Iron Oxyhydroxide: Structure and Applications in Electrocatalytic Oxygen Evolution Reaction

Oxygen evolution reaction (OER) is the anodic half-reaction for crucial energy devices, such as water electrolysis, metal–air battery, and electrochemical CO₂ reduction. Fe-based materials are recognized as one of the most promising electrocatalysts for OER because of its extremely low price and high activity. In particular, iron oxyhydroxide (FeOOH) is not only highly active toward OER, but also widely accepted as the true active species of Fe-based OER electrocatalysts for plenty of Fe-based materials are converted into FeOOH during OER test. Herein, the recent advances of FeOOH-based nano-structure and its application in OER are reviewed. The relationship between FeOOH structure and its catalytic performance, followed by the introduction of current strategies for enhancing the OER activity (i.e., crystalline phase engineering, element doping, and construction of hybrid materials) is mainly focused. Finally, a summary and perspective about the remaining challenges and future opportunities in this area and further the design of Fe-based OER electrocatalysts are provided.     

Dual-polarized dielectric resonator antennas

Two high input-isolation dual-polarized dielectric resonator (DR) antennas are presented in this communication. First, a slot-coupled feed technique with two narrow slots forming a "T" configuration is employed to design a dual-polarized DR antenna. Input isolation exceeding 35 dB has been obtained in the band for this design. Secondly, a hybrid feed mechanism with a coplanar waveguide (CPW) feed and a slot feed is used to achieve a dual-polarized DR antenna. A vertical strip is added at the center strip of the CPW feed to improve the coupling to the DR antenna. Also, input isolation exceeding 35 dB has been obtained in the band. Good cross-polarization levels less than -20 dB in the broadside direction are attained. The measured far-field radiation patterns are stable in the passband and the measured gains are around 5.5 dBi for the two feed ports of both cases.     

基于规则引擎的自动运维虚拟器件模型

云计算的普及离不开虚拟化技术的支撑,虚拟化技术的广泛应用给众多企业数据中心带来了极大的好处.其中虚拟器件软件形态的发展,加速了大型软件开发和部署流程,但是在虚拟器件的管理维护阶段对用户来说存在一定困难.本文针对虚拟器件的运维管理对现在虚拟器件模型进行了扩展,提出了基于规则引擎的自动运维虚拟器件模型,并且设计了一个实现方案进行验证.     

基于查表方式的雷达波束扫描技术

相控阵雷达波束控制系统的性能极大地影响雷达功能的发挥,采用查表法完成雷达天线波束快速布相,具有速度快、移相精度高、控制灵活及便于扩展等特点,在相控阵雷达波束控制中应用广泛。     

基于FPGA的8PSK解调器设计

8PSK是一种高带宽效率的多相位键控调制解调技术,在高速数据传输领域具有广阔的应用前景。对Gardner算法和PFD频相联合检测算法进行了仿真研究,给出了实现8PSK全数字解调器符号同步和载波同步的完整结构。在XILINX公司的ISE环境下,用Verilog语言设计实现了8PSK全数字解调器。对该8PSK解调器的解调性能进行了测试,在误码率为10^-6时,解调损失小于1 dB。     

110kV某变电站电容式电压互感器的故障分析

通过对110kV某变电站的故障电容式电压互感器进行现场检查、电气试验等,逐步对其进行分析,找出发生缺陷的根本原因。     

主被动传感器异地配置下的数据关联

在雷达和ESM传感器异地配置的情况下，分别基于角度统计量和距离统计量提出了二种异类传感器数据关联算法，对算法进行了讨论，进行了计算机仿真。仿真结果表明：二种算法有基本相同的正确关联概率，但基于距离统计量的异类传感器数据关联算法有相对较低的错误关联概率。     

一种特殊的非对称量子阱中的光整流效应

运用量子力学密度矩阵算符理论，推导出在一种特殊非对称量子阱中的光整流系数的解析表达式．最后利用典型的GaAs／A1GaAs非对称量子阱进行数值计算，得到了系统的非线性光整流效应和量子阱的非对称性以及入射光子能量之间的变化规律，并在此特殊量子阱中得到了较大的光整流系数，从而为实验上制作较好的非线性材料提供了一种可行的途径。     

Screening for yeasts incorporating the exogenous eicosapentaenoic and docosahexaenoic acids from crude fish oil

The screening for yeasts incorporating exogenous eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into their cellular lipids was conducted. Two percent of oil from fish scraps was added to a yeast isolation medium as a sole carbon source. From 143 soil samples, we isolated 23 yeast strains, nine of them were found to be capable of quickly assimilating the scrap fish oil. These nine strains, in addition to four previously isolated triglyceride-assimilating and lipase-producing strains, Yarrowia lipolytica and three Geotrichum species (FO274A, FO347-2 and FO401B), were cultured in a growth medium at 30 degrees C. Strains FO726A, FO765A and FO347-2 were selected on the basis of dry cell weight production and ability to store EPA and DHA in their cells, and their performance was further compared by varying cultivation temperature and time. From 1 g of the scrap fish oil, FO726A yielded 620 mg of dry cells, containing 47.1% lipid, 38.1% triglyceride, 3.3% EPA, and 4.9% DHA, when cultured at 25 degrees C for 36 h. Strain FO726A apparently has the highest ability to incorporate EPA and DHA into its cellular lipids. Results from further experiments showed that the incorporated EPA and DHA mainly existed in the form of triglyceride in the FO726A cell. These results suggest that FO726A is suitable for the production of cell mass rich in EPA and DHA for feed.