Effect of carbon surface oxidation on platinum supported carbon particles on the performance of gas diffusion electrodes for the oxygen reduction reaction

The effect of carbon surface oxidation on platinum supported carbon particles (Pt/C) with nitric acid was investigated by cyclic voltammetry, electrochemical impedance spectroscopy, polarization experiments and chronoamperometry. Cyclic voltammograms, polarization curves and electrochemical impedance spectra showed that the treated catalyst had much larger active surface area and higher ionic conductivity than the untreated catalyst, and provided enhanced performance for oxygen reduction. The formation of acidic groups was examined by IR spectra. The Pt/C surface oxidation had a large effect on the performance of a gas diffusion electrode for oxygen reduction reaction.     

Antimicrobial finishing of regular and modified polyethylene terephthalate fabrics

An effective two-stage method has been developed for imparting antimicrobial properties to regular polyethylene terephthalate (R-PET), polyethylene glycol modified polyethylene terephthalate (PEG-M-PET), R-PET/Cotton blend (R-PET/C) and PEG-M-PET/Cotton blend (PEG-M-PET/C) fabrics. The method consists of partial hydrolysis of the fabrics to create carboxylic groups in PET macromolecules followed by subsequent reaction with dimethylalkylbenzyl ammonium chloride (DMABAC) under alkaline conditions. The reaction conditions such as pH, reaction temperature and time, carboxylic content, and DMABAC concentration were studied. Characterization of the finished fabrics was carried out through scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). All the modified PET fabrics showed excellent antibacterial activity towards Gram-positive (Bacillus mycoides), Gram-negative (Escherichia coli), and nonfilamentous fungus (Candida albicans). The achieved antimicrobial functions on the PET fabrics are durable in repeated laundering processes. Even after laundering 10 times the fabrics could still provide more than 85% of its antimicrobial activity against B. mycoides, E. coli, and C. albicans. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Studies on jute–asphalt composites

The tensile properties of jute make it a suitable raw material for asphalt overlay (A/O) fabric. In this study, the thermal stability of jute under conditions of asphalt overlaying process was investigated and the compatibility of jute with asphalt was assessed through experimentation on jute–asphalt composites under mechanical and hygral loads. Fourier transform infra red (FTIR) spectroscopic study revealed probable chemical bonding between jute and asphalt. The test for ascertaining the capability of asphalt encasement for protecting jute against biodegradation under enzymatic attack was found positive. A 6‐month hygral treatment, of the jute–asphalt composite, showed significant increase in modulus of the material. The results indicate that although the strength of jute deteriorates by about 10% under asphalt overlaying condition, the overall tensile behavior of jute fabric–asphalt composite material is considerably superior to that of the pure jute fabric, even under biological and extended hygral loading conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

浅谈天然彩棉织物的质量

从生产实践出发 ,阐述了彩棉纤维物理指标对彩棉纱的性能、织物的强力、色牢度及色泽的影响。     

Characterization of supported Pd-Pt catalysts by chemical probes

The temperature programmed (palladium) hydride decomposition appeared very effective method for diagnosing the extent of alloying in Pd-Pt/SiO₂ catalysts. Introduction of Pt to Pd catalysts moves the TPHD peak gradually towards lower temperatures and the shift in hydride decomposition peak is accompanied by a decrease in the amount of released hydrogen. The catalysts prepared the direct redox method showed much better alloy homogeneity than the samples prepared by coimpregnation. The results of probing with other techniques, i.e. catalytic probing with hydrodechlorination of CCl₂F₂ and XRD, were in line with TPHD data. The catalytic probing showed the presence of synergistic effect, a clear indication of Pd-Pt mixing. XRD data of post-reaction samples showed carbon incorporation into Pd-rich phase, whereas separate Pt-rich phase did not experience any bulk carbiding.     

激光诱导H_2S催化裂解制备H_2的研究

在室温常压静态条件下研究了以Ｖ２Ｏ５／ＴｉＯ２为催化剂，紫外脉冲激光诱导Ｈ２Ｓ催化分解为Ｈ２和Ｓ的反应及其机理。考察了产氢量与激光不同照射条件之间的关系。     

SnO催化合成环烷酸乙二醇酯增塑剂的研究

介绍了用SnO非酸性催化剂催化合成环烷酸乙二醇酯增塑剂(NAEP)的方法。讨论了反应温度、醇酸摩尔比、催化剂用量和反应时间等因素对酯化反应的影响,给出了适宜的工艺条件。 NAEP应用于PVC电缆料及丁腈橡胶配方中取得了良好的效果。与邻苯二甲酸酯增塑剂相比,具有更好的经济价值。     

Ammoxidation of methylaromatics over vanadium phosphate catalysts II. Catalyst formation, active sites and reaction mechanism

The interactions of VOHPO₄· 0.5H₂O and (VO)₂P₂O₇ with the ammoxidation feed and the single components such as ammonia, oxygen, water and component mixtures were studied in detail using XRD and temperature-programmed reaction spectroscopy. The aim of this work was to improve the knowledge of the formation of the active phases or active sites of the catalysts from their precursors under the condition of the ammoxidation reaction. Similar catalytic properties of various applied VPO materials were discussed in terms of the presence of similar structure elements (domains of adjacent edge-sharing VO₆ octahedra-units and P-O-NH₄ groups).     

HDPE装置超负荷低能耗生产方案的设计与实施

本文介绍大庆ＨＤＰＥ装置提高生产能力及产品质量的方法。通过采用釜外络合催化剂新技术和提浆液浓度可将ＨＤＰＥ装置聚合釜单釜的生产能力由４．７５ｔ／ｈ提高到５．０ｔ／ｈ，各项能耗下降，收到了增产降耗的显著效果，并使产品质量，产量，品种，能耗，物耗，环保６项指标全部达到了设计要求。     

上向分层尾砂充填法在仓上金矿的新应用

本文介绍了垂直矿体走向布置的上向分层尾砂充填采矿法新方案的特点及其在仓上金矿中厚矿体的具体应用。