Purely siliceous MCM 41 with a narrow pore-size distribution , different pore size , high surface area was synthesized . As prepared , calcined and catalytically tested MCM 41 materials have been comprehensively chara...Purely siliceous MCM 41 with a narrow pore-size distribution , different pore size , high surface area was synthesized . As prepared , calcined and catalytically tested MCM 41 materials have been comprehensively characterized by N2 adsorption/desorption at 77K and 129Xe NMR . By adding mesitylene during the synthesis , the pore size of MCM 41 was enlarged to 5.2nm. The chemical shift in 129Xe NMR spectroscopy of adsorbed xenon indicates that the MCM 41 is one dimensional pore channels .展开更多
In the present study, the analytical method for ^129iodine (^129I) in ferromanganese crusts is developed and ^129iodine/^127iodine (^129I/^127I) ratio in ferromanganese crusts is measured by the accelerator mass s...In the present study, the analytical method for ^129iodine (^129I) in ferromanganese crusts is developed and ^129iodine/^127iodine (^129I/^127I) ratio in ferromanganese crusts is measured by the accelerator mass spectrometry (AMS). The developed method is applied to analyze ^129I/^127I ratio in two ferromanganese crusts MP5D44 and CXD08-1 collected from the Mid-Pacific Ocean. The results show that ^129I/^127I ratio in MP5D44 and CXD08-1 crusts varies from 7×10^-14 to 1.27×10^-12, with the lowest value falling on the detection limit level of AMS reported by previous literatures. For the depth distribution of ^129I/^127I, it is found that both MP5D44 and CXD08-1 crusts have two growth generations, and the ^129I/^127I profiles in two generations all displayed an approximate exponential decay. According to the ^129I/^127I ratio, the generate age of bottom layer of MP5D44 and CXD08-1 was estimated to be 54.77 and 69.69 Ma, respectively.展开更多
A novel Micro-Reactor-GC system was used to study the performance of two kinds of FCC catalysts coked in a FFB reactor under simulated industrial conditions using dodecane and octene as probe molecules. The result sho...A novel Micro-Reactor-GC system was used to study the performance of two kinds of FCC catalysts coked in a FFB reactor under simulated industrial conditions using dodecane and octene as probe molecules. The result shows that the performance of the two cokedcatalysts differed significantly. The 129Xe NMR technique was used to detect the location of coke deposition on the catalysts, which gave a good explanation of the experimental results.展开更多
文摘Purely siliceous MCM 41 with a narrow pore-size distribution , different pore size , high surface area was synthesized . As prepared , calcined and catalytically tested MCM 41 materials have been comprehensively characterized by N2 adsorption/desorption at 77K and 129Xe NMR . By adding mesitylene during the synthesis , the pore size of MCM 41 was enlarged to 5.2nm. The chemical shift in 129Xe NMR spectroscopy of adsorbed xenon indicates that the MCM 41 is one dimensional pore channels .
基金The National Natural Science Foundation of China under contract No.41073044
文摘In the present study, the analytical method for ^129iodine (^129I) in ferromanganese crusts is developed and ^129iodine/^127iodine (^129I/^127I) ratio in ferromanganese crusts is measured by the accelerator mass spectrometry (AMS). The developed method is applied to analyze ^129I/^127I ratio in two ferromanganese crusts MP5D44 and CXD08-1 collected from the Mid-Pacific Ocean. The results show that ^129I/^127I ratio in MP5D44 and CXD08-1 crusts varies from 7×10^-14 to 1.27×10^-12, with the lowest value falling on the detection limit level of AMS reported by previous literatures. For the depth distribution of ^129I/^127I, it is found that both MP5D44 and CXD08-1 crusts have two growth generations, and the ^129I/^127I profiles in two generations all displayed an approximate exponential decay. According to the ^129I/^127I ratio, the generate age of bottom layer of MP5D44 and CXD08-1 was estimated to be 54.77 and 69.69 Ma, respectively.
文摘A novel Micro-Reactor-GC system was used to study the performance of two kinds of FCC catalysts coked in a FFB reactor under simulated industrial conditions using dodecane and octene as probe molecules. The result shows that the performance of the two cokedcatalysts differed significantly. The 129Xe NMR technique was used to detect the location of coke deposition on the catalysts, which gave a good explanation of the experimental results.