This study examined the evolution of morphology and nanostructure of soot particles from the plasma-flame interaction for various gas flow rates.The current study used both optical diagnostic and sampling methods to e...This study examined the evolution of morphology and nanostructure of soot particles from the plasma-flame interaction for various gas flow rates.The current study used both optical diagnostic and sampling methods to explore the soot production and combustion characteristics.Soot particles were characterized at the same positions downstream from the flame zone by thermophoretic sampling and transmission electron microscopy.Moreover,X-ray diffraction analysis,and thermogravimetric analysis were performed to study the nanostructure and oxidation reactivity of soot.A reduction in soot concentration was found with the plasma addition,which illustrated an inhibition effect of plasma on soot emission.The increased gas flow rate promoted soot concentration since a growing number of carbons participated in the combustion process.Depending on the gas flow rate(carbon content)variation and plasma activation,either liquid-like soot material with irregularly shaped protrusions or chain-like structure,or a mixture of both,were generated from the diffusion flames.The soot produced by plasma-flame interaction also demonstrated a high correlation between nanostructure and reactivity.The soot from lower carbon content with plasma activation had a shorter fringe length and larger fringe tortuosity related to higher oxidation reactivity.On the contrary,soot from the highest carbon content without plasma-flame interaction exhibited prevalent fullerene-like nanostructures with evident large or small shells and also had a higher carbonization degree resulting in lower oxidation reactivity.展开更多
目的:探讨持续隐匿性乙型肝炎病毒(HBV)感染(OBI)对树鼩肠道菌群的影响。方法:新生树鼩接种人HBV DNA(OBI组,n=10),对照组(NC组,n=8)不予任何干预。第72周收集树鼩粪便,16S r DNA V3+V4区测序比较两组树鼩肠道菌群改变。结果:OBI组与NC...目的:探讨持续隐匿性乙型肝炎病毒(HBV)感染(OBI)对树鼩肠道菌群的影响。方法:新生树鼩接种人HBV DNA(OBI组,n=10),对照组(NC组,n=8)不予任何干预。第72周收集树鼩粪便,16S r DNA V3+V4区测序比较两组树鼩肠道菌群改变。结果:OBI组与NC组树鼩肠道菌群α多样性比较,差异无统计学意义(P>0.05),β多样性显著降低(P<0.01)。OBI组树鼩肠道内厚壁菌门(Firmicutes)、梭状芽孢杆菌纲(Clostridia)、梭状芽孢杆菌目(Clostridiales)相对丰度显著升高,大肠埃希-志贺菌属(Escherichia-Shigella)、嗜冷杆菌属(Psychrobacter)相对丰度降低(均P<0.05)。LEf Se分析显示,OBI组和NC组差异性菌群主要包括梭状芽孢杆菌纲(Clostridia)、梭状芽孢杆菌目(Clostridiales)、瘤胃球菌(Ruminococcaceae)、毛螺菌(Lachnoclostridium)、脆弱拟杆菌(Bacteroides_fragilis)等。结论:OBI影响树鼩肠道菌群,肠道菌群可能参与介导OBI特异性免疫应答。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52076110 and 52376115)。
文摘This study examined the evolution of morphology and nanostructure of soot particles from the plasma-flame interaction for various gas flow rates.The current study used both optical diagnostic and sampling methods to explore the soot production and combustion characteristics.Soot particles were characterized at the same positions downstream from the flame zone by thermophoretic sampling and transmission electron microscopy.Moreover,X-ray diffraction analysis,and thermogravimetric analysis were performed to study the nanostructure and oxidation reactivity of soot.A reduction in soot concentration was found with the plasma addition,which illustrated an inhibition effect of plasma on soot emission.The increased gas flow rate promoted soot concentration since a growing number of carbons participated in the combustion process.Depending on the gas flow rate(carbon content)variation and plasma activation,either liquid-like soot material with irregularly shaped protrusions or chain-like structure,or a mixture of both,were generated from the diffusion flames.The soot produced by plasma-flame interaction also demonstrated a high correlation between nanostructure and reactivity.The soot from lower carbon content with plasma activation had a shorter fringe length and larger fringe tortuosity related to higher oxidation reactivity.On the contrary,soot from the highest carbon content without plasma-flame interaction exhibited prevalent fullerene-like nanostructures with evident large or small shells and also had a higher carbonization degree resulting in lower oxidation reactivity.
文摘目的:探讨持续隐匿性乙型肝炎病毒(HBV)感染(OBI)对树鼩肠道菌群的影响。方法:新生树鼩接种人HBV DNA(OBI组,n=10),对照组(NC组,n=8)不予任何干预。第72周收集树鼩粪便,16S r DNA V3+V4区测序比较两组树鼩肠道菌群改变。结果:OBI组与NC组树鼩肠道菌群α多样性比较,差异无统计学意义(P>0.05),β多样性显著降低(P<0.01)。OBI组树鼩肠道内厚壁菌门(Firmicutes)、梭状芽孢杆菌纲(Clostridia)、梭状芽孢杆菌目(Clostridiales)相对丰度显著升高,大肠埃希-志贺菌属(Escherichia-Shigella)、嗜冷杆菌属(Psychrobacter)相对丰度降低(均P<0.05)。LEf Se分析显示,OBI组和NC组差异性菌群主要包括梭状芽孢杆菌纲(Clostridia)、梭状芽孢杆菌目(Clostridiales)、瘤胃球菌(Ruminococcaceae)、毛螺菌(Lachnoclostridium)、脆弱拟杆菌(Bacteroides_fragilis)等。结论:OBI影响树鼩肠道菌群,肠道菌群可能参与介导OBI特异性免疫应答。
