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991.
《Petroleum Science and Technology》2013,31(5-6):641-650
In this paper the aging processes of two penetration-grade paving asphalt which conform to the standard of Esson Company have been studied by rotation thin film oven (RTFO). The first order aging kinetic model has been established and some kinetics parameters were calculated. The relationship between pavement properties of asphalt and aging course was revealed. The intervention of oxygen in high temperature caused oxidation reactions, which changed the composition and structure of asphalt, the aging resistant performance of asphalt was weak, and the service performance went to bad. 相似文献
992.
A cold repeated forming process of compacts for producing metal foams was developed in order to strongly bond powder particles. In this process, the compact undergoes severe plastic deformation for the strong bonding of particles by repeated backward extrusion and cup compression, and thus the compact largely foams owing to the accumulation of gas released from blowing agents inside the compact during heating. The cold repeated forming process without heating is much simpler than that for the conventional hot extrusion process. The relative density of the foam was decreased by adding silicon powder to the compact, and an aluminium foam having a relative density of 0.27 was obtained using two repeats of backward extrusion and cup compression, 1.5 mass% titanium hydride powder and 4 mass% silicon powder. In addition, a one-piece foam was successively produced from the bonding of two compacts during the foaming in a die. It was found that the cold repeated forming of compacts is effective for the production of metal foams. 相似文献
993.
An optical strain measurement system for asphalt mixtures 总被引:1,自引:1,他引:0
Bjorn Birgisson Antonio Montepara Elena Romeo Riccardo Roncella Reynaldo Roque Gabriele Tebaldi 《Materials and Structures》2009,42(4):427-441
Knowledge of the conditions governing the initiation and propagation of cracks in hot mix asphalt (HMA) mixtures is a prerequisite
for a comprehensive understanding of HMA cracking mechanisms. Traditional strain measurement sensors have proved to be not
completely adequate in the sense that they do not provide pointwise measurements, thus not pinpointing the location of crack
initiation, and not accounting for non-uniform strain distributions. This paper presents a digital image correlation (DIC)
system for non-contact and full strain field measurements, conceived for the purpose of investigating the cracking behavior
of HMA mixtures. The whole system was developed so as to account for the special nature of typical HMA testing configurations.
An image matching technique (least squares matching) was employed for providing matches with sub-pixel accuracy. The performance
of the method was investigated by several tests. The DIC system was shown to overcome the shortcomings of traditional on-specimen
strain measurement devices achieving satisfactory accuracy compared to strain gauges. 相似文献
994.
995.
Three types of foam concentration measurement techniques are examined: total fluorine content, optical absorption, and specific conductivity. Specific conductivity was found to be the most useful for field measurements and was therefore compared with the traditional refractive index approach. It was found that electrical conductance provides a more accurate method of estimating the concentration of AFFF solution than does the refractive index technique described in NFPA 11. 相似文献
996.
欠平衡钻井技术的应用 总被引:4,自引:0,他引:4
介绍了胜利油田在2口井上采用欠平衡钻井的情况,讲述了欠平衡钻井的技术特点和开展欠平衡钻井需要考虑的问题以及一些解决问题的方法,为以后欠平衡钻井技术的应用提供了一些实践经验。 相似文献
997.
三峡工程建设中若干重大技术问题的突破 总被引:1,自引:0,他引:1
三峡工程规模巨大 ,技术复杂 ,到 2 0 0 1年三峡工程建设已在大江截流和混凝土防渗墙施工技术、大坝电站高强度混凝土施工、永久船闸高边坡施工技术、电站大型钢衬钢筋混凝土压力管道和蜗壳保温保压技术、沥青混凝土心墙等重大技术问题上有突破 相似文献
998.
999.
冷43块稠油油藏氮气泡沫调剖实验研究 总被引:7,自引:1,他引:6
在模拟辽河冷43块稠油油藏的烧结模型上进行了氮气泡沫调剖实验研究。起泡剂HL-1溶液与氮气质量比为1:1,驱替流量按相似条件求出,驱替程序包括:饱和地层水,水驱,氮气泡沫驱,后续水驱。常压下在均质模型中注入起泡剂溶液和氮气时,阻力因子随LH-1浓度增大而增大,随温度升高而略减小,在30、60、80℃下,0.5%LH-1浓度时分别为5.81,5.78,5.67;后续注水时残余阻力因子随温度升高略有减小,在以上3个温度下分别为1.83,1.78,1.68。在非均质模型上,在围压高于内压2MPa条件下,高渗低渗层流量比在水驱时为3.00~3.17。注入1.0%LH-1溶液和氮气时下降至1.44~1.67,后续水驱时回升至2.08~2.23;常压(0.1MPa)、60℃或80℃下该组流量比值相差不大;60℃、压力0.1、10、20MPa下的该流量比,注剂时分别为1.44,1.63,1.67,后续水驱时分别为2.08,2.08,2.13。两组实验结果表明:LH-1的浓度宜选择0.5%~0.6%;同时注入起泡剂溶液和氮气可在岩心中产生泡沫,泡沫先进入高渗层,起调剖和使后续泡沫流和水流转向的作用;在高压下泡沫仍具有这种调剖和使流体流转向能力,只是略有减弱。表2表4. 相似文献
1000.
介绍了石油沥青,特别是道路沥青的用途及在国民经济中的重要地位。针对我国石油沥青产量不足、品种不全、质量不高,导致近年来大量进口的现状,重点论述了加快优质石油沥青生产的措施,如选择适于生产沥青的原油(包括进口原油),修订国家标准,创建名牌产品等,力争尽快提高我国石油沥青的产量和质量,扩大其市场占有率。 相似文献