Self-assembled cubic-hexagonal perovskite nanocomposite as intermediate-temperature solid oxide fuel cell cathode

Self-assembly is an emerging strategy for preparing composite cathodes with good oxygen electrochemical reduction activity and congenital chemical compatibility for intermediate-temperature solid oxide fuel cell (IT-SOFC). Here we report that a self-assembled BaCo_0.6Zr_0.4O_3-δ (BZC-BC) nanocomposite is prepared through one-pot glycine-nitrate process and exhibits high cathode performance. The BZC-BC nanocomposite is composed of 62 mol% cubic perovskite BaZr_0.82Co_0.18O_3-δ (BZC) as an ionic conductor and 38 mol% hexagonal perovskite BaCo_0.96Zr_0.04O_2.6+δ (12H-BC) as a mixed ionic and electronic conductor. The BZC-BC nanocomposite has the pomegranate-like particles aggregated with a larger number of nanoparticles (50-100 nm) which greatly enlarge the three-phase boundary sites. The BZC-BC nanocomposite exhibits a thermal expansion coefficient of 12.89 × 10⁻⁶ K⁻¹ well-matched with that of Ce_0.8Gd_0.2O_3-δ (12.84 × 10⁻⁶ K⁻¹) electrolyte. The high electro-catalytic activity of BZC-BC nanocomposite cathode for oxygen reduction is reflected by the low polarization resistances of oxygen ions incorporation at cathode/electrolyte interface (0.02823 Ω cm²), oxygen species diffusion (0.03702 Ω cm²) and oxygen adsorptive dissociation (0.07609 Ω cm²) at 700 °C. The single cell with BZC-BC nanocomposite cathode achieves the maximum power density of 1094 mW cm⁻² at 650 °C and shows good stability under 25 h run.     

中低温煤焦油基炭微球的制备

通过馏分切割、温和加氢相结合对中低温煤焦油进行精制处理，精制后的原料采用分级热聚制备中间相炭微球。考察了精制处理条件对原料性质、中间相炭微球宏观外貌及微晶结构的影响。采用FTIR、GC-MS、族组成、元素分析对原料进行表征，采用SEM、XRD对中间相炭微球进行表征。结果表明：中低温煤焦油中300～430℃馏分油是制备中间相炭微球的较佳馏分。300～430℃馏分油中正庚烷可溶物（HS）质量分数高达84.76%，吡啶不溶物（PI）质量分数低至0.23%，杂原子含量低，芳烃化合物的环数为2～4环。300～430℃馏分油在T_H=350℃、p=8MPa、t=1.5h、剂油比1∶40（质量比）的条件下温和加氢得到的精制原料，经420℃热聚6h得制备的中间相炭微球宏观外貌、微晶结构较好。中低温煤焦油基炭微球的粒径范围为5～15μm，小球表面光滑，微观结构为地球仪型，经1450℃高温煅烧后，石墨化度达到12.33%。     

机械合金化FeS/Cu复合材料的摩擦磨损性能

以FeS和CuSn8Ni1粉末为原料，利用机械合金化技术和粉末冶金技术制备了FeS/Cu复合材料，探讨了不同载荷情况下所制备的FeS/Cu复合材料的摩擦学性能及润滑膜与转移膜特征。结果表明：机械合金化提高了FeS与铜合金基体界面结合性能，进而提高了材料减摩耐磨性能；当载荷较小时，摩擦副表面接触不稳定，复合转移膜不连续，摩擦因数波动大；载荷较大时，复合转移膜易破损，材料的减摩耐磨性能变差；当载荷为150 N时，载荷适宜，材料表面软化，复合转移膜更加完整，摩擦因数较小。     

工业园区混合能源优化配置方法应用与实践

为了充分挖掘多能源之间的互补潜力,使工业园区混合能源系统的配置方式由传统粗放式转变为精确优化配置并降低系统配置方案的保守性,基于粒子群联合CPLEX求解算法对工业园区的系统配置和运行调度方案进行分析优化,并以某生物园区为例进行了实例分析,得到了目标函数下的最优设计方案和运行策略。仿真分析结果表明,优化配置方法的应用能够协调冷热电多种能源的混合利用,提升系统的综合经济性。同时,为工业园区能源供应项目的规划、设计提供参考性支撑,丰富设计手段。     

高等级生物安全实验室通风空调系统冗余设计原则探讨

对比分析了国内外标准有关高等级生物安全实验室通风空调系统冗余设计的要求。结合我国已有高等级生物安全实验室,重点分析了送风机、排风机、排风高效过滤器冗余设计的具体实施形式和存在的问题,给出了冗余设计原则建议。     

45 t门座起重机顶升方案设计

针对国内45 t门座起重机大车行走机构平衡梁裂缝问题。分析平衡梁裂缝产生原因并提出相应的维修方案,并对维修关键技术中的顶升方案设计,采用Ansys软件对其强度进行了有限元分析,同时对维修前后的平衡梁进行分析并对比。将维修方案应用于实际工程,取得了较好效果。该顶升机构修复方案设计符合工程实际,对工程实践具有一定的指导意义。     

PC2425锤式破碎机的篦子改造

PC2425破碎机是较为常用的锤式破碎机规格之一，主要用于石灰石的破碎，台时产量800~1 000 t，出料粒度≤70 mm，筛余5%，配套4 500~5 000 t水泥生产线。PC2425破碎机篦条为易损件，由于物料的冲击会导致篦条变形，但其原有的弓形架与篦条型式，更换时很难将篦条从弓形架中抽出，导致更换非常不便。此次改造，用户最初适量降低破碎机的出料粒度，以提高生料磨的产量及降低生料粉磨的电耗，虽然通过调整篦条与锤头的间距及篦条间隙可以达到降低出料粒度的要求。但是为了彻底解决篦条更换困难问题，重新设计了篦架结构。     

New exact solutions of the Tzitzéica-type equations in non-linear optics using the expa function method

One specific class of non-linear evolution equations, known as the Tzitzéica-type equations, has received great attention from a group of researchers involved in non-linear science. In this article, new exact solutions of the Tzitzéica-type equations arising in non-linear optics, including the Tzitzéica, Dodd–Bullough–Mikhailov and Tzitzéica–Dodd–Bullough equations, are obtained using the exp_a function method. The integration technique actually suggests a useful and reliable method to extract new exact solutions of a wide range of non-linear evolution equations.     

基于粒子群优化算法的五自由度机械臂轨迹规划

为了让机械臂的工作时间达到最优,以自主研发的抛光机器人样机为研究对象,针对手表表壳表耳部分的抛光过程,提出PSO算法对五自由度机械臂轨迹规划进行优化,并通过MATLAB软件进行机械臂的仿真与分析。仿真结果表明,基于PSO算法的轨迹规划使机械臂在工作过程中加加速度不会产生突变,运动轨迹精度高,机械臂工作时间达到最优。     

Physicochemical and technological properties of beef burger as influenced by the addition of pea fibre

This study aimed to evaluate the physicochemical characteristics and sensory attributes of beef burgers with the addition of pea fibre as a partial substitute of meat or fat. Three formulations were prepared: control (CON) – similar to the commercial formulation; fibre/less meat (FLM)—5% meat reduction and addition of 1% pea fibre; fibre/less fat (FLF)—7% fat reduction and addition of 1% pea fibre. Non-significant differences were obtained for pH, colour parameters (L* and b*), texture profile, cooking loss and size reduction among formulations. Moreover, sensory analysis with consumers of beef burgers did not indicate differences among the formulations for all the analysed attributes. Therefore, pea fibre is a promising partial replacer for meat and fat in beef burgers due to the preservation of technological parameters and sensory acceptance.