A comprehensive model for predicting the sulfur retention performance in circulating fluidized bed combustors was developed which involves the different residence times, the wide particle size distribution and the d...A comprehensive model for predicting the sulfur retention performance in circulating fluidized bed combustors was developed which involves the different residence times, the wide particle size distribution and the different forms of sulfur in the coal. In addition, the reductive decomposition of CaSO 4 is highlighted. The simulation results from the model show that the sulfur contents, the bed temperature, the sorbent particle size distribution and the sorbent activity or the maximum conversion rate can significantly influence the sulfur retention performance in circulating fluidized bed (CFB) combustors. 展开更多
高温等离子体作用下的中子辐照损伤和氢氦滞留行为一直是聚变堆钨基材料面临的两个关键问题,尤其是预辐照损伤对氢氦滞留的协同作用.鉴于制约因素的复杂性和实验上的困难,相关基础问题的理论研究至关重要.我们基于发展的顺序多尺度模拟...高温等离子体作用下的中子辐照损伤和氢氦滞留行为一直是聚变堆钨基材料面临的两个关键问题,尤其是预辐照损伤对氢氦滞留的协同作用.鉴于制约因素的复杂性和实验上的困难,相关基础问题的理论研究至关重要.我们基于发展的顺序多尺度模拟方法研究了多晶钨的中子预辐照损伤及其对低能(20 e V)氢注入下缺陷动力学演化和氢滞留分布的影响.通过定量对比有无中子预辐照的多晶钨中氢的滞留行为,我们发现中子预辐照损伤产生的稳定空位团簇作为新的氢捕获点,加剧了氢在近表面处的滞留和表面损伤,限制了其向深度的扩散,从而导致了低能氢滞留量的急剧增加.相关结果将直接为实际等离子体环境下聚变堆钨基材料的辐照损伤和氢氦效应提供理论指导与预测.展开更多
Polychlorinated dibenzothiophenes（PCDTs） are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 ...Polychlorinated dibenzothiophenes（PCDTs） are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 PCDTs congeners at the B3LYP/6-31G＊ level of theory.By means of the VSMP（variable selection and modeling based on prediction） program,one optimal descriptor（molecular polarizability,α） was selected to develop a QSRR model for the prediction of gas chromatographic retention indices（GC-RI） of PCDTs.The estimated correlation coefficients（r2） and LOO-validated correlation coefficients（q2）,all more than 0.99,were built by multiple linear regression,which shows a good estimation ability and stability of the models.A prediction power for the external samples was validated by the model built from the training set with 17 polychlorinated dibenzothiophenes.展开更多
基金the Major Research Project of the Ninth-Five Plan (1996 2 0 0 0 ) of China (96 - A19- 0 2 - 0 3)
文摘A comprehensive model for predicting the sulfur retention performance in circulating fluidized bed combustors was developed which involves the different residence times, the wide particle size distribution and the different forms of sulfur in the coal. In addition, the reductive decomposition of CaSO 4 is highlighted. The simulation results from the model show that the sulfur contents, the bed temperature, the sorbent particle size distribution and the sorbent activity or the maximum conversion rate can significantly influence the sulfur retention performance in circulating fluidized bed (CFB) combustors.
文摘高温等离子体作用下的中子辐照损伤和氢氦滞留行为一直是聚变堆钨基材料面临的两个关键问题,尤其是预辐照损伤对氢氦滞留的协同作用.鉴于制约因素的复杂性和实验上的困难,相关基础问题的理论研究至关重要.我们基于发展的顺序多尺度模拟方法研究了多晶钨的中子预辐照损伤及其对低能(20 e V)氢注入下缺陷动力学演化和氢滞留分布的影响.通过定量对比有无中子预辐照的多晶钨中氢的滞留行为,我们发现中子预辐照损伤产生的稳定空位团簇作为新的氢捕获点,加剧了氢在近表面处的滞留和表面损伤,限制了其向深度的扩散,从而导致了低能氢滞留量的急剧增加.相关结果将直接为实际等离子体环境下聚变堆钨基材料的辐照损伤和氢氦效应提供理论指导与预测.
基金Sponsored by the NSF of Guangxi Province (No. 2011XNSFA018059)Guangxi Key Laboratory Research Fund of Environmental Engineering and Protection Assessment (No. 0801Z026)+1 种基金Major Science of Water Pollution Control and Management (No. 2008ZX07317-02)the Guangxi Zhuang Autonomous Region Department of Education Research (No. 201010LX174) Funding
文摘Polychlorinated dibenzothiophenes（PCDTs） are a group of important persistent organic pollutants.In the present study,geometrical optimization and electrostatic potential calculations have been performed for all 135 PCDTs congeners at the B3LYP/6-31G＊ level of theory.By means of the VSMP（variable selection and modeling based on prediction） program,one optimal descriptor（molecular polarizability,α） was selected to develop a QSRR model for the prediction of gas chromatographic retention indices（GC-RI） of PCDTs.The estimated correlation coefficients（r2） and LOO-validated correlation coefficients（q2）,all more than 0.99,were built by multiple linear regression,which shows a good estimation ability and stability of the models.A prediction power for the external samples was validated by the model built from the training set with 17 polychlorinated dibenzothiophenes.
