Hetero-assembly of colloidal particles in concentrated non-aqueous suspensions by polymer dispersant design

Although many colloidal assembling systems have been reported, most systems suffer from severe aggregation under high solid concentrations, which can often be observed in typical hetero-aggregation system. In this study, we created a hetero-assembly system using concentrated (~50 vol%) suspensions by mixing large SiO₂ particles modified with polyacrylic acid partially complexed with oleylamine (PAA-OAm) and small SiO₂ particles modified with polyethyleneimine partially complexed with oleic acid (PEI-OA) in a non-aqueous solvent. We demonstrated that hetero-assembly is driven by the interactions between the uncomplexed carboxyl/amine groups of the PAA/PEI present on the particles, while severe aggregation is simultaneously prevented by the steric repulsions of the aliphatic oleyl chains. Comparison of the cross sections of the in-situ solidified hetero-assembled suspensions with those of ideally assembled structures which were reproduced by a simulation considering the statistical distribution of particles strongly supported successful particle assembling via the proposed approach. The results revealed that the OA content in the PEI-OA complex was the dominant factor that controlled the dispersion and assembling state of the binary particles. The significance of this study is that our findings will provide a class of colloidal dispersion state which binary particles were assembled in a high solid content suspension without forming strong aggregates.     

Relationship between the adhesion properties of UV-curable alumina suspensions and the functionalities and structures of UV-curable acrylate monomers for DLP-based ceramic stereolithography

Digital light processing (DLP)-based ceramic stereolithography has attracted significant attentions due to the high printing speed and high dimensional accuracy of DLP printers. However, undesired dropping of unfinished ceramic parts during printing, owing to inadequate adhesion between the first cured layer and the substrate of the building platform, still remains a challenge. In this study, the relationship between the adhesion properties of ultraviolet (UV)-curable alumina (α-Al₂O₃) suspensions and the functionalities and structures of UV-curable acrylate monomers was investigated. With an increase in the proportions of monofunctional monomers, the adhesion abilities of UV-curable alumina suspensions enhanced because of reduced volume shrinkage, however, inferior curing performances were observed due to a decrease in the double bond densities. Furthermore, the large-volume branched chain structures in monofunctional monomers and ethyoxyl groups in polyfunctional monomers effectively decreased the volume contraction, improving the adhesion performances of UV-curable alumina suspensions and facilitating the conversion of double bonds to provide excellent curing properties, further guaranteeing strong adhesion of these suspensions to the substrate.     

忠武输气管道悬索跨越设计创新及探讨

忠武输气管道有4次悬索跨越,分别是蚂蝗溪悬索跨越、木龙河悬索跨越、马水河悬索跨越、野三河悬索跨越。文章介绍了这几座悬索跨越管桥设计中采用的多项新技术,如采用热聚乙烯半平行钢丝索代替以往的钢丝绳;采用钢管塔架代替以往的角钢塔架;根据地形地貌特点变换风索型式或取消塔架等。这些新技术、新设计在工程中均取得了良好的效果。另外,文章还针对悬索跨越桥面结构型式、预拱度设置、不对称荷载的影响、风索基础的设置等问题进行了探讨。     

斜拉索-磁流变阻尼器系统半主动控制的神经网络法

磁流变阻尼器具有良好的可变阻尼特性，能用于结构的半主动控制。针对斜拉桥拉索-磁流变阻尼器系统，本文提出了利用神经控制器进行半主动控制的神经网络法，该神经控制器根据过去时刻的加速度响应和控制信号预测下一时间步的控制信号，并给出了训练方法及开展了数值仿真研究。仿真结果显示，采用神经网络半主动控制能取得很好的减振效果，证明该方法是可行的。     

重介选煤厂自动化控制系统

介绍了重介选煤厂实现全自动控制的系统原理及所能实现的各项功能。     

从烟草悬浮细胞中分离液泡前体的方法研究

通过跟踪含有液泡前体特异标记物的组分, 利用细胞壁酶水解胞壁制造原生质体, 并用真针头挤压的方法裂解细胞, 用蔗糖密度梯度离心的方法分离液泡前体. 通过相差显微镜观察, 发现所分离的液泡前体保持完整的结构. 利用不同细胞器的标记物抗体进行免疫标记检测, 证明所纯化的液泡前体不含其他细胞器, 具有较高的纯度.     

丙烯酸2-乙基己酯与醋酸乙烯酯共聚合成高吸油性树脂的研究

以丙烯酸2－乙基己酯与醋酸乙烯酯为单体，采用悬浮聚合法，以单体自交联制得高吸油性树脂。对影响其吸油性能的多种因素，如单体配比、引发剂、油水相比的用量等，进行了系统的研究，得到的高吸油性树脂吸苯最高达16．1g/g，吸甲苯为14．8g/g，吸环己烷为13．3g/g，吸煤油为12．5g/g，可用于河面、海洋浮油的回收及工厂废水处理等领域.     

基于泛布尔代数的结构振动控制机理

本文介绍了泛布尔代数的数学模型、公理体系和化简方法 ;针对高层建筑的特点 ,舍弃寻求被控制对象的精确数学模型 ,提出了“基于泛布尔代数的结构振动控制” ,分析了其的逻辑机理 ,建立了基于泛布尔代数的MR阻尼器的半主动控制算法。应用本文提出的控制方针对 12层的高层结构受控地震反应的模拟仿真 ,结果表明其控制简单、灵活、方便 ,能满足这种结构的控制要求。     

树脂悬浮光度法测定微量银

在ｐＨ６．９的缓冲溶液中，银与硫代米Ｃｈｉ酮（ＴＭＫ）形成的螯合物在树脂甘油相中悬浮富集，用光度法测定银在波长４６１ｎｍ处有最大吸收，银在０～６μｇ／１０ｍＬ范围内遵守比尔定律，可用于样品中微量银的测定。