X The catalysts of air electrode were prepared by sintering the active carbon loaded with manganese nitrate and potassium permanganate at 360 ℃ . The air electrode was made up of a catalyst layer, a waterproof and ga...X The catalysts of air electrode were prepared by sintering the active carbon loaded with manganese nitrate and potassium permanganate at 360 ℃ . The air electrode was made up of a catalyst layer, a waterproof and gas-permeable layer, a current collecting substrate and a second wa-terproof and gas-permeable layer. The cell was assembled by the air electrode, pure magnesium anode and 10% NaCl solution used as electrolyte. The microstructures of air electrodes before and after discharging were characterized by SEM. The electrochemical behaviors of the air electrodes were determined by means of polarization curves, volt-ampere curves and constant current discharge curves. The polarization voltage of air electrode is-173 mV （vs SCE） at the current density of 50 mA/cm2. The air electrodes exhibits good activity and stability in neutral electrolyte. The magnesium-air cell could work at 5 W for more than 7 h.展开更多
Purpose: This was a preliminary study to assess surgical construction and regeneration of mastoid air cells in the treatment of cholesteatoma. Methods: Two-stage tympanoplasty with mastoidectomy was performed in four ...Purpose: This was a preliminary study to assess surgical construction and regeneration of mastoid air cells in the treatment of cholesteatoma. Methods: Two-stage tympanoplasty with mastoidectomy was performed in four cases of unilateral cholesteatoma with sclerotic mastoid. During the first-stage operation, small fragments of autologous cortical bone were inserted into the cavity after mastoidectomy to form a honeycomb-like structure. Reconstruction of the lateral wall of the mastoid cavity was performed using the mastoid cortical bony plate. Pre- and postoperative mastoid volume was evaluated by three-dimensional reconstruction based on high-resolution computed tomography (HR-CT) images. Results: HR-CT images after the first-stage operation showed that mastoid volume had increased in all subjects. Macroscopic inspection during the second-stage operation revealed that the honeycomb-like structure made of bony fragments and covered by thin mucosa in the mastoid cavity was stable, with no evidence of effusion or granulation tissue. No retraction of the eardrum, middle ear effusion or recurrence of cholesteatoma was observed, and the hearing level on a pure-tone audiogram was improved in any subject 60 - 94 months after the second-stage operation. Conclusion: Surgical construction and regeneration of mastoid air cells using autologous cortical bone can be useful in treatment of cholesteatoma with arrested mastoid pneumatization.展开更多
A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt, air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃. Performa...A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt, air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃. Performance of the fuel cell was dependent on anode compartment H2S flow rate and concentration. The cell open-circuit voltage increased with increasing H2S flow rate. It was found that increasing both H2S flow rate and H2S concentration improved current-voltage and power density performance. This is resulted from improved gas diffusion in anode and increased concentration of anodic electroactive species. Operation at elevated H2S concentration improved the cell performance at a given gas flow rate. However, as low as 5% H2S in gas mixture can also be utilized as fuel feed to cells. Highest current and power densities, 17500mA·cm-2 and 200mW·cm-2, are obtained with pure H2S flow rate of 50ml·min-1 and air flow rate of 100ml·min-1 at 850℃.展开更多
Air flow control is one of the most important control methods for maintaining the stability and reliability of a fuel cell system, which can avoid oxygen starvation or oxygen saturation. The oxygen excess ratio （OER...Air flow control is one of the most important control methods for maintaining the stability and reliability of a fuel cell system, which can avoid oxygen starvation or oxygen saturation. The oxygen excess ratio （OER） is often used to indicate the air flow condition. Based on a fuel cell system model for vehicles, OER performance was analyzed for different stack currents and temperatures in this paper, and the results show that the optimal OER was affected weakly by the stack temperature. In order to ensure the system working in optimal OER, a control scheme that includes an optimal OER regulator and a fuzzy control was proposed. According to the stack current, a reference value of air flow rate was obtained with the optimal OER regulator and then the air compressor motor voltage was controlled with the fuzzy controller to adjust the air flow rate provided by the air compressor. Simulation results show that the control method has good dynamic and static characteristics.展开更多
An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species （RS） in the medium produced by the plasma, the concentr...An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species （RS） in the medium produced by the plasma, the concentration of the long-lived RS such as hydrogen peroxide, nitrate, and ozone in the plasma-treated liquid （phosphate-buffered saline solution） is measured. When vitamin C is added to the medium as a ROS quencher, the viability of C6 glioma cells after the plasma treatment is different from that without vitamin C. The results demonstrate that reactive oxygen species （ROS） such as H2O2, and O3 constitute the main factors for inactivation of C6 glioma cells and the reactive nitrogen species （RNS） may only play an auxiliary role in cell death.展开更多
To prevent the oxygen starvation and improve the system output performance, an adaptive inverse control （AIC） strategy is developed to regulate the air supply flow of a proton exchange membrane fuel cell （PEMFC） s...To prevent the oxygen starvation and improve the system output performance, an adaptive inverse control （AIC） strategy is developed to regulate the air supply flow of a proton exchange membrane fuel cell （PEMFC） system in this paper. The PEMFC stack and the air supply system including a compressor and a supply manifold are modeled for the purpose of performance analysis and controller design. A recurrent fuzzy neural network （RFNN） is utilized to identify the inverse model of the controlled system and generates a suitable control input during the abrupt step change of external disturbances. Compared with the PI controller, numerical simulations are performed to validate the effectiveness and advantages of the proposed AIC strategy.展开更多
Cell count, LDH, total protein, Clara cell protein (CC16) and lysozyme in bronchoalveolar lavage fluid (BAL) and serum were determined in rats. 30 - 50 ppm sulfur dioxide for 4 h, 12 h and 2 week exposure didn't p...Cell count, LDH, total protein, Clara cell protein (CC16) and lysozyme in bronchoalveolar lavage fluid (BAL) and serum were determined in rats. 30 - 50 ppm sulfur dioxide for 4 h, 12 h and 2 week exposure didn't produce any change of above parameters. 1. 0 ppm, 0. 5 ppm, 0. 38 ppm, 0. 25 ppm and 0. 20 ppm ozone for 7 h exposure tests were performed. CC16, total protein and LDH in BAL had significantly changes in BAL in ozone groups. Only serum CC16 showed significant increase among ozone groups. Both BAL and serum CC16 were of the best exposure-response relationship with ozone concentration.The change of BAL fluid reached high peak 18-24 h after ozone exposure.Serum CC16 seemed to be a valid marker of the distal airway damages caused by air pollutants.展开更多
文摘X The catalysts of air electrode were prepared by sintering the active carbon loaded with manganese nitrate and potassium permanganate at 360 ℃ . The air electrode was made up of a catalyst layer, a waterproof and gas-permeable layer, a current collecting substrate and a second wa-terproof and gas-permeable layer. The cell was assembled by the air electrode, pure magnesium anode and 10% NaCl solution used as electrolyte. The microstructures of air electrodes before and after discharging were characterized by SEM. The electrochemical behaviors of the air electrodes were determined by means of polarization curves, volt-ampere curves and constant current discharge curves. The polarization voltage of air electrode is-173 mV （vs SCE） at the current density of 50 mA/cm2. The air electrodes exhibits good activity and stability in neutral electrolyte. The magnesium-air cell could work at 5 W for more than 7 h.
文摘Purpose: This was a preliminary study to assess surgical construction and regeneration of mastoid air cells in the treatment of cholesteatoma. Methods: Two-stage tympanoplasty with mastoidectomy was performed in four cases of unilateral cholesteatoma with sclerotic mastoid. During the first-stage operation, small fragments of autologous cortical bone were inserted into the cavity after mastoidectomy to form a honeycomb-like structure. Reconstruction of the lateral wall of the mastoid cavity was performed using the mastoid cortical bony plate. Pre- and postoperative mastoid volume was evaluated by three-dimensional reconstruction based on high-resolution computed tomography (HR-CT) images. Results: HR-CT images after the first-stage operation showed that mastoid volume had increased in all subjects. Macroscopic inspection during the second-stage operation revealed that the honeycomb-like structure made of bony fragments and covered by thin mucosa in the mastoid cavity was stable, with no evidence of effusion or granulation tissue. No retraction of the eardrum, middle ear effusion or recurrence of cholesteatoma was observed, and the hearing level on a pure-tone audiogram was improved in any subject 60 - 94 months after the second-stage operation. Conclusion: Surgical construction and regeneration of mastoid air cells using autologous cortical bone can be useful in treatment of cholesteatoma with arrested mastoid pneumatization.
基金Supported by the Natural Science Foundation of Guangdong Province (No. 031424).
文摘A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt, air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃. Performance of the fuel cell was dependent on anode compartment H2S flow rate and concentration. The cell open-circuit voltage increased with increasing H2S flow rate. It was found that increasing both H2S flow rate and H2S concentration improved current-voltage and power density performance. This is resulted from improved gas diffusion in anode and increased concentration of anodic electroactive species. Operation at elevated H2S concentration improved the cell performance at a given gas flow rate. However, as low as 5% H2S in gas mixture can also be utilized as fuel feed to cells. Highest current and power densities, 17500mA·cm-2 and 200mW·cm-2, are obtained with pure H2S flow rate of 50ml·min-1 and air flow rate of 100ml·min-1 at 850℃.
基金supported by the National Natural Science Foundation of China (No. 51177138)the Research Fund for the Doctoral Program of High Education of China (No.20100184110015)Sichuan Province International Technology Cooperation and Exchange Program (No. 2012HH0007)
文摘Air flow control is one of the most important control methods for maintaining the stability and reliability of a fuel cell system, which can avoid oxygen starvation or oxygen saturation. The oxygen excess ratio （OER） is often used to indicate the air flow condition. Based on a fuel cell system model for vehicles, OER performance was analyzed for different stack currents and temperatures in this paper, and the results show that the optimal OER was affected weakly by the stack temperature. In order to ensure the system working in optimal OER, a control scheme that includes an optimal OER regulator and a fuzzy control was proposed. According to the stack current, a reference value of air flow rate was obtained with the optimal OER regulator and then the air compressor motor voltage was controlled with the fuzzy controller to adjust the air flow rate provided by the air compressor. Simulation results show that the control method has good dynamic and static characteristics.
基金jointly supported by the Education and Research Foundation of Anhui Province(KJ2015A327)Science Foundation of Institute of Plasma Physics,Chinese Academy of Sciences No.DSJJ-14-YY02Hong Kong Research Grants Council(RGC)General Research Funds(GRF)No.CityU 11301215
文摘An atmospheric-pressure air plasma is employed to treat C6 glioma cells in vitro. To elucidate on the mechanism causing cell death and role of reactive species （RS） in the medium produced by the plasma, the concentration of the long-lived RS such as hydrogen peroxide, nitrate, and ozone in the plasma-treated liquid （phosphate-buffered saline solution） is measured. When vitamin C is added to the medium as a ROS quencher, the viability of C6 glioma cells after the plasma treatment is different from that without vitamin C. The results demonstrate that reactive oxygen species （ROS） such as H2O2, and O3 constitute the main factors for inactivation of C6 glioma cells and the reactive nitrogen species （RNS） may only play an auxiliary role in cell death.
基金Project supported by the National Natural Science Foundation of China (Grant No.20576071)the Natural Science Foundation of Shanghai Municipality (Grant No.08ZR1409800)
文摘To prevent the oxygen starvation and improve the system output performance, an adaptive inverse control （AIC） strategy is developed to regulate the air supply flow of a proton exchange membrane fuel cell （PEMFC） system in this paper. The PEMFC stack and the air supply system including a compressor and a supply manifold are modeled for the purpose of performance analysis and controller design. A recurrent fuzzy neural network （RFNN） is utilized to identify the inverse model of the controlled system and generates a suitable control input during the abrupt step change of external disturbances. Compared with the PI controller, numerical simulations are performed to validate the effectiveness and advantages of the proposed AIC strategy.
文摘Cell count, LDH, total protein, Clara cell protein (CC16) and lysozyme in bronchoalveolar lavage fluid (BAL) and serum were determined in rats. 30 - 50 ppm sulfur dioxide for 4 h, 12 h and 2 week exposure didn't produce any change of above parameters. 1. 0 ppm, 0. 5 ppm, 0. 38 ppm, 0. 25 ppm and 0. 20 ppm ozone for 7 h exposure tests were performed. CC16, total protein and LDH in BAL had significantly changes in BAL in ozone groups. Only serum CC16 showed significant increase among ozone groups. Both BAL and serum CC16 were of the best exposure-response relationship with ozone concentration.The change of BAL fluid reached high peak 18-24 h after ozone exposure.Serum CC16 seemed to be a valid marker of the distal airway damages caused by air pollutants.
