Study on stability of self-breathing DFMC with EIS method and three-electrode system

In this paper, direct methanol fuel cell's (DMFC's) electrochemical process was successfully investigated in situ using Electrochemical Impedance Spectroscopy (EIS) method. Under three-electrode system, anode and cathode's polarization overpotential, charge transferring resistance and active surface were independently measured in order to reveal the degradation factors after 50 h stability testing. The results showed that Ru's dispersing, membrane's swelling and water flooding were main reasons resulting in performance decline. And SEM images confirmed these conclusions. Moreover, cathode's degradation was less serious than anode and it could be recovered. Traditional equivalent circuit model of self-breathing DMFC was modified according to a fact that the dielectric relaxation phenomenon of porous electrode occurred at cathode rather than anode.     

柱前衍生高效液相色谱法测定饮料中4-甲基咪唑的含量

建立了丹磺酰氯柱前衍生高效液相色谱法测定饮料中4-甲基咪唑含量的方法。以C_(18)柱为色谱柱,乙腈和0.02 mol/L的乙酸铵水溶液为流动相,梯度洗脱,荧光检测器检测。该方法快速、准确,在0.05～1.0 mg/ L范围内线性相关系数为r~2=0.998 5,平均回收率达到71.6%～88.7%,相对标准偏差为3.6%～5.5%。方法的最低检测浓度为10.0μg/L。     

在煤矿应用中的SVC控制原理与参数选择

大型煤矿在供电方式中采用了很多不同类型的变流装置和大量变载负荷,导致输配电网无功缺乏和大量的谐波注入电网.采用了SVC(TCR+FC)的静止型无功补偿和滤波装置.介绍了SVC组成原理、相关参数的选择和依据,并在潞安新疆煤化工(集团)有限公司二矿得到了实践.     

The physical–chemical properties and electrocatalytic performance of iridium oxide in oxygen evolution

An IrO₂ anode catalyst was prepared by using the Adams method for the application of a solid polymer electrolyte (SPE) water electrolyzer. The effect of calcination temperature on the physical–chemical properties and the electrochemical performance of IrO₂ were examined to obtain a low loading and a high catalytic activity of oxygen evolution at the electrode. The physical–chemical properties were studied via thermogravimetry–differential scanning calorimetry (TG–DSC), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrochemical activity was investigated by using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and chronopotentiometry in 0.1 mol L⁻¹ H₂SO₄ at room temperature. The optimum condition was found to be at the calcination temperature of 500 °C, where the total polarization reached a minimum at high current densities (>200 mA cm⁻²). The optimized catalyst was also applied to a membrane electrode assembly (MEA) and stationary current–potential relationships were investigated. With an optimized catalytic IrO₂ loading of 1.5 mg cm⁻² and a 40% Pt/C loading of 0.5 mg cm⁻², the terminal applied potential difference was 1.72 V at 2 A cm⁻² and 80 °C in a SPE water electrolysis cell.     

某厂670t/h锅炉燃烧调整试验研究

针对锅炉严重结焦、过热汽温超温等使机组被迫维持低负荷运行的问题,通过燃烧优化调整试验,结焦和超温问题得到有效缓解,锅炉可长期维持高负荷运行。     

火焰原子吸收法测定指甲中锌的含量

采用火焰原子吸收法测定人指甲中锌的含量．方法简单、可靠、准确度较高,在医学检测方面有较重要的实用价值.     

利用铬渣制备铬酸铅的研究

利用铬盐生产中的含铬废渣制备出了铬酸铅,并副产浅绿色颜料.全部铬渣均转变为有用的产品,制备过程中无废渣排放.制备方法是对铬渣在95*!℃下用水浸取溶解可溶性铬盐,然后用15% NaOH溶液调pH值至13,再用双氧水将Cr(Ⅲ)氧化为Cr(Ⅵ),加入PbAc溶液,沉淀生成PbCrO4.确定了最佳工艺条件,详细讨论了各种因素对制备铬酸铅的影响.     

Cerium Oxide Film Prepared from Molten Salts

Cerium oxide film is used in many fields,such as corrosion and protection, cell, high-temperature condition, superconductor, catalyst,electronic equipmeflt and meter indication. Nonaqueous oxide film is needed under many actualsituations. Oxide film prepared by electrochemical deposition in aqueous solution, however, isat least partly hydrated. Though dehydration canbe realized by heat tramment, the quality of thefilm will be apparently abased because of the afresh arrangement of atom/molecula…     

基于一二维耦合模型的洪水风险区划研究

萍水河湘东段区域受洪水灾害影响较大,历年损失严重。本文使用MIKE FLOOD 构建了萍水河湘东段区域洪水演进一二维耦合模型,结合2019 年实测水位过程和调查洪痕等资料验证了模型合理性。根据研究区设防情况,确定了20年、50 年和100 年一遇3 种设计洪水计算方案,并分别提取了3 种计算方案下的洪水风险特征要素（包括最大淹没水深、最大演进流速和淹没历时等）,使用综合风险度法开展了萍水河湘东段区域洪水风险区划研究。结果表明：萍水河湘东段区域洪水风险区划分为极高、高、中和低风险4 个等级;其中,中下游无堤防保护区域洪水风险等级为极高或高风险;湘东区县城区域洪水风险等级主要为高风险和中风险,县政府驻地区域属于洪水灾害高风险等级区。本文洪水风险区划成果可为湘东区防洪规划及非工程措施建设提供科学依据。     

钢铁行业烟气多污染物协同控制技术应用实践

本研究分析了钢铁企业焦化和烧结两个重点工序中烟气污染物排放现状和钢铁行业当前的环保政策。对焦化及烧结烟气污染物的排放特征进行了分析,并通过对比燃煤电厂烟气特点,提出可以综合电厂烟气治理模式和自身特点改进的技术路线。结合某大型国有钢铁企业的脱硫脱硝装备对其环保现状进行了分析。针对焦化和烧结工序的典型污染物硫、硝、尘现有的源头减排、过程控制及末端处理技术,分析其优缺点。进而提出了3条可实现烟气污染物超低排放的技术路线,即半干法脱硫耦合选择性催化还原脱硝、半干法/湿法耦合臭氧氧化脱硝、活性焦脱硫脱硝一体化技术,重点介绍了这些技术在某大型钢铁企业的应用实践及应用效果。并基于全过程耦合技术,分别在焦化和烧结工序中提出了多污染物协同去除技术及应用,即焦炉低氮燃烧技术耦合末端活性焦多污染物协同控制技术、烧结烟气循环技术耦合末端活性焦多污染物协同控制技术。最后结合几种技术路线的应用实践,对未来钢铁产业的烧结及焦化工序超低排放技术的选择提出合理化建议。