检索结果-南通市图书馆

Interpreting hourly mass concentrations of PM_(2.5)chemical components with an optimal deep-learning model

Journal of Environmental Sciences 2025年第5期151卷 125-139页

作者： Hongyi Li Ting Yang Yiming Du Yining Tan zifa wang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Shenyang Environmental Monitoring Center Shenyang 110167China

PM_(2.5)constitutes a complex and diversemixture that significantly impacts the environment,human health,and climate ***,existing observation and numerical simulation techniques have limitations,such as a lack of data,high acquisition costs,andmultiple *** limitations hinder the acquisition of comprehensive information on PM_(2.5)chemical composition and effectively implement refined air pollution protection and control *** this study,we developed an optimal deep learning model to acquire hourly mass concentrations of key PM_(2.5)chemical components without complex chemical *** model was trained using a randomly partitioned multivariate dataset arranged in chronological order,including atmospheric state indicators,which previous studies did not *** results showed that the correlation coefficients of key chemical components were no less than 0.96,and the root mean square errors ranged from 0.20 to 2.11μg/m^(3)for the entire process(training and testing combined).The model accurately captured the temporal characteristics of key chemical components,outperforming typical machine-learning models,previous studies,and global reanalysis datasets(such asModern-Era Retrospective analysis for Research and Applications,Version 2(MERRA-2)and Copernicus Atmosphere Monitoring Service ReAnalysis(CAMSRA)).We also quantified the feature importance using the random forest model,which showed that PM_(2.5),PM_(1),visibility,and temperature were the most influential variables for key chemical *** conclusion,this study presents a practical approach to accurately obtain chemical composition information that can contribute to filling missing data,improved air pollution monitoring and source *** approach has the potential to enhance air pollution control strategies and promote public health and environmental sustainability.

关键词： Pm2.5 chemical composition Hourly mass concentration Deep learning Bayesian optimization Feature importance

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Elucidating Secondary Organic Aerosol Processes through High-Resolution Aerosol Mass Spectrometry in Beijing

引用

Advances in Atmospheric Sciences 2025年第4期42卷 670-681页

作者： Weiqi XU Chun CHEN Zhijie LI Zhiqiang ZHANG Yu ZHANG zifa wang Yele SUN Key Laboratory of Atmospheric Environment and Extreme Meteorology Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China China Meteorological Administration Training Centre Beijing 100081China

Exploring secondary organic aerosol(SOA)processes is crucial for understanding climate and air pollution in *** study introduces a new method using positive matrix factorization(PMF)to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry *** mass spectra and time series of primary OA(POA)and less oxidized oxygenated OA(OOA)identified by this new method resembled those resolved by traditional ***,more oxidized OOA(MO-OOA)identified by traditional PMF can be further subdivided into multiple OA factors,including nitrogen-enriched OA(ON-OA)and sulfur-enriched OA(OS-OA)in summer,and ON-OA,OS-OA,and OOA in *** findings highlight the significant role of photochemical processes in the formation of OS-OA compared to *** compositions of reconstructed MO-OOA varied under different Ox(=O_(3)+NO_(2))and relative humidity conditions,emphasizing the limitations of using a constant mass *** biomass burning OA(BBOA)and coal combustion OA(CCOA),previously misattributed as POA,contributed 9.2%(0.43μg m^(−3))and 7.0%(0.33μg m^(−3))to SOA,*** BBOA was more prone to forming OS-OA,whereas ON-OA showed higher correlations with aged CCOA,indicating distinct molecular compositions of SOA from different aged POA *** to aged BBOA,aged CCOA was more subject to conversion during aqueous phase *** results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.

关键词： secondary organic aerosol positive matrix factorization aerosol mass spectrometry nitrogen-enriched organic aerosol sulfur-enriched organic aerosol

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Exploring Boundary Layer Physics and Atmospheric Chemistry in Megacities:Insights from the Beijing 325 m Meteorological Tower

引用

Advances in Atmospheric Sciences 2025年第4期42卷 713-730页

作者： Yele SUN zifa wang Linlin wang Xueling CHENG Weiqi XU Yu SHI Wei ZHOU Yan LI Fei HU Zhiqiu GAO Zhongxiang HONG State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The Beijing 325 m meteorological tower stands as a pivotal research platform for exploring atmospheric boundary layer physics and atmospheric *** a legacy spanning 45 years,the tower has played a crucial role in unraveling the complexities of urban air pollution,atmospheric processes,and climate change in Beijing,*** review paper provides a comprehensive overview of the measurements on the tower over the past two *** long-term comprehensive observations,researchers have elucidated the intricate relationships between anthropogenic emissions,meteorological dynamics,and atmospheric composition,shedding light on the drivers of air pollution and its impacts on public *** vertical measurements on the tower also enable detailed investigations into boundary layer dynamics,turbulent mixing,and pollutant dispersion,providing invaluable data for validating chemical transport *** findings from the tower’s research include the identification of positive feedback mechanisms between aerosols and the boundary layer,the characterization of pollutant sources and transport pathways,the determination of fluxes of gaseous and particulate species,and the assessment of the effectiveness of pollution control ***,isotopic measurements have provided new insights into the sources and formation processes of particulate matter and reactive nitrogen ***,the paper outlines future directions for tower-based research,emphasizing the need for long-term comprehensive measurements,the development of innovative tower platforms,and integration of emerging technologies.

关键词： meteorological tower boundary layer physics aerosol composition vertical distributions formation mechanisms aerosol-boundary interactions

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High-resolution Simulation Dataset of Hourly PM_(2.5)Chemical Composition in China(CAQRA-aerosol)from 2013 to 2020

引用

Advances in Atmospheric Sciences 2025年第4期42卷 697-712页

作者： Lei KONG Xiao TANG Jiang ZHU zifa wang Bing LIU Yuanyuan ZHU Lili ZHU Duohong CHEN Ke HU Huangjian WU Qian WU Jin SHEN Yele SUN Zirui LIU Jinyuan XIN Dongsheng JI Mei ZHENG Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China China National Environmental Monitoring Centre Beijing 100012China Guangdong Ecological Environment Monitoring Centre Guangzhou 510308China Wuhan Environmental Monitoring Centre Hubei 430015China Hubei Province Academy of Eco-environmental Sciences Hubei 430072China Peking University Beijing 100871China

Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategies.A high-resolution PM_(2.5) chemical composition dataset(CAQRA-aerosol)is developed in this study,which provides hourly maps of organic carbon,black carbon,ammonium,nitrate,and sulfate in China from 2013 to 2020 with a horizontal resolution of 15 *** paper describes the method,access,and validation results of this *** shows that CAQRA-aerosol has good consistency with observations and achieves higher or comparable accuracy with previous PM_(2.5) composition *** on CAQRA-aerosol,spatiotemporal changes of different PM_(2.5) compositions were investigated from a national viewpoint,which emphasizes different changes of nitrate from other *** estimated annual rate of population-weighted concentrations of nitrate is 0.23μg m^(−3)yr^(−1) from 2015 to 2020,compared with−0.19 to−1.1μg m^(−3)yr^(−1) for other *** whole dataset is freely available from the China Air Pollution Data Center(https://***/10.12423/capdb_***).

关键词： PM_(2.5)composition dataset black carbon organic carbon ammonium nitrate sulfate

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A preliminary report on the Great Wenchuan Earthquake

引用

Earthquake Engineering and Engineering Vibration 2008年第2期7卷 225-234页

作者： wang zifa Institute of Engineering Mechanics China Earthquake Administration Harbin 150080 China

The May 12, 2008 Great Wenchuan Earthquake has resulted in more than 68,858 deaths and losses in the hundreds of billions RMB as of May 30, 2008, and these numbers will undoubtedly increase as more information becomes available on the extent of the event. Immediately after the earthquake, the China Earthquake Administration （CEA） responded quickly by sending teams of experts to the affected region, eventually including over 60 staff members from the Institute of Engineering Mechanics （IEM）. This paper reports preliminary information that has been gathered in the first 18 days after the event, covering seismicity, search and rescue efforts, observed ground motions, and damage and loss estimates. The extensive field investigation has revealed a number of valuable findings that could be useful in improving research in earthquake engineering in the future. Once again, this earthquake has shown that the vertical component of ground motion is as significant as horizontal ground motions in the near-source area. Finally, note that as more information is gathered, the numbers reported in this paper will need to be adjusted accordingly.

关键词： Wenchuan Earthquake field investigation ground motions vertical acceleration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Elucidating Secondary Organic Aerosol Processes through High-Resolution Aerosol Mass Spectrometry in Beijing

引用

Advances in Atmospheric Sciences 2025年第4期 670-681页

Exploring secondary organic aerosol（SOA） processes is crucial for understanding climate and air pollution in megacities. This study introduces a new method using positive matrix factorization（PMF） to investigate the SOA process by integrating the OA and associated ions previously misidentified as inorganic aerosol in high-resolution aerosol mass spectrometry data. The mass spectra and time series of primary OA（POA） and less oxidized oxygenated OA（OOA）identified by this new method resembled those resolved by traditional PMF. However, more oxidized OOA（MO-OOA）identified by traditional PMF can be further subdivided into multiple OA factors, including nitrogen-enriched OA（ON-OA）and sulfur-enriched OA（OS-OA） in summer, and ON-OA, OS-OA, and OOA in winter. Our findings highlight the significant role of photochemical processes in the formation of OS-OA compared to ON-OA. The compositions of reconstructed MO-OOA varied under different Ox（= O3+ NO2） and relative humidity conditions, emphasizing the limitations of using a constant mass spectrum. Aged biomass burning OA（BBOA） and coal combustion OA（CCOA）,previously misattributed as POA, contributed 9.2%(0.43 μg m-3) and 7.0%(0.33 μg m-3) to SOA, respectively. Aged BBOA was more prone to forming OS-OA, whereas ON-OA showed higher correlations with aged CCOA, indicating distinct molecular compositions of SOA from different aged POA sources. Compared to aged BBOA, aged CCOA was more subject to conversion during aqueous phase processing. These results suggest that the variations in mass spectra and compositions need to be considered when simulating SOA processes.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

外包钢板组合槽形梁的剪切挠度求解及修正分析

引用

建筑结构 2025年第2期55卷 92-97,22页

作者：田林杰王自法袁炎徐向春河南大学建筑工程学院开封475004 中震科建(广东)防灾减灾研究院韶关512000 东南大学交通学院南京211189

外包钢板组合槽形梁结合了预应力混凝土槽形梁和波形钢腹板组合槽形梁的优点,表现出良好的弯曲工作性能,具有较好的发展前景。为分析外包钢板组合槽形梁的挠度计算方法,首先推导出集中荷载和均布荷载作用下梁体剪切挠度和总挠度的计算公... 详细信息

外包钢板组合槽形梁结合了预应力混凝土槽形梁和波形钢腹板组合槽形梁的优点,表现出良好的弯曲工作性能,具有较好的发展前景。为分析外包钢板组合槽形梁的挠度计算方法,首先推导出集中荷载和均布荷载作用下梁体剪切挠度和总挠度的计算公式;然后将理论值与试验测试值和ABAQUS模拟值进行对比,证明推导的挠度计算公式具有较好的精确性;最后以梁体腹板高度、腹板厚度和腹板形状为分析指标,研究不同参数对剪切挠度和总挠度的影响,并基于影响分析对推导的剪切挠度公式进行修正及验证。

关键词：外包钢板组合槽形梁剪切挠度弯曲挠度缩尺试验有限元模拟

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Exploring Boundary Layer Physics and Atmospheric Chemistry in Megacities:Insights from the Beijing 325 m Meteorological Tower

引用

Advances in Atmospheric Sciences 2025年第4期 713-730页

作者： Yele SUN zifa wang Linlin wang Xueling CHENG Weiqi XU Yu SHI Wei ZHOU Yan LI Fei HU Zhiqiu GAO Zhongxiang HONG State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences

The Beijing 325 m meteorological tower stands as a pivotal research platform for exploring atmospheric boundary layer physics and atmospheric chemistry. With a legacy spanning 45 years, the tower has played a crucial role in unraveling the complexities of urban air pollution, atmospheric processes, and climate change in Beijing, China. This review paper provides a comprehensive overview of the measurements on the tower over the past two decades. Through long-term comprehensive observations, researchers have elucidated the intricate relationships between anthropogenic emissions,meteorological dynamics, and atmospheric composition, shedding light on the drivers of air pollution and its impacts on public health. The vertical measurements on the tower also enable detailed investigations into boundary layer dynamics,turbulent mixing, and pollutant dispersion, providing invaluable data for validating chemical transport models. Key findings from the tower's research include the identification of positive feedback mechanisms between aerosols and the boundary layer, the characterization of pollutant sources and transport pathways, the determination of fluxes of gaseous and particulate species, and the assessment of the effectiveness of pollution control measures. Additionally, isotopic measurements have provided new insights into the sources and formation processes of particulate matter and reactive nitrogen species. Finally, the paper outlines future directions for tower-based research, emphasizing the need for long-term comprehensive measurements, the development of innovative tower platforms, and integration of emerging technologies.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Variations and drivers of aerosol vertical characterization after clean air policy in China based on 7-years consecutive observations

引用

Journal of Environmental Sciences 2023年第3期125卷 499-512页

作者： Xi Chen Ting Yang Haibo wang Futing wang zifa wang State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Understanding the aerosol vertical characterization is of great importance to both climate and atmospheric environment. This study investigated the variations of aerosol profiles over eight regions of interest in China after clean air policy(2013-2019) and discussed the drivers of the vertical aerosol structure, using observations from active satellite measurements(CALIPSO). From the annual variation, the amplitude of extinction coefficient profiles showed a decreasing trend with fluctuations, and the maximum was 0.21 km-1in BeijingTianjin-Hebei(JJJ). For regions suffered from air pollution, the variation was greatest below 0.45 km, while it was between 1-1.5 km for Sichuan Basin. The correlation coefficient between the relative humidity(RH) and the extinction coefficient indicated that the increase of RH inhibited the decrease of the extinction coefficient in the Yangtze River Delta. In most regions, the main aerosol subtypes were polluted dust and polluted continental, but they were coarser in JJJ and North West. The frequency of concurrency of dust and polluted dust aerosols decreased in JJJ, but polluted continental aerosols occurred more frequently. Further, the aerosol extinction coefficient profiles under different pollution conditions showed that it changed most during heavy pollution periods in JJJ, especially in 2017, with a significant aerosol loading between700 and 1200 m. The atmospheric reanalysis data revealed that the weak convergence at low level and the divergence at high level supported the upward transport of aerosols in 2017. Overall, the differences in divergence allocation, RH, and wind filed were the main meteorological drivers.

关键词： Aerosol Vertical characteristic China CALIPSO Pollution period

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

考虑滞后效应的CNN-BIGRU-Attention预测降水型滑坡位移

引用

人民黄河 2025年第03期47卷 135-140+145页

作者：肖金涛王自法王超赵登科李兆焱河南大学土木建筑学院中震科建(广东)防灾减灾研究院中国地震局工程力学研究所

为研究降水对滑坡的影响，基于大沙窝滑坡日降水量和位移数据，采用移动平均法将位移分解为趋势项位移和周期项位移，采用卷积神经网络（CNN）预测趋势项位移，采用带有注意力机制（Attention）的卷积神经网络-双向门控循环单元（CNN-BI... 详细信息

为研究降水对滑坡的影响，基于大沙窝滑坡日降水量和位移数据，采用移动平均法将位移分解为趋势项位移和周期项位移，采用卷积神经网络（CNN）预测趋势项位移，采用带有注意力机制（Attention）的卷积神经网络-双向门控循环单元（CNN-BIGRU）模型预测周期项位移，通过叠加趋势项位移和周期项位移得到最终预测位移结果。采用斯皮尔曼相关系数结合滞后性研究分析变量间的滞后关系。以BIGRU-Attention、门控循环单元（GRU）、长短期记忆网络（LSTM）模型为对照，比较CNN-BIGRU-Attention模型预测周期项位移的精确性。结果表明：CNN模型预测以3、6、12 h步长的趋势项位移的R2值分别为0.992、0.977、0.965;CNN-BIGRU-Attention模型预测以3、6、12 h步长的周期项位移的R2值分别为0.963、0.939、0.896,预测精度均高于BIGRU-Attention、GRU、LSTM模型；基于呷任依村滑坡监测数据，验证了CNN-BIGRU-Attention模型的泛化性。

关键词：位移预测 CNN BIGRU Attention 大沙窝滑坡呷任依村滑坡

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：