Contribution of the Internal and External Oxygen to the Oxidation of Microencapsulated Fish Oil

Microencapsulation aims to protect polyunsaturated fatty acids against oxidation by embedding oil droplets in a solid matrix. In such a system the internal (dissolved and entrapped) and external (in the environment) oxygen can be differentiated. The study aims to quantify the impact of both oxygen sources on the oxidation of microencapsulated fish oil. The impact of the solubilized oxygen in bulk fish oil is investigated by saturating the oil with nitrogen, synthetic air, and pure oxygen. Even though more dissolved oxygen results in more oxidation products, the difference between the oxidation of the nitrogen and air saturated oil is significant but low. For encapsulated fish oil powders, the internal oxygen is modified by preparing oil‐in‐water emulsions under atmospheric and inert conditions. The feed is atomized and spray dried with either nitrogen or air. Powders are stored under vacuum and in vials and the hydroperoxides and anisidine value are determined in the total‐ and encapsulated oil. The internal oxygen has a minor impact, whereas the external oxygen is the main determinant for autoxidation. Apart from oxidizing the non‐encapsulated oil, the external O₂ penetrates into the particle and reacts with the encapsulated oil. Practical Applications: Comparing the contribution of the internal and external oxygen to the oxidative stability shows that the internal O₂ plays a minor role and can be neglected. This means that the emulsion preparation as well as the spray drying process can be conducted under ambient conditions. An inert production is not extending the shelf life significantly as long as the external O₂ determines oxidation. The focus should be on optimizing the diffusion barrier properties of the wall matrix to reduce the penetration of the external oxygen into the particle system. Alternatively, packaging solution reducing the external O₂ will extend the shelf life of the microencapsulated oil.     

The origin of the modulated structure in Sr2CuO3+δ (δ = 0.4): [CuO2] in-plane oxygen vacancy or apical oxygen vacancy?

We propose the question of the modulated structures of copper oxide is caused by the [CuO₂] in-plane oxygen vacancy or apical oxygen vacancy. Sr₂CuO_3+δ single-crystal samples were prepared using high-temperature and high-pressure methods. The major phase of Sr₂CuO_3+δ (δ = 0.4) single-crystal system is found to be constituted by the 5 a modulated structure with the Fmmm space group, which originates from the [CuO₂] in-plane oxygen vacancy appearing in octahedral Cu-O. Besides, the presence of the [CuO₂] in-plane oxygen vacancy may obliterate the superconductivity of the system. Experimental results deduce that the oxygen vacancy may appear in the apical oxygen sites in high-temperature copper oxide superconductors.     

基于改进NSGA-Ⅱ算法的乙烯裂解炉操作优化

现有的乙烯裂解炉优化通常只针对两个目标函数即产物乙烯和丙烯的收率，并且采用遗传算法的收敛效果一般，故提出一种基于改进NSGA-Ⅱ算法来研究一个多目标运行的解决方案，以此来解决乙烯裂解炉的固定周期操作优化问题，即在增大产物乙烯和丙烯收率的同时减少原料以及蒸汽流量来提高整体运行状况。把具体问题量化为数学模型，分析了原料气烃比、原料流量、出口温度对乙烯和丙烯收率的影响。实验结果表明，相较于原有操作条件，提出的优化方案具有良好的可行性。     

黑匣子高温测试仪的开发

采用物质的相变吸热原理，可以将高温环境传人保温箱的热量重新排回至高温环境，有效地提高了保温箱的抗高温能力，并对保温箱的隔热性能做了简单的理论推算和测温反向试验。温度测试仪选用超低功耗CPU，具有体积小、耗电少的优点，使黑匣子高温测试仪在运行过程中具有很好的安全可靠性。     

氧气底吹熔炼氧枪浅析

系统地论述了氧气底吹熔炼氧枪的结构、工作原理、设计计算方法、材质及蚀损机理．指出了延长氧枪使用寿命的措施。     

首钢1号高炉增产节焦生产实践

对首钢1号高炉焦炭质量恶化后增产节焦的生产经验进行了总结分析。认为提高入炉原燃料质量，综合优化高炉基本制度，合理控制稳定的操作炉型是保证炉况长期顺稳、实现效益最大化的有效手段。     

常压炉炉管及转油线的腐蚀

通过对常压炉炉管及转油线腐蚀情况的分析,认为该炉发生转油线腐蚀泄漏的主要原因是原油含硫量升高、冲刷加剧、材质不适合以及设备老化等。针对腐蚀的成因采取了对整个转油线进行包盒子处理、材质升级、摸清活性硫在装置中的分布情况和腐蚀规律、开展高温部位定点测厚、避免高含硫原油直接进入装置等措施。     

延迟焦化装置加热炉炉管在线烧焦技术的应用

介绍了加热炉炉管在线烧焦技术在扬子石油化工股份有限公司炼油厂新建1.6 Mt/a延迟焦化装置一炉三室加热炉上的应用情况:在线烧焦的工艺流程、操作过程、操作要点以及效果等.该项专有技术的成功实施,提高了加热炉的能力,有效地解决了因炉管结焦需整体停车处理所造成的损失,消除了制约加热炉长周期运行的瓶颈,取得了良好的经济效益和社会效益.     

集输系统热回水管线腐蚀分析

中国石油天然气股份有限公司华北分公司第三采油厂油气集输系统热回水管线普遍存在着腐蚀问题,影响原油生产和集输的正常运行。介绍了腐蚀较严重的13个站点的水质普查、水质结垢倾向和腐蚀性情况,并在水质分析的基础上进行了热水管线腐蚀因素的试验研究,确定腐蚀主要因素为水中的溶解氧含量高,从而造成腐蚀。