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The effect of cations(NH_4^+,Na^+,K^+,and Ca^(2+)) on chemical deactivation of commercial SCR catalyst by bromides 被引量:6
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作者 Huazhen Chang Chuanning Shi +4 位作者 Mingguan Li Tao Zhang Chizhong Wang Lilong Jiang Xiuyun Wang 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第4期710-717,共8页
Alkali and alkaline‐earth metals from fly ash have a significant deactivation effect on catalysts used for selective catalytic reduction of NOx by NH3(NH3‐SCR).Bromides are considered effective additives to improve ... Alkali and alkaline‐earth metals from fly ash have a significant deactivation effect on catalysts used for selective catalytic reduction of NOx by NH3(NH3‐SCR).Bromides are considered effective additives to improve Hg0 oxidation on SCR catalysts.In this work,the effects of different bromides(NH4Br,NaBr,KBr,and CaBr2)on a commercial V2O5‐WO3/TiO2 catalyst were studied.NOx conversion decreased significantly over the KBr‐poisoned catalyst(denoted as L‐KBr),while that over NaBr‐and CaBr2‐poisoned catalysts(denoted as L‐NaBr and L‐CaBr,respectivity)decreased to a lesser extent compared with the fresh sample.Poor N2 selectivity was observed over L‐NaBr,L‐KBr and L‐CaBr catalysts.The decrease in the ratio of chemisorbed oxygen to total surface oxygen(Oα/(Oα+Oβ+Ow)),reducibility and surface acidity might contribute to the poor activity and N2 selectivity over L‐KBr catalyst.The increased Oαratio was conducive to the enhanced reducibility of L‐CaBr.Combined with enhanced surface acidity,this might offset the negative effect of the loss of active sites by CaBr2 covering.The overoxidation of NH3 and poor N2 selectivity in NH3 oxidation should retard the SCR activity at high temperatures over L‐CaBr catalyst.The increased basicity might contribute to increased NOx adsorption on L‐KBr and L‐CaBr catalysts.A correlation between the acid‐basic and redox properties of bromide‐poisoned catalysts and their catalytic properties is established. 展开更多
关键词 BROMIDE CATION Catalyst deactivation SCR catalyst N2 selectivity Surface acidity
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Supportive Technologies and Roadmap for China’s Carbon Neutrality 被引量:30
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作者 Wang Can Sun Ruoshui Zhang Jiutian 《China Economist》 2021年第5期32-70,共39页
The vision of carbon neutrality is a climate ambition of milestone significance for China and a key step for China’s transition from industrial civilization to ecological civilization.The realization of carbon neutra... The vision of carbon neutrality is a climate ambition of milestone significance for China and a key step for China’s transition from industrial civilization to ecological civilization.The realization of carbon neutrality requires profound changes in China’s technological and socioeconomic systems involving zero-carbon electric power,lowcarbon and zero-carbon end-use energy consumption,and negative emission technologies.Achievement of carbon neutrality is subject to the choice of pathways for various sectors,especially the electric power,industrial,transportation and construction sectors with significant carbon emissions and decarbonization difficulties.The goal of carbon neutrality will influence China’s economic and industry systems,resource and industrial layout,technological innovation and ecological environment in profound ways.Hence,China’s future policymaking on carbon neutrality needs to consider environmental,technological,economic and social impacts,establish a correlation between carbon peak and carbon neutrality,identify climate-friendly clean technology innovations in real earnest,and put carbon neutrality into the overall plan for ecological civilization. 展开更多
关键词 carbon neutrality low-carbon technology low-carbon development path
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Low-temperature catalytic degradation of the odorous pollutant hexanal by γ-MnOOH:The effect of Mn vacancies 被引量:3
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作者 Shanhong Sui Pengyi Zhang +1 位作者 Huiyu Zhang Ranran Cao 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2019年第10期1525-1533,共9页
irritation to human beings.The removal of hexanal has rarely been investigated.In this study,we found that the amount of Mn vacancies inγ-MnOOH significantly affects its catalytic activity toward hexanal degradation ... irritation to human beings.The removal of hexanal has rarely been investigated.In this study,we found that the amount of Mn vacancies inγ-MnOOH significantly affects its catalytic activity toward hexanal degradation and transformation into CO2.The as-synthesized Mn vacancy-richγ-MnOOH exhibited high efficiency toward hexanal removal,achieving 100%degradation of 15 ppm hexanal at 85℃ and complete transformation into CO2 at 160 ℃ under the gas hourly space velocity of 240 L/(g·h);its activity could be completely regenerated by in-situ heat treatment at 180°C.Moreover,it was found that the degradation of hexanal occurred in a stepwise manner,i.e.,losing one CH2 unit per step.Electron spinning resonance studies detected strong indicative signals for the presence of the superoxide anion radical(?O2^–)on Mn-vacancy-richγ-MnOOH,which may act as active oxygen species for the hexanal degradation.Understanding the role of Mn-vacancy and the mechanism of hexanal degradation byγ-MnOOH are essential for developing efficient oxide catalysts for volatile organic compounds besides hexanal. 展开更多
关键词 Γ-MNOOH Manganese vacancy Hexanal degradation Indoor air Catalysis
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Comparative genome analysis on intraspecific evolution and nitrogen fixation of Leptospirillum ferriphilum isolates 被引量:3
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作者 Hong-wei LIU Liang-feng XU +5 位作者 Xue GUO Hui-dan JIANG Xue-duan LIU Yi-li LIANG Hua-qun YIN Ya-zi LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第6期1635-1646,共12页
To reveal the intraspecific evolution of Leptospirillum ferriphilum isolates which thrived in industrial bioleaching ecosystems and acid mine drainages,genome sequences of L.ferriphilum YSK,L.ferriphilum DX and L.ferr... To reveal the intraspecific evolution of Leptospirillum ferriphilum isolates which thrived in industrial bioleaching ecosystems and acid mine drainages,genome sequences of L.ferriphilum YSK,L.ferriphilum DX and L.ferriphilum ZJ were determined to compare with complete genome of L.ferriphilum ML-04.The genome comparisons reveal that extensive intraspecific variation occurs in their genomes,and that the loss and insertion of novel gene blocks of probable phage origin may mostly contribute to heterogeneity of gene content among L.ferriphilum genomes.Surprisingly,a nif gene cluster is identified in L.ferriphilum YSK and L.ferriphilum ZJ genomes.Intensive analysis and further experiments indicate that the nif gene cluster in L.ferriphilum YSK inherits from ancestor rather than lateral gene transfer.Overall,results suggest that the population of L.ferriphilum undergoes frequent genetic recombination,resulting in many closely related genome types in recent evolution.The combinatorial processes profoundly shape their physiologies and provide the basis for adaptation to different niches. 展开更多
关键词 Leptospirillum ferriphilum comparative genome nitrogen fixation intraspecific variation recombination
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亚洲东部森林的小气候特征:1.辐射和能量的平衡 被引量:15
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作者 谭正洪 于贵瑞 +16 位作者 周国逸 韩士杰 夏禹九 前田高尚 小杉绿子 山野井克己 李胜功 太田岳史 平田竜一 安田幸生 中野隆志 小南裕志 北村兼三 溝口康子 廖志勇 赵俊福 杨廉雁 《植物生态学报》 CAS CSCD 北大核心 2015年第6期541-553,共13页
森林小气候是森林植被与区域气候相互作用所形成的局地环境系统。森林小气候的研究,不仅是一项关于森林生态系统运行机理的理论研究工作,对农林业生产也具有现实的指导意义,在全球变化形势下其重要性又进一步凸显。辐射的收支、能量的... 森林小气候是森林植被与区域气候相互作用所形成的局地环境系统。森林小气候的研究,不仅是一项关于森林生态系统运行机理的理论研究工作,对农林业生产也具有现实的指导意义,在全球变化形势下其重要性又进一步凸显。辐射的收支、能量的平衡与分配是小气候特征形成的基础。对森林辐射收支和能量分配的研究,过去主要以单站点为主,系统的区域分析十分匮乏。该文采用亚洲东部17个森林站点的实测数据,分析了生态系统的辐射收支和能量平衡,探讨了区域尺度上辐射特征量的纬度变异性及其预测关系式,建立了亚洲东部森林带典型森林生态系统的辐射和能量收支模式。所选站点以水平地带性为主,为区域分析奠定了基础。研究发现,辐射特征量具有明显的纬度依赖性,辐射特征量和纬度二者的关系可以用于相应的预测。比如,太阳辐射随着纬度的变化关系为:y=6205–42.15x(p<0.01),即纬度每上升1°,太阳辐射年总量下降42 MJ,理论最大值为6 205 MJ。净辐射的纬度趋势更加显著(r=–0.89,p<0.000 1),其线性回归关系为:y=4340–45.60x。亚洲东部森林蒸散比(EF)与降水量(P)之间的定量关系为:EF=0.7098(1–exp(–0.0026P))。通过对比不同森林带的辐射和能量模式,发现亚热带森林在辐射收支上与温带森林相近,波文比既高于温带森林,也高于热带森林,表明更多的净辐射能用于显热交换。关于亚热带森林在小气候和物质代谢方面的特殊性,值得进一步分析研究。 展开更多
关键词 亚热带森林 纬度地带性 蒸散比 太阳辐射 能量分配
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