In situ adsorption-catalysis system for the removal of o-xylene over an activated carbon supported Pd catalyst

An activated carbon (AC) supported Pd catalyst was used to develop a highly efficient in situ adsorption-catalysis system for the removal of low concentrations of o-xylene. In this study, three kinds of Pd/AC catalysts were prepared and tested to investigate the synergistic efficiency between adsorption and catalysis for o-xylene removal. The Pd/AC catalyst was first used as an adsorbent to concentrate dilute o-xylene at low temperature. After saturated adsorption, the adsorbed o-xylene was oxidized to CO2 and H2O by raising the temperature of the catalyst bed. The results showed that more than 99% of the adsorbed o-xylene was completely oxidized to CO2 over a 5% Pd/AC catalyst at 140℃. Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), temperature-programmed desorption (TPD), and temperature-programmed oxidation (TPO) were applied to investigate the physical properties of o-xylene adsorption-desorption and the in situ adsorption-catalysis activity of the AC support and Pd/AC catalyst. A synergistic relationship between the AC support and the active Pd species for the removal of low concentrations of o-xylene was established.     

低合金钢实海腐蚀电化学阻抗谱研究

采用交流阻抗,结合线性极化,研究低合金钢实海全浸初期电化学阻抗谱行为。结果表明,低合金钢实海腐蚀最初1周是腐蚀最剧烈阶段;低合金钢实海腐蚀分为2个阶段,浸泡的第1周为第1阶段,阻抗值迅速减小,采用等效电路Rs（Cdl,Rt）拟合;浸泡1周之后,阻抗值变化缓慢,且呈现波动趋势,采用等效电路Rs（Cf（Rf（Cdl,Rt）））拟合。     

Some 2D–3D aspects of shielding of longitudinal sources of extremely low frequency magnetic fields

Typical sources of extremely low frequency magnetic fields include components of the power network and, as an extension, AC railway powering. The majority of these sources have longitudinal shapes. There is sometimes the need to reduce these fields in specific areas of interest. In this article, practical aspects are studied of shielding design when this type of source is involved. The focus is on design features not often treated in the shielding literature. One aspect relates to the differences between 2D and 3D simulations and experimental validation for a relatively long system of conductor and shield; as an example, the screening of the magnetic field of a railway system is presented. Another aspect relates to issues that arise when edge effects become relevant for actual systems. It is established that shielding factors are considerably improved when shielding of the edges is properly taken into account. The presence of gaps or loose contacts that are often responsible for low shielding efficiency is also studied. Experimental tests show that overlapping shields or the use of conductive patches significantly improves shielding efficiency. A last aspect is related to cost-effectiveness of shielding designs; in this case, numerical computations are used for benchmarking shielding properties for long busbars in secondary substations.     

环境友好缓蚀剂聚天冬氨酸在自来水中对碳钢的缓蚀性能研究

通过电化学极化测试与交流阻抗实验,研究了聚天冬氨酸(PASP)在自来水中对碳钢的缓蚀性能.结果表明:在20℃时,随着PASP浓度的增大,其缓蚀性能增强;PASP是以抑制阳极腐蚀为主的缓蚀剂.缓蚀率随PASP浓度的增加而迅速增加,当PASP(单一组分)质量浓度达到1.0g/L时,缓蚀率增加趋缓,当PASP质量浓度达到5.0g/L时,缓蚀率达到93.1％.PASP在碳钢表面的吸附基本服从Freundlich吸附等温式.     

负载型纳米铁吸附剂去除饮用水中As(Ⅴ)的研究

以活性炭为载体制备了一种负载型纳米铁吸附剂.纳米铁在活性炭孔内为针状,其直径为30～500 nm,长度为1 000～3 000 nm,载入量[m(Fe)/m(炭)]为82.1 mg/g.用1.5 g/L该吸附剂对pH 6.5、 (25±2)℃、 2 mg/L的As(Ⅴ)进行吸附其去除率为99.5%,在平衡浓度1.0 mg/L时,该吸附剂对As(Ⅴ)的吸附容量为15.4 mg/g;吸附速度较快,12 h可达91.4%,72 h达到吸附平衡.吸附过程可由孔内扩散模型较好地说明.除PO_4~(3-)、SiO_4~(2-)外其它常见阴阳离子均对As(Ⅴ)的去除影响不大.吸附剂可以用0.1 mol/L NaOH溶液再生,再生效率较高.实验室初步实验数据表明,该吸附剂对饮用水砷去除具有较好的应用前景.     

油罐常用环氧煤沥青涂层的防护寿命研究

利用电化学阻抗谱（EIS）测试技术,研究储油罐起防护作用的环氧煤沥青涂层逐渐被破坏后的阻抗变化规律。结果表明,涂层上孔洞面积增大到一定程度时,10mHz频率处10^3Ω数量级的总阻抗值是判定环氧煤沥青涂层防护性能失效的量值。     

活性碳纤维的应用

本文在比较活性碳纤维与活性碳的结构和吸附特点的基础上,综述了这种吸附材料在废水处理,饮用水净化,空气净化,溶剂回收等各个领域的应用。     

Electrochemical Detection of Pathogen Infection Using Cell Chip

The immobilized cell using self-assembled synthetic oligopeptide was applied to the electrochemical detection of pathogen infection. Thin films based on cysteine-terminated synthetic oligopeptides were fabricated for the immobilization of HeLa cell on gold (Au) substrate. Layer formation and immobilization of the cell were investigated with surface plasmon resonance (SPR) and electrochemical impedance spectroscopy (EIS). Experimental results showed that the thin film of cysteine-terminated synthetic oligopeptide was successfully fabricated and it could be applied for the immobilization of HeLa cells. The adhered living cell was exposed to E. coli O157:H7, which induced the change of SPR angle and electrochemical impedance signal. The proposed cell immobilization method using self-assembly technique can be applied to construct the cell microarray for on-site pathogen monitoring.     

1000 kV交流输电线路噪声的计算模式和减缓措施

介绍了几家国内外研究机构建立的用来计算预测输电线路电晕可听噪声的模式,针对皖电东送淮南至上海1000 kV特高压交流示范工程输电线路的实际参数,建立了相应的计算公式,可以较为准确的预测该类型输电线路可听噪声的大小;交流输电线路电晕产生可听噪声的影响因素众多,根据是否可控将这些因素分为两大类,并分析了单个因素对可听噪声预测值的影响程度,针对输电电路导线参数、杆塔型式和附加材料三个方面的内容,提出了几类切实可行的输电线路可听噪声减缓措施,为后续1000 kV交流输电线路的设计和建设提供参考。     

钛合金表面微弧氧化涂层在模拟海洋环境下摩擦腐蚀规律研究

目的 研究TC17钛合金及其表面微弧氧化(Microarc Oxidation,MAO)涂层在模拟海洋大气环境下发生摩擦腐蚀行为的规律及特征.方法 利用微弧氧化技术,在TC17钛合金表面原位生长MAO涂层,通过SEM、EDS以及XRD对MAO涂层微观结构、元素分布以及相组成进行检测分析.采用电化学工作站和摩擦腐蚀设备研...