The micelle generating process of the sodium dodecyl sulfate(SDS) solution with the addition of chemical inhibitors was elucidated using phase separation model, and the descending order of the capacity for the selecte...The micelle generating process of the sodium dodecyl sulfate(SDS) solution with the addition of chemical inhibitors was elucidated using phase separation model, and the descending order of the capacity for the selected chemical inhibitors to reduce the critical micelle concentrations of the solution are Mg Cl_2, Ca Cl_2,NH_4HCO_3 and NH_4Cl. The data to quantitatively describe the foam decay process, including foaming ratio,foam life and decay behaviors, was obtained by pressure measuring system. The results indicate that chemical inhibitors can improve the solution foamability. The capacity of the inhibitors to enhance the solution foamability is sorted as NH_4 Cl, NH_4HCO_3, Mg Cl2 and Ca Cl_2 which can distinctly improve the foam stability as well. The capacity of the inhibitors to enhance the SDS foam stability can be arranged as Mg Cl_2, NH_4 Cl, NH_4HCO_3 and Ca Cl_2. It is observed that the gravity drainage plays a leading role in the increase of proportion of diffusion drainage. The oxidation dynamic parameters of the coal samples treated by inhibition foams were investigated using thermal analysis technique, and their synergistic effects on inhibiting coal oxidation were explored.展开更多
目的基于Web of Science核心合集数据库运用知识图谱分析玫瑰痤疮的研究现状及发展趋势。方法以玫瑰痤疮为主题,检索Web of Science核心合集数据库,检索时间跨度为2012年1月1日至2022年11月1日。运用CiteSpace 6.1.R4及VOSviewer 1.6.1...目的基于Web of Science核心合集数据库运用知识图谱分析玫瑰痤疮的研究现状及发展趋势。方法以玫瑰痤疮为主题,检索Web of Science核心合集数据库,检索时间跨度为2012年1月1日至2022年11月1日。运用CiteSpace 6.1.R4及VOSviewer 1.6.18对玫瑰痤疮的发文国家/地区、机构、作者、关键词及被引文献进行可视化分析。结果共纳入1776篇文献。发文最多的国家是美国;主要研究机构是加州大学圣地亚哥分校;中心度最高的被引文献主要与伊维菌素的治疗相关;高频关键词主要为疗效、病理生理学等。结论玫瑰痤疮病因复杂,发病机制不明,目前对氧化应激关注较多,而皮肤屏障受损、蠕形螨感染等其他病因也应深入研究。展开更多
In this paper,the effect of disturbances on the operation process of a methane-fueled free-piston engine generator(FPEG)was experimentally investigated.Four disturbance sources,namely step change of external load,mixt...In this paper,the effect of disturbances on the operation process of a methane-fueled free-piston engine generator(FPEG)was experimentally investigated.Four disturbance sources,namely step change of external load,mixture flow rate fluctuation,random misfire of a cylinder,and elastic collision,were identified and applied to the FPEG.The results showed that the FPEG successfully achieved a steady-state operation with load.The maximum instantaneous electric power of 127 W and the average effective electric power of 38.9 W were obtained.When an external load was instantaneously disconnected,the engine frequency increased from 26.7 Hz to 31.3 Hz.The fluctuation amplitudes of induced voltage,pressure and compression ratio were 18.9%,24.7%and 52.2%respectively in the disturbance.By contrast,when the external load was instantaneously connected,the corresponding values were 42.2%,31.3%and 64.3%respectively,indicating that the instantaneous external load connection had a greater disturbance impact on the FPEG operation stability.Despite encountering the step change of external load,the FPEG can still restore stable operation and show good anti-disturbance ability.Compared with increasing mixture flow rate,reducing the mixture flow rate has a greater disturbance impact on the engine operation stability.Although random misfire of a cylinder will cause remarkable fluctuations in piston displacement and cylinder pressure,the FPEG will not stop running,but continues to work as a single-piston engine.Minor collision event may adversely affect the stability of engine operation,but will not lead to the FPEG shutdown.However,serious collision event may lead to ignition failure and shutdown accident.展开更多
基金supported by the National Natural Science Foundation of China(No.51274205)the State Key Laboratory for Coal Resources and Safe Mining,China University of Mining&Technology(No.SKLCRSM10KFB13)the Hebei Key Laboratory for Mine Disaster Prevention of China(No.KJZH2013K02)
文摘The micelle generating process of the sodium dodecyl sulfate(SDS) solution with the addition of chemical inhibitors was elucidated using phase separation model, and the descending order of the capacity for the selected chemical inhibitors to reduce the critical micelle concentrations of the solution are Mg Cl_2, Ca Cl_2,NH_4HCO_3 and NH_4Cl. The data to quantitatively describe the foam decay process, including foaming ratio,foam life and decay behaviors, was obtained by pressure measuring system. The results indicate that chemical inhibitors can improve the solution foamability. The capacity of the inhibitors to enhance the solution foamability is sorted as NH_4 Cl, NH_4HCO_3, Mg Cl2 and Ca Cl_2 which can distinctly improve the foam stability as well. The capacity of the inhibitors to enhance the SDS foam stability can be arranged as Mg Cl_2, NH_4 Cl, NH_4HCO_3 and Ca Cl_2. It is observed that the gravity drainage plays a leading role in the increase of proportion of diffusion drainage. The oxidation dynamic parameters of the coal samples treated by inhibition foams were investigated using thermal analysis technique, and their synergistic effects on inhibiting coal oxidation were explored.
文摘目的基于Web of Science核心合集数据库运用知识图谱分析玫瑰痤疮的研究现状及发展趋势。方法以玫瑰痤疮为主题,检索Web of Science核心合集数据库,检索时间跨度为2012年1月1日至2022年11月1日。运用CiteSpace 6.1.R4及VOSviewer 1.6.18对玫瑰痤疮的发文国家/地区、机构、作者、关键词及被引文献进行可视化分析。结果共纳入1776篇文献。发文最多的国家是美国;主要研究机构是加州大学圣地亚哥分校;中心度最高的被引文献主要与伊维菌素的治疗相关;高频关键词主要为疗效、病理生理学等。结论玫瑰痤疮病因复杂,发病机制不明,目前对氧化应激关注较多,而皮肤屏障受损、蠕形螨感染等其他病因也应深入研究。
基金supported by the National Natural Science Foundation of China(No.52076007)Project of Educational Commission of Henan Province of China(No.22A470007 and No.20A470008)。
文摘In this paper,the effect of disturbances on the operation process of a methane-fueled free-piston engine generator(FPEG)was experimentally investigated.Four disturbance sources,namely step change of external load,mixture flow rate fluctuation,random misfire of a cylinder,and elastic collision,were identified and applied to the FPEG.The results showed that the FPEG successfully achieved a steady-state operation with load.The maximum instantaneous electric power of 127 W and the average effective electric power of 38.9 W were obtained.When an external load was instantaneously disconnected,the engine frequency increased from 26.7 Hz to 31.3 Hz.The fluctuation amplitudes of induced voltage,pressure and compression ratio were 18.9%,24.7%and 52.2%respectively in the disturbance.By contrast,when the external load was instantaneously connected,the corresponding values were 42.2%,31.3%and 64.3%respectively,indicating that the instantaneous external load connection had a greater disturbance impact on the FPEG operation stability.Despite encountering the step change of external load,the FPEG can still restore stable operation and show good anti-disturbance ability.Compared with increasing mixture flow rate,reducing the mixture flow rate has a greater disturbance impact on the engine operation stability.Although random misfire of a cylinder will cause remarkable fluctuations in piston displacement and cylinder pressure,the FPEG will not stop running,but continues to work as a single-piston engine.Minor collision event may adversely affect the stability of engine operation,but will not lead to the FPEG shutdown.However,serious collision event may lead to ignition failure and shutdown accident.
