Lower down both ohmic and cathode polarization resistances of solid oxide fuel cell via hydrothermal modified gadolinia doped ceria barrier layer

Hydrothermal reaction in Cerium and Gadolinium solution as an optimization method is developed and first reported for the densification of gadolinia doped ceria, the barrier layer between Zirconia electrolyte and (La,Sr)(Co,Fe)O_3-δ cathode. This method is based on the hydrothermal reaction for nano particles in-situly grown on porous surface, to improve barrier layer density, alongside the sintering of cathode at 1075 °C. As a result, the ohmic resistance is prominently decreased by ～16.4 % at 750 °C for electrolyte supported symmetrical cell. Whereas, the cathode polarization resistance is decreased by as much as a factor of ～3 from 0.3702 Ω·cm² to 0.1325 Ω·cm² at 750 °C and $p_{O_2}=0.21atm$. Furthermore, the anode supported cell exhibits higher open circuit voltage, smaller area specific resistance, elevated performance output and less degradation. And this modified barrier layer shows reduced Sr migration in 300 h operation at 750 °C. The hydrothermal reaction is demonstrated to prepare denser and sintering-active barrier layer with faster oxygen ion transfer and better interface connection, with large-scale application prospects and cost-competitiveness.     

Reaction environment self-modification on low-coordination Ni2+ octahedra atomic interface for superior electrocatalytic overall water splitting

Large scale synthesis of high-efficiency bifunctional electrocatalyst based on cost-effective and earth-abundant transition metal for overall water splitting in the alkaline environment is indispensable for renewable energy conversion. In this regard, meticulous design of active sites and probing their catalytic mechanism on both cathode and anode with different reaction environment at molecular-scale are vitally necessary. Herein, a coordination environment inheriting strategy is presented for designing low-coordination Ni²⁺ octahedra (L-Ni-8) atomic interface at a high concentration (4.6 at.%). Advanced spectroscopic techniques and theoretical calculations reveal that the self-matching electron delocalization and localization state at L-Ni-8 atomic interface enable an ideal reaction environment at both cathode and anode. To improve the efficiency of using the self-modification reaction environment at L-Ni-8, all of the structural features, including high atom economy, mass transfer, and electron transfer, are integrated together from atomic-scale to macro-scale. At high current density of 500 mA/cm², the samples synthesized at gram-scale can deliver low hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) overpotentials of 262 and 348 mV, respectively.

     

Research on corrosion performance of 6061 aluminum alloy in salt spray environment

Salt spray corrosion test was carried out on 6061 aluminum alloy, and quasi-static tensile test at room temperature was carried out on the sample with universal testing machine. The effect of salt spray corrosion on the mechanical properties of 6061 aluminum alloy was studied by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and electrochemistry. The corrosion rate of 6061 aluminum alloy was quantitatively characterized by different corrosion parameters. It was found that local corrosion of 6061 aluminum alloy occurred in salt spray environment, mainly pitting corrosion and intergranular corrosion. With the increase of corrosion time, the polarization resistance of 6061 aluminum alloy decreases, and the corrosion rate significantly increases. The average corrosion rate and the maximum corrosion rate of 6061 aluminum alloy were characterized by corrosion weight loss and corrosion pit depth. And they can be transformed into each other. The mechanical properties of 6061 aluminum alloy were mainly affected by the depth of corrosion pit. With the increase of corrosion time, the tensile strength and fracture strain decreased, resulting in poor plasticity of the sample. At the same time, the change of elongation of 6061 aluminum alloy can be accurately predicted by the depth of corrosion pit.     

凹凸棒石黏土脱色剂对航空煤油脱色研究

介绍了凹凸棒石黏土作为脱色剂,对航空煤油脱色.通过正交实验研究了活化酸度、焙烧温度、AlCl3加入量、脱色剂的用量和脱色时间对航空煤油脱色的影响.结果表明,经6%的硫酸酸化和450℃焙烧处理后的凹凸棒石黏土,加入1%AlCl;,制备的脱色剂脱色效果最佳,可使航空煤油的脱色率达到98.3%.     

锚杆支护回采巷道围岩类型的最优模糊识别

针对锚杆支护特点，提出了适合于锚杆支护回采巷道分类的指标，并通过构造拉格朗日函数的方法，建立了最优模糊识别的模型，实例表明，用该方法所识别的围岩与实际符合较好，具有较高的应用价值。     

同步发电机无功功率摆动的原因分析与对策

该文以山东王晁煤电集团热电厂发电机无功功率摆动为题,从理论上分析无功功率摆动的原因,阐述了引起发电机无功功率摆动的主要原因及处理措施,并提出改进意见.     

大面积复杂场地条件下高等级施工测量技术研究

针对上海国际赛车场大面积高等级工程测量控制的要求，介绍了用GPS（卫星导航定位系统）与全站仪相结合布设二级控制网，建（构）筑物定位放样测量及控制实施过程，确保工程达到网际汽联的质量验收标隹。     

大跨度门式刚架屋面梁平面外稳定的研究

近年来,门式刚架在工业厂房的设计中得到广泛的应用。对于一般的轻型门式刚架,通过设置隅撑来保证屋面梁受压下翼缘的平面外稳定,经多年的工程实践已经被证明是一种行之有效的构造措施。但对于大跨度、屋面荷载比较大的建筑物,经实例分析,如果仍采用这一措施则很难达到预期的效果。为保证结构的安全性和可靠性,探讨了一种行之有效的解决方案———摇摆支撑的设置。     

新的哈龙替代物--NOVEC 1230

最近 3M公司推出了一种新的哈龙替代物——NOVEC12 30。该替代物脱离了原来在卤代烷家族中寻找哈龙替代物的思路。NOVEC12 30是一种氟化酮 ,其分子式为 C6F12 O。该药剂对人员是安全的 ,不破坏臭氧层 (不在蒙特利尔议定书所规定的淘汰物质之列 ) ,不会对地球气候变化有影响 (不在京都议定书所规定的控制排放的物质之列 ) ,具有良好的灭火性能 ,是技术上可行的哈龙替代物。一、其物化性能参数和环保参数与哈龙、其他哈龙化学替代物的比较NOVEC12 30的物理参数分子式 CF3 CF2 C(O) CF(CF3 ) 2分子量 316 .0 4沸点 (一个大气压 ) 4…     

衢州安居工程四期地基承载力试验研究

《建筑地基基础设计规范》GB5 0 0 0 7— 2 0 0 2取消了有关承载力表的条文和附录。为配合新规范的实施 ,本文结合浙西衢州市安居工程四期地基静载荷试验结果 ,因地制宜地开展地区地基承载力的研究 ,为区域性地基承载力选择提供参考。