This study developed a highly accurate retrieval algorithm for the column-averaged CO2 dry-air mixing ratio (XCO2) to be observed by TanSat, China's carbon dioxide observation satellite that will be launched in 20...This study developed a highly accurate retrieval algorithm for the column-averaged CO2 dry-air mixing ratio (XCO2) to be observed by TanSat, China's carbon dioxide observation satellite that will be launched in 2015. The Greenhouse Gases Observing Satellite (GOSAT) L1B spectrum was applied in retrieval experiment, and the results were validated with ground-observed measurements from the Total Column Carbon Observing Network (TCCON). At mid-latitudes, most results fell in the 1% error region, which correspond to the performance of GOSAT algorithm. The results also showed seasonal variation in XCO2 in both hemispheres.展开更多
The study on the special phenomenon,occurrence process and control mechanism of gasoline-air mixture thermal ignition in underground oil depots is of important academic and applied value for enriching scientific theor...The study on the special phenomenon,occurrence process and control mechanism of gasoline-air mixture thermal ignition in underground oil depots is of important academic and applied value for enriching scientific theories of explosion safety,developing protective technology against fire and decreasing the number of fire accidents.In this paper,the research on thermal ignition process of gasoline-air mixture in model underground oil depots tunnel has been carried out by using experiment and numerical simulation methods.The calculation result has been demonstrated by the experiment data.The five stages of thermal ignition course,which are slow oxidation stage,rapid oxidation stage,fire stage,flameout stage and quench stage,have been firstly defined and accurately descried.According to the magnitude order of concentration,the species have been divided into six categories,which lay the foundation for explosion-proof design based on the role of different species.The influence of space scale on thermal ignition in small-scale space has been found,and the mechanism for not easy to fire is that the wall reflection causes the reflux of fluids and changes the distribution of heat and mass,so that the progress of chemical reactions in the whole space are also changed.The novel mathematical model on the basis of unification chemical kinetics and thermodynamics established in this paper provides supplementary means for the analysis of process and mechanism of thermal ignition.展开更多
The laminar burning velocities and Markstein lengths of the hydrogen-air-diluent mixtures were meas-ured at different equivalence ratios (0.4―1.5), different diluents (N2, CO2 and 15%CO2+85%N2) and di-lution ratios (...The laminar burning velocities and Markstein lengths of the hydrogen-air-diluent mixtures were meas-ured at different equivalence ratios (0.4―1.5), different diluents (N2, CO2 and 15%CO2+85%N2) and di-lution ratios (0, 0.05, 0.10 and 0.15) by using the outwardly expanding flame. The influences of flame stretch rate on the flame propagation characteristics were analyzed. The results show that both the laminar burning velocities and the Markstein lengths of the hydrogen-air-diluent mixtures decrease with the increase of dilution ratio. The decrease in Markstein lengths means that adding diluents into the hydrogen-air mixtures will decrease the diffusional-thermal instability of the flame front. For a specified dilution ratio, the laminar burning velocities give their maximum values at an equivalence ratio of 1.8. The Markstein lengths increase with the increase of the equivalence ratio monotonously regardless of the diluents. The study shows that CO2 as the diluent has a greater impact on the laminar flame speed and the flame front stability than N2 as the diluent.展开更多
基金supported by the Strategic Priority Research Program-Climate Change:Carbon Budget and Relevant Issues (XDA05040200)the National High-tech R&D Program (2011AA12A104)
文摘This study developed a highly accurate retrieval algorithm for the column-averaged CO2 dry-air mixing ratio (XCO2) to be observed by TanSat, China's carbon dioxide observation satellite that will be launched in 2015. The Greenhouse Gases Observing Satellite (GOSAT) L1B spectrum was applied in retrieval experiment, and the results were validated with ground-observed measurements from the Total Column Carbon Observing Network (TCCON). At mid-latitudes, most results fell in the 1% error region, which correspond to the performance of GOSAT algorithm. The results also showed seasonal variation in XCO2 in both hemispheres.
文摘The study on the special phenomenon,occurrence process and control mechanism of gasoline-air mixture thermal ignition in underground oil depots is of important academic and applied value for enriching scientific theories of explosion safety,developing protective technology against fire and decreasing the number of fire accidents.In this paper,the research on thermal ignition process of gasoline-air mixture in model underground oil depots tunnel has been carried out by using experiment and numerical simulation methods.The calculation result has been demonstrated by the experiment data.The five stages of thermal ignition course,which are slow oxidation stage,rapid oxidation stage,fire stage,flameout stage and quench stage,have been firstly defined and accurately descried.According to the magnitude order of concentration,the species have been divided into six categories,which lay the foundation for explosion-proof design based on the role of different species.The influence of space scale on thermal ignition in small-scale space has been found,and the mechanism for not easy to fire is that the wall reflection causes the reflux of fluids and changes the distribution of heat and mass,so that the progress of chemical reactions in the whole space are also changed.The novel mathematical model on the basis of unification chemical kinetics and thermodynamics established in this paper provides supplementary means for the analysis of process and mechanism of thermal ignition.
基金Supported by the National Basic Research Program of China (Grant No. 2007CB210006)National Natural Science Foundation of China (Grants Nos. 50636040 and 50521604)
文摘The laminar burning velocities and Markstein lengths of the hydrogen-air-diluent mixtures were meas-ured at different equivalence ratios (0.4―1.5), different diluents (N2, CO2 and 15%CO2+85%N2) and di-lution ratios (0, 0.05, 0.10 and 0.15) by using the outwardly expanding flame. The influences of flame stretch rate on the flame propagation characteristics were analyzed. The results show that both the laminar burning velocities and the Markstein lengths of the hydrogen-air-diluent mixtures decrease with the increase of dilution ratio. The decrease in Markstein lengths means that adding diluents into the hydrogen-air mixtures will decrease the diffusional-thermal instability of the flame front. For a specified dilution ratio, the laminar burning velocities give their maximum values at an equivalence ratio of 1.8. The Markstein lengths increase with the increase of the equivalence ratio monotonously regardless of the diluents. The study shows that CO2 as the diluent has a greater impact on the laminar flame speed and the flame front stability than N2 as the diluent.
