嵌入式数字智能涡街流量计的设计开发

针对目前涡街流重计存在精度不高的问题，采用Toeplitz自相关矩阵近似的准牛顿算法，对涡街传感器输出信号进行数字信号处理。针对客户超低功耗的要求，开发设计以超低功耗的混合信号处理器(MSP430F149)为微处理器，以采用KS0713为控制器的LCD为液晶显示模块，符合HART总线协议的嵌入式智能涡街流量计。     

大管径混凝土管道模板设计及施工技术

珠海火力发电厂循环水混凝土管道施工中,成功地应用了定型钢模板,不但加快了施工进度,而且节约了模板施工成本,浇筑的管道混凝土色泽均匀,结构成型质量较好,达到了清水混凝土质量标准,实现了预期目标。     

麦草碱-氧蒸煮脱木素

用碱－氧蒸煮麦草脱木素,考察了工艺条件对麦草脱木素的影响．结果表明：适宜的麦草脱木素的条件为温度 １６０℃,碱浓度 ８％,氧压 ０．８ ＭＰａ,固液比 ０．８,保温时间 １ｈ．同时,通过 ＩＲ和 １Ｈ－ＮＭＲ对木素结构进行了分析．     

重整甲醇高温聚合物电解质膜燃料电池研究进展与展望

甲醇作为一种安全便捷的液态储氢燃料,具有高含氢量以及高体积能量密度,可经重整为富氢气后与燃料电池系统集成为重整甲醇高温聚合物电解质膜燃料电池,从而高效地将甲醇和氧气的化学能转变为电能。本文针对重整甲醇高温聚合物电解质膜燃料电池的不同类型（外置重整型和内置重整型）,分别对其系统集成的实现与发展进行了总结,并介绍了其现阶段在军用和民用方面的应用情况,同时指出了技术研究与应用存在的瓶颈,并对未来的研究方向进行了展望。未来提升重整甲醇高温聚合物电解质膜燃料电池性能的努力在于开发低温工作的高效甲醇重整催化剂,以及高温稳定运行的聚合物电解质膜和非贵金属材料等燃料电池关键材料。     

High‐Performance Alkaline Polymer Electrolyte for Fuel Cell Applications

Although the proton exchange membrane fuel cell (PEMFC) has made great progress in recent decades, its commercialization has been hindered by a number of factors, among which is the total dependence on Pt‐based catalysts. Alkaline polymer electrolyte fuel cells (APEFCs) have been increasingly recognized as a solution to overcome the dependence on noble metal catalysts. In principle, APEFCs combine the advantages of and alkaline fuel cell (AFC) and a PEMFC: there is no need for noble metal catalysts and they are free of carbonate precipitates that would break the waterproofing in the AFC cathode. However, the performance of most alkaline polyelectrolytes can still not fulfill the requirement of fuel cell operations. In the present work, detailed information about the synthesis and physicochemical properties of the quaternary ammonia polysulfone (QAPS), a high‐performance alkaline polymer electrolyte that has been successfully applied in the authors' previous work to demonstrate an APEFC completely free from noble metal catalysts (S. Lu, J. Pan, A. Huang, L. Zhuang, J. Lu, Proc. Natl. Acad. Sci. USA 2008 , 105, 20611), is reported. Monitored by NMR analysis, the synthetic process of QAPS is seen to be simple and efficient. The chemical and thermal stability, as well as the mechanical strength of the synthetic QAPS membrane, are outstanding in comparison to commercial anion‐exchange membranes. The ionic conductivity of QAPS at room temperature is measured to be on the order of 10^?2 S cm^?1. Such good mechanical and conducting performances can be attributed to the superior microstructure of the polyelectrolyte, which features interconnected ionic channels in tens of nanometers diameter, as revealed by HRTEM observations. The electrochemical behavior at the Pt/QAPS interface reveals the strong alkaline nature of this polyelectrolyte, and the preliminary fuel cell test verifies the feasibility of QAPS for fuel cell applications.     

Waveguides with inner dielectric cylinder(s) for Cerenkov free electron laser

Waveguides with inner dielectric cylinder(s) for Cerenkov free electron laser are presented. An analysis on the dispersion relations and the distributions of the axial electric field components of the waveguide modes, which are important to determine the operating frequency and gain, has been carried out. The results show that the waveguides can be employed to generate radiations at lower millimeter wavelength with higher gain and larger power output.     

The study of diffraction radiation oscillation

Theoretical and experimental study of Diffraction Radiation Oscillator (DRO) is reported in this paper, it is the first work done in P. R. China. The sphere-cylindrical open cavity used in the DRO has been analysed, the method for testing the field profile and the cold measurement of the open cavity have been worked out. The experimental device was manufactured in our lab. and the theoretical analysis and experimental study of the device have been carried out. The main experimental results are: from 2000 V to 4000 V, the tube operates in the 60–87 GHz band, and the maximum output power is about 800 mW.     

Nickel Promoted Palladium Nanoparticles for Electrocatalysis of Carbohydrazide Oxidation Reaction

Carbohydrazide is a potential alternative to toxic hydrazine for fuel cell applications to overcome the challenges of storage and transportation of hydrogen. In this work, Ni‐alloyed Pd nanoparticles (NPs) with varied Pd–Ni ratios supported on carbon black (PdNi_x/C) are prepared and their catalytic performance for the carbohydrazide electro‐oxidation reaction is investigated. The catalytic performance of PdNi_x/C NPs is significantly improved in comparison to Pd/C NPs. The current density of PdNi_x/C NPs with optimized Pd–Ni atom ratio can reach 3.26 A mg^?1_metal at a potential of 0.4 V (vs reversible hydrogen electrode), which is an increase of 2.4 times compared to that of Pd/C. The density functional theory calculation indicates the enhanced catalytic activity is caused by the change of adsorption energy of carbohydrazide molecules on the metal surface. It exhibits a volcano relationship between the adsorption energy and the catalytic current density of PdNi_x/C with varied Pd–Ni atom ratios.     

高层建筑混凝土小型砌块配筋砌体试验研究

通过对高层应用配筋砌体的试验研究和试点工程实践表明,配盘砌体具有良好的抗震性能。     

The effects of different dimensional carbon additives on performance of PEMFC with low-Pt loading cathode catalytic layers

The addition of carbon additives to the catalytic layers (CLs) with low-Pt loadings significantly improves the cell performance of proton exchange membrane fuel cells. However, the structure-activity relationship between the different dimensional carbon materials in CLs and the cell performance is still unknown. In the present work, three different dimensional carbon materials have been added into the cathode CLs with low Pt loading. The addition of one-dimensional carbon nanotubes and zero-dimensional XC-72R significantly enhanced the power density of the fuel cell because of the improved Pt dispersion and porous structures of the CL. This resulted in enhanced gas transfer and water removal accessibility. Nevertheless, the tortuous transfer path of gas and water after the presence of graphene nanosheet in the CL results in increased mass transfer resistance, although it reduces the charge transfer of the CL due to the improved catalyst utilization at low current density regions of polarization curves.