Direct methanol fuel cell bubble removal mechanism using magnetic actuation

This article develops a direct methanol fuel cell (DMFC) with a magnet-actuated bubble removal mechanism. A micro-DC motor is used to control the bubble removal mechanism. The lower magnetic device is operated to extrude a Polydimethylsiloxane (PDMS) runner to compress the liquid fuel in the anode flow channel, forcing the CO₂ bubbles in the runner to flow toward the outlet end. The bubble retention in the anode flow channel is thereby improved, enhancing the cell performance. The proposed mechanism stability and performance and Polymethylmethacrylate (PMMA) runner are also discussed.     

微生物絮凝剂M-C11处理高岭土悬浊液的响应曲面优化

采用响应曲面法对微生物絮凝剂M-C11处理高岭土悬浊液的过程参数进行优化,选取中心复合实验设计(CCD),以p H、M-C11投加量和Ca Cl2投加量等因素为自变量,以处理后的高岭土悬浊液絮凝率(Fr)为响应值,并借助扫描电镜对絮凝剂的作用机理进行初步探讨。结果表明,微生物絮凝剂M-C11可显著改善高岭土悬浊液的絮凝性能,且选取的3种单因素水平均可影响絮凝剂活性。经多元回归拟合分析,在M-C11投加量为2.56 m L,Ca Cl2投加量为0.37 g/L的最优条件下,微生物絮凝活性实验值可达92.37%,接近模型预测值(92.30%)。Ca Cl2投加量对絮凝效果的影响高于M-C11投加量(PCa Cl2相似文献   

煤炭企业发展低碳经济的动力机制

将影响煤炭企业发展低碳经济的动力因素分为四大类,包括4个拉力因素、1个支撑因素、2个压力因素和4个推动力因素。设计了煤炭企业发展低碳经济的动力机制模型,在分析各个动力因素的基础上,构建了煤炭企业发展低碳经济的拉力机制模型、支撑机制模型、压力机制模型和推动力机制模型。     

城市旅游综合体发展模式与对策研究

旅游综合体顺应了世界休闲业发展的潮流,它以旅游为主导,是一种全新的生产力形态。界定了城市旅游综合体的基本概念,归纳了城市旅游综合体的主要特征,探讨了城市旅游综合体形成的机制,认为旅游消费转型发展、地方特色文化传承、城市商业发展、旅游供给能力升级、政府的城市发展政策支持是城市旅游综合体形成的主要因素。依据城市旅游综合体发展的核心驱动功能不同,将城市旅游综合体的开发模式分为娱乐旅游综合体、休闲度假游综合体、会展旅游综合体和商业旅游综合体4种类型,在此基础上,提出了促进城市旅游综合体健康持续发展的对策。     

充分利用环保倒逼机制促进产业结构调整升级

淄博市污染聚集,环境质量易受外来因素影响,产业结构不合理,污染物排放量大,排放强度高。但其充分发挥环保的倒逼作用,通过建立健全环保政策法规体系,严格执行高于省及国家标准的地方环保标准,大力发展高新技术和现代服务业,加快改造传统产业,极大地促进了产业结构升级和经济发展方式的转变。     

Photocatalytic oxidation of monuron in the suspension of WO3 under the irradiation of UV-visible light

A comprehensive study of the degradation of monuron, one of the phenylurea herbicides, was conducted by UV-Vis/WO₃ process. It was found that hydroxyl radicals played a major role in the decay of monuron while other radicals (e.g. superoxide) and hole might also contribute to the decomposition of monuron. The oxidation path likely plays a major role in the generation of hydroxyl radicals. The effects of initial pH level, initial concentration of monuron, and inorganic oxidants on the performance of UV-Vis/WO₃ process were also investigated and optimized. Comparison between monuron decay pathways by UV-Vis/WO₃ and UV/TiO₂ was conducted. The decay mechanisms, including N-terminus demethylation, dechlorination and direct hydroxylation on benzene ring, were observed to be involved in the oxidation of monuron in these two processes. Sixteen intermediates were identified during the photodegradation of monuron and degradation pathways were proposed accordingly.     

Catalytic destruction of pentachlorobenzene in simulated flue gas by a V2O5-WO3/TiO2 catalyst

Pentachlorobenzene (PeCB) in simulated flue gas was destructed by a commercial V₂O₅-WO₃/TiO₂ catalyst in this study. The effects of reaction temperature, oxygen concentration, space velocity and some co-existing pollutants on PeCB conversion were investigated. Furthermore, a possible mechanism for the oxidation of PeCB over the vanadium oxide on the catalysts was proposed. Results show that the increase of gas hourly space velocity (GHSV) and the decrease of operating temperature both resulted in the decrease of PeCB removal over the catalyst, while the effect of the oxygen content in the range of 5-20% (v/v) on PeCB conversion was negligible. PeCB decomposition could be obviously affected by the denitration reactions under the conditions because of the positive effect of NO but negative effect of NH₃. The introduction of SO₂ caused the catalyst poisoning, probably due to the sulfur-containing species formed and deposited on the catalyst surface. The PeCB molecules were first adsorbed on the catalyst surface, and then oxidized into the non-aromatic acyclic intermediates, low chlorinated aromatics and maleic anhydride.     

The OH-induced degradation mechanism of 4-chloro-2-methylphenoxyacetic acid (MCPA) with two forms in the water: a DFT comparison

The initial degradation mechanisms of OH and 4-chloro-2-methylphenoxyacetic acid (MCPA) including molecular form and anionic form are studied at the MPWB1K/6-311+G(3df, 2p)//MPWB1K/6-31+G(d, p) level. Possible reaction pathways of H-atom abstraction and OH addition are considered in detail. By result comparison analysis, it is found that the reaction mechanisms for OH and two forms of MCPA are different, and most reactions for anionic MCPA are easier than those for molecular MCPA. For H-atom abstraction reactions, the calculated energies show that OH abstracting H-atom from -CH₃ group of molecular MCPA is the most kinetically favorable process; the potential energy surface for anionic MCPA indicates that H-atom in -CH₂ group is slightly easier to be abstracted than that in -CH₃ group. For OH addition reactions, the addition of OH to the C1 site is the initial step for molecular MCPA and the predominant product is 4-chloro-2-methylphenol (denoted P3), while the C4 site is the most reactive site for anionic MCPA and the primary product results from the hydroxylation of the aromatic ring, which is in good agreement with the experimental observation. In additional, results from PCM calculations show that most reactions in water phase are more kinetically favorable than those in gas phase, though the mechanisms discussed above will not be changed.     

磁性海泡石吸附Cr(VI)特性及动力学

采用化学共沉淀法合成磁性海泡石,通过静态吸附实验研究磁性海泡石对Cr(Ⅵ)的吸附特性及其动力学。结果表明,磁性海泡石对Cr(Ⅵ)的吸附在90 min内即可达到平衡;体系的初始pH是影响磁性海泡石吸附Cr(Ⅵ)性能的重要因素;当废水中Cr(Ⅵ)的初始浓度为50 mg/L时,磁性海泡石的适宜投加量为10 g/L;随反应温度的升高,磁性海泡石对Cr(Ⅵ)的吸附量增加;温度为25、35和45℃时,磁性海泡石对Cr(Ⅵ)的饱和吸附量分别为3.32、3.72、4.08 mg/g;吸附动力学曲线可以用拟二级反应动力学模型拟合;内扩散和液膜扩散联合控制Cr(Ⅵ)在磁性海泡石上的吸附过程,其中内扩散的控速作用大于液膜扩散。     

清洁发展机制在石油行业的潜力分析

系统分析了石油行业清洁发展机制项目的潜力,并提出了建议。在统计与石油行业相关的清洁发展机制方法学及其注册项目和温室气体减排量的基础上,给出了各方法学与石油行业的相关性。从勘探与生产、天然气与管道、炼油与化工三大领域,分析了石油行业潜在的清洁发展机制项目领域。最后,提出了对石油行业开展清洁发展机制相关工作的建议。