Effect of transition layer on the performance of hydroxyapatite/titanium nitride coating developed on Ti-6Al-4V alloy by magnetron sputtering

A gradient transition multilayer hydroxyapatite/titanium nitride (HA/TiN) coating was prepared on the Ti-6Al-4V alloy by magnetron sputtering. The composition, surface topography, microstructure, adhesion strength and electrochemical properties of the as-deposited coatings were characterized by SEM/EDS, AFM, XRD, FT-IR and electrochemical workstation. The experimental results showed that the single TiN coating deposited at a partial pressure of nitrogen (N₂) of 0.08?Pa had the best internal stress and tribological performance, and its volume loss was only 0.89% of that of Ti-6Al-4V alloy. The introduction of the TiN transition layer greatly improved the wear resistance of the Ti-6Al-4V alloy, and the adhesion strength of the HA layer to the substrate increased from 6.50?±?0.5?N to 11.70?±?1.2?N, an increase of 56%. The HA/TiN coating surface consisted of uniform hemispherical particles with dense structure and invisible defects (micro-cracks and pores). For the HA surface layer, the crystal structure and active hydroxyl (-OH) group was restored after heat treatment. Potentiodynamic polarization experiments indicated that the HA/TiN coating achieved the lowest corrosion current density and the most positive corrosion potential compared to the single TiN layer and Ti-6Al-4V alloy. In summary, it can be conclude that the gradient transition layer can well improve the mechanical properties and electrochemical behavior of the titanium alloy, and largely ensuring the stability of the surface bioactive coating.     

珠江口盆地陆丰13东洼新生代构造演化与油气成藏特征

陆丰13东洼是珠江口盆地油气勘探的重点区域。结合区域构造背景,在精细解释高品质三维地震资料的基础上,对陆丰13东洼的洼陷结构和构造特征进行综合分析,并运用平衡剖面技术对洼陷的构造演化进行了恢复与研究,探讨了构造演化对圈闭形成与成藏的影响。研究结果表明：(1)陆丰13东洼新生代构造演化可划分为早—中始新世断陷、晚始新世断坳转换、渐新世—第四纪区域热沉降坳陷等3个阶段,其中断陷阶段具有完整的断陷旋回,根据断陷活动的强弱可进一步划分为断陷初始期、断陷高峰期、断陷萎缩期,断陷初始期和断陷萎缩期储层较为发育,断陷高峰期烃源岩较为发育。(2)在多期次构造活动的影响下,陆丰13东洼新生代形成了多种类型的圈闭,包括披覆背斜圈闭、断背斜圈闭、断块圈闭、断鼻圈闭、构造-地层圈闭（削截、超覆）、构造-岩性圈闭。众多的圈闭类型表明研究区油气勘探潜力巨大,特别是断陷阶段与断坳转换阶段沉积的文昌组和恩平组均发育大量各类型圈闭,且邻近优质烃源岩,成藏条件优越,是陆丰13东洼油气勘探的重点层系;平面上,南部缓坡带发育圈闭类型及数量最多,其次是中央隆起带与低凸起,均是研究区油气勘探的重要区带。     

包兰铁路青天寺隧道运营通风及防灾救援设计

青天寺隧道长度超过20 km,隧道的运营通风、防灾及救援(含紧急救援站)等,考虑的因素非常多,本文通过包兰铁路青天寺隧道运营通风及防灾救援设计的工程实例,介绍了特长隧道运营通风及防灾救援设计主要应考虑的问题和工程措施。通过数值模型计算,青天寺隧道运营通风得出可采用自然通风方式的结论;论述了定点救援和隧道内随机停车救援的原理和措施;对隧道内需要设置的通风机功率进行了详细的计算,对不同火灾工况的防灾通风形式、人员的疏散、风机的配置等进行了系统的论述。为以后类似工程设计提供参考。     

Catalytic decomposition of methane on impregnated nickel based anodes with molecular-beam mass spectrometry and tunable synchrotron vacuum ultraviolet photoionization

The molecular-beam spectrometric technique coupled with tunable synchrotron vacuum ultraviolet photoionization is applied to reveal the catalytic decomposition of methane over Ni-based composites with and without impregnated nano-sized samaria-doped ceria (SDC) particles. It is shown that the coating of SDC nanoparticles not only decreases the decomposition temperature, but also increases the conversion ratio, thus indicating that those impregnated SDC nanoparticles are highly catalytically active for methane decomposition. In addition, C₂H₄ is observed when the impregnated Ni-SDC composites are used as the catalyst, suggesting that SDC coating also suppresses carbon deposition at the anodes of solid oxide fuel cells.     

Effect of impregnation phases on the performance of Ni-based anodes for low temperature solid oxide fuel cells

Impregnated nanoparticles are very effective in improving the electrochemical performance of solid oxide fuel cell (SOFC) anodes possibly due to the extension of reaction sites and/or the enhancement of catalytic activity. In this work, samaria-doped ceria (SDC), pure ceria, samaria, and alumina oxides impregnated Ni-based anodes are fabricated to compare the site extending and the catalytic effects. Except for alumina, the impregnation of the other three nano-sized oxides could substantially enhance the performance of the anodes for the hydrogen oxidation reactions. Moreover, single cells with CeO₂ and Sm₂O₃ impregnated anodes could exhibit as great performance as those with SDC impregnated anodes. When the impregnation loading reached the optimal value, 1.7 mmol cm⁻³, these cells exhibit very high performance, with peak power densities around 750 mW cm⁻². The high performance of CeO₂ and Sm₂O₃ impregnated anodes demonstrates that the improved performance are mainly attributed to the significantly improved electrochemical activities of the anodes, but not to the extension of triple-phase-boundary, and wet impregnation is indeed an alternative and effective technique to introduce these nano-sized catalytic active oxides into the anode configuration of SOFCs to enhance cell performance, stability and reliability.     

非线性负载的供配电系统无功补偿及谐波分析

文章对采用可控硅移相调压装置控制电加热器的供配电系统无功补偿及谐波进行了分析,给出谐波含量、系统功率因数的准确计算公式以及有源滤波和无功补偿的选择方法。得出在非线性电路中仅靠无功补偿难以满足电网对功率因数的要求的结论。并指出解决方法重点应在工艺方案的合理选择,不产生污染或少产生污染。     

MRPⅡ在我国企业的实践和再认识

对MRPⅡ实际中的问题进行总结,从MRPⅡ的核心和管理思想、它与深化改革、强化管理的关系等方面再认识MRPⅡ.旨在推动我国企业进一步完善和发展MRPⅡ,加快企业网的建设和我国的信息化进程.     

台湾河流、湿地治理的思路、技术和问题

介绍台湾地区综合治水策略,从集水区涵养保护开始,配合流域洪水历线,综合配置集水区、河道、下水道及滞洪设施,并降低河道洪水位,同时兼顾环境及生态的维护。从台湾的河川湿地治理经验出发,介绍"台北大沟溪生态滞洪池"、"新店溪阳光运动公园"、"台北关渡自然公园人工湿地(离槽式)"、"大汉溪河岸人工湿地(在槽式)"等工程实例,说明只有师法自然,才能推动生态资源保护以达到永续发展的终极目标。     

Development of three-layer intermediate temperature solid oxide fuel cells with direct stainless steel based anodes

Metal-supported solid oxide fuel cells (SOFCs) are usually four-layer structure consisting of the metal support, the anode, the electrolyte and the cathode. This communication reports a simplified three-layer design without the anode interlayer. The novel design is demonstrated by co-firing yttria-stabilized zirconia electrolytes and 430L stainless steel substrates, where Ni and doped ceria are impregnated to increase the catalytic activity toward electrochemical oxidation. Peak power density as high as 246 mW cm⁻² is obtained at 700 °C, and good tolerance to complete redox cycles is also initially demonstrated, suggesting that this design is feasible for high performance metal-supported SOFCs.     

烟气制酸装置净化工序出口氟含量的优化控制

介绍了昆鹏公司硫酸装置净化工序的除氟工艺流程和运行效果.为解决净化工序出口烟气氟含量过高,对后续设备造成腐蚀等问题,技术人员在净化工序二级动力波洗涤器处增加钠水玻璃除氟装置,由原来的一级除氟改为两级除氟.改造后,有效防止了冶炼烟气中氟含量突然大幅升高对净化工序造成的影响,将一级动力波循环液氟质量浓度控制小于8 g/L,二级动力波循环液氟质量浓度控制小于1 g/L,使干燥塔出口氟质量浓度小于1 mg/m3.