The conversion of CH4 with oxygen and steam in a dielectric barrier discharge （DBD） was studied in the paper to discuss the effects of different factors, such as the content of feed-in gas, the applied voltage and f...The conversion of CH4 with oxygen and steam in a dielectric barrier discharge （DBD） was studied in the paper to discuss the effects of different factors, such as the content of feed-in gas, the applied voltage and frequency. The results showed that a lower ratio of CH4 to O2 always resulted in a higher conversion of CH4. When it was 2, the conversion reached 32.43% without steam introduced into the system. The main effect of steam was increasing the selectivity to CO. The reaction was accelerated and the selectivities to CO and hydrocarbons were enhanced by increasing the applied voltage. It was also observed that a higher frequency led to a lower current and then restrained the reaction.展开更多
Experimental investigation was conducted to convert dimethyl ether (DME) in the presence of steam using dielectric barrier discharge (DBD) at atmospheric pressure and 373 K. The flow rate of DME was 20 ml/min. The int...Experimental investigation was conducted to convert dimethyl ether (DME) in the presence of steam using dielectric barrier discharge (DBD) at atmospheric pressure and 373 K. The flow rate of DME was 20 ml/min. The introduction of steam resulted in an increase in the DME conversion and the selectivity of oxygenates. Plasma steam-enhanced dimethyl ether (DME) conversion led to a direct synthesis of DMMT and DMET, with a high selectivity of 5.78% and 17.99%, respectively. The addition of steam promoted the formation of 'plasma aerosol' that was favored for the formation of liquid oxygenates. The reaction pathway of plasma DME conversion was proposed.展开更多
目的:观察舒敏医学护肤品联合中药熏蒸治疗面部激素依赖性皮炎的疗效及对皮肤屏障功能的影响。方法:将面部激素依赖性皮炎患者87例随机分为两组。治疗组41例,对照组46例。两组均予氯雷他定分散片口服。治疗组予薇诺娜舒敏系列医学护肤...目的:观察舒敏医学护肤品联合中药熏蒸治疗面部激素依赖性皮炎的疗效及对皮肤屏障功能的影响。方法:将面部激素依赖性皮炎患者87例随机分为两组。治疗组41例,对照组46例。两组均予氯雷他定分散片口服。治疗组予薇诺娜舒敏系列医学护肤品外用及中药熏蒸治疗;对照组予凡士林外用。疗程8周。治疗前后检测患者面部皮肤的经皮水丢失(Trans Epidermal Water Loss,TEWL)、角质层含水量(以下简称水分)、皮脂含量(以下简称皮脂)。观察疗效、复发率及安全性。结果:治疗组总有效率95.12%,对照组76.09%,差异有统计学意义(P<0.05)。治疗组复发率9.09%,对照组77.78%,差异有统计学意义(P<0.05)。两组治疗后TEWL均比治疗前降低,差异均有统计学意义(P<0.05);治疗组降低比对照组更多,两组差异有统计学意义(P<0.05)。两组治疗后角质层含水量、皮脂含量均比治疗前升高,差异均有统计学意义(P<0.05);治疗组升高比对照组更多,两组差异有统计学意义(P<0.05)。研究中两组均未发生与所用药物、医学护肤品相关的不良反应。结论:研究提示舒敏医学护肤品联合中药熏蒸治疗面部激素依赖性皮炎疗效较好,复发率较低,且能明显改善患处皮肤屏障功能。展开更多
采用自制的介质阻挡放电实验系统,进行了甲烷/水蒸气大气压下重整制氢实验研究。考察了水碳比(水蒸气/甲烷物质的量比)、气体总流量、放电电压和放电频率对甲烷转化率及氢气等主要产物产率的影响。结果表明,甲烷转化率和氢气产率随着水...采用自制的介质阻挡放电实验系统,进行了甲烷/水蒸气大气压下重整制氢实验研究。考察了水碳比(水蒸气/甲烷物质的量比)、气体总流量、放电电压和放电频率对甲烷转化率及氢气等主要产物产率的影响。结果表明,甲烷转化率和氢气产率随着水碳比和放电电压的增加而增大,随着气体总流量和放电频率的增加呈现先增大后减小的变化规律。在放电电压18.6 k V、放电频率9.8 k Hz、水碳比3.4、反应气体总流量79 mL/min时,获最大氢气产率(14.38%)。此外,利用发射光谱对放电过程中的活性基团进行了原位诊断,得到了CH~·、OH~·、H_2及H_α活性粒子的光谱信号强度随实验参数的变化规律,并结合放电机理推测了氢气的生成路径。展开更多
基金Supported by the National Natural Science Foundation of China (No.20606023)National Key Natural Science Foundation of China (No. 20490203)
文摘The conversion of CH4 with oxygen and steam in a dielectric barrier discharge （DBD） was studied in the paper to discuss the effects of different factors, such as the content of feed-in gas, the applied voltage and frequency. The results showed that a lower ratio of CH4 to O2 always resulted in a higher conversion of CH4. When it was 2, the conversion reached 32.43% without steam introduced into the system. The main effect of steam was increasing the selectivity to CO. The reaction was accelerated and the selectivities to CO and hydrocarbons were enhanced by increasing the applied voltage. It was also observed that a higher frequency led to a lower current and then restrained the reaction.
基金The project supported by the National Natural Science Foundation of China (No. 20376060)
文摘Experimental investigation was conducted to convert dimethyl ether (DME) in the presence of steam using dielectric barrier discharge (DBD) at atmospheric pressure and 373 K. The flow rate of DME was 20 ml/min. The introduction of steam resulted in an increase in the DME conversion and the selectivity of oxygenates. Plasma steam-enhanced dimethyl ether (DME) conversion led to a direct synthesis of DMMT and DMET, with a high selectivity of 5.78% and 17.99%, respectively. The addition of steam promoted the formation of 'plasma aerosol' that was favored for the formation of liquid oxygenates. The reaction pathway of plasma DME conversion was proposed.
文摘目的:观察舒敏医学护肤品联合中药熏蒸治疗面部激素依赖性皮炎的疗效及对皮肤屏障功能的影响。方法:将面部激素依赖性皮炎患者87例随机分为两组。治疗组41例,对照组46例。两组均予氯雷他定分散片口服。治疗组予薇诺娜舒敏系列医学护肤品外用及中药熏蒸治疗;对照组予凡士林外用。疗程8周。治疗前后检测患者面部皮肤的经皮水丢失(Trans Epidermal Water Loss,TEWL)、角质层含水量(以下简称水分)、皮脂含量(以下简称皮脂)。观察疗效、复发率及安全性。结果:治疗组总有效率95.12%,对照组76.09%,差异有统计学意义(P<0.05)。治疗组复发率9.09%,对照组77.78%,差异有统计学意义(P<0.05)。两组治疗后TEWL均比治疗前降低,差异均有统计学意义(P<0.05);治疗组降低比对照组更多,两组差异有统计学意义(P<0.05)。两组治疗后角质层含水量、皮脂含量均比治疗前升高,差异均有统计学意义(P<0.05);治疗组升高比对照组更多,两组差异有统计学意义(P<0.05)。研究中两组均未发生与所用药物、医学护肤品相关的不良反应。结论:研究提示舒敏医学护肤品联合中药熏蒸治疗面部激素依赖性皮炎疗效较好,复发率较低,且能明显改善患处皮肤屏障功能。
文摘采用自制的介质阻挡放电实验系统,进行了甲烷/水蒸气大气压下重整制氢实验研究。考察了水碳比(水蒸气/甲烷物质的量比)、气体总流量、放电电压和放电频率对甲烷转化率及氢气等主要产物产率的影响。结果表明,甲烷转化率和氢气产率随着水碳比和放电电压的增加而增大,随着气体总流量和放电频率的增加呈现先增大后减小的变化规律。在放电电压18.6 k V、放电频率9.8 k Hz、水碳比3.4、反应气体总流量79 mL/min时,获最大氢气产率(14.38%)。此外,利用发射光谱对放电过程中的活性基团进行了原位诊断,得到了CH~·、OH~·、H_2及H_α活性粒子的光谱信号强度随实验参数的变化规律,并结合放电机理推测了氢气的生成路径。
