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91.
辽河油田东部凹陷火山岩油藏较为集中分布.然而常规酸化效果较差.经采用三元酸(粉末硝酸、盐酸和氢氟酸)前置液压裂酸化后.获得显著的增产效果,进一步表明该项酸化工艺技术成熟,宜于推广应用。同时也面临技术集成再创新机遇.适应更广泛的地质需求。 相似文献
92.
93.
节理岩体的代表单元集合体模型及弹性参数预测 总被引:8,自引:0,他引:8
本文明确提出了节理岩体“代表单元集合体”的概念和模型,通过对节理岩体的“代表单元集合体”进行数值模拟,研究了节理岩体的“代表单元集合体”的变形特性,建立了节理岩体的弹性模型,提出了预测节理岩体宏观等效弹性参数的计算机模拟方法,并将其应用于岩体工程稳定性分析中。 相似文献
94.
成都市三环路建设中 ,膨胀土边坡稳定性研究是大家关心的重要课题。膨胀土边坡土体中的吸力变化直接影响到其稳定性 ,参照“人工神经网络技术”中的吸力经验公式 ,以三环路东一B标段的路堤边坡为例 ,采用“条分法”进行预测分析 ,并有针对性地进行防护处理取得了较好的效果。 相似文献
95.
加氢润滑油基础油光安定性研究进展 总被引:10,自引:3,他引:7
加氢处理基础油与溶剂精制基础油相比具有硫、氮含量低,颜色浅,粘度指数高,挥发性低,饱和烃含量高,对添加剂的感受性好等优点。但是,加氢处理润滑油基础油的一个明显缺点就是其光安定性差,即在有氧条件下通过光照(有时也需加热),油品颜色加深、透明度变差,继而有絮凝物或沉淀生成。文章综述了国内外有关加氢润滑油基础油光安定性的原因和解决办法的研究进展情况。 相似文献
96.
The effect of a range of organic additives on the thermal stability of poly(vinyl chloride), both with and without a chloroparaffin extender, was studied using a number of experimental techniques. Of the additives used the best overall balance was provided by pentaerythritol, which increased stability when the extender was present and had no effect when it was absent. The congo red test emerged as the most suitable technique, being consistent and inexpensive and able to screen several additives simultaneously. Isothermal differential thermal analysis correlated with the congo red test but required more expensive equipment, was time-consuming and demanded good mixing of the poly(vinyl chloride) compound to give reproducible results. Thermogravimetry was not sufficiently sensitive and the heat stability test was the least useful of all. 相似文献
97.
V. N. Reva 《Journal of Mining Science》2002,38(1):31-34
Using the energy approach as the base, the criteria are developed for brittle rock failure in outcropping in the workings driven in the rock masses of different degree of disturbance. A method is presented for estimating the stability of workings under conditions of zonal disintegration. 相似文献
98.
Many new speciality polymers have been developed in the last few years. In this paper polymeric stabilizers (antioxidants, flame retardants and ultraviolet stabilizers) will be discussed. Polymeric antioxidants of the hindered-phenol type, copolymers of 2,6-ditertiarybutyl-4-vinyl(or isopropenyl)phenol with styrene, methyl methacrylate, or more importantly butadiene or isoprene have been prepared; hydrogenation of the latter copolymers gave copolymers of the two polymerizable phenolic antioxidants with ethylene or ethylene/propylene. The polymeric antioxidants have been blended with diene polymers and selected polyolefins and have improved the long-term oxidative stability of these polymers. Polymeric flame retardants have been prepared by copolymerizing styrene and/or acrylonitrile with acrylates and methacrylates of aliphatic bromine-containing alcohols or bromine-containing phenols. Polymers with polymer-bound flame retardants have a higher limiting oxygen index compared with the original polymer. A new class of polymerizable ultraviolet stabilizers has also been developed; these stabilizers are styryl, α-methylstyryl, acryloyl and methacryloyl derivatives of 2(2-hydroxyphenyl)2H-benzotriazoles. These monomers have been copolymerized with styrene, acrylates and methacrylates. 2(2-Hydroxyphenyl)2H-benzotriazoles substituted in the 4 position of the benzotriazole ring with hydroxyl, acetoxy or carboxyl groups suitable for incorporation into polyesters, polycarbonates, polyamides and epoxy resins have also been synthesized. All 2(2-hydroxyphenyl)2H-benzotriazole ultraviolet absorbers and the polymers into which they are incorporated have high light absorbency with γmax between 330 and 350 nm and extinction coefficients in some cases as high as 4.5 × 104 1 mol?1 cm?1. 相似文献
99.
Rubina H. Shreiner 《Journal of research of the National Institute of Standards and Technology》2002,107(5):393-399
The stability of solutions having an electrolytic conductivity, κ, of 5 μS/cm to 100 000 μS/cm packaged in glass screw-cap bottles, glass serum bottles, and glass ampoules was monitored for 1 year to 2 years. The conductivity was determined by measuring the ac resistance of the solution. Mass loss was also monitored for solutions packaged in bottles. The solutions were prepared using KCl in water (κ ≥100 μS/cm) or KCl in 30 % (by mass) n-propanol 70 % (by mass) water (κ ≤ 15 μS/cm). The conductivity changes were compared by packaging type and by nominal κ. The main causes of the κ changes are evaporation (screw-cap bottles) and leaching (screw-cap bottles, serum bottles, and ampoules). Evaporation is determined from mass loss data; leaching occurs from the glass container with no change in mass. The choice of optimal packaging, which depends on the conductivity level, is the packaging in which κ changes the least with time. Ampoules are the most suitable packaging for standards having nominal κ values of 500 μS/cm to 100 000 μS/cm. Screw-cap bottles are most suitable for standards having a nominal κ of 5 μS/cm to 100 μS/cm. 相似文献
100.
Anthony L. Whitear 《Journal of the Institute of Brewing》1991,97(1):47-51
Laurence Bishop's contribution to the brewing industry over more than 50 years of research endeavour and committee activities is reviewed. Three research areas — prediction of extract, the effect of turbidity on yeast activity during fermentation and the development of a 3-vessel fermentation system — are used to highlight his achievements. Five topics with which the author was intimately involved, three of which were connected with Laurence Bishop's own researches, are used to describe the author's activities. These concerned the assessment of beer foam, the prediction of beer stability, the assessment of the bittering value of hops, time course changes in the analytical characteristic of an ale fermentation and the use of fractional factorial designs to facilitate experimental programmes. 相似文献