A detailed mechanism covering 545 species and 3105 reactions for high-temperature combustion of n-propylcyclohexane（n-PCH）, generated via a mechanism generation program（ReaxGen） developed by our research group, wa...A detailed mechanism covering 545 species and 3105 reactions for high-temperature combustion of n-propylcyclohexane（n-PCH）, generated via a mechanism generation program（ReaxGen） developed by our research group, was validated in this study. A semi-detailed mechanism involved with 195 species and 573 reactions and a skeletal mechanism concerned with 108 species and 393 reactions were obtained by means of rate-of-production analysis and path flux analysis（PFA）, respectively. In order to validate the reliability of these mechanisms, ignition delay time, laminar flame speed and concentration profiles of important species were simulated with the help of CHEMKIN software. Numerically predicted results of our mechanisms are in very good agreement with available experimental data. Finally, major reaction pathways of n-PCH combustion and important reactions during the combustion process were investigated by reaction pathway analysis and sensitivity analysis, respectively. The results indicate that these mechanisms are reliable for describing the auto-ignition characteristics of n-PCH. These mechanisms would also be helpful to computational fluid dynamics（CFD） for engine design. Moreover, this systematic approach used in our study, which combines mechanism construction, simplification, validation and analysis for n-PCH, may also be employed to construct mechanisms for the high-temperature combustion of other cycloalkanes with one ring.展开更多
高温燃气红外光谱特征是判断燃气成分和浓度的有效途径。针对高温燃气红外辐射特性复杂、建模难度高的问题,研究了一种基于间隔偏最小二乘(interval Partial Least Squares,iPLS)和核主成分分析(Kernel Principal Component Analysis,KP...高温燃气红外光谱特征是判断燃气成分和浓度的有效途径。针对高温燃气红外辐射特性复杂、建模难度高的问题,研究了一种基于间隔偏最小二乘(interval Partial Least Squares,iPLS)和核主成分分析(Kernel Principal Component Analysis,KPCA)的特征提取算法。首先通过iPLS进行预筛选,确定具有最优预测能力的特征光谱波段,避免单个子区间建模过程中有用吸收峰信息的遗失;其次,利用KPCA降低数据维度,保留贡献率高的关键特征,降低成分预测模型的复杂度。仿真结果表明,经过iPLS-KPCA方法特征提取后,预测模型的复杂度大幅下降,且预测能力显著提升。展开更多
The application of cross flow ultrafiltration(CFF) techniques to separate colloidal organic carbon(COC) from truly dissolved organic carbon(TDOC) was investigated; COC and TDOC were determined by the high temperature ...The application of cross flow ultrafiltration(CFF) techniques to separate colloidal organic carbon(COC) from truly dissolved organic carbon(TDOC) was investigated; COC and TDOC were determined by the high temperature combustion method(HTC) and UV/persulphate method. It was found that CFF can quantitatively separate COC from seawater. The determination results by the HTC and UV/persulphate method for COC and TDOC showed little difference, which suggested that the oxidation efficiency of the two methods are identical. Colloidal particles have no remarkable influence on the oxidation efficiency of the UV/persulphate method.展开更多
基金Supported by the National Natural Science Foundation of China （No.91016002）.
文摘A detailed mechanism covering 545 species and 3105 reactions for high-temperature combustion of n-propylcyclohexane（n-PCH）, generated via a mechanism generation program（ReaxGen） developed by our research group, was validated in this study. A semi-detailed mechanism involved with 195 species and 573 reactions and a skeletal mechanism concerned with 108 species and 393 reactions were obtained by means of rate-of-production analysis and path flux analysis（PFA）, respectively. In order to validate the reliability of these mechanisms, ignition delay time, laminar flame speed and concentration profiles of important species were simulated with the help of CHEMKIN software. Numerically predicted results of our mechanisms are in very good agreement with available experimental data. Finally, major reaction pathways of n-PCH combustion and important reactions during the combustion process were investigated by reaction pathway analysis and sensitivity analysis, respectively. The results indicate that these mechanisms are reliable for describing the auto-ignition characteristics of n-PCH. These mechanisms would also be helpful to computational fluid dynamics（CFD） for engine design. Moreover, this systematic approach used in our study, which combines mechanism construction, simplification, validation and analysis for n-PCH, may also be employed to construct mechanisms for the high-temperature combustion of other cycloalkanes with one ring.
文摘高温燃气红外光谱特征是判断燃气成分和浓度的有效途径。针对高温燃气红外辐射特性复杂、建模难度高的问题,研究了一种基于间隔偏最小二乘(interval Partial Least Squares,iPLS)和核主成分分析(Kernel Principal Component Analysis,KPCA)的特征提取算法。首先通过iPLS进行预筛选,确定具有最优预测能力的特征光谱波段,避免单个子区间建模过程中有用吸收峰信息的遗失;其次,利用KPCA降低数据维度,保留贡献率高的关键特征,降低成分预测模型的复杂度。仿真结果表明,经过iPLS-KPCA方法特征提取后,预测模型的复杂度大幅下降,且预测能力显著提升。
文摘The application of cross flow ultrafiltration(CFF) techniques to separate colloidal organic carbon(COC) from truly dissolved organic carbon(TDOC) was investigated; COC and TDOC were determined by the high temperature combustion method(HTC) and UV/persulphate method. It was found that CFF can quantitatively separate COC from seawater. The determination results by the HTC and UV/persulphate method for COC and TDOC showed little difference, which suggested that the oxidation efficiency of the two methods are identical. Colloidal particles have no remarkable influence on the oxidation efficiency of the UV/persulphate method.
