Preparation and characterization of high metal content Pt-Ru alloy catalysts on various carbon blacks for DMFCs

High metal content Pt-Ru alloy catalysts (80 and 90 wt.%) with various carbons were prepared by the colloidal method without increasing particle size. As increasing the specific areas of supporting materials, catalysts exhibited homogeneous dispersions. The 90 wt.% Pt-Ru/Ketjen Black showed the best performance as the anode catalyst in unit cell and the 80 wt.% Pt-Ru/Ketjen Black in electrochemical experiments. This difference comes from types of electrolytes, i.e. liquid and solid.     

灌注桩加内支撑的基坑围护设计实例

本文结合工程实例,详细介绍了灌注桩加内支撑这种基坑支护方式的计算过程,包括模型选定、围护桩设计、支撑设计、圈梁设计等一系列全过程。     

设计凿岩钻车液压平移机构的新方法

本文提出了把支臂在拐点角位置时的推进器设计成水平。把油缸行程平均分配在拐点角位置两侧的设计新方法,可实现断面中部的孔向与巷道纵向轴线的偏差和两相邻炮孔的平行误差同时为最小。     

巷道掘进支护计算机辅助决策系统研究

为了克服个人决策进行支护时的不合理，实现专家的集体决策，本文采用面向对象的计算机编程技术和可视化的设计方法，利用人工智能等科学开发了井巷掘进支护设计的智能专家系统，其中包括决策系统的总体设计思路、知识库的建立、推理机制的调试等，并将神经网络技术应用到专家系统中。将该系统应用于某巷道支护设计方案的决策，其运行结果比较令人满意。     

对传统电子邮件系统的改进

针对传统电子邮件系统存在的缺点进行改进,介绍了改进后的电子邮件系统的特点及新系统设计过程中要解决的技术难点.     

岩巷掘进配套装备及工艺技术

本文就岩巷快速掘进技术进行了具体的探究,从不同的角度对该项技术进行了探析。     

Supporting electrolyte interaction with the AACVD synthesized Rh thin film influences the OER activity

Electrocatalytic oxygen evolution reaction (OER) is one of the most promising candidates for the sustainable energy. This has led researchers to focus towards developing highly active electrocatalysts. Our work takes a wholistic approach to understanding the key factors that influence the OER process. We focused on preparing a metallic electrocatalyst and tested out its OER performance using two different supporting electrolytes. We also studied the effect of crystal planes of the electrocatalyst on the OER process using computational simulation (CS) methods. For this, rhodium (Rh) thin film (RhTF) electrocatalysts on indium tin oxide (RhTF_ITO) were fabricated for OER through aerosol assisted chemical vapor deposition (AACVD). The prepared electrodes showed excellent electrocatalytic activity for OER (for 10 mA/cm² η = 273 mV in 1.0 M KOH). The effect of the supporting electrolytes and the crystal planes of RhTF electrodes were analyzed using electroanalytical techniques and CS methods. Tafel slope (TS) analysis revealed that electron transfer kinetics was slower for the NaOH compared to the KOH. The scan rate (ν) analysis indicated that there is weak electrostatic interaction between the hydrated outer Helmholtz plane (OHP) of Na⁺ and K⁺ ions with the adsorbed OH_(ad) that impacts the OER process. With increasing ν the restructuring of the electrochemical double layer (EDL) increases resulting in similar OER performance for both the supporting electrolytes. The micro-kinetic analysis showed that the rate determining step (RDS) for NaOH and KOH required around 1.67 eV and 1.07 eV. The density functional theory (DFT) analysis revealed that these energy values are closest to the Rh (111) plane reaction pathway. Adsorption locator (AL) analysis further revealed that the hydrated cations could directly get adsorbed on the Rh crystal planes hindering the electron transfer (ET) in the OER process. The DFT analysis further revealed that the lowest energy pathway for the OER process is followed on the Rh (220) plane. These analyses demonstrated that it is possible to fine tune the OER using supporting electrolyte and electrocatalysts that can work synergistically for getting the optimal OER performance.     

线支承扇形瓦推力轴承热动力润滑性能分析

建立了线支承扇形瓦推力轴承中油膜压力、油膜厚度、能量方程和粘温方程等的无量纲表达式，研究了各种刮瓦形式和支承线的倾斜度对推力轴承的油有膜厚度分布和温度分布的影响，研究表明，对于可倾瓦来说，各种刮瓦形式并不能有效降低润滑油的温升，不会明显改善推力轴承的润滑性能；推力轴承在经过长期运行后，推力瓦块支承线因受压缩将会向内倾斜，瓦块外半径处沿圆周方向上的油膜厚度显著减小，从而使润滑油温升大大提高，明显降低了推力轴承的润滑性能。     

大型多支承回转窑调窑参数模糊优化

分析了大型多支承变截面回转窑的力学特征 ,以回转窑运行轴线偏差最小及各托轮受力均衡为优化目标 ,建立了调窑参数模糊优化模型 ,应用模糊集理论和方法获得了最优解。在中国长城铝业公司氧化铝厂 2 #窑的应用中表明 ,根据本文研究的调窑参数模糊优化结果进行调窑 ,显著提高了回转窑的运转率。     

滚珠丝杠副支承方式的力学模型及对加工精度的影响

简述了数控机床中滚珠丝杠副的几种常见支承方式 ,分析了它们水平安装时在自重作用下的力学模型 ,并由力学模型推导出它们在不同支承方式下的变形量的数学表达式即弯曲曲线方程 ;同时简要分析了在加工精密工件时 ,由于自重原因引起丝杠弯曲导致的加工工件的误差。