Designing independent water transport channels to improve water flooding in ultra-thin nanoporous film cathodes for PEMFCs

Utilization of 3D nanostructured Pt cathodes could obviously improve performances of proton exchange membrane fuel cells (PEMFCs) owing to the reduced tortuosity and the bi-continuous nanoporous structure. However, these cathodes usually suffer from the flooding problem ascribed to the ionomer-free and nanoscale pores which are more susceptible to water condensation. In this paper, ultra-thin nanoporous metal films (100 nm) were utilized to construct PEMFC cathodes and independent transport channels were designed separately for water and gas aiming at the flooding problem. Nanoporous gold (NPG) film was used as the model support for loading Pt nanoparticles owing to its controllable and stable structure. After optimizing the polytetrafluoroethylene (PTFE) content and carbon loading in the gas diffusion layer (GDL), plasma treatment under O₂ atmosphere was used to pattern the GDL with independent water transport channels. The obtained liquid permeation coefficients and oxygen gains demonstrated the obviously improved water and O₂ transport. By using a home-made optimized GDL and a nanoporous film cathode with pore size ～60 nm, the flooding problem could be facilely solved. With a Pt loading of ～16 μg cm^?2, this 3D nanostructured cathode exhibits a PEMFC performance of ～957 mW cm^?2 at 80 °C. The Pt power efficiency is about 4 times higher than that of the commercial Pt/C cathode (50 μg cm^?2, 756 mW cm^?2). Obviously, this study provides a simple but effective methodology to solve the water flooding problem in the ultra-thin nanoporous film cathodes which is applicable for other types of 3D nanostructured PEMFC cathodes.     

裸眼井中扩张式封隔器力学行为研究

封隔器在石油天然气开采中起着非常重要的作用,而扩张式封隔器在裸眼井中广泛应用。本文采用有限元软件建立了裸眼封隔器与地层的模型,对胶筒在坐封过程中与井壁接触应力的变化进行了研究,并研究了在不同摩擦系数下接触压力的变化,结果表明,建立粗糙井壁面能够更加符合实际情况,胶筒肩部为应力集中的区域,地层与胶筒的接触应力会随着摩擦系数的增加而减小。研究结果为裸眼扩张式封隔器的设计和改进提供了理论依据。     

Ag–Cu–BTC prepared by postsynthetic exchange as effective catalyst for selective oxidation of toluene to benzaldehyde

A mixed-node MOF catalyst Ag–Cu–BTC was prepared by postsynthetic exchange (PSE) method. It is believed that PSE method can realize isomorphous replacement of Ag ion to framework Cu ion in Cu–BTC successfully. The catalytic performance of Ag–Cu–BTC was investigated via selective oxidation of toluene to benzaldehyde by molecular oxygen in the absence of solvent and initiator. This catalyst exhibits good catalytic performance: on the premise of keeping highly selective catalysis of Cu–BTC for toluene oxidizing to benzaldehyde, the introduction of Ag (Ag content is 2.76 wt.%) can promote toluene conversion from 6.5% to 12.7%.     

超临界流体萃取技术生产重交通道路沥青的研究

研究了采用超临界流体萃取技术(SFEF),以减压渣油和催化裂化油浆为原料,制备重交通道路沥青产品的可行性.结果表明:当原料中油浆掺入量为10%～30%时,可以生产出牌号为AH70,AH90,AH110的重交通道路沥青产品.工业试验表明,生产牌号为AH70,AH90的重交通道路沥青,采用此技术方案是可行的.     

天然气合成油技术

综述了天然气合成气技术、气转液（GTL）技术以及天然气合成油加工精制工艺，对目前比较成熟的天然气合成油工艺技术进行了比较；介绍了天然气合成柴油、润滑油、煤油以及石脑油的优势，并简述了目前世界范围内筹建GTL厂的情况，最后对中国天然气合成油发展提出了建议。     

基于网点形状与平版印刷关系的研究

通过研究网点的作用和基本参数，以及网点形状与平版印刷的关系，对比了2种常用网点形状（正方形网点和圆形网点）的印刷特性，从而说明不同的网点形状会产生不同的复制效果。     

基于ERP供应链管理带来的石油销售公司管理变革

该文介绍了ERP系统在石油销售企业中应用的特点,阐述了ERP系统在石油销售管理中所带来的积极变化,并详细分析了石油销售企业的供应链管理流程。     

铈基SCR脱硝催化剂研究进展

近年来铈（Ce）基脱硝催化剂成为低温脱硝领域的研究热点,按载体类型可分为金属氧化物催化剂、二氧化钛载体催化剂、分子筛载体催化剂、活性炭及氧化铝载体催化剂等。按催化剂种类分别介绍了掺杂改性、制备工艺、反应条件等对催化剂性能的影响,并阐述了可能的原因机理。目前,铈基催化剂大多处于实验室阶段,工业化应用尚存在问题,尤其作为低温脱硝催化剂,活性中心堵塞问题更加突出,并且催化剂成本较高。未来可从催化剂制备工艺入手解决催化剂成型问题,以实现工业应用。同时探讨催化剂中毒机理,进一步提升其抗中毒能力。另外,寻求适宜的材料与铈掺杂组合,达到高效脱硝和经济效益最大化。     

国内动态硫化技术产业化的探讨

根据国外动态硫化技术的发地趋势，结合国内科研情况．对ＴＰＶ推广应用的可能性进行了分析，并对今后的发展提出了建议。国内ＴＰＶ的主要应用市场是轿车及电线电缆行业。顶计２０００年，轿车行业对ＴＰＥ的需求量达３２５０ｔ／ａ。国内ＥＰＤＭ／ＰＰＴＰＶ工厂成本不超过１．７万元／ｔ．售价将远低于Ｓａｎｔｏｐｒｅｎｅ。     

316L不锈钢在硫酸盐还原菌与铁氧化菌溶液中的腐蚀及电化学行为

1 INTRODUCTION Type 316L stainless steel has good corrosion re- sistance and has been used increasingly for cooling water service in the chemical, petrochemical and power utility industries. However stainless steel is susceptible to localized corrosion by chloride ions and reduced sulfur compounds[1]. The presence of micro- organisms on a metal surface often leads to highly localized damages in the concentration of the electro- lyte constituents, pH and oxygen levels[2]. These mi- croorg…