两步法油田油井结垢处理技术及其发展

本文简要介绍了油田油井结垢的成因、化学清洗及防治的机理、两步法施工工艺方法、施工效果分析。证明了清防结合的两步法施工工艺、在增产和稳产方面有一定的优势。     

微波两步法烧结氧化铝陶瓷及对韧性的影响

采用微波两步法制备细晶氧化铝陶瓷,研究了烧结温度、保温时间等工艺参数对氧化铝陶瓷致密化、晶粒生长和韧性的影响,并通过与传统两步法烧结对比,分析探讨微波两步法烧结的影响机制。研究发现,微波两步法能有效降低传统两步法的烧结温度,缩短烧结时间;由于微波具有促进扩散的非热效应,微波两步法对晶粒生长的抑制作用表现的不明显,但是在相似的晶粒尺寸下,微波两步法烧结的样品表现出了更优的硬度和韧性。     

分子筛膜合成的研究进展

作者主要就分子筛膜最新合成方法展开论述,主要介绍了最近十年来分子筛膜合成方法取得的新进展,如二次合成法、微波合成法、堵孔法、脉冲激光沉积法、电泳沉积法、汽相法、两步变温法、两步变浓度法等方法的应用,能够给该领域或即将踏入该领域的研究者提供一定的参考价值.     

两步法改为一步法生产烷基糖苷的工业技术及发展

结合两步法烷基糖苷的生产实际,指出了国内两步法生产过程中存在的问题,阐述了两步法改为一步法生产APG的生产技术路线,并从设备技术、工艺技术和监控技术3个主要方面,总结了改进措施,展示了两步法改为一步法烷基糖苷工业生产技术的未来发展前景。     

两步法挤出无卤阻燃增强PBT的研制

对比了两步法挤出造粒的无卤阻燃增强聚对苯二甲酸丁二酯( PBT)与一步法挤出造粒的无卤阻燃增强PBT的力学性能、阻燃性能、电性能.结果表明,在相同配方条件下,两者的综合力学性能相当;但两步法的无卤阻燃增强PBT的电性能和阻燃性能明显优于一步法.     

两步光气化法生产MDI中试研究

旨在通过MDI中试实验探索两步光气化法的最佳工艺参数,以便降低能耗,提高产品在市场中的竞争力.逐一考察了两步光气化法中光气与多胺质量比、溶剂与多胺质量比、第一热反应釜温度以及第二热反应釜温度对光气化收率的影响,得到了两步光气化法生产MDI的最佳工艺条件:光气与多胺质量比为4.5,MCB与多胺质量比为6,第一热反应釜温度为90℃,第二热反应釜温度为120℃.     

明胶文摘

猪皮的不同脱脂方法对胶原提取率的影响赵帅,巩旭,李国英.中国皮革2007,36(9):33~36.分别用4种有机溶剂、2种非离子型脱脂剂、不同用量的脂肪酶、非离子型脱脂剂AX-AUT-50和异丙醇两步法、非离子型脱脂剂AXAUT-50和脂肪酶两步法,脱除新鲜猪皮中的脂肪。对脱脂后的碎皮块提取胶原。结果表明:用单一试剂脱脂时,2种非离子型脱脂剂的脱脂效果最好,脱脂率均高达67%以上,相应的胶原提取率也在22%以上。两步法脱脂的效果比任何单一试剂脱脂的效果都好,尤其是AXAUT-50和异丙醇两步脱脂,其脱脂率高达90%以上,相应的胶原提取率也高达28.52%。十…     

两步法与三步法抛光工艺的应用对比探讨

抛光是在轿车涂膜后处理工艺中不可缺少的重要工序,使得漆面具有柔和、稳定的光泽,保证涂膜表面平整光滑,是提高面漆涂层装饰性的一种工艺手段.通过在实际生产中的使用情况,对传统的三步抛光法和新型的两步抛光法工艺进行对比,表明两步抛光法在工时、材料设备和抛光效果等方面占有优势,是现场应用的最佳抛光工艺.     

核/壳结构磁性Fe3O4@SiO2纳米粒子的制备及表征

在Triton X-100/正己醇/环己烷/水反相微乳液体系中,分别采用一步法和两步法制备具有核/壳结构的磁性Fe3O4@SiO2复合纳米粒子.考察了搅拌方式和超声条件对一步法产物结构、形貌的影响,并与两步法进行了对比研究.通过XRD、FT-IR、DLS、TEM和VSM对复合颗粒进行了表征.结果表明,反相微乳液体系下,...     

AZ31镁合金化学镀镍的酸洗活化工艺研究

为寻找AZ31镁合金化学镀镍适宜的酸洗活化工艺,采用酸洗活化一步法和两步法制备了化学镀镍磷层.通过膜厚、附着力、扫描电镜以及盐水浸泡、极化测试分析表征了两种膜层的耐蚀性.结果 表明:两种处理法都在基体上制备了均匀、完整、连续的灰色Ni-P镀层;对基体都有一定的保护性,但结构都不致密,有较多空隙;两步法处理获得的镀层在膜...     

聚硅酸硫酸铝絮凝剂处理炼油废水的研究

用自制的聚硅酸硫酸铝处理炼油废水,效果优于传统使用的聚合氯化铝,采用两次投加(100mg/L和50mg/L)既可减少絮凝剂用量,处理后又可达到国家一级排放标准,其中pH范围为7.0～8.0,沉淀时间为30min。若采用一次投加絮凝后砂滤,效果更佳,也简化了处理工艺流程。     

Ultrasound‐facilitated electro‐oxidation for treating cyan ink effluent

The feasibility of using ultrasonication in combination with the Fenton's reaction was investigated for treating cyan ink effluent. A two‐step treatment process was developed—the first step was an ultrasound‐assisted electro‐oxidation, while the second was chemical oxidation through the addition of hydrogen peroxide. The use of electro‐oxidation in the first step significantly reduced the amount of iron needed compared with the conventional Fenton's reaction, resulting in a 98% reduction in the amount of sludge produced. A simple technique based on refractive index measurements was introduced as a rapid way to quantify the amount of sludge produced. It was postulated that ultrasonication in the presence of iron (from electrolysis) in the first step converted the ink components into reaction intermediates which were more amenable to peroxide oxidation in the second step. These intermediates were quantified by ultra‐violet absorption at wavelengths of 275–400 nm. The two‐step treatment process was able to reduce the COD and copper contents in the ink waste water to within the discharge limit, which conventional Fenton's reaction was unable to meet for copper discharge. The same COD removal was also achieved in about half the time. Kinetics study performed to further understand the reaction mechanisms show second‐order kinetics for both steps with activation energies of 18.2 and 20.4 kJ/mol for steps 1 and 2, respectively.     

Hydrolysis of mercerized cotton fibers due to cellulase treatment

Cotton fibers mercerized under the relaxed state were hydrolyzed with crude cellulase. The mercerization treatment examined included ammonia treatment, sodium hydroxide treatment, and two combined treatments using ammonia and sodium hydroxide. Crystalline regions of the mercerized fibers were hydrolyzed in the first step of hydrolysis. In this step, ammonia treatment decreased the crystallite size to a great extent due to the hydrolysis of the cellulose III crystalline phase. Cellulase treatment rendered the crystallite surface highly accessible to water molecules. The crystalline phase was closely related to water sorption of cellulase‐treated fibers. The sequence of treatment had an influence on the fiber structure in the case of the combined mercerization treatment with ammonia and sodium hydroxide. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 364–370, 2000     

Reaction Mechanisms of Silicon Carbide Fiber Synthesis by Heat Treatment of Polycarbosilane Fibers Cured by Radiation: I, Evolved Gas Analysis.

SiC fibers were synthesized from polycarbosilane (PCS) fibers by heat treatment after electron beam irradiation curing. The pyrolysis reaction mechanisms from the organic PCS to ceramic SiC were investigated by the analysis of gases evolved during heat treatment. There were two steps in the major reaction: the first step was at 800–1200 K where H₂ and CH₄ evolved by scission of Si-CH₃ and Si-H and by rearrangement reactions, and the second step was at 1000–1700 K where H₂ evolved by reactions related to C atoms in the PCS main chain. H₂ evolution in the first step was reduced with increasing oxygen content in the cured PCS fibers.     

Cost reduction of the wastewater treatment plant operation by MPC based on modified ASM1 with two-step nitrification/denitrification model

The Activated Sludge Model No. 1 (ASM1) considers that nitrification and denitrification are single step processes and nitrite nitrogen (NO₂-N), which is an intermediate for the two processes, is not accounted for. The first part of this paper presents the development of an enhanced ASM1 with two step nitrification/denitrification processes and its implementation in the Benchmark Simulation Model No.1 wastewater treatment plant (WWTP). The secondary settler was considered to be reactive in order to achieve a better fit between the simulation model and the behavior of the real WWTP. The second part presents the investigation of Model Predictive Control approach for the advanced control of the WWTP. Two control strategies are implemented for the wastewater treatment plant and they are analyzed from the perspective of the benefits brought to the WWTP operation. The proposed control strategy shows a reduction of the operational costs and the improvement of the effluent quality index.     

An assessment of acid wash and bioleaching pre-treating options to remove mercury from coal

The United States Environmental Protection Agency is expected to begin regulating the release of vapor-phase mercury from coal-fired power plants in the year 2007. Chemical pre-treatment methods were investigated for mercury removal effectiveness from pulverized low-sulfur North Dakota lignite coal. More limited results were obtained for a pulverized high-sulfur Blacksville bituminous coal. A two-step acid wash treatment showed removal rates of 60-90%, compared to one-step treatments with concentrated HCl, which yielded removals of 30-38%. Removal effectiveness is similar for first step solvents of water, pH 5.0 acid, or pH 2.0 acid followed by concentrated HCl as the second step solvent, and is independent of first step incubation time. Neither of two bacterial strains, Thiobacillus ferrooxidans and T. thiooxidans, was found effective for mercury removal.     

Kinetik und Reaktionstechnik der anaeroben Abwasserreinigung

Kinetics and reaction engineering of anaerobic sewage treatment. In numerous papers the reaction rate of acetic acid metabolism by methanogenic bacteria, which is frequently suspected as the slowest step in anaerobic digestion, is described by Monod kinetics using total acetic acid concentration as the substrate for catabolism. However, in some papers the authors try to include the influence of pH by using only the un-ionized acetic acid as the substrate in a Haldane-kinetic term taking substrate inhibition into account. From this viewpoint, some conclusions regarding reaction engineering aspects of anaerobic waste water treatment are drawn and simple models for the conventional and for the contact process are discussed. The advantage of using support materials for anaerobic bacteria is shown. The space loading can be increased in a two step cascade of fixed bed reactors with external loops for water recycling, with the system being filled with synthetic foam particles as support.     

Wood‐fiber/high‐density‐polyethylene composites: Compounding process

The compounding process directly influenced the compounding quality of wood–polymer blends and finally affected the interfacial bonding strength and flexural modulus of the resultant composites. With 50 wt % wood fiber, the optimum compounding parameters for the wood‐fiber/high‐density‐polyethylene blends at 60 rpm were a temperature of 180°C and a mixing time of 10 min for the one‐step process with a rotor mixer. The optimum compounding conditions at 90 rpm were a temperature of 165°C and a mixing time of 10 min. Therefore, a short compounding time, appropriate mixing temperatures, and a moderate rotation speed improved the compounding quality of the modified blends and the dynamic mechanical properties of the resultant composites. The melt torque and blend temperature followed a polynomial relationship with the loading ratio of the wood fiber. The highest melt torque and blend temperature were obtained with 50% wood fiber. The coupling treatment was effective for improving the compatibility and adhesion at the interface. The two‐step process was better than the one‐step process because the coupling agents were more evenly distributed at the interface with the two‐step process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2570–2578, 2004     

关于醋酸加氢制乙醇技术的分析

本文针对醋酸一步法和两步法加氢制乙醇技术进行了简要介绍,并对两种方法进行了分析比较,得出了一步法相对两步法在技术合理性及生产成本方面具有一定的优势的结论。     

二苯甲烷双马来酰亚胺的合成工艺研究

以顺丁烯二酸酐和4,4'-二氨基二苯基甲烷(DDM)为原料,采用甲苯为溶剂、共沸蒸馏法,分别用一步法和两步法合成N,N'-4,4'-二苯甲烷双马来酰亚胺(BDM)。通过产物核磁氢谱、红外色谱、示差扫描量热(DSC)及产物收率的计算和双键含量、酸值、凝胶时间、凝胶温度等的测定,对BDM一步法、两步法合成工艺进行了研究并对两种方法中生成的副产物进行了分析。结果表明,一步法比两步法产品产率有很大提高,得到的残渣较少,主要是由DDM与BDM的加成反应生成的低聚物,重新利用价值较小;两步法副产物较多,如高温条件下BMA发生分子间脱水形成的线形低聚物,其可以水解成BMA重新利用。