饮用水中挥发性三卤甲烷(THM)_s测定方法的改进

本文使用吹扫捕集法来前处理水样,用带有电子捕获检测(ECD)的气相色谱仪来测定水中三卤甲烷(THM)_s。水样加标回收率在85%～115%之间,相对标准偏差在5%左右。实验结果表明,该法具有简单、快速、灵敏的特点。     

Hydrophilicity modification of polypropylene microfiltration membrane by ozonation

To improve surface hydrophilicity and to reduce fouling, commercial polypropylene microfiltration membranes were ozonated to generate peroxides as grafting sites for hydrophilic monomers. Ozonation was conducted in aqueous and gaseous phases, respectively. In both phases, the amount of peroxides increased with the ozonation time. A novel way to enhance the generation of peroxides was tested, i.e., adding homogeneous catalyst, CuSO₄, to aqueous ozonation. Results showed that with an optimum dose of 0.05 g/L of CuSO₄, the peroxides generated were 18.2% more than that by the non-catalyzed ozonation in aqueous phase. It was also confirmed by scavenger tests that during the aqueous ozonation both molecular ozone and free radicals contributed to the oxidation of the membranes, the latter was formed from the self-decomposition of ozone in water. Graft polymerization was also conducted after the generation of peroxides. A hydrophilic monomer, acrylic amide, was graft polymerized onto the membrane surface. The successful grafting of acrylic amide was confirmed by the formation of new peaks corresponding to amide groups in FTIR spectra. Results of contact angle measurements and filtration tests indicated that aqueous ozonation was more effective than its gaseous counterpart in terms of hydrophilicity improvement. In addition, the XRD analysis revealed that the ratio of the membrane surface crystallinity to amorphousity was changed by both ozonation and graft polymerization. Results of SEM scanning also showed changes in membrane surfaces after modification.     

长背鳍波动推进游动研究

以依靠长背鳍推进的“尼罗河魔鬼”为研究对象,对弓鳍目模式推进进行了研究。在“尼罗河魔鬼”巡航游动试验的基础上,通过对鱼体几何形态和柔性长背鳍波动的运动学分析,建立了“尼罗河魔鬼”长背鳍波动推进的简化运动学模型,并利用大摆幅伸长体理论分析了长背鳍波动推进的水动力学特性。计算表明:“尼罗河魔鬼”在0．728～0．985身长／s的速度范围内,长背鳍波动推进的水动力学效率介于81．664％-86．420％之间,表明长背鳍波动推进游动是一种适应水中环境的高效游动模式。     

纳米聚合物微球/表面活性剂复合调驱体系评价及应用

针对长庆低渗透油藏特点,提出聚合物微球/表面活性剂复合调驱提高采收率技术。以丙烯酸、2-丙烯酰胺-2-甲基丙磺酸、2-巯基苯甲酸、过硫酸铵、亚硫酸氢钠等为原料制备聚合物微球,以烷醇酰胺聚氧乙烯聚醚磺酸盐与椰子油脂肪酸二乙醇酰胺为原料制得表面活性剂。研究了表面活性剂和表面活性剂/聚合物微球混合液的油水界面张力,考察了聚合物微球与混合液的调驱性能,优选了复合调驱注入方式,并在安塞油田进行了现场应用。结果表明,聚合物微球初始粒径为50～300 nm,具有水化膨胀特性,膨胀倍数为20～100倍。微球在水化膨胀过程中产生聚集特性,分散性、球形度均较好,且粒径呈高斯正态分布。表面活性剂适宜用量为3 g/L。聚合物微球加入表面活性剂后混合液黏度增大,微球分散相颗粒屏蔽了表面活性剂的界面活性以及形成胶束的能力,导致油水界面张力降幅变小,不利于表面活性剂驱油。聚合物微球溶液对岩心的封堵性较好,微球质量浓度大于4 g/L时的封堵率约80%。体积比为1∶1的聚合物微球与表面活性剂段塞式注入岩心的驱油效果好于二者混合式注入。该体系在安塞油田现场的应用效果显著,累计增油3576 t。     

时钟驱动的原理和实现

介绍了基于MC146818RTC和Intel8254PIT的一种通用时钟驱动的实现方法,给出了硬件和软件方面的实现流程。     

应用大气污染估算模式分析解决空分装置CO2污染

通过借鉴环境影响评价方法,应用大气污染估算模式对不同排放方式下CO2落地浓度进行计算及对比分析,确认空分装置CO2污染源,找出低成本消除污染的方法。     

Combined salience based person re-identification

Human eye perceives an object as the entity with global information and local information. Human salience is distinctive local information in matching pedestrians across disjoint camera views, and matching on overall foreground guarantees reliable and robust identification. In this paper, we propose a strategy for the matching of mean salience to identify pedestrians. Also, we consider that person re-identification based on the local single directional matching suffers from the variations of pose, illumination and overlapping, and propose a global bi-directional matching to solve the challenging problems of person re-identification. Furthermore, our matching of mean salience is tightly combined with the global bi-directional matching. Patch matching is utilized to handle the misalignment problem in pedestrian images. We test our feature and matching approaches in person re-identification scenario. Experimental results demonstrate that the mean salience and the global bi-directional matching have promising discriminative capability in comparison with other ones.     

单相方波逆变器中GTR的驱动与缓冲

本文简单介绍了大功率晶体管ＧＴＲ的特性及解决驱动与缓冲问题的途径，重点分析了在研制单相方波逆变器时所使用的驱动电路与缓冲电路的工作原理及工作特性。