水利工程施工过程中的现场签证

现场签证作为工程管理的一种辅助手段，其产生并得以广泛运用有其必然性，并且在工程管理中发挥了重要作用。但由于到目前为止还没有统一的定义和格式，再加上参与各方对现场签证的重视程度不同、参与各方人员素质不一，所以目前现场签证在具体操作过程中还存在诸多问题。本文主要就现场签证现状、现场签证应遵循的原则、提高现场签证质量的措施等方面谈谈自己的一点观点和看法，希望能起到抛砖引玉的作用。     

由三面投影图生成三维立体图的方法研究

针对创新设计中零部件的三维虚拟造型问题，提出了一种由二维投影图生成三维立体图的计算机化辨识方法。通过辨识简单三维立体的形状和空间位置，克服了二维图形中面的积聚性和零件之间不规则相贯和截交曲线的识别问题，进而实现了复杂组合形体的计算机化设计与造型。最后，以箱体类零件为例，在AutoCAD环境下利用VC 和ObiectARX开发工具编程验证了该方法的有效性。     

用添加剂改善柴油的颜色稳定性

利用实验室筛选出的一种柴油安定性改进剂改善柴油的颜色稳定性。贮存实验表明：成品柴油(催化裂化柴油组分占30％)中加入该剂300～400μg/g，可改善比色0．5-1．5个号，同时可抑制柴油氧化沉渣的生成，改善柴油的氧化安定性和颜色稳定性。     

添加剂强化重油催化裂化的过程分析与应用

运用工程化学原理分析讨论了添加剂强化重油催化裂化的过程，包括分散稳定气泡、改善雾化、保护酸中心、抑制焦炭生成以及提高重油气化率的胶体结构改性、降低表面张力和改善微孔润湿，并用以指导强化重油催化裂化添加剂的筛选。建立小型固定流化床催化裂化实验装置评价了添加剂的强化效果。结果表明，添加剂强化重油催化裂化可降低催化剂生焦1．0％左右，提高总液体收率1．0％～2．8％。     

N,N′-二(β-十八酰氧基)乙基乙二胺二乙酸钠的合成及性能研究

用 N,N′-二羟乙基乙二胺、氯乙酸钠合成了 N,N′-二羟乙基乙二胺二乙酸钠(中间体),中间体再与硬脂酰氯反应制备了一种新型 Gemini 两性表面活性剂 N,N′-二(β-十八酰氧基)乙基乙二胺二乙酸钠。对产物合成条件进行了考察,优化的反应条件为:n(硬脂酰氯):n(中间体)=2.5,溶剂 V(水):V(氯仿)=1:2,pH=9.0～10.0,反应温度15～20℃,反应时间5 h。通过红外光谱和质谱分析确定了产物结构,并测试了产物的表面性能。结果表明,在25℃时,该产物的临界胶束浓度为0.24 mmol/L,临界胶束浓度下的表面张力为35.7 mN/m;即时泡沫高度为250 mm,5 min 后泡沫高度为220 mm;乳化时间为22.48 min(甲苯-水物系)和4.65 min(正己烷-水物系),亲水-亲油平衡值为5.4,等电点为 pH 3.3～6.5。     

国家粮储库屋面防水APP卷材施工技术

针对国家粮食储备库的特点，就屋面防水APP卷材热熔法施工的施工准备及工艺流程进行了介绍，提出了具体的施工技术要点及质量通病的防治措施，取得了良好的施工效果。     

Synthesis and characterization of a novel proton‐exchange membrane for fuel cells operating at high temperatures and low humidities

The synthesis of a p‐toluidine/formaldehyde (PTF) resin was performed, and the effects of the molar ratio of the individual monomers and the polymerization conditions on the structure of the PTF resin were studied. Fourier transform infrared and ¹³C‐NMR spectra were used to characterize the PTF. Wide‐angle X‐ray diffraction patterns revealed the crystalline structures of various PTFs. Polarized optical microscopy revealed that the molar ratio of the monomers had a strong effect on the crystalline morphologies. A longer polymerization time turned out a polymer with a higher intrinsic viscosity and molecular weight, which led to differences in the proton conductivity. All of the PTFs showed a higher proton conductivity than a commercial Nafion membrane at 90–100°C and 0% relative humidity. The proton conductivity of the PTF series could be improved by sulfonation with sulfuric acid and could be maintained after blending with polyurethane. Pure methanol could be used as a fuel source because of the insolubility and nonwetting properties of PTF in methanol to increase the output current density for a PTF membrane electrode assembly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Preparation and adsorption behavior of a cellulose‐based,mixed‐mode adsorbent with a benzylamine ligand for expanded bed applications

A novel mixed‐mode expanded bed adsorbent with anion‐exchange properties was explored with benzylamine as the functional ligand. The cellulose composite matrix, densified with stainless steel powder, was prepared with the method of water‐in‐oil suspension thermal regeneration. High activation levels of the cellulose matrix were obtained with allyl bromide because of the relative inertness of the allyl group under the conditions of the activation reaction. After the formation of the bromohydrin with N‐bromosuccinimide and coupling with benzylamine, the activated matrix was derived to function as a mixed‐mode adsorbent containing both hydrophobic and ionic groups. The protein adsorption capacity was investigated with bovine serum albumin as a model protein. The results indicated that the prepared adsorbent could bind bovine serum albumin with a high adsorption capacity, and it showed salt tolerance. Effective desorption was achieved by a pH adjustment across the isoelectric point of the protein. The interactions between the cell and adsorbent were studied, and the bioadhesion was shielded by the adjustment of the salt concentration above 0.1M. Stable fluidization in the expanded bed was obtained even in a 2% (dry weight) yeast suspension. The direct capture of target proteins from a biomass‐containing feedstock without extra dilution steps could be expected with the mixed‐mode adsorbent prepared in this work, and this would be especially appropriate for expanded bed adsorption applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008