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Visibility Characteristics over the South China Sea during 1980-2018 Based on Gridded Data Generated by Artificial Neural Network

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Journal of Meteorological Research 2021年第4期35卷 690-700页

作者： Lifeng LI yulong shan Shijun ZHAO School of Meteorology and Oceanography National University of Defense TechnologyChangsha 430073

This paper generated gridded visibility(Vis)data from 1980 to 2018 over the South China Sea(SCS)based on artificial neural network(ANN),and the accuracy of the generated data was ***,temporal and spatial characteristics of Vis in the area were analyzed based on the generated Vis *** results showed that Vis in the southern SCS was generally better than that in the northern *** the past 39 years,Vis in both spring and winter has improved,especially in winter at a significant increased speed of 0.37 km decade^(-1).However,Vis in both summer and autumn has decreased,especially in summer with an obvious reduction of 0.84 km decade^(-1).Overall,Vis is best in summer and worst in winter,averaging 31.89 km in summer and 20.96 km in winter,which may be related to the difference of climatic conditions and wind speed in different *** the same time,probability of low Vis in spring is significantly higher than that in other seasons,especially in the northwest of Hainan Island and the northwest of Malaysia.

关键词： visibility(Vis) spatiotemporal characteristics South China Sea

Investigation of the common intermediates over Fe-ZSM-5 in NH 3-SCR reaction at low temperature by in situ DRIFTS

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Journal of Environmental Sciences 2020年第8期32卷 32-39页

作者： Xiaoyan Shi Yingjie Wang yulong shan Yunbo Yu Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China

The surface species formed in the reaction of NO and NO2 with pre-adsorbed NH 3 over a Fe-ZSM-5 catalyst(1.27 wt.%Fe,SiO2/Al2O3=25)at low temperature(140°C)were studied by in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS).Through using a background spectrum of NH3-saturated Fe-ZSM-5,we clearly observed the formation of common intermediates resulting from the reaction of NO2 or NO+O2 with pre-adsorbed *** presents strong evidence that the oxidation of NO to form surface nitrates and nitrites is the key step for standard SCR at low *** addition,the results suggest that in the SCR reaction at low temperature,the NH^4+ions absorbed on Brønsted acid sites are less active than NH3 adsorbed on Lewis acid sites related to Fe species.

关键词： Fe-ZSM-5 NH 3-SCR SCR mechanism Intermediates In situ DRIFTS

Promoted NH_(3)-SCR activity and hydrothermal stability of Cu-SSZ-50 catalyst synthesized by one-pot method

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Chinese Chemical Letters 2024年第3期35卷 135-139页

作者： Jinpeng Du Jingyi Wang yulong shan Shichao Han Wenpo shan Hong He Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control Ningbo Urban Environment Observation and Research StationInstitute of Urban EnvironmentChinese Academy of SciencesNingbo 315800China University of Chinese Academy of Sciences Beijing 100049China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Nitrogen oxide(NO_(x))is one of the most critical contaminants in the air,and the control of NO_(x)emission from diesel vehicles is very ***-based small-pore zeolites have already been applied for NO_(x)abatement on diesel *** the small-pore zeolites,Cu-SSZ-50 catalysts with good NH_(3)-SCR catalytic activity were believed to have potential for *** this study,a one-pot synthesis method for Cu-SSZ-50 catalysts was developed for the first time,using the co-templates of Cu-TEPA and 2,6-dimethyl-N-methylpyridinium *** this synthesis method,Cu-SSZ-50 with various Cu contents can be obtained by adjusting the amount of Cu-TEPA without the need for a further after-treatment *** addition of Cu-TEPA affected the framework atoms and Cu species,and a lower Si/Al ratio and more SCR active Cu species were *** synthesized catalyst with a Cu/Al ratio of 0.40 exhibited over 90%NO_(x)conversion between 200℃and 450℃for the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR).Meanwhile,over 80%NO_(x)conversion could be obtained from 250℃to 450℃after hydrothermal aging at 750℃for 16 *** addition,both L-H and E-R mechanisms were proven to exist for the one-pot-synthesized Cu-SSZ-50 by in situ DRIFTS *** simple synthesis procedure,excellent catalytic activity and hydrothermal stability brighten the prospects for the application of Cu-SSZ-50.

关键词： NH_(3)-SCR Cu-SSZ-50 One-pot synthesis Si/Al ratio Cu species distribution Reaction mechanism

Efficient Pt/KFI zeolite catalysts for the selective catalytic reduction of NOxby hydrogen

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Journal of Environmental Sciences 2024年第4期138卷 102-111页

作者： Ligang Zhang yulong shan Zidi Yan Zhongqi Liu Yunbo Yu Hong He School of Rare Earths University of Science and Technology of ChinaHefei 230026China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341119China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Aiming at purification of NO_(x)from hydrogen internal combustion engines(HICEs),the hydrogen selective catalytic reduction(H_(2)-SCR)reaction was investigated over a series of Pt/KFI zeolite catalysts.H_(2)can readily reduce NO_(x)to N_(2)and N_(2)O while O_(2)inhibited the deNO_(x)efficiency by consuming the reductant H_(2).The Pt/KFI zeolite catalysts with Pt loading below 0.1wt.% are optimized H_(2)-SCR catalysts due to its suitable operation temperature window since high Pt loading favors the H_(2)-O_(2)reaction which lead to the insufficient of *** to metal Pt^(0)species,Pt^(δ+)species showed lower activation energy of H_(2)-SCR reaction and thought to be as reasonable active ***,Eley-Rideal(E-R)reaction mechanism was proposed as evidenced by the reaction orders in kinetic ***,the optimized reactor was designed with hybrid Pt/KFI catalysts with various Pt loading which achieve a high NO_(x)conversion in a wide temperature range.

关键词： Pt/KFI zeolite Pt loading H_(2)-SCR Reaction conditions Kinetics studies

Modulation of Madden-Julian Oscillation Activity by the Tropical Pacific-Indian Ocean Associated Mode

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Advances in Atmospheric Sciences 2020年第12期37卷 1375-1388页

作者： Lifeng LI Xin LI Xiong CHEN Chongyin LI Jianqi ZHANG yulong shan College of Meteorology and Oceanography National University of Defense TechnologyNanjing 211101China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

In this study,the impacts of the tropical Pacific–Indian Ocean associated mode(PIOAM)on Madden–Julian Oscillation(MJO)activity were investigated using reanalysis *** the positive(negative)phase of the PIOAM,the amplitudes of MJO zonal wind and outgoing longwave radiation are significantly weakened(enhanced)over the Indian Ocean,while they are enhanced(weakened)over the central and eastern *** eastward propagation of the MJO can extend to the central Pacific in the positive phase of the PIOAM,whereas it is mainly confined to west of 160°E in the negative *** PIOAM impacts MJO activity by modifying the atmospheric circulation and moisture *** ascending(descending)motion and positive(negative)moisture anomalies occur over the western Indian Ocean and central-eastern Pacific(Maritime Continent and western Pacific)during the positive phase of the *** anomalous circulation is almost the opposite in the negative phases of the *** anomalous circulation and moisture can modulate the activity of the *** stronger moistening over the Indian Ocean induced by zonal and vertical moisture advection leads to the stronger MJO activity over the Indian Ocean in the negative phase of the *** the positive phase of the PIOAM,the MJO propagates farther east over the central Pacific owing to the stronger moistening there,which is mainly attributable to the meridional and vertical moisture advection,especially low-frequency background state moisture advection by the MJO’s meridional and vertical velocities.

关键词： tropical Pacific-Indian Ocean associated mode MJO moisture budget analysis anomalous circulation

Selective catalytic reduction of NOx with NH3:opportunities and challenges of Cu-based small-pore zeolites

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National Science Review 2021年第10期8卷 139-158页

作者： yulong shan Jinpeng Du Yan Zhang Wenpo shan Xiaoyan Shi Yunbo Yu Runduo Zhang Xiangju Meng Feng-Shou Xiao Hong He State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental Sciences Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical Technology Key Laboratory of Applied Chemistry of Zhejiang Province Department of Chemistry Zhejiang University

Zeolites, as efficient and stable catalysts, are widely used in the environmental catalysis field. Typically,Cu-SSZ-13 with small-pore structure shows excellent catalytic activity for selective catalytic reduction of NOxwith ammonia（NH3-SCR） as well as high hydrothermal stability. This review summarizes major advances in Cu-SSZ-13 applied to the NH3-SCR reaction, including the state of copper species, standard and fast SCR reaction mechanism, hydrothermal deactivation mechanism, poisoning resistance and synthetic methodology. The review gives a valuable summary of new insights into the matching between SCR catalyst design principles and the characteristics of Cu2+-exchanged zeolitic catalysts, highlighting the significant opportunity presented by zeolite-based catalysts. Principles for designing zeolites with excellent NH3-SCR performance and hydrothermal stability are proposed. On the basis of these principles, more hydrothermally stable Cu-AEI and Cu-LTA zeolites are elaborated as well as other alternative zeolites applied to NH3-SCR. Finally, we call attention to the challenges facing Cu-based small-pore zeolites that still need to be addressed.

关键词： environmental catalysis Cu-SSZ-13 NH3-SCR reaction mechanism small-pore zeolites

Advances in emission control of diesel vehicles in China

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Journal of Environmental Sciences 2023年第1期123卷 15-29页

作者： Guangyan Xu Wenpo shan Yunbo Yu yulong shan Xiaodong Wu Ye Wu Shaojun Zhang Liqiang He Shijin Shuai Hailong Pang Xuefeng Jiang Heng Zhang Lei Guo Shufen Wang Feng-Shou Xiao Xiangju Meng Feng Wu Dongwei Yao Yan Ding Hang Yin Hong He Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Institute of Urban Environment Chinese Academy of SciencesXiamen 361021China Tsinghua University Beijing 100084China Army Military Transportation University Tianjin 300161China Dongfeng Motor Corporation Wuhan 430101China China National Heavy Duty Truck Group Company Limited Jinan 250000China Zhejiang University Hangzhou 310027China Chinese Research Academy of Environmental Sciences Beijing 100012China

Diesel vehicles have caused serious environmental problems in ***,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI *** fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel ***,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted *** to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine *** the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.

关键词： Diesel vehicles Legislation Emission control Aftertreatment system Nitrogen oxides Particulate matter

机动式激光测风雷达三维风场反演模型仿真研究

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地球物理学报 2023年第12期66卷 4863-4874页

作者：单雨龙赵世军姬文明国防科技大学气象海洋学院长沙410000

激光测风雷达具有探测精度高、环境适应性好等优点,发展其机动式应用技术,在军事保障、抢险救灾、海洋调查等领域具有广阔应用前景.雷达在机动条件下工作时,会由于载体的运动及倾斜造成数据探测误差,且不同光束之间的实际探测仰角不一致... 详细信息

激光测风雷达具有探测精度高、环境适应性好等优点,发展其机动式应用技术,在军事保障、抢险救灾、海洋调查等领域具有广阔应用前景.雷达在机动条件下工作时,会由于载体的运动及倾斜造成数据探测误差,且不同光束之间的实际探测仰角不一致,导致无法基于传统VAD算法反演大气三维风场.本文研究探索了激光测风雷达机动探测条件下的数据订正算法,及同一组VAD扫描中光束仰角不同条件下的三维风场反演算法,并通过数值仿真试验对算法进行验证.结果表明,数据订正算法能够有效订正载体运动带来的雷达探测误差,数据反演算法能够有效反演得到三维风场,但同一组VAD扫描中光束仰角差越大,三维风场反演误差越大.

关键词：激光测风雷达机动探测数据订正风场反演

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基于人工神经网络的北极海域大气能见度格点数据生成技术

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极地研究 2019年第3期31卷 276-283页

作者：单雨龙张韧李明国防科技大学气象海洋学院

随着北极航线的逐渐开通,北极航道的通航风险评估工作得到更多的关注。针对当前北极航道风评工作中存在的能见度数据稀缺等问题,提出一种基于能见度推理结果与观测数据相结合的能见度格点数据生成技术。通过确定能见度影响因子、生成样... 详细信息

随着北极航线的逐渐开通,北极航道的通航风险评估工作得到更多的关注。针对当前北极航道风评工作中存在的能见度数据稀缺等问题,提出一种基于能见度推理结果与观测数据相结合的能见度格点数据生成技术。通过确定能见度影响因子、生成样本数据集、人工神经网络技术和贝叶斯推理技术的拟合效果对比、订正推理所得能见度数据等流程,构建了基于人工神经网络推理结果和观测数据相结合的能见度格点数据生成模型,并将该推理结果与传统插值结果进行对比。结果表明,基于该模型生成的能见度格点数据的准确度高于插值结果,且结果更为科学,能够为我国的极地航道风评工作提供重要参考。

关键词：北极航道人工神经网络能见度格点数据