DPP-250型包装机控制系统设计

介绍了DPP-250型包装机工艺流程,设计了以FX1N系列PLC为基础的DPP-250型包装机控制系统,重点论述了控制系统的硬件配置、输入输出点分配和软件设计。     

凹版醇水性复合塑料油墨及其制备工艺

研制了一种凹版醇水性复合塑料油墨,该油墨的组分为：多元丙烯酸酯共聚树脂、聚酮树脂、颜料、分散剂、附着力促进剂以及鳌合剂和乙醇.选用了具有醇溶性的多元丙烯酸酯作用油墨的主体树脂,使油墨具有良好的醇溶性和溶剂释放性,再配合采用特殊合成树脂,用以研磨颜料,提高油墨的展色性、流动性,最后添加附着力促进剂和鳌合剂,提高油墨的附着力、耐热性及后工序的各项要求;采用乙醇和水做溶剂,不使用有毒、有害的溶剂,减少了有害溶剂对大气的污染,印刷中以乙醇和水作稀释溶剂,无有毒、有害溶剂残留和排放,安全、无毒、卫生、环保.     

集装箱码头泊位调度问题的启发式算法研究

为优化集装箱码头泊位的分配,提高泊位的利用率,把码头泊位的调度问题转化为带有约束条件的特殊二维装箱问题。通过建立连续泊位调度的非线性规划模型,提出了一种求解集装箱码头连续泊位分配问题启发式算法。仿真算例结果表明该算法能在实际的集装箱码头泊位调度中有效的提高泊位的利用率。     

FRP加固矩形RC短柱极限承载力分析

通过FRP复合材料包裹RC短柱,从而提高RC短柱的承载力已被众多的工程实践证明是有效的,但FRP约束RC短柱的承载力计算公式却没有统一的规定,存在着许多问题值得商榷.通过对FRP约束矩形柱约束机理的讨论,在现有的本构模型分析的基础上,推导出FRP加固矩形短柱的极限承载力的计算公式,并分析了粘帖层数、粘帖方式、FRP的间距以及倒角半径r对RC短柱承载力的影响.     

基于视觉注意力模型的红外人体图像兴趣区域提取*

由于红外人体图像所处背景的复杂性,使用阈值分割定位红外人体图像往往把大量的非人体图像一起分离出来,这给后续工作带来了巨大的计算量.研究了红外人体图像的典型特点和人眼视觉判断人体轮廓图像的敏感特征,使用该特征建立了简单的人眼视觉对人体的注意力模型,并构建特征判别概率函数,对待定目标进行概率的估算,最终使用该模型快速地剔除非人体红外图像的干扰,并准确地定位人体兴趣区域.     

新型中空纤维膜接触器用于乙醇/水体系分离的探索

引言 醇/水体系分离一直是化工生产中的重要环节,高效的醇/水分离技术能够使醇的产量大大提高,满足日益增长的工业生产需求.传统的分离方法如精馏、萃取等已经相当成熟,但是这些方法在工业生产过程中能耗巨大,越来越受到面临能源资源匮乏的当代社会的关注和制约.在此背景下,面向高效、节能的新型膜接触分离器应运而生,如Alan等[1]指出,工业化或半工业化的过程已经包括膜吸收、膜萃取以及渗透蒸馏等多个耦合分离单元[2-6].     

Computational fluid dynamics (CFD) modeling of spouted bed: Influence of frictional stress, maximum packing limit and coefficient of restitution of particles

Following the previous article [Du, W., Bao, X., Xu, J., Wei, W., 2006. Computational fluid dynamics (CFD) modeling of spouted bed: assessment of drag coefficient correlations. Chemical Engineering Science 61 (5), 1401-1420], this contribution describes the influences of the frictional stress, maximum packing limit and coefficient of restitution of particles on CFD simulation of spouted beds. Using the two-fluid method embedded in the commercial CFD simulation package Fluent 6.1, the spouting hydrodynamics of a cylindrical-conical spouted bed was simulated and verified with the experimental data of He et al. [He, Y.L., Lim, C.J., Grace, J.R., Zhu, J.X., Qin, S.Z., 1994a. Measurements of voidage profiles in spouted beds. Canadian Journal of Chemical Engineering 72 (4), 229-234; He, Y.L., Qin, S.Z., Lim, C.J., Grace, J.R., 1994b. Particle velocity profiles and solid flow patterns in spouted beds. Canadian Journal of Chemical Engineering 72(8), 561-568]. The results showed that, for coarse particles, the frictional stress is important only for the annulus computation and has no obvious effects on the hydrodynamics of the solids flow in the spout region. The specification of the maximum packing limit could significantly affect the properties of the pseudo-fluid phase of the particles by changing the radial distribution function. The strong dependence of the pseudo-fluid properties of the particle phase, such as pressure, bulk viscosity and shear viscosity, on the granular temperature accounts for the influence of the coefficient of restitution of particles on CFD modeling. The solids volume fraction at loose packing state is suitable for spouted bed simulations, and a pretest of the coefficient of restitution of particles must be conducted when no experimental datum is available.     

An Application of Silica‐Based Monolithic Membrane Emulsification Technique for Easy and Efficient Preparation of Uniformly Sized Polymer Particles

Summary: Uniformly sized polymer particles were prepared by an emulsification and polymerization technique utilizing a silica monolithic membrane, namely the “silica monolithic membrane emulsification technique”. In this paper, we utilized silica monolithic membrane as a device for the preparation of uniformly sized polymer particles. A mixture of monomers, diluents and oil‐soluble initiator was emulsified into a continuous medium through the silica monolithic membrane and polymerized. The particles obtained had a higher size uniformity than that of particles prepared by previously reported membrane emulsification techniques, such as the Shirasu Porous Glass (SPG) emulsification technique. Through the silica monolithic membrane emulsification technique, we could prepare particles having availability as a possible packing material for solid‐phase extraction (SPE) and high performance liquid chromatography (HPLC).

SEM photograph of silica particles prepared through capillary plate membrane.     

面向纸板三维装箱问题的剩余空间最优算法

针对瓦楞纸板在装箱过程中遇到的多种实际约束,提出一种基于剩余空间最优和多种实际约束的快速求解算法。该算法先根据纸板的先进后出和组合装载约束,确定纸板的装箱序列,接着将三维装箱问题转换成带高度约束的二维装箱问题,再基于剩余空间最优策略,选择空间的分割方式和纸板的放置方式,并对剩下的空间进行合并和重新分割,从而求解得到纸板装载放置的结果,实现容器空间利用率最高和使用数目最小的目标。通过计算随机算例和实际算例,以及对结果的三维可视化显示,验证该算法能实现多种约束,空间利用率高,运算效率高并具有有效性和实用性。