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81.
介绍了调剖剂XJF的配方,讨论了影响调剖剂性能的配方因素(膨润土含量、HPAM溶液浓度、XJ用量及添加剂Fc的浓度),考察了封堵能力和应用范围,简介了在火烧山油田现场试验的结果。 相似文献
82.
Scale and sludge from Bulalo geothermal field, Philippines, have been characterized by whole rock analysis, radioactivity counting, size analysis, light microscopy, scanning electron microscopy, and X-ray diffraction. Their leachability was assessed by regulatory leaching procedures and by sequential extraction. Both scale and sludge consisted mostly of oxides of Si, Al, and Fe with no radionuclides detected. The scale had 10% S content. Sulfides and silicates were important phases in both samples having size ranges from submicron to 2 mm. Geothermal soils at Bulalo have higher than normal soil levels of As, S, Cu, Cr, Zn, and Pb but regulatory leaching tests indicated that these elements are not released. However, the sequential extraction showed that As, Cu, and Zn were leachable under extreme conditions. 相似文献
83.
The hydrodynamic characteristics and mass transfers of halide quaternary salts between two immiscible phases in a stirred membrane permeation cell were investigated. The concentration of quaternary salt, temperature, solvent and the four kinds of halide quaternary salts were evaluated to achieve the extractive optimum condition. The diffusivity, overall mass‐transfer coefficients and individual mass‐transfer coefficients were determined and correlated in terms of the conventional Sh‐Re‐Sc relationship. The transfer time of quaternary salts across the membrane and the thickness of the hydrodynamic diffusion boundary layer were determined as well, so as to characterize the extractive phenomenon of quaternary salts between the two phases that is useful in phase‐transfer catalysis. 相似文献
84.
Analysis of lipid classes by solid-phase extraction and high-performance size-exclusion chromatography 总被引:1,自引:0,他引:1
Anu I. Hopia Vieno I. Piironen Pekka E. Koivistoinen Lea E. T. Hyvönen 《Journal of the American Oil Chemists' Society》1992,69(8):772-776
An improved method to analyze lipid classes of edible oils and fats by solid-phase extraction (SPE) and high-performance size-exclusion chromatography (HPSEC) is presented. A mixture of lipid standards was fractionated by the solid-phase extraction procedure (NH2 phase) into polar and nonpolar fractions; these were then submitted to analysis by HPSEC. The size-exclusion chromatographic columns were three styrene/divinylbenzene columns with pore sizes of 100 Å and 50 Å. Light-scattering was used for the detection system, and the parameters of the detector were optimized to minimize the difference between the responses of the compounds studied. With this procedure it was possible to separate the following lipid classes: triacylglycerols, diacylglycerols, monoacylglycerols and free fatty acids, sterols, sterol esters, tocopherols and carotenoids. Quantitative analysis was studied for a light-scattering detector with several lipid standards of different molecular weights and unsaturation levels. 相似文献
85.
本文提出用尿素作为pⅡ调节剂,加快硫酸亚铁单液法调剖剂中亚铁离子在地层温度下的沉淀,增大沉淀率,提高封堵效能。岩芯流动试验结果表明,15%FeSO4.7II 2O/5%尿素调剖剂体系的封堵能力比不含尿素的体系增大近一倍。 相似文献
86.
微波萃取在食品化学中的应用 总被引:16,自引:0,他引:16
介绍了微波萃取技术在食品化学中的应用。其实质是用微波对萃取溶剂及物料加热,使溶剂的渗透率和扩散率大大提高,因此对食品营养成分或风味物质可以有铲地萃取分离。 相似文献
87.
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89.
R.A. Jacques J.G. Santos C. Dariva J. Vladimir Oliveira E.B. Caramo 《The Journal of Supercritical Fluids》2007,40(3):354-359
This work presents a study concerning the chemical characteristics and analytical separation process of the essential oil obtained from high-pressure carbon dioxide extraction of Ilex paraguariensis. The experiments were performed in a laboratory-scale unit in the temperature range of 20–40 °C, from 100 to 250 bar. A blend of the I. paraguariensis extracts was percolated through a preparative chromatographic column, containing silica gel, and successively eluted with 150 mL of each of the following solvents: hexane, toluene, dichloromethane, ethyl acetate, acetone and methanol. The raw extract and its fractions were analyzed by gas chromatography coupled to mass spectrometry detection (GC/MS). The fractionation procedure showed to be a good clean up technique due to the isolation of different classes of compounds in each fraction. Chromatographic analyses allowed the identification of caffeine, fatty acids and esters, phytol, squalene, Vitamin E, stigmasterol derivatives and saturated hydrocarbons. 相似文献
90.