This work aims at solving the problems of difficult dispersion,easy oxidation and high cost of nano carbon during application,carbon/magnesium aluminate spinel(C/MgAl_(2)O_(4))composite powders were prepared using MgC...This work aims at solving the problems of difficult dispersion,easy oxidation and high cost of nano carbon during application,carbon/magnesium aluminate spinel(C/MgAl_(2)O_(4))composite powders were prepared using MgC2O4·2H2O,MgO2,Al2O3 powder,and Al powder as raw materials by combustion synthesis.The results indicate that with the maximum MgC2O4·2H2O addition of 33.34 mass%,the prepared powder contains 1.17 mass%of carbon and carbon distributes among spinel grains.The MgAl_(2)O_(4)spinel shows both granular and rod-like morphologies.The granular MgAl_(2)O_(4)spinel is generated from mutual diffusion between MgO and Al2O3;while the rod-like MgAl_(2)O_(4)spinel is mainly formed by the vapor-solid growth mechanism from Mg vapor and Al2O3.展开更多
A scramjet engine combustion efficiency measure system was designed.The combustion efficiency was measured by chromatography method,and the results of chromatography method were compared with those of temperature meth...A scramjet engine combustion efficiency measure system was designed.The combustion efficiency was measured by chromatography method,and the results of chromatography method were compared with those of temperature method.The results indicate that the combustion efficiency measured by chromatography method was 80.7%,lower than the combustion efficiency of 84.5%measured by temperature method;the combustion efficiency could be measured more precisely by chromatogram method than by temperature method.The combustion efficiency measure system based on chromatogram method can work well,and thus can be used to measure the combustion efficiency of scramjet engine.展开更多
文摘This work aims at solving the problems of difficult dispersion,easy oxidation and high cost of nano carbon during application,carbon/magnesium aluminate spinel(C/MgAl_(2)O_(4))composite powders were prepared using MgC2O4·2H2O,MgO2,Al2O3 powder,and Al powder as raw materials by combustion synthesis.The results indicate that with the maximum MgC2O4·2H2O addition of 33.34 mass%,the prepared powder contains 1.17 mass%of carbon and carbon distributes among spinel grains.The MgAl_(2)O_(4)spinel shows both granular and rod-like morphologies.The granular MgAl_(2)O_(4)spinel is generated from mutual diffusion between MgO and Al2O3;while the rod-like MgAl_(2)O_(4)spinel is mainly formed by the vapor-solid growth mechanism from Mg vapor and Al2O3.
文摘A scramjet engine combustion efficiency measure system was designed.The combustion efficiency was measured by chromatography method,and the results of chromatography method were compared with those of temperature method.The results indicate that the combustion efficiency measured by chromatography method was 80.7%,lower than the combustion efficiency of 84.5%measured by temperature method;the combustion efficiency could be measured more precisely by chromatogram method than by temperature method.The combustion efficiency measure system based on chromatogram method can work well,and thus can be used to measure the combustion efficiency of scramjet engine.
