Pan Xinxiang

Elastic-plastic deformation analysis of multi-layer surface coating under sliding contact

Abstract The sliding contacts of gradient layer, sandwich layer and ordinary multi-layer coatings subjected to the same surface load have been investigated under elastic-plastic deformation in this paper. The result shows that the positive gradient layer coating, in which the elastic modulus reduced gradually from the top layer to the substrate, can improve the strain and stress fields near the layer-substrate interface greatly and its stress contour in the vertical direction is very smooth. The coating has as well a small stress on the layer-substrate interface and in the substrate. The sandwich layer coating can greatly reduce the maximum shear stress on the interface of the layer-substrate and the stress at the crack tip, but the stress and the strain gradients near the interface are very large. The stress and strain distributions of the ordinary layer have not evidently improved compared to those of single layer. Known from the analysis of the stress and strain distributions and the crack stress fields for the four kinds of coatings, the gradient layer coating has more advantages in these aspects. The results of this paper can provide the reference for the selection and design of coatings.

NaClO 2 海水溶液强化烟气脱硝效果的实验研究

海水中富含多种盐类，具有一定碱性，是天然的缓冲剂，在脱硫脱硝方面具有良好的应用前景.利用不同浓度的NaClO2溶液进行废气循环喷淋脱硝实验.结果表明，NaClO2模拟海水溶液与NaClO2淡水溶液都能将NO完全脱除，且当NO完全被脱除时，模拟海水溶液的持续时间比淡水溶液更长，模拟海水中所含有的少量HCO3-和OH-是造成这种差异的主要原因.滴定实验结果显示0.066 mmol的HCl就可使NaClO2淡水溶液的pH值降到7，而NaClO2模拟海水溶液的pH值降到7需要0.114 mmol的HCl；在循环喷淋脱硝过程中NaClO2模拟海水溶液的pH值基本维持在7以上.离子色谱检测结果显示脱硝后溶液中主要阴离子为Cl-和NO3-.基于质量平衡计算结果，当NaClO2浓度为20 mmol·L-1时，在脱硝过程中淡水溶液中NaClO2的利用率为56%，而模拟海水溶液中NaClO2的利用率可达67.25%，提高幅度为20.1%.