The influence of F doping on the activity of PbO2 film electrodes in oxygen evolution reaction

The PbO₂ and F⁻-doped PbO₂ (F-PbO₂) film electrodes have been prepared by an electrodeposition process onto platinum substrate. The changes of their electrochemical activity for oxygen evolution (OE) reaction with accelerated electrolysis time have been studied. The results show that the activity of the electrodes decreases with increasing electrolysis time. This can be attributed to the conductivity variations, which are caused by the decrease of the oxygen vacancy concentration in PbO₂ films during OE. The mechanism of the decrease of the oxygen vacancies has been investigated. For F-PbO₂ film electrodes, though its electrochemical activity is somewhat lower than that of undoped one, its activity stability is much higher in comparison with that of PbO₂. The influence of F⁻ doping on the activity of PbO₂ film electrodes has been also discussed.     

改性胶粉/SBR共混胶料的结构性能研究

研究了硫黄、促进剂、改性胶粉用量对胶粉／ＳＢＲ共混胶料性能的影响。结果表明；改性胶粉用量在１０－３５份的范围内．对共混胶料的静态力学性能影响不大：在１０－２２份的范围内对动态压缩疲劳生热影响不大．适当调整基质胶中硫黄、促进剂的用量．有利于降低胶料的动态压缩疲劳生热。扫描电子能谱微区分析的研究表明：由于硫黄的迁移形成了具有特殊结构的界面过渡层．该过渡层是降低动态压缩疲劳生热的关键。     

水体中苯胺类化合物测定方法的改进

本文分别利用活性炭吸附、三氯甲烷萃取和前两种方法联用对显色剂 N-(1 -萘基 )乙二胺进行了提纯 ,从而使水体中苯胺类化合物测定方法的显色时间由 1 2 0 min(未提纯法 )缩短至 90 min(经三种方法提纯 ) ,显色剂溶液的稳定性有了明显的提高 ,测定方法的精密度得到了显著的改善 ,同时检出限也由 0 .3 0 mg/L (未提纯法 )分别降至 0 .0 48mg/L (活性炭吸附提纯法 )、0 .0 59mg/L(三氯甲烷萃取提纯法 )和 0 .0 3 1 mg/L(两种方法联用提纯法 ) ,用经三种方法提纯后的显色剂溶液测定水样中的苯胺 ,测定结果均令人满意     

Rapid pyrolysis of brown coal and oil shale

A brown coal, peat and oil shale were subjected to a rapid pyrolysis process and medium-heat-value gases together with tar were collected. The char residue was of high activity and suitable for gasification to create a two-stage gasification system. The coal-tar is used for manufacturing liquid fuels and chemicals.     

Integrated UV-based photo microreactor-distillation technology toward process intensification of continuous ultra-high-purity electronic-grade silicon tetrachloride manufacture

Ultra-high-purity silicon tetrachloride (SiCl₄) is demanded as an electronic-grade chemical to meet the stringent requirements of the rapidly developing semiconductor industry. The high requirement for ultra-high-purity SiCl₄ has created the need for a high-efficient process for reducing energy consumption as well as satisfying product quality. In this paper, a mass of production technology of ultra-high-purity SiCl₄ was successfully developed through chlorination reaction in the ultraviolet (UV)-based photo microreactor coupled with the distillation process. The influences of key operational parameters, including temperature, pressure, UV wavelength and light intensity on the product quality, especially for hydrogen-containing impurities, were quantified by the infrared transmittance of Fourier transform infrared spectroscopy (FT-IR) at 2185 cm^-1 and 2160 cm^-1 indicating that characteristic vibrational modes of Si—H bonds, as well as the operating conditions of distillation were also investigated as key factors for metal impurities removing. The advanced intensification of SiCl₄ manufactured by the integration of photo microreactor and distillation achieves the products with superior specifications higher than the standard commercial products.     

CAE软件操作小百科（23）

正1 RecurDyn如何在仿真之前检查模型的各种设置是否正确?在动力学分析之前,若要检验样机,可以先进行运动学分析,且在施加作用力之前确定各种约束是否正确.在RecurDyn中,还提供模型预分析功能,在simulation type中有预分析功能(pre analysis),检查模型自由度、是否有冗余约束及其相关信息.2 RecurDyn怎样解决有冗余约束的问题?当模型存在冗余约束时,软件在求解过程中会     

校车车身结构的有限元分析

建立某型校车的有限元模型,计算在不同工况下其车身骨架的静态强度.计算结果表明:在弯曲和扭转工况下,该校车最大应力分别为154.8和171.4 MPa,均小于Q235屈服应力235 MPa;最大变形分别为4.925和12.92 mm,满足《客车定型试验规程(GB/T 13043—2006)》中所规定的弯曲和扭转工况下10及12 mm的限额;车身结构整体应力大多集中在30 MPa左右,有较大的安全裕度.分析结果可为该校车车身骨架结构优化提供参考.     

Preparation and catalytic performance of Co3O4 catalysts for low-temperature CO oxidation

Without use of any surfactant or oxidant, a series of Co₃O₄ catalysts have been prepared from cobalt nitrate aqueous solution via a very simple liquid-precipitation method with ammonium acid carbonate followed by calcination at various temperatures. The catalytic performance of the Co₃O₄ for CO oxidation has been studied with a continuous flowing laboratory microreactor system. The results show that the CO conversion of all the samples can reach 100% at ambient temperature. The catalyst calcined at 300 °C is able to maintain its activity for CO complete oxidation more than 500 min at 25 °C and about 240 min even at −78 °C. High reaction temperature results in a high catalytic stability, while the catalytic stability decreases with further increasing the reaction temperature. Characterizations with X-ray powder diffraction and transmission electron microscopy suggest that all the samples exist as a pure Co₃O₄ phase with the spinel structure, the samples are apt to aggregate and the specific surface area gradually decreases with increasing the calcination temperature, which directly leads to the decrease of catalytic stability. Furthermore, the amount of active oxygen species measured by CO titration experiments appears to be critical for catalytic performance.     

Integrated UV-based photo microreactor-distillation technology toward process intensification of continuous ultra-high-purity electronic-grade silicon tetrachloride manufacture

Ultra-high-purity silicon tetrachloride (SiCl₄) is demanded as an electronic-grade chemical to meet the stringent requirements of the rapidly developing semiconductor industry. The high requirement for ultra-high-purity SiCl₄ has created the need for a high-efficient process for reducing energy consumption as well as satisfying product quality. In this paper, a mass of production technology of ultra-high-purity SiCl₄ was successfully developed through chlorination reaction in the ultraviolet (UV)-based photo microreactor coupled with the distillation process. The influences of key operational parameters, including temperature, pressure, UV wavelength and light intensity on the product quality, especially for hydrogen-containing impurities, were quantified by the infrared transmittance of Fourier transform infrared spectroscopy (FT-IR) at 2185 cm⁻¹ and 2160 cm⁻¹ indicating that characteristic vibrational modes of SiH bonds, as well as the operating conditions of distillation were also investigated as key factors for metal impurities removing. The advanced intensification of SiCl₄ manufactured by the integration of photo microreactor and distillation achieves the products with superior specifications higher than the standard commercial products.     

轻质油品氧化脱硫技术进展

介绍了国内外轻质油品氧化脱硫技术的研究进展情况，分析了选择性氧化脱硫、超声波氧化脱硫、光催化氧化脱硫、等离子体液相氧化脱硫等技术的优缺点，展望了氧化脱硫技术应用前景。