The initial behaviour of freshly etched copper in moderately acid, aerated chloride solutions

When freshly etched samples of various types of copper were exposed in moderately acid, aerated chloride solutions, two phenomena were observed. First the corrosion potential and the pH of the solution decreased over a shorter time, then the potential increased over a long period (600-1500 min), following an s-shaped pattern. Increase in pH during the second stage was avoided using a pH-stat. The corrosion rate increased little or not at all over the entire period. A tentative interpretation of the short-term behaviour is presented with some reservation. The long-term development of the potential suggests phase formation or transformation following the Avrami pattern. By suitable derivations it was possible to fit the development of potentials to the Avrami equation. Subsequent examinations by Auger spectroscopy proved the presence of thin layers of Cu₂O on the copper surfaces, increasing in thickness with exposure time. The dissolution kinetics can be described in terms of two parallel electrochemical reactions and a simultaneous non-electrochemical dissolution reaction.     

英台地区天然水驱油藏的开发特点及稳产技术

掌握边底水运动规律，控制并利用活跃的边底水能量，是成功开发天然水驱油藏的关键。英台地区的英台、四方坨子和一棵树等三个油田均为天然水驱油藏，天然能量充足。油藏投入开发后初期含水较高，含水上升极快，造成产油量大幅度递减。针对其开发特点，适时采用大泵、电潜泵提液强采，通过大量补孔层间接替以及加密调整和扩边等稳产技术措施，确保了油藏以3％-5％的采油速度长期稳产，水驱采收率高达50％以上。     

龙滩电站大法坪料场爆破施工技术研究

结合龙滩水电站大法坪料场爆破的技术难点,针对不同的岩石和要求,通过对采场的爆破分区,应用车制乳化炸药使料场开挖爆破施工取得成功,爆破料级配良好,满足了供料强度要求。     

龙滩水电站左岸地下引水发电系统开挖支护

龙滩水电站左岸地下引水发电系统工程规模浩大,在0.5 km 2的范围内共布置有119条洞室。这些洞室在空间重叠,平竖相贯,形成庞大复杂的地下洞室群,且主要洞室尺寸庞大,其中地下厂房是目前世界上规模最大的地下厂房。龙滩水电站引水发电系统主要洞室的开挖支护方法,可供其他类似工程参考借鉴。     

加热炉烟气在线自动测氧技术的研究

介绍了武钢热轧厂烟气中残氧量自动监测技术及燃烧工艺试验 ,评述该项技术研究动态 ,指出它对节能降耗和环境保护的作用     

30t转炉三位一体护炉实践

以转炉终点高拉碳操作法及降低出钢温度等操作护炉为根本护炉手段，溅渣为主要护炉方法，贴砖作为护炉的辅助措施，有效地提高了转炉炉龄，达到了1万炉以上，实现了根据设备检修计划下炉。     

Production of phosphoric acid with low content of impurities

The present work is to study the possibility for controlled distribution of the impurities when they are decomposed by sulphuric acid to wet phosphoric acid and phosphogypsum, as well as generating technological conditions for production of clean wet phosphoric acid and its derivatives - phosphoric fertilizers, food phosphates and other phosphoric products.A coefficient of distribution D_A is introduced as a general criterion for elements dispersion. The study includes relationships between the weight ratio sulphuric acid/natural phosphate and D_A; the period of decomposition and D_A; the particle's size content of the natural phosphate and D_A. The obtained experimental data and relationships about the influence of the above discussed technological parameters on dispersion of more than 23 elements allow for control of that process in wet phosphoric acid and phosphogypsum by selecting specific technological conditions. Thus, depending on the requirements of acid's consumers and procedures for secondary processing of phosphogypsum to end-products, a selective decomposition of the natural phosphates to phosphoric acid and phosphogypsum can be carried out with content of the impurities in those products varying in narrow limits.     

被Kerr介质包围的J—C模型中光场位相特性

本文应用Pegg-Barnett位相理论讨论了被Kerr介质包围的J-C模型中光场的位相性质。     

济钢第一炼钢厂降低钢铁料消耗实践

济钢第一炼钢厂通过优化入炉原料结构,改进冶炼工艺,实施少渣炼钢,有效减少了转炉吹损,降低了钢铁料消耗成本,2002年增加炼钢综合经济效益3100多万元。