Electrochemical characteristics of Ba0.5Sr0.5Co0.8Fe0.2O3−δ–Sm0.2Ce0.8O1.9 composite materials for low-temperature solid oxide fuel cell cathodes

In this paper, Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3−δ–xSm_0.2Ce_0.8O_1.9 (BSCF–xSDC, x = 0–60 wt.%) composite cathodes were prepared by soft chemical methods, and then examined for potential applications in lower temperature solid oxide fuel cells. Both DC polarization and AC impedance spectroscopy measurements indicated that the addition of SDC electrolyte into BSCF remarkably improved the electrochemical properties. The optimum composition was found to be BSCF–30SDC, which exhibited 5.5 times higher polarization current density and 15.1% polarization resistance, compared with the pure-phase BSCF cathode at 550 °C.     

霍尔探测液位计

文中介绍了一种新型液位计，它是基于磁浮测量原理，但是选用了霍尔开关器件为敏感元件，它克服了干簧的缺欠，满足了测量高温介质的要求，可达１ｍｍ的分辨度。测量精度也大有提高。     

Half-metallic ferromagnetism in the half-Heusler compounds GeKCa and SnKCa from first-principles calculations

The structural, electronic and magnetic properties of the compounds GeKCa and SnKCa with half-Heusler structure excluding transition metals are investigated by using the first-principles pseudopotential plane wave method based on density functional theory. From the calculated total energies of three possible atomic arrangements we obtain the most stable structure for GeKCa and SnKCa where Ge (Sn), K and Ca occupy the (0, 0, 0), (1/4, 1/4, 1/4) and (3/4, 3/4, 3/4) positions, respectively. It is shown that both GeKCa and SnKCa with the most stable atomic arrangement exhibit half-metallicity with large half-metallic gaps (0.28 and 0.27 eV, respectively) and with an integer magnetic moment of 1.00 μ_B per formula unit. The magnetic moment mainly originates from Ge (Sn) p electrons, and the ferromagnetic state is more favourable in energy than the antiferromagnetic state for both compounds. We also find that the half-metallicity can be maintained up to the lattice contraction of 10% and 13% for GeKCa and SnKCa, respectively.     

葡萄糖、淀粉、苯酚电化学氧化耦合制氢行为

电化学氧化处理有机废水的过程中阳极区降解废水中的有机物,同时在阴极耦合制氢回收清洁能源。选取苯酚、葡萄糖和淀粉为研究对象,研究了相同COD浓度不同有机物的降解效果、产氢量以及他们之间的关系。研究结果表明不同有机物的降解效果由于结构和性质的不同而不同,产氢量也随之变化。苯酚降解效果最好,产氢量和产氢速率最大。对苯酚降解动力学进一步研究表明苯酚的降解是一级动力学过程,在5 V和10 V条件下的反应平衡常数分别为0.01498 h 1和0.1202 h 1,反应速率随电压升高而增大。研究结果为不同类型的有机废水选择合理的处理工艺提供了理论依据。     

采煤机自动控制技术在无人工作面的应用

运用采煤机记忆截割、自主定位、移动通讯和远程监控等技术,设计开发薄煤层采煤机滚筒自动调高、远程通信与操作控制等功能,在峰峰集团薛村矿成功实现了"无人开采工作面"对采煤机的自动控制要求。     

电子束辐照诱导Cu超微粒子发生反应的HREM研究

用高分辨电子显微镜中的电子束对Ｃｕ超微粒子进行了连续的照射和跟踪观察，结果表明，电子束的辐照，首先使Ｃｕ发生了氧化反应，反应途径：Ｃｕ＋Ｏ２→成分为Ｃｕ和Ｏ的非晶膜→Ｃｕ的晶体氧化物：接着，新生的Ｃｕ的晶体氧化物，在电子束的继续照射下，又发生还原反应，Ｃｕ的氧化物不断地还原为Ｃｕ。在整个还原反应中，伴随着样品局部的多重又氧化还原现象交替出现。     

基于粗糙集和支持向量数据描述的发动机视情维修研究

每个热力参数都可从某一角度反映航空发动机的性能状态,在分析各个性能参数变化特点基础上,选取能够最大程度反映发动机性能变化的参数组合。运用统计粗糙集理论属性重要性判定方法,确定各个参数的权值,从而进一步对所选参数组合进行信息融合,能够更加准确的判断发动机性能状况。提出了利用支持向量数据描述的发动机视情维修阈值确定方法。利用非目标数据即性能下降到限制值附近时刻的数据,来提高视情维修的准确率。仿真实验结果表明,该方法能够准确确定视情维修时机,对发动机视情维修时机选择有一定的参考价值。