A new indicator with temperature dependence of the NO3 loss frequency, was developed to study the contribution of NO3 to the oxidation of monoterpenes and NOx removal in the atmosphere. The new indicator arises from t...A new indicator with temperature dependence of the NO3 loss frequency, was developed to study the contribution of NO3 to the oxidation of monoterpenes and NOx removal in the atmosphere. The new indicator arises from the temperature dependence of kinetic constant. The new indicator was applied to data of observation based on differential optical absorption spectroscopy system on the outskirts of Hefei, China. According to the findings, the contribution of monoterpenes to the loss of NO3 was 70%-80%.展开更多
An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and...An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and its commercial application,but it has not been systematically investigated.Herein,regenerating HNO3 from Ca(NO3)2 solution with low-cost H2SO4,and simultaneous synthesis of fibrous CaSO4·2H2O by-products were studied.As a theoretical basis,the solubility of CaSO4·2H2O in HNO3 medium is studied.It is concluded that the solubility of CaSO4·2H2O increases with increasing temperature or increasing HNO3 concentration,which has considerable guiding significance for the subsequent experimental research and analysis.Then,the effects of various factors on the residual Ca^2+ concentration of filtrate,the regenerated HNO3 concentration and the morphology of synthesized products are investigated using ICP-AES and SEM.And the effect mechanism is also analyzed.The results indicate the regenerated HNO3 concentration reaches 116 g/L with the residual Ca^2+ concentration being 9.7 g/L at the optimum conditions.Moreover,fibrous CaSO4·2H2O by-products with high aspect ratios(length,406.32μm;diameter,14.71μm;aspect ratio,27.62)can be simultaneously synthesized.展开更多
基金ACKNOWLEDGMENTS We acknowledged to DOAS groups. This work was supported by the Key Project of Chinese Ministry of Education （No.209057）, the Anhui Provincial Natural Science Foundation （No.090412028）, and the Natural Science Foundation of Anhui Province Colleges and University （No.KJ2008A114）.
文摘A new indicator with temperature dependence of the NO3 loss frequency, was developed to study the contribution of NO3 to the oxidation of monoterpenes and NOx removal in the atmosphere. The new indicator arises from the temperature dependence of kinetic constant. The new indicator was applied to data of observation based on differential optical absorption spectroscopy system on the outskirts of Hefei, China. According to the findings, the contribution of monoterpenes to the loss of NO3 was 70%-80%.
基金Project(2182040)supported by the Beijing Natural Science Foundation,ChinaProjects(51674026,51974025,U1802253)supported by the National Natural Science Foundation of ChinaProject(FRF-TT-19-001)supported by the Fundamental Research Funds for the Central Universities,China。
文摘An innovative technology,nitric acid pressure leaching of limonitic laterite ores,was proposed by our research team.The HNO3 regeneration is considerable significance for the improvement of the proposed technology and its commercial application,but it has not been systematically investigated.Herein,regenerating HNO3 from Ca(NO3)2 solution with low-cost H2SO4,and simultaneous synthesis of fibrous CaSO4·2H2O by-products were studied.As a theoretical basis,the solubility of CaSO4·2H2O in HNO3 medium is studied.It is concluded that the solubility of CaSO4·2H2O increases with increasing temperature or increasing HNO3 concentration,which has considerable guiding significance for the subsequent experimental research and analysis.Then,the effects of various factors on the residual Ca^2+ concentration of filtrate,the regenerated HNO3 concentration and the morphology of synthesized products are investigated using ICP-AES and SEM.And the effect mechanism is also analyzed.The results indicate the regenerated HNO3 concentration reaches 116 g/L with the residual Ca^2+ concentration being 9.7 g/L at the optimum conditions.Moreover,fibrous CaSO4·2H2O by-products with high aspect ratios(length,406.32μm;diameter,14.71μm;aspect ratio,27.62)can be simultaneously synthesized.
