Microstructure optimization of fuel electrodes for high-efficiency reversible proton ceramic cells

Reversible protonic ceramic cells (R-PCCs) are efficient energy storage and conversion devices that can operate in two modes, namely, in the fuel cell mode for the conversion of fuel to electricity, and in the electrolysis (EC) mode for the EC of water into hydrogen and oxygen. Fuel electrode is a critical component of fuel-electrode-supported R-PCCs, and its pore structure directly affects the electrochemical performance of the R-PCCs, but it has not been fully studied yet. Herein, the pore structure of Ni–BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3−δ (Ni–BZCYYb) fuel electrodes was systematically modulated by varying the weight ratio (0, 5, 10, and 15 wt.%) of the pore-former added to Ni–BZCYYb, and the electrochemical performance characteristics in the fuel cell and EC modes were investigated. The cell with 10 wt.% pore-former in the Ni–BZCYYb electrode achieved a remarkable peak power density of 540.7 mW cm⁻² and a high current density of –2.28 A cm⁻² at 1.3 V at 700°C in the fuel cell and EC modes, respectively, and showing excellent durability for over 100 h. These results further highlight the critical role of the microstructure of fuel electrodes, which can be modified to achieve exceptional performance, particularly in EC operations.     

The rheological properties of shear thickening fluid reinforced with ZnO of different friction characteristics

The viscosity of shear thickening fluid (STF) changes significantly with low concentrations of additives. However, existing research has suggested that there has not been any consistent enhancement mechanism of additives. The possible reason for this research gap is that existing research has focused on the effect of the shape and content of additives on shear thickening (ST) performance, whereas the friction characteristics of additives on ST performance have not been considered. Accordingly, nanoparticle-enhanced STF with various friction characteristics of ZnO was synthesized in this study to investigate the enhancement mechanism of additives. The aspect ratio of ZnO with different shapes was obtained through SEM analysis. The friction characteristics of ZnO were examined. Lastly, the rheological behavior of reinforced STFs was evaluated. The results indicated that ST performance was enhanced compared with that of neat STF, which was significantly dependent on the friction characteristics of ZnO.     

基于非球面检测的磁力微动间隙控制技术研究

在非球面检测中,为了能很好的控制参考波面的变化,需要对参考镜的位置进行微移动,针对此问题,研究了一种磁动式微动间隙调节结构,该结构以3个通电电磁线圈为驱动力,直线导轨为运动平台,通过电磁力驱动使参考镜的位置进行微小的变化,结构简单、方便,可以实现波面的位置控制,通过实验验证了该结构设计的正确性和可行性。     

基于机器视觉的重复定位精度测量技术

重复定位精度是机床、机械手、工件台等工业设备的重要指标之一,它直接影响零件加工的一致性以及生产设备工作的可靠性,为此对设备的重复定位精度进行测定是评估设备能否满足精密产品生产需求的首要工作.而目前重复定位精度的测量主要有千分尺和激光干涉仪,但千分尺具有测量、读取数值不方便以及测量精度不高的缺点,而用激光干涉仪测量成本又较高.在设备的实际生产过程中,为了能够方便且又能精确的测定其重复定位精度,提出一种基于机器视觉的重复定位精度测量方法,该方法测定方便,测量精度达到亚像素级且可控,其随着测定相机分辨率的提高而提高,可以用于精度要求在微米级以下的设备的重复定位精度测定.     

浊度计掐头与活性炭吸附联用技术在白酒除浊中的应用

为了解决白酒在生产过程中出现的浑浊问题,该研究从白酒风味物质测定及添加试验方面对白酒浑浊现象进行成因分析,并通过浊度计掐头与活性炭吸附的联用技术对酒样进行除浊处理。结果表明,酒体浑浊现象与所含三种高级脂肪酸乙酯（棕榈酸乙酯、油酸乙酯和亚油酸乙酯）含量及环境温度有关。在10 ℃条件下,棕榈酸乙酯、油酸乙酯和亚油酸乙酯总含量＞250 mg/L的酒样有浑浊风险。采用浊度计掐去1.94 NTU的酒头能够避免酒体浑浊的风险。对酒头进行0.05%的活性炭吸处理36 h,在保障酒体风味的同时有效降低了高级脂肪酸乙酯的含量,还能基本维持原有的香气,适用于酒厂生产。     

虾青素DHA单酯对脂多糖诱导炎症反应的保护作用

目的：通过构建脂多糖（lipopolysaccharide,LPS）诱导的BV2小鼠小胶质细胞和斑马鱼炎症模型研究虾青素二十二碳六烯酸（docosahexaenoic,DHA）单酯的抗炎活性。方法：采用光学显微镜观察细胞形态,四甲基偶氮唑蓝法检测细胞活性,Griess法测定NO水平。向斑马鱼胚胎显微注射虾青素,体视显微镜下观察胚胎发育,采用试剂盒检测胚胎中活性氧（reactive oxygen species,ROS）产生量和丙二醛（malondialdehyde,MDA）含量;采用实时荧光定量聚合酶链式反应测定炎症因子的表达水平。结果：虾青素DHA单酯干预后,细胞内炎症因子表达水平与模型组相比极显著下降（P＜0.01）,接近于空白对照组;游离虾青素和虾青素DHA单酯均能保护斑马鱼胚胎的发育,降低LPS诱导的胚胎畸形率,有效抑制炎症斑马鱼体内ROS产生,同时显著降低MDA含量,下调炎症因子的表达水平,并且虾青素DHA单酯的效果更佳。结论：虾青素DHA单酯比游离虾青素具有更好的抗炎活性,对LPS诱导的炎症反应有明显的保护作用。     

辽河西部凹陷古近系页岩类型及测井识别

辽河西部古近系广泛发育泥页岩层,是页岩油气勘探的热点层系。利用测井技术识别该地区页岩并区分页岩类型,有助于提高页岩油气勘探开发效率。本次研究利用辽河西部凹陷常规老井的钻测录井资料,对该地区页岩的岩性特征及测井特征进行分析。研究表明,研究区古近系沙河街组页岩类型主要有油页岩、暗色泥岩、砂质泥岩以及钙质和白云质泥岩。泥页岩主要发育在沙河街组三段、水体稳定的深湖相区,矿物组分以黏土矿物为主。星形图测井相统计认为泥岩可表征为CAL>10 in且1Ω·m相似文献   

Exergy evaluation of biomass steam gasification via interconnected fluidized beds

This paper presents the thermodynamic assessment of biomass steam gasification via interconnected fluidized beds (IFB) system. The performance examined included the composition, yield and higher heating value (HHV) of dry syngas, and exergy efficiencies of the process. Two exergy efficiencies were calculated for the cases with and without heat recovery, respectively. The effects of steam‐to‐biomass ratio (S/B), gasification temperature, and pressure on the thermodynamic performances were investigated based on a modified modeling of the IFB system. The results showed that at given gasification temperature and pressure, the exergy efficiencies and dry syngas yield reached the maximums when S/B was at the corresponding carbon boundary point (S/B_CBP). The HHV of the dry syngas continuously decreased with the increase of S/B. Moreover, the exergy efficiency with heat recovery was averagely a dozen percentage points higher than that without heat recovery. Under atmospheric conditions, lower gasification temperature favored the yield and HHV of dry syngas at various S/B. In addition, it also favored the exergy efficiencies of the process when S/B is approximately larger than 0.75. Under pressurized conditions, higher gasification pressure favored both the yield and HHV of dry syngas, as well as the exergy efficiencies at different S/B. Copyright © 2013 John Wiley & Sons, Ltd.     

大学英语四级听力教学策略探究与设计

听力在改革后的大学英语四级考试中占有更大的比重,因此,如何提高学生的听力水平是学生通过四级考试或取得高分的关键.本文针对学生在听力中存在的问题和大学英语四级听力考试的特点,利用多媒体技术,结合合作原则、图式理论,听写法来探索促进学生听力理解能力的教学策略.     

Simple Approach for Quantifying the Thermodynamic Potential of Polymer–Polymer Adhesion

The free energies of mixing a series of water-soluble polymers with cellulose were calculated using the UNIFAC (universal functional group activity coefficients) algorithm, and the results were correlated with measurements of polymer/cellulose adhesion. The more negative the minimum free energy of mixing, the greater the measured adhesion. Adhesion was quantified by single-lap shear test in which regenerated cellulose films were laminated with aqueous polymer. The results are relevant to the use of adsorbed water-borne polymers to strengthen cellulose fiber–fiber bonds in paper. The calculations did not anticipate the exceptional strength-enhancing properties of carboxymethyl cellulose, nor did they predict molecular-weight effects. Nevertheless, the approach may have utility as a general tool to relate polymer chemistry to adhesion performance.