together with lactic acid bacteria, yeasts and moulds, Aspergillus flavus and A. parasiticus . Fresh dates were the most heavily contaminated of all samples, probably owing to the high moisture content. 相似文献
99.
100.
Madan G. Sood Jagjit Singh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1985,35(1):11-13
Cladosporium herbarum grown as a surface culture in a chemically defined medium of sucrose and inorganic salts gave a high yield of fat (29.2%). The component acids of this fat have been found to be palmitic (34.2%); oleic (15.9%); linoleic (34.2%) and linolenic (15.7%). The combined proportion of linoleic and linolenic acids being about 50 per cent, the fat will be of great value for the manufacture of oil-modified resins as the films produced by such resins do not become yellow with age. 相似文献