Cobalt-free perovskite-type oxides BaFel_yTayO3-6 （0 _〈 y -〈 0.2） were synthesized via a simple solid state reac- tion. The cubic perovskite structure can be obtained when y is over 0.1. BaFeo.Ta0.lO3-6 （BFT0.1）...Cobalt-free perovskite-type oxides BaFel_yTayO3-6 （0 _〈 y -〈 0.2） were synthesized via a simple solid state reac- tion. The cubic perovskite structure can be obtained when y is over 0.1. BaFeo.Ta0.lO3-6 （BFT0.1） membrane shows the highest oxygen permeation flux, which can reach 1.6 ml. min- 1. cm-2 at 950 ℃ under the gradient of air/He. The O2-TPD results reveal that BaFe0.9Ta0.lO3-a material shows an excellent reversibility and phase structure stability in air. The oxygen permeation flux is limited by the bulk diffusion when the membrane thick- ness is over 0.8 mm, and it is limited by both the bulk diffusion and the surface exchange when the membrane thickness is below 0.5 mm. Stable oxygen permeation fluxes are obtained during 180 h operation.展开更多
Permeabilities and selectivities of gases such as carbon dioxide （CO2）, sulfur dioxide （SO2）, nitrogen （N2） and methane （CH4） in six imidazolium-based ionic liquids （[emim][BF4], [bmim][BF4], [bmim][PF6], [ba...Permeabilities and selectivities of gases such as carbon dioxide （CO2）, sulfur dioxide （SO2）, nitrogen （N2） and methane （CH4） in six imidazolium-based ionic liquids （[emim][BF4], [bmim][BF4], [bmim][PF6], [banim][BF4], [bmim][Tf2N] and [emim][CF3SO3]） supported on polyethersulfone microfiltration membranes are investigated in a single gas feed system using nitrogen as the environment and reference component at temperature from 25 to 45℃ and pressure of N2 from 100 to 400 kPa. It is found that SO2 has the highest permeability in the tested supported ionic liquid membranes, being an order of magnitude higher than that of CO2, and about 2 to 3 orders of magnitude larger than those of N2 and CH4. The observed selectivity of SO2 over the two ordinary gas components is also striking. It is shown experimentally that the dissolution and transport of gas components in the supported ionic liquid membranes, as well as the nature of ionic liquids play important roles in the gas permeation. A nonlinear increase of permeation rate with temperature and operation pressure is also observed for all sample gases. By considering the factors that influence the permeabilities and selectivities of CO2 and SO2, it is expected to develop an optimal supported ionic liquid membrane technology for the isolation of acidic gases in the near future.展开更多
To observe the regulating effects of vascular endothelial growth factor (VEGF) and angiotensinⅡ (ANG II) on the frog’s pericardium, lymphatic stomata and angiogenesis so as to reveal their effects and mechanism on t...To observe the regulating effects of vascular endothelial growth factor (VEGF) and angiotensinⅡ (ANG II) on the frog’s pericardium, lymphatic stomata and angiogenesis so as to reveal their effects and mechanism on the mesothelial permeability, lymphatic stoma regulation and myocardial hypertrophy. Methods. VEGF and ANGⅡ were injected into the frog’s peritoneal cavity so as to examine the changes of the pericardial stromata by using transmission electron microscopy, scanning electron microscopy and computerized imaging analysis. Results. Scattered distributed pericardial stomata were found on the parietal pericardium of the frog with a few sinusoid mesothelial cells, whose blood supply was directly from the cardiac chambers flowing into the trabecular spaces of the myocardium (because there are no blood vessels in the myocardium of the frog). The average diameters of the pericardial stomata in VEGF and ANGⅡ groups were 1.50μ m and 1.79μ m respectively, which were much larger than those in the control group (0.72μ m, P Conclusions. VEGF and ANGⅡ could strongly regulate the pericardial stomata by increasing their numbers and openings with larger diameters and higher distribution density. They could also increase the sinusoid areas with the result of the higher permeability of the pericardium, which clearly indicated that VEGF and ANGⅡ could speed up the material transfer of the pericardial cavity and play an important role in preventing myocardial interstitial edema. Yet there was no strong evidence to show the angiogenesis in the myocardium.展开更多
基金the National Science Fund for Distinguished Young Scholars of China(No.21225625)the National Natural Science Foundation of China(No.21176087)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20110172110013)
文摘Cobalt-free perovskite-type oxides BaFel_yTayO3-6 （0 _〈 y -〈 0.2） were synthesized via a simple solid state reac- tion. The cubic perovskite structure can be obtained when y is over 0.1. BaFeo.Ta0.lO3-6 （BFT0.1） membrane shows the highest oxygen permeation flux, which can reach 1.6 ml. min- 1. cm-2 at 950 ℃ under the gradient of air/He. The O2-TPD results reveal that BaFe0.9Ta0.lO3-a material shows an excellent reversibility and phase structure stability in air. The oxygen permeation flux is limited by the bulk diffusion when the membrane thick- ness is over 0.8 mm, and it is limited by both the bulk diffusion and the surface exchange when the membrane thickness is below 0.5 mm. Stable oxygen permeation fluxes are obtained during 180 h operation.
基金Supported by the National Natural Science Foundation of China （20776065）, the Natural Science Foundation of Jiangsu Province （BK2008023）, and the National Found for Fostering Talents of Basic Science 00630425）.
文摘Permeabilities and selectivities of gases such as carbon dioxide （CO2）, sulfur dioxide （SO2）, nitrogen （N2） and methane （CH4） in six imidazolium-based ionic liquids （[emim][BF4], [bmim][BF4], [bmim][PF6], [banim][BF4], [bmim][Tf2N] and [emim][CF3SO3]） supported on polyethersulfone microfiltration membranes are investigated in a single gas feed system using nitrogen as the environment and reference component at temperature from 25 to 45℃ and pressure of N2 from 100 to 400 kPa. It is found that SO2 has the highest permeability in the tested supported ionic liquid membranes, being an order of magnitude higher than that of CO2, and about 2 to 3 orders of magnitude larger than those of N2 and CH4. The observed selectivity of SO2 over the two ordinary gas components is also striking. It is shown experimentally that the dissolution and transport of gas components in the supported ionic liquid membranes, as well as the nature of ionic liquids play important roles in the gas permeation. A nonlinear increase of permeation rate with temperature and operation pressure is also observed for all sample gases. By considering the factors that influence the permeabilities and selectivities of CO2 and SO2, it is expected to develop an optimal supported ionic liquid membrane technology for the isolation of acidic gases in the near future.
文摘To observe the regulating effects of vascular endothelial growth factor (VEGF) and angiotensinⅡ (ANG II) on the frog’s pericardium, lymphatic stomata and angiogenesis so as to reveal their effects and mechanism on the mesothelial permeability, lymphatic stoma regulation and myocardial hypertrophy. Methods. VEGF and ANGⅡ were injected into the frog’s peritoneal cavity so as to examine the changes of the pericardial stromata by using transmission electron microscopy, scanning electron microscopy and computerized imaging analysis. Results. Scattered distributed pericardial stomata were found on the parietal pericardium of the frog with a few sinusoid mesothelial cells, whose blood supply was directly from the cardiac chambers flowing into the trabecular spaces of the myocardium (because there are no blood vessels in the myocardium of the frog). The average diameters of the pericardial stomata in VEGF and ANGⅡ groups were 1.50μ m and 1.79μ m respectively, which were much larger than those in the control group (0.72μ m, P Conclusions. VEGF and ANGⅡ could strongly regulate the pericardial stomata by increasing their numbers and openings with larger diameters and higher distribution density. They could also increase the sinusoid areas with the result of the higher permeability of the pericardium, which clearly indicated that VEGF and ANGⅡ could speed up the material transfer of the pericardial cavity and play an important role in preventing myocardial interstitial edema. Yet there was no strong evidence to show the angiogenesis in the myocardium.
