超浓乳液聚合研究近况

总结了国内外在超浓乳液聚合研究方面的近况 ,包括新的聚合体系及聚合产物结构和性能的研究 ,展示了其在新的聚合物材料开发和应用中的前景和价值。     

Particulate character, inertial effects and diffusion effects in concentrated suspensions

In the sedimentation of suspensions, the particles modify their settling velocity in accordance with the solids concentration. Kynch's theory assumes that in each layer, the settling velocity only depends on the solids concentration, and neglects the acceleration and deceleration processes when the particles descend with a velocity distinct from that corresponding to the solids concentration at this layer. The Kynch theory also assumes that there are so many small particles that the solid mass can be considered homogeneously distributed in the suspension, so the particulate character of the suspension is ignored. Kynch's theory also neglects the diffusion effects. An analysis of the particulate character of the suspension, the inertial effects and the diffusion effects are discussed in this paper, deducing a critical value for considering the particulate character negligible and a critical size for considering the diffusion effect also negligible. Finally, several data of different flocculated suspensions are satisfactorily analysed in view of the conclusions obtained previously.     

硫化机群的集散控制系统应用

叙述了两种取代轮胎硫化机三针记录仪的控制方案及对硫化机群进行集散控制的具体方法。     

CONCENTRATED ACID CONVERSION OF PINE SAWDUST TO SUGARS. PART II: HIGH-TEMPERATURE BATCH REACTOR KINETICS OF PRETREATED PINE SAWDUST

A study of high-temperature, concentrated-acid hydrolysis kinetics was undertaken for pretreated pine utilizing a corotating twin-screw extruder reactor. Five different acid concentrations were prepared ranging from 5 to 30 wt.% acid. These solutions were subjected to high-temperature acid hydrolysis at 110°, 120°, and 130°C using a custom-fabricated zirconium batch reactor. A number of nonlinear and linear regression analyses were undertaken so that the concentration of less resistant cellulose, resistant cellulose, glucose, and decomposition products could be obtained as a function of time, temperature, and acid concentration. Application of the kinetic rate constants obtained from the static batch reactor hydrolysis studies demonstrates that more than 50% of the theoretical glucose available in the pine sawdust can be obtained in roughly 25 minutes and 41% of the theoretical glucose available can be achieved in as little as 3 minutes. Further analysis highlights the importance of the pretreatment technique in achieving significant quantities of theoretical glucose in a short high-temperature reaction time.     

SK40P数控车床尾座数控化改造方法及实现

提出在SK40P数控车床基础上对其尾座进行数控化改造的方案,以实现油缸盖轴类零件批量生产时车削、钻削工序集中的工艺流程需求。该方案采用PLC、伺服驱动和伺服电动缸组成的系统带动尾座、锥柄套筒及钻头进给实现中心孔的自动钻削加工,原车床数控系统GSK980TD与PLC之间通过I/O端口实现通信,构成主从式结构。实际运行表明,该改造方案拓展了普通数控车床的工艺能力。     

基于工业机器人的自动取袋称量装置的设计

针对包装流程中取袋称量自动化程度低,取袋装置与称量装置各自独立、结构分散、功能不集中的问题,提出了一种基于工业机器人的自动取袋称量的方案。设计出了可配合机器人的末端执行器,并同时实现取袋与称量功能的装置。通过对工业机器人的移动路径进行合理设计,将装置移动到指定位置,采用气缸控制装置的张开闭合,完成取袋动作,运用称量传感器,实现称量功能。该装置与工业机器人配合使用,提高了包装机的自动化水平,实现了取袋与称量的结构与功能的统一。     

超浓乳液聚合苯乙烯—甲基丙烯酸的乳胶粒径及羧基分布

以苯乙烯、甲基丙烯酸为主要原料进行超浓乳液聚合 ,制备了含功能基的单分散性复合物。考察了乳化剂浓度、内相比、聚合程度对乳胶粒大小及分布的影响。同时 ,用电导滴定法测定了乳胶粒表面羧基的含量 ,探讨了乳化剂浓度、羧酸含量及内相比对羧基分布的影响。结果表明 ,随乳化剂浓度减小、内相比增加、聚合时间延长、乳胶粒径增大 ,随乳化剂浓度减小、内相比增加、粒子表面羧基减少 ,而羧酸含量对羧基分布的影响不太明显     

高效液相色谱测定浓缩沙棘汁中的维生素C

提出了一种高效液相色谱法测定浓缩沙棘汁中的维生素C的方法,方便简便、快速、准确。对样品进行测定,变异系数为0.41％,加标回收试验,回收率为99.7％～101.2％。     

DT-RO处理垃圾渗滤液工程介绍

重庆长生桥垃圾卫生填埋渗滤液处理工程,是我国第一座采用碟管式反渗透(DT-RO)技术处理的工程。在半年多的运行中,该系统效能高且稳定。CODCr、TOC和电导率去除率均在99%以上,NH3-N去除率达98%,Ca2+、Ba2+、Mg2+截留率均在99.9%以上,出水中未检出SS。浓缩液回灌于垃圾填埋场,形成回灌型生物反应器。     

以浸没式超滤膜为核心的短流程净水工艺的应用与思考

以浸没式超滤膜为核心的短流程净水工艺自问世以来受到业界的广泛关注.该工艺为净水厂建设和改造提出了一条将预处理、超滤、浓水回收、污泥浓缩、排泥等工序集合在一个构筑物中运行的全新技术路线,有着广阔的应用前景.从该工艺各个环节的特点出发,进行从设计到运行的多角度思考,提出了一些自己的理解,抛砖引玉与大家共同探讨.