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带化学反应的边界层流动问题中一类弱奇异Volterra积分方程的近似解 被引量:1
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作者 季鹭 王同科 高广花 《工程数学学报》 CSCD 北大核心 2023年第1期147-158,共12页
研究带化学表面反应的边界层流动问题导出的一类弱奇异Volterra积分方程的近似解。以一些化学反应的阶数为例求出解在零点的分数阶级数展开式及其Pade有理逼近。通过将发散积分解释为Hadamard有限部分积分,并借助数值积分方法导出解在... 研究带化学表面反应的边界层流动问题导出的一类弱奇异Volterra积分方程的近似解。以一些化学反应的阶数为例求出解在零点的分数阶级数展开式及其Pade有理逼近。通过将发散积分解释为Hadamard有限部分积分,并借助数值积分方法导出解在无穷远点的带高阶对数项的渐近展开式。实际计算表明,给出的解在零点和无穷远点展开式的联合使用可以在整个半无限区间上高效地求解这类带化学表面反应的边界层流动问题。 展开更多
关键词 边界层流动 化学表面反应 弱奇异Volterra积分方程 Hadamard有限部分积分 解在零点的展开式 解在无穷远点的展开式
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Desilication kinetics of calcined boron mud in molten sodium hydroxide media 被引量:4
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作者 NING Zhi-qiang SONG Qiu-shi +2 位作者 ZHAI Yu-chun XIE Hong-wei YU Kai 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2191-2198,共8页
Desilication kinetics of calcined boron mud(CBM) occurring in molten sodium hydroxide media was investigated. The effects of factors such as reaction temperature and Na OH-to-CBM mass ratio on silicon extraction effic... Desilication kinetics of calcined boron mud(CBM) occurring in molten sodium hydroxide media was investigated. The effects of factors such as reaction temperature and Na OH-to-CBM mass ratio on silicon extraction efficiency were studied. The results show that silicon extraction efficiency increases with increasing the reaction time and Na OH-to-CBM mass ratio. There are two stages for the desilication process of the calcined boron mud. The overall desilication process follows the shrinking-core model, and the first and second stages of the process were determined to obey the shrinking-core model for surface chemical reaction and the diffusion through the product layer, respectively. The activation energies of the first and second stages were calculated to be 44.78 k J/mol and 15.94 k J/mol, respectively. 展开更多
关键词 boron mud sodium hydroxide silicon dioxide KINETICS DESILICATION
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Defect-free surface of quartz glass polished in elastic mode by chemical impact reaction 被引量:1
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作者 彭文强 关朝亮 李圣怡 《Journal of Central South University》 SCIE EI CAS 2014年第12期4438-4444,共7页
Removal of brittle materials in the brittle or ductile mode inevitably causes damaged or strained surface layers containing cracks, scratches or dislocations. Within elastic deformation, the arrangement of each atom c... Removal of brittle materials in the brittle or ductile mode inevitably causes damaged or strained surface layers containing cracks, scratches or dislocations. Within elastic deformation, the arrangement of each atom can be recovered back to its original position without any defects introduced. Based on surface hydroxylation and chemisorption theory, material removal mechanism of quartz glass in the elastic mode is analyzed to obtain defect-free surface. Elastic contact condition between nanoparticle and quartz glass surface is confirmed from the Hertz contact theory model. Atoms on the quartz glass surface are removed by chemical bond generated by impact reaction in the elastic mode, so no defects are generated without mechanical process. Experiment was conducted on a numerically controlled system for nanoparticle jet polishing, and one flat quartz glass was polished in the elastic mode. Results show that scratches on the sample surface are completely removed away with no mechanical defects introduced, and microroughness(Ra) is decreased from 1.23 nm to 0.47 nm. Functional group Ce — O — Si on ceria nanoparticles after polishing was detected directly and indirectly by FTIR, XRD and XPS spectra analysis from which the chemical impact reaction is validated. 展开更多
关键词 defect-free surface chemical impact reaction nanoparticle jet polishing elastic mode
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