In order to design and predict the dechlorination processes for remediating the halogenated aromatic com- pounds in the biobarrier system applied in situ, an anaerobic continuous-flow column was set up with the introd...In order to design and predict the dechlorination processes for remediating the halogenated aromatic com- pounds in the biobarrier system applied in situ, an anaerobic continuous-flow column was set up with the introduction of an enriched 2, 4, 6-trichlorophenol （TCP） reductive dechlorinating consortium. The fates of TCP and its metabo- lites were simulated according to the first-order sequential dechlorination kinetic model. The enriched TCP anaerobic dechlorinating consortium dechlorinated 100 p.mol/L TCP to 4-chlorophenol （4-CP） via 2,4-dichlorophenol （DCP） in 10 d. The consortium was predominated with the phylum of Firmicutes and Bacteroidetes, based on the PCR- denaturing gradient gel electrophoresis （DGGE） analysis. After the consortium was applied to the colunm, the ex- perimental data in the steady state were fitted by the least square method, and the first-order dechlorination kinetic constants from TCP to 2,4-DCP, from 2,4-DCP to 4-CP and from 4-CP to phenol, were 1.58 d-1, 2.23 d 1 and 0.206 d-1, respectively. According to the fitting results, the required biobarrier width for the complete remediation of TCP, 2,4- DCP and 4-CP were 126 cm, 130 cm and 689 cm, respectively. The dechlorination/degradation of 4-CP must be in- creased when the technology is applied to the real site.展开更多
目的探讨4 d头低位卧床(head-down bed rest,HDBR)模拟失重对人体运动能力的影响及人工重力联合中等强度运动锻炼的对抗效果。方法 12名健康男性志愿者随机分为2组:对照组(n=6)仅进行4 d HDBR;对抗组(n=6)HDBR期间每天上下午各进行1次30...目的探讨4 d头低位卧床(head-down bed rest,HDBR)模拟失重对人体运动能力的影响及人工重力联合中等强度运动锻炼的对抗效果。方法 12名健康男性志愿者随机分为2组:对照组(n=6)仅进行4 d HDBR;对抗组(n=6)HDBR期间每天上下午各进行1次30 min基于人工重力(足水平2 Gz)的中等强度运动锻炼。HDBR前后对所有志愿者分别进行有氧和无氧运动能力测试。结果 HDBR后对照组递增负荷累计运动应激指数、最大摄氧量、无氧阈及30 s最大负荷运动中的最小无氧功较卧床前均显著下降(P<0.05),无氧功递减率显著升高(P<0.05)而无氧功峰值、平均无氧功均无显著改变;HDBR后对抗组上述各项指标均无显著改变。结论 4 d HDBR可致人体运动能力下降,其中对有氧运动能力影响最大,对无氧运动能力影响较小。基于人工重力的中等强度运动锻炼可有效对抗模拟失重所致的有氧及无氧运动耐力下降。展开更多
采用数值模拟方法对气体搅拌下厌氧消化反应器内气液两相流动进行研究,探讨不同流量下反应器内非牛顿液相的速度场、流场及动力黏度等流体动力学信息,并进一步分析不同多相流模型、相间作用力以及多相湍流模型对液相速度的影响。结果表...采用数值模拟方法对气体搅拌下厌氧消化反应器内气液两相流动进行研究,探讨不同流量下反应器内非牛顿液相的速度场、流场及动力黏度等流体动力学信息,并进一步分析不同多相流模型、相间作用力以及多相湍流模型对液相速度的影响。结果表明:入口气体流量的增大并没有对流场形态和旋涡分布产生明显影响,但能有效降低液相动力黏度峰值,改善厌氧消化反应器内液相的流动性,尤其影响着反应器四周底部区域液相动力黏度。入口流量为2.05 m L/s及5.3 m L/s时,欧拉双流体模型与欧拉双流体模型耦合群体平衡模型(Population balance model,PBM)模拟得到的液相速度与实验值较为接近,并优于欧拉-拉格朗日模型;采用标准k-ε模型(Standard k-ε),重整化群k-ε模型(RNG k-ε)得到的液相速度模拟值优于可实现k-ε模型(Realizable k-ε)。相间作用力考虑为升力及曳力组合时,模拟得到的液相速度与实验值吻合良好。展开更多
基金Supported by Grant-in-Aids for Scientific Research from the Ministry of Education,Culture,Sports,Science and Technology of Japan (No.23310055 and No.23658272)
文摘In order to design and predict the dechlorination processes for remediating the halogenated aromatic com- pounds in the biobarrier system applied in situ, an anaerobic continuous-flow column was set up with the introduction of an enriched 2, 4, 6-trichlorophenol （TCP） reductive dechlorinating consortium. The fates of TCP and its metabo- lites were simulated according to the first-order sequential dechlorination kinetic model. The enriched TCP anaerobic dechlorinating consortium dechlorinated 100 p.mol/L TCP to 4-chlorophenol （4-CP） via 2,4-dichlorophenol （DCP） in 10 d. The consortium was predominated with the phylum of Firmicutes and Bacteroidetes, based on the PCR- denaturing gradient gel electrophoresis （DGGE） analysis. After the consortium was applied to the colunm, the ex- perimental data in the steady state were fitted by the least square method, and the first-order dechlorination kinetic constants from TCP to 2,4-DCP, from 2,4-DCP to 4-CP and from 4-CP to phenol, were 1.58 d-1, 2.23 d 1 and 0.206 d-1, respectively. According to the fitting results, the required biobarrier width for the complete remediation of TCP, 2,4- DCP and 4-CP were 126 cm, 130 cm and 689 cm, respectively. The dechlorination/degradation of 4-CP must be in- creased when the technology is applied to the real site.
文摘目的探讨4 d头低位卧床(head-down bed rest,HDBR)模拟失重对人体运动能力的影响及人工重力联合中等强度运动锻炼的对抗效果。方法 12名健康男性志愿者随机分为2组:对照组(n=6)仅进行4 d HDBR;对抗组(n=6)HDBR期间每天上下午各进行1次30 min基于人工重力(足水平2 Gz)的中等强度运动锻炼。HDBR前后对所有志愿者分别进行有氧和无氧运动能力测试。结果 HDBR后对照组递增负荷累计运动应激指数、最大摄氧量、无氧阈及30 s最大负荷运动中的最小无氧功较卧床前均显著下降(P<0.05),无氧功递减率显著升高(P<0.05)而无氧功峰值、平均无氧功均无显著改变;HDBR后对抗组上述各项指标均无显著改变。结论 4 d HDBR可致人体运动能力下降,其中对有氧运动能力影响最大,对无氧运动能力影响较小。基于人工重力的中等强度运动锻炼可有效对抗模拟失重所致的有氧及无氧运动耐力下降。
文摘采用数值模拟方法对气体搅拌下厌氧消化反应器内气液两相流动进行研究,探讨不同流量下反应器内非牛顿液相的速度场、流场及动力黏度等流体动力学信息,并进一步分析不同多相流模型、相间作用力以及多相湍流模型对液相速度的影响。结果表明:入口气体流量的增大并没有对流场形态和旋涡分布产生明显影响,但能有效降低液相动力黏度峰值,改善厌氧消化反应器内液相的流动性,尤其影响着反应器四周底部区域液相动力黏度。入口流量为2.05 m L/s及5.3 m L/s时,欧拉双流体模型与欧拉双流体模型耦合群体平衡模型(Population balance model,PBM)模拟得到的液相速度与实验值较为接近,并优于欧拉-拉格朗日模型;采用标准k-ε模型(Standard k-ε),重整化群k-ε模型(RNG k-ε)得到的液相速度模拟值优于可实现k-ε模型(Realizable k-ε)。相间作用力考虑为升力及曳力组合时,模拟得到的液相速度与实验值吻合良好。
