改性膨润土防渗浆材的性能研究

以聚乙烯醇为改性剂制得有机化膨润土,并与水泥、粉煤灰及辅助添加剂组成防渗浆材,通过正交试验法,分析了浆材固结体的渗透性、吸附阻滞性和耐久性。结果表明,以改性膨润土代替天然膨润土获得的浆材具有更低的渗透系数、更好的吸附阻滞性及耐腐蚀性,完全满足抗渗要求。     

Theoretical and experimental studies on low-temperature adsorption drying of fresh ginger

The working principle of low-temperature adsorption drying and the advantages of its application for biological materials drying were introduced in this paper. By using fresh ginger as the drying material, the effects of temperature and relative humidity on its drying characteristics were examined. The results show that the drying rate increases with the temperature increasing or the humidity decreasing. The drying time to the equilibrium is almost the same under different humidity conditions, but low equilibrium moisture content can be acquired under low humidity. The shrinkage characteristics of fresh ginger were also studied. The change of its surface appearance during the drying process was characterized by the new Charged Coupled Device (CCD) and the Environmental Scanning Electron Microscopy (ESEM) technique. A mathematical model of drying dynamics was set up according to the experiments.     

黑河金盆水利枢纽引水系统水力设计

黑河水库为西安市城市供水的水源地,在满足城市供水为主的任务要求外,兼顾灌溉、发电等任务。同时又与石头河供水渠道汇流,满足西安市的用水需求,因此引水系统较为繁杂。通过对引水系统水工模型试验时存在的问题的妥善解决,并采取一定的工程措施,取得了较好的运用效果。     

Comparative Performance of Different Sector Arrangement in a Desiccant Wheel Using a Mathematical Model

A one‐dimensional mathematical model has been used for a three‐sector desiccant wheel (two sectors with purge) with different flow arrangements. The model considers both gas and solid side resistance and shows a good agreement with experimental results. This model has been used to conduct a comparative performance analysis in both the effective adsorption and effective regeneration sector of a desiccant wheel. It was found that an effective regeneration sector gives better results for the performance parameters (rotation of wheel, regeneration temperature, velocity, and ambient moisture) as compared to an effective adsorption sector. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.21103     

太阳能吸附式空气取水器的技术方案及其理论和实验研究

报道了一种太阳能吸附式空气取水器的技术方案，对其进行了原理分析和实验验证。     

Flux pattern and fouling of membranes during ultrafiltration of some dairy products

The flux pattern of milk (whole milk, skimmed milk and buttermilk) showed a distinct contrast to whey (sweet whey and acid casein whey) systems during ultrafiltration (UF) at constant composition. For milk systems, the initial flux was lower than for whey systems, but the flux stabilised within a few minutes of operation. However, for both acid and sweet whey, the flux continued to fall with time for nearly 1 h. The fouling coefficient (FC) for buttermilk was 0.6 after 5 min, rising to 0.68 after 60 min. During this time flux did not decline, suggesting that concentration polarisation (CP), rather than fouling, was controlling the flux rate. In contrast, the FC for whey was 0.5 after 5 min with a progressive rise over the next 55 min, but the flux also fell throughout this period suggesting that flux was controlled by fouling rather than CP. The higher concentration of protein in milk systems appeared to be responsible for CP, rather than fouling, being the controlling mechanism.     

Time-dependent competitive adsorption of milk proteins and surfactants in oil-in-water emulsions

Competitive adsorption of pure milk proteins and non-ionic surfactants has been studied in model oil-in-water emulsions (4 g kg^?1 β-lactoglobulin or β-casein, 200 g kg^?1 n-hexadecane) as a function of the age of the adsorbed protein layer at the oil-water interface. With β-lactoglobulin-stabilised emulsions containing oil-soluble surfactant C₁₂ E₂ (diethylene glycol n-dodecyl ether), there is found to be a steadily increasing amount of protein associated with the emulsion droplets over a few hours following emulsification. Addition of water-soluble surfactant Tween 20 (polyoxyethylene (20) sorbitan monolaurate) to a β-lactoglobulin-stabilised emulsion (with or without C₁₂E₂) leads to less protein displacement if the emulsion is aged prior to addition of Tween 20. Moderate additions of C₁₂E₂ or Tween 20 produce no time dependence in the competitive adsorption in β-casein-stabilised emulsions, although some time dependence is observed when C₁₂E₂ and a high concentration of Tween 20 are present together. Crystallisation of the oil phase in β-casein-stabilised emulsions at pH 7 leads to a lowering of the measured protein surface concentration, especially in the presence of C₁₂E₂ and a reduction in the surfactant to protein molar ratio required for complete protein displacement by water-soluble surfactant (Tween 20 or octaethylene glycol n-dodecyl ether). Under more acidic conditions of pH 5 or pH 3, the surface coverage and ease of displacement of β-lactoglobulin at the surface of liquid emulsion droplets is substantially different from that under neutral pH conditions.     

漂白麦草浆细杂组份对阳离子淀粉吸附的影响

本文研究了漂白麦草浆中细杂组份(通过100目,其中大部分是杂细胞,如薄壁细胞,表皮细胞)对阳离子淀粉吸附的影响。 实验表明,漂白麦草浆中细杂组份的比表面积明显大于纤维组份(保留在100目以上)的比表面积。阳离子淀粉优先吸附在比表面积大的细杂组份上。纤维组份的吸附能力受化学环境的影响较细杂组份更为敏感。     

分形理论在煤储层物性研究中的应用

基于分形理论在地质问题研究中的标度不变性 ,利用煤层的自然粒级组成和压汞法测出的煤中不同孔径段的比孔密资料。进行了煤岩破碎结构的块度分形和孔隙结构分形 ,并就分形特征在构造煤破碎程度的划分中的意义及其对煤层气开发的影响进行了探讨。尤其指出了煤层孔隙结构分形存在两个“无标度区” ,孔径大于 10 -10 m的分数维 (D1) ,可用于评价煤层气的解吸和运移 ,小于 10 -10 m的分数维 (D2 )可用于评价煤层气的吸附与扩散。     

高压喷射注浆法产生的超孔隙水压分析

介绍了高压喷射注浆法的作用机理 ,探讨了在施工过程中高压喷射注浆法引起的超孔隙水压。根据半无限土体中小孔扩张问题的解 ,分析了在超孔隙水压作用的瞬时 ,土体中的应力、变形等 ,并提出了经验公式。结合一具体工程事故的成功处理 ,验证了所建议超孔隙水压公式的可行性 ,同时提出了减少超孔隙水压的对策和方法。