A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three g...A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three groups of rats were determined including control rats, rats treated with blended cigarettes(nonmenthol cigarettes) and rats treated with menthol cigarettes. The total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol(NNAL), total 1-hydroxypyrene(1-HOP) and 3-hydroxybenzo[a] pyrene(3-HOBaP) were determined for assessing exposure to cigarette sidestream smoke toxins. Urinary endogenous metabolites in the three groups of rats were also analyzed and the data were processed by chemometrics. Eleven endogenous metabolites were found and identified. Their relative levels were compared among the three groups. The results show that cigarette sidestream smoke has complex effect on rats. Blended cigarette group makes difference to menthol cigarette group in the rats' urinary metabolic changes. Menthol adding to cigarettes has positive and negative effects on rats, respectively. The urinary metabolic profiling of menthol cigarette group is closer to that of control group.展开更多
Coalbed gas non-Darcy flow has been observed in high permeable fracture systems,and some mathematical and numerical models have been proposed to study the effects of non-Darcy flow using Forchheimer non-Darcy model.Ho...Coalbed gas non-Darcy flow has been observed in high permeable fracture systems,and some mathematical and numerical models have been proposed to study the effects of non-Darcy flow using Forchheimer non-Darcy model.However,experimental results show that the assumption of a constant Forchheimer factor may cause some limitations in using Forchheimer model to describe non-Darcy flow in porous media.In order to investigate the effects of non-Darcy flow on coalbed methane production,this work presents a more general coalbed gas non-Darcy flow model according to Barree-Conway equation,which could describe the entire range of relationships between flow velocity and pressure gradient from low to high flow velocity.An expanded mixed finite element method is introduced to solve the coalbed gas non-Darcy flow model,in which the gas pressure and velocity can be approximated simultaneously.Error estimate results indicate that pressure and velocity could achieve first-order convergence rate.Non-Darcy simulation results indicate that the non-Darcy effect is significant in the zone near the wellbore,and with the distance from the wellbore increasing,the non-Darcy effect becomes weak gradually.From simulation results,we have also found that the non-Darcy effect is more significant at a lower bottom-hole pressure,and the gas production from non-Darcy flow is lower than the production from Darcy flow under the same permeable condition.展开更多
基金Project(20805045)supported by National Natural Science Foundation of China
文摘A metabonomic approach was undertaken in order to detect urinary endogenous and exogenous metabolites and to evaluate the effects of passive exposure to cigarette sidestream smoke on rats. Urinary samples from three groups of rats were determined including control rats, rats treated with blended cigarettes(nonmenthol cigarettes) and rats treated with menthol cigarettes. The total urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol(NNAL), total 1-hydroxypyrene(1-HOP) and 3-hydroxybenzo[a] pyrene(3-HOBaP) were determined for assessing exposure to cigarette sidestream smoke toxins. Urinary endogenous metabolites in the three groups of rats were also analyzed and the data were processed by chemometrics. Eleven endogenous metabolites were found and identified. Their relative levels were compared among the three groups. The results show that cigarette sidestream smoke has complex effect on rats. Blended cigarette group makes difference to menthol cigarette group in the rats' urinary metabolic changes. Menthol adding to cigarettes has positive and negative effects on rats, respectively. The urinary metabolic profiling of menthol cigarette group is closer to that of control group.
基金Projects(91330106,11171190)supported by the National Natural Science Foundation of ChinaProjects(15CX05065A,15CX05003A)supported by the Fundamental Research Funds for the Central Universities,China
文摘Coalbed gas non-Darcy flow has been observed in high permeable fracture systems,and some mathematical and numerical models have been proposed to study the effects of non-Darcy flow using Forchheimer non-Darcy model.However,experimental results show that the assumption of a constant Forchheimer factor may cause some limitations in using Forchheimer model to describe non-Darcy flow in porous media.In order to investigate the effects of non-Darcy flow on coalbed methane production,this work presents a more general coalbed gas non-Darcy flow model according to Barree-Conway equation,which could describe the entire range of relationships between flow velocity and pressure gradient from low to high flow velocity.An expanded mixed finite element method is introduced to solve the coalbed gas non-Darcy flow model,in which the gas pressure and velocity can be approximated simultaneously.Error estimate results indicate that pressure and velocity could achieve first-order convergence rate.Non-Darcy simulation results indicate that the non-Darcy effect is significant in the zone near the wellbore,and with the distance from the wellbore increasing,the non-Darcy effect becomes weak gradually.From simulation results,we have also found that the non-Darcy effect is more significant at a lower bottom-hole pressure,and the gas production from non-Darcy flow is lower than the production from Darcy flow under the same permeable condition.
