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.

     

Inactivation efficacy of plasma-activated water: influence of plasma treatment time,exposure time and bacterial species

This study aimed to evaluate the influence of plasma treatment time, bacterial exposure time to PAW and bacterial species on the inactivation efficacy of plasma-activated water (PAW), with additional investigation of the inactivation mechanisms of PAW. Six bacterial species, including Listeria innocua, Staphyloccus aureus, Escherichia coli, Pseudomonas fluorescens, Shewanella putrefaciens and Aeromonas hydrophila were selected as the representative bacteria. The initial bacterial concentration was around 7 log CFU ml⁻¹ after mixing with PAW, and the inactivation efficacy was measured after different exposure times during the 4 °C storage. Scanning electron microscopy (SEM) images of the bacteria after PAW treatment were carried out to inspect the cell structure damage, and physicochemical properties of PAW, including pH, conductivity and long-living reactive species of H₂O₂, , and , were examined. The results showed that the inactivation efficacy of PAW was positively correlated with plasma treatment time and bacterial exposure time, and for the species examined in this study, the Gram-negative species were more sensitive to PAW than the Gram-positive species. Cell structure damage, including shrinkage, distortion, or holes, was observed after PAW treatment. The pH of PAW was acidified to 2.5–2.9, and conductivity was significantly increased to 518.0 μs cm⁻¹. and H₂O₂ were reduced during the 48 h storage, while an increased concentration was observed for . This study demonstrated that the processing parameters of plasma treatment time, exposure time and characteristics of bacteria can significantly affect the inactivation efficacy of PAW.     

Effects of Sr2+ substitution on the crystal structure,Raman spectra,bond valence and microwave dielectric properties of Ba3-xSrx(VO4)2 solid solutions

The effects of Sr²⁺ substitution for Ba²⁺ on microwave dielectric properties and crystal structure of Ba_3-xSr_x(VO₄)₂ (0 ≤ x ≤ 3, BSVO) solid solution were investigated. Such Sr²⁺ substitution contributes to significant reduction in sintering temperature from 1400 °C to 1150 °C. Both permittivity (∑_r) and quality factor (Q × f) values decreased with increasing x value, which was determined to be related with the descending values of average polarizability and packing fraction, whereas the increase in τ_f value was explained by the decreased average VO bond length, A-site bond valence. BSVO ceramics possessed encouraging dielectric performances with ∑_r = 12.2–15.6 ± 0.1, Q × f = 44,340 - 62,000 ± 800 GHz, and τ_f = 24.5–64.5 ± 0.2 ppm/°C. Low-temperature sintering was manipulated by adding B₂O₃ as sintering additive for the representative Sr₃V₂O₈ (SVO) ceramic and only 1 wt.% B₂O₃ addition successfully contributed to a 21.7% decrease in sintering temperature to 900 °C, showing good chemical compatibility with silver electrodes, which render BSVO series and SVO ceramics potential candidates in multilayer electronic devices fabrication.     

氰化工艺过程中金属存量计算方法探讨

为搞好金属平衡，减少理论与实际差值，依据某黄金矿山氰化工艺流程特点，对脱药用单层浓密切、漫出槽、三层洗涤浓密机三个作业中的金属存量的计算方法进行了探讨。     

会泽铅锌矿方铅矿、闪锌矿和黄铁矿的浮游性研究

本文考查了ZnSO4和可溶性淀粉对方铅矿、闪锌矿和黄铁矿浮游性的影响，为会泽铅锌矿铅硫异步等可浮工艺提供了理论依据。试验结果表明，在乙黄药浮选体系中，ZnSO4和可溶性淀粉强烈抑制闪锌矿，而对方铅矿和黄铁矿的浮游性影响不大，且两者的浮游性相近。     

认识服务的商品属性加快企业后勤改革

用马克思主义价值法则和市场经济理论，分析了国有企业后勤改革必须遵循商品交换法则，运用价值规律进行调节，以适应市场经济的客观要求。     

保康白竹磷矿构造控矿特征

本文从地质力学观点阐述白竹磷矿的构造控矿特征,分析保康磷矿的古构造、古地理环境,以及构造的复合关系,预测隐伏矿体的存在远景。     

清水泵间接驱动竖井液力提升技术模拟研究

工业过程的连续化是提高效率,降低消耗和改善作业环境的有效技术途径,也是其工艺技术水平发展的重要标志.清水泵间接驱动竖井液力提升技术借鉴相关领域的已有技术成就,并结合竖井提升的功能要求综合设计而成的一个全新的提升方案.有别于国外在矿山竖井液力管道连续提升的破磨造浆-浆泵(均质两相流)-固液分离的技术思路,对妨碍其大规模工业应用的提升能力(尤其是提升高度)、设备磨损、增压给矿及浓度控制、能耗等一系列技术难题均有所突破.模拟试验证明了这一创新方案的可行性.     

利用光聚合反应制作表面平整的聚合物光栅

提出利用紫外光聚合反应来制作聚合物光栅的方法．实验发现,光栅的表面起伏深度很小,约为12.4～0.7nm;折射率调制较大,达到0.010左右．这种方法在低阶分布反馈聚合物激光器的制作中具有很好的应用前景．