马家岩水库右岸石英砂岩中软弱夹层的试验研究

为了解马家岩水库右岸Z11,Z12,Z13岩层中软弱夹层的特性,在R1#平洞中对该软弱泥化夹层进行了现场直剪试验和室内中型直剪试验.通过分析试验成果,提出了该泥化夹层的力学设计参数,对工程设计和施工具有一定的指导意义.     

光纤测温技术在断桩检测模型试验中的应用

制作了夹泥断桩模型,采用不同功率对埋置于模型桩中光纤进行加热,连续监测了光纤温升情况,研究了桩中光纤温升规律,结果表明:模型桩中夹泥段温升明显高于正常桩段,不同功率下温差不同;研究了加热功率大小对光纤温升的影响,通过分析发现温升与加热功率具有良好线性关系.对光纤测温技术用于桩基断桩缺陷检测做了一定探讨,完善了光纤测温技术在桩基缺陷检测中的应用研究.     

高岭石有机插层复合材料的研究及应用现状

高岭石是一种层状硅酸盐矿物,有机物可进入其层间形成高岭石有机插层复合物。本文综述了高岭石有机插层复合物的发展及其制备,分析了高岭石插层复合物的插层反应特点和插层影响因素,并概述了该领域目前的研究重点和应用前景。     

钛插层蒙脱石对Zn2+的吸附研究

为了去除废水中Zn²⁺,以提纯钠化蒙脱石(Na-mt)为原料,采用溶胶凝胶法将Ti⁴⁺插层进入Na-mt层间制备钛插层蒙脱石(Ti-Imt)材料。XRD、SEM及表面积分析表明Ti-Imt的晶面间距增大到2.94 nm,具有较大的比表面积,片层之间存在着较大且形状不均匀的空隙结构。采用Ti-Imt对Zn²⁺进行吸附,升温有利于吸附; pH值为6时吸附性能最佳,吸附平衡时间为60 min,饱和吸附量为38.47 mg/g,Zn²⁺去除率达到96.18%。     

Incorporating multiscale micromechanical approach into PLSNs with different intercalated morphologies

The objective of the present study is to predict Young's modulus of polymer‐layered silicate nanocomposites (PLSNs) containing fully intercalated structures. The particular contribution of this article is to consider the changes in structural parameters of different intercalated morphologies in vicinity of each other. These parameters include aspect ratio of intercalated stacks, number of silicate layers per stack, d‐spacing between the layers, modulus of the gallery phase, and volume fraction of each intercalated morphology. To do this, the effective particle concept has been employed and combined with the Mori‐Tanaka micromechanical model. It has been shown that the simultaneous effects of d‐spacing between the silicate layers and gallery phase modulus remarkably influence the nanocomposite's modulus. Finally, the micromechanical modeling results have been compared with the experimental data and illustrates that the new approach is more accurate than the earlier model developed by the same authors. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

溪洛渡电站夹层抗剪参数(c,f)取值研究

用5种计算方法讨论了抗剪参数c,f的取值问题，对误差来源从不同角度进行了评述，使该值的选取有了更大的可比性，提高了c,f值的选取精度和可靠性，对大型和特大型水电工程来说这样做是非常必要的。     

季铵型壳聚糖插层蒙脱土的制备及对Cr(Ⅵ)吸附作用的研究

制备季铵型壳聚糖插层蒙脱土,采用红外光谱、X-射线图谱和扫描电镜分析研究表明,壳聚糖季铵盐—2-羟丙基三甲基氯化铵壳聚糖进入到了蒙脱土的层间,使层间距增大,形成了插层复合物。利用所得产品对含Cr(Ⅵ)水样进行处理,在pH为4、吸附t为100 min、吸附剂质量浓度为2 g/L和Cr(Ⅵ)初始质量浓度为50 mg/L的优化条件下,季铵型壳聚糖插层蒙脱土复合吸附剂对Cr(Ⅵ)的吸附量为5.61 mg/g,去除率为89.73%。季铵型壳聚糖插层蒙脱土复合吸附剂对Cr(Ⅵ)的吸附符合Langmuir吸附模型。     

Adsorption mechanism of fulvic acid onto freeze dried poly(hydroxo aluminum) intercalated bentonites

Two poly(hydroxo aluminum) intercalated Wyoming bentonites were prepared starting from two different aluminum pillaring solutions. The sorption mechanism of Laurentian fulvic acid (FA) onto these poly(hydroxo aluminum) intercalated bentonites was investigated at different pH values and at different ionic strengths (NaCl or CaCl₂). Three mechanisms contribute to the FA adsorption, depending on the pH and the nature (NaCl or CaCl₂) and ionic strength of the background electrolyte. In the presence of NaCl the FA sorption onto poly(hydroxo aluminum) intercalated bentonites can be mainly ascribed to ligand exchange between the amphoteric poly(hydroxo aluminum) hydroxyl groups and the deprotonated carboxylic groups of the FA. The FA adsorption due to ligand exchange reactions decreases with increasing pH. In presence of Ca²⁺ ions the FA adsorption is enhanced, compared to the presence of Na⁺, due to Ca²⁺ bridging between negatively charged groups on the FA molecules and the poly(hydroxo aluminum) intercalated bentonite. The FA adsorption due to Ca²⁺ bridging increases with increasing pH. A third mechanism is enhanced FA adsorption ascribed to FA-Ca-FA bridging and was detected from the FA adsorption in presence of Ca²⁺ at the zero point of charge of the poly(hydroxo aluminum) bentonite (pH 5).     

水滑石类热稳定剂在聚氯乙烯中的应用研究进展

聚氯乙烯(PVC)全球三大通用树脂之一,广泛应用于国名经济诸多重要领域。但是,因结构的不稳定性,其热加工成型温度远高于其热老化脱氯化氢温度,严重制约其可加工性和应用性能,因此,在其加工过程中必须加入适量的高效热稳定剂以提高其热稳定性。水滑石类(LDHs)热稳定剂作为一种二维阴离子型层状化合物,作为一类新型高效环保型热稳定剂已引起国内外科研界和产业界的广泛关注,有望逐步替代传统有毒有害如铅盐等热稳定剂。本文简要从水滑石热稳定作用机理、主体和客体层板组成及其在PVC复合材料中分散性等方面综述了国内外研究进展,以期有助于对类水滑石热稳定剂结构的可调变性和性能提升的了解。