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Jian-Xin Nie 《中国物理 B》2022,31(4):44703-044703
The combustion mechanism of aluminum particles in a detonation environment characterized by high temperature (in unit 103 K), high pressure (in unit GPa), and high-speed motion (in units km/s) was studied, and a combustion model of the aluminum particles in detonation environment was established. Based on this model, a combustion control equation for aluminum particles in detonation environment was obtained. It can be seen from the control equation that the burning time of aluminum particle is mainly affected by the particle size, system temperature, and diffusion coefficient. The calculation result shows that a higher system temperature, larger diffusion coefficient, and smaller particle size lead to a faster burn rate and shorter burning time for aluminum particles. After considering the particle size distribution characteristics of aluminum powder, the application of the combustion control equation was extended from single aluminum particles to nonuniform aluminum powder, and the calculated time corresponding to the peak burn rate of aluminum powder was in good agreement with the experimental electrical conductivity results. This equation can quantitatively describe the combustion behavior of aluminum powder in different detonation environments and provides technical means for quantitative calculation of the aluminum powder combustion process in detonation environment. 相似文献
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利用溶胶-凝胶法合成了固溶体Ce1-xPrxO2-δ (x=0.05~0.30). X射线衍射(XRD)分析表明, 在x≤0.30的范围内形成了单相萤石结构固溶体Ce1-xPrxO2-δ; X射线光电子能谱(XPS)结果表明, 样品中氧缺位浓度随掺杂量增大而增大, 铈离子主要为Ce4+离子, 镨离子以混合价态Pr3+和Pr4+存在; 拉曼光谱(Raman)观察到两个峰, 458 cm-1峰为特征F2g振动谱带, 较宽的570 cm-1峰与样品中氧离子缺位有关; 交流阻抗谱测试表明, 固溶体Ce1-xPrxO2-δ的电导率随掺杂量增加而增大, x=0.2时, 电导率达到最大, 活化能较低, σ600 ℃=3.28×10-2 S/cm, σ700 ℃=6.06×10-2 S/cm, Ea=0.54 eV (250~650 ℃), Ea=0.49 eV (650~800 ℃). 相似文献
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利用X射线衍射(XRD)、拉曼光谱(Raman)、X射线光电子能谱(XPS)和交流阻抗谱对溶胶-凝胶法制备的稀土双掺杂固溶体Ce0.8Cd0.2-xPrxO1.9(x=0,0.02,0.10)的结构和导电性进行了研究.XRD结果表明,经800℃焙烧所得样品都形成了单相立方萤石结构,平均晶粒尺寸在23~30 nm之间;X... 相似文献
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钴掺杂二氧化钛的光催化制氢性能 总被引:2,自引:0,他引:2
采用聚合络合法(PCM)制备出钴掺杂二氧化钛(CO/TiO2)光催化剂.以热重-差示扫描量热同步热分析(TGA-DSC),傅里叶变换红外(FT-IR)光谱,X射线粉末衍射(XRD),氮气吸附-脱附,紫外-可见漫反射光谱(UV-Vis DRS),X射线光电子能谱(XPS)等手段对材料进行了表征.采用光催化制氧作为探针反应,以氧气的产量评价材料的光催化性能结果表明:采用聚合络合法制备的样品主体成分为锐钛矿晶型的二氧化钛,钴元素呈高度分散,钴的掺杂能够明显提升二氧化钛光催化材料的光催化制氢活性,当钴钛物质的量之比为0.3%时,催化剂具有最佳的光催化制氢活性,达到2499μmol,是同等条件下制备的无掺杂二氧化钛的近六倍.还对钴离子掺杂增强机理进行了探讨. 相似文献
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