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封闭采样式高温氧化锆氧分析仪的试验及应用 被引量:1
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作者 李俊华 张仲生 韩月奇 《原子能科学技术》 EI CAS CSCD 北大核心 1997年第2期173-176,共4页
封闭采样式高温氧化锆氧分析仪主要用于钢铁冶金行业的加热炉、均热炉等高温烟气中测定氧含量,以便指导合理的空燃气配比。该仪器采用独特的闭环抽取技术,以压缩空气为动力源(流量≥30L/min),将取样和冷却一体化,使氧化锆... 封闭采样式高温氧化锆氧分析仪主要用于钢铁冶金行业的加热炉、均热炉等高温烟气中测定氧含量,以便指导合理的空燃气配比。该仪器采用独特的闭环抽取技术,以压缩空气为动力源(流量≥30L/min),将取样和冷却一体化,使氧化锆电池处在最佳烟温区(300-500℃),探头寿命达2年以上。该仪器工作性能稳定,安装、使用。 展开更多
关键词 氧分析仪 高温烟气 封闭采样 氧化锆 冶金
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我国几种典型树种非甲烷烃类的排放特征 被引量:41
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作者 赵美萍 邵敏 +2 位作者 白郁华 李金龙 唐孝炎 《环境化学》 CAS CSCD 北大核心 1996年第1期69-75,共7页
采用封闭式采样法和带有预浓缩及程序升温装置的熔融毛细管柱气相色谱仪,对我国的松、柏、杨、槐等几种典型树种排放非甲烷烃类(NMHC)的组成和排放速率进行了定性和定量测定,初步确定了不同树种排放的特征物种和排放规律.结果表明,针叶... 采用封闭式采样法和带有预浓缩及程序升温装置的熔融毛细管柱气相色谱仪,对我国的松、柏、杨、槐等几种典型树种排放非甲烷烃类(NMHC)的组成和排放速率进行了定性和定量测定,初步确定了不同树种排放的特征物种和排放规律.结果表明,针叶树种和阔叶树种排放的NMHC组成差别很大,各树种的排放规律除了与自身的结构和生理活动等内在因素有关外,还在不同程度上受到外界因素(主要是温度和光强)的影响,一般温度越高,光强越大,植物的排放速率也越大.本文还对NMHC天然源和人为源的排放特征做了比较,得到一些初步结论. 展开更多
关键词 NMHC 生物源 排放特征 松柏 封闭采样
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Using the contact network model and Metropolis-Hastings sampling to reconstruct the COVID-19 spread on the “Diamond Princess” 被引量:10
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作者 Feng Liu Xin Li Gaofeng Zhu 《Science Bulletin》 SCIE EI CAS CSCD 2020年第15期1297-1305,M0004,共10页
Traditional compartmental models such as SIR(susceptible,infected,recovered)assume that the epidemic transmits in a homogeneous population,but the real contact patterns in epidemics are heterogeneous.Employing a more ... Traditional compartmental models such as SIR(susceptible,infected,recovered)assume that the epidemic transmits in a homogeneous population,but the real contact patterns in epidemics are heterogeneous.Employing a more realistic model that considers heterogeneous contact is consequently necessary.Here,we use a contact network to reconstruct unprotected,protected contact,and airborne spread to simulate the two-stages outbreak of COVID-19(coronavirus disease 2019)on the‘‘Diamond Princess"cruise ship.We employ Bayesian inference and Metropolis-Hastings sampling to estimate the model parameters and quantify the uncertainties by the ensemble simulation technique.During the early epidemic with intensive social contacts,the results reveal that the average transmissibility t was 0.026 and the basic reproductive number R0 was 6.94,triple that in the WHO report,indicating that all people would be infected in one month.The t and R0 decreased to 0.0007 and 0.2 when quarantine was implemented.The reconstruction suggests that diluting the airborne virus concentration in closed settings is useful in addition to isolation,and high-risk susceptible should follow rigorous prevention measures in case exposed.This study can provide useful implications for control and prevention measures for the other cruise ships and closed settings. 展开更多
关键词 Contact network model SMALL-WORLD Chain-binomial model Airborne spread TRANSMISSIBILITY The basic reproductive number R0
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