检索结果-南通市图书馆

Intensified haze formation and meteorological feedback by complex terrain in the North China Plain region

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2023年第2期16卷 1-8页

作者： Jingyi Liu Lian Xue Xin Huang Zilin Wang Sijia Lou aijun ding School of Atmospheric Sciences Nanjing UniversityNanjingChina Jiangsu Provincial Collaborative Innovation Center for Climate Change NanjingChina Frontiers Science Center for Critical Earth Material Cycling Nanjing UniversityNanjingChina

华北平原地区冬季雾霾污染频发,本研究结合地面观测,卫星反演和大气动力-化学耦合模拟发现,该地区复杂地形加剧了细颗粒物污染及其与大气边界层之间的相互作用.一方面,复杂地形导致污染在山麓平原积聚,加强迎风坡上升气流.在污染事件中... 详细信息

华北平原地区冬季雾霾污染频发,本研究结合地面观测,卫星反演和大气动力-化学耦合模拟发现,该地区复杂地形加剧了细颗粒物污染及其与大气边界层之间的相互作用.一方面,复杂地形导致污染在山麓平原积聚,加强迎风坡上升气流.在污染事件中,污染层易被抬升至1-2公里高度,高空较强的氧化能力利于二次气溶胶生成;另一方面,地形导致的污染层抬升和二次生成进一步加强气溶胶-边界层相互作用,削弱垂直扩散并加剧近地面大气污染.

关键词： PM_(2.5) 复杂地形二次污染气溶胶-边界层相互作用

A 14-year measurement of toxic elements in atmospheric particulates in Hong Kong from 1995 to 2008

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2014年第4期8卷 553-560页

作者： Wei NIE Tao WANG aijun ding Xuehua ZHOU Wenxing WANG Environment Research Institute Shandong University Jinan 250100 China Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong China Institute for Climate and Global Change Research Nanjing University Nanjing 210009 China

Toxic elements in the atmosphere can enter and accumulate in the human body, seriously impacting human health. In this study, we analyzed a 14-year （1995-2008） measurement of three toxic elements （As, Cd and Cr） in PMlo in Hong Kong, China. The pollution of these toxic elements in Hong Kong was not serious. The trend analysis showed that As and Cr in PM10 increased at a statistically significant level （p〈0.05） during the 14-year period, while the Cd in PM10 did not change significantly. Typical seasonal variations were observed for all three toxic elements, largely in relation to the Asian monsoon. Hourly 10-day backward trajectories were computed and cate- gorised into four groups. The continental air masses showed much higher concentrations of the three toxic elements than the marine air masses. The abundances of As and Cd in the PM10 were much higher in the continental air masses than those in the marine air masses, while the abundances of Cr showed an opposite pattern. The trends of the three toxic elements in East China＇s air mass were consistent with those in the overall data set ofHong Kong. Examination of the toxic element data recorded at urban sites and a roadside site also indicated a large contribution of external air masses to particulate As and Cd in Hong Kong. These results suggest that the long-range transport from the mainland of China is the dominant contributor to particulate As and Cd, while both local and long-distance sources determine the particulate Cr in Hong Kong.

关键词： toxic elements increasing trends seasonal variations air masses long-distance sources

Observation-based Estimation of Aerosol-induced Reduction of Planetary Boundary Layer Height

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2017年第9期34卷 1057-1068页

作者： Jun ZOU Jianning SUN aijun ding Minghuai WANG Weidong GUO Congbin FU School of Atmospheric Sciences and Institute for Climate and Global Change Nanjing University Joint International Research Laboratory of Atmospheric and Earth System Sciences of Ministry of Education Nanjing University

Radiative aerosols are known to influence the surface energy budget and hence the evolution of the planetary boundary layer. In this study, we develop a method to estimate the aerosol-induced reduction in the planetary boundary layer height （PBLH） based on two years of ground-based measurements at a site, the Station for Observing Regional Processes of the Earth System （SORPES）, at Nanjing University, China, and radiosonde data from the meteorological station of Nanjing. The observations show that increased aerosol loads lead to a mean decrease of 67.1 W m-2 for downward shortwave radiation （DSR） and a mean increase of 19.2 W m-2 for downward longwave radiation （DLR）, as well as a mean decrease of 9.6 W m-2 for the surface sensible heat flux （SHF） in the daytime. The relative variations of DSR, DLR and SHF are shown as a function of the increment of column mass concentration of particulate matter （PM2.5）. High aerosol loading can significantly increase the atmospheric stability in the planetary boundary layer during both daytime and nighttime. Based on the statistical relationship between SHF and PM2.5 column mass concentrations, the SHF under clean atmospheric conditions （same as the background days） is derived. In this case, the derived SHF, together with observed SHF, are then used to estimate changes in the PBLH related to aerosols. Our results suggest that the PBLH decreases more rapidly with increasing aerosol loading at high aerosol loading. When the daytime mean column mass concentration of PM2.5 reaches 200 mg m-2, the decrease in the PBLH at 1600 LST （local standard time） is about 450 m.

关键词： aerosol radiation atmospheric stability surface sensible heat flux planetary boundary layer height

Response of organic aerosol characteristics to emission reduction in Yangtze River Delta region

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2023年第9期17卷 221-232页

作者： Jinbo Wang Jiaping Wang Wei Nie Xuguang Chi Dafeng Ge Caijun Zhu Lei Wang Yuanyuan Li Xin Huang Ximeng Qi Yuxuan Zhang Tengyu Liu aijun ding Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric SciencesNanjing UniversityNanjing 210023China Jiangsu Provincial Collaborative Innovation Center of Climate Change Nanjing 210023China National Observation and Research Station for Atmospheric Processes and Environmental Change in Yangtze River Delta Nanjing 210023China

Organic aerosol(OA)is a major component of atmospheric particulate matter(PM)with complex composition and formation processes influenced by various factors.Emission reduction can alter both precursors and oxidants which further affects secondary OA formation.Here we provide an observational analysis of secondary OA(SOA)variation properties in Yangtze River Delta(YRD)of eastern China in response to large scale of emission reduction during Chinese New Year(CNY)holidays from 2015 to 2020,and the COVID-19 pandemic period from January to March,2020.We found a 17%increase of SOA proportion during the COVID lockdown.The relative enrichment of SOA is also found during multi-year CNY holidays with dramatic reduction of anthropogenic emissions.Two types of oxygenated OA(OOA)influenced by mixed emissions and SOA formation were found to be the dominant components during the lockdown in YRD region.Our results highlight that these emission-reduction-induced changes in organic aerosol need to be considered in the future to optimize air pollution control measures.

关键词： Emission control Secondary organic aerosol Atmospheric oxidizing capacity Holiday effects COVID-19 lockdown

ENSO and Southeast Asian biomass burning modulate subtropical trans-Pacific ozone transport

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2021年第6期8卷 120-127页

作者： Lian Xue aijun ding Owen Cooper Xin Huang Wuke Wang Derong Zhou Zhaohua Wu Audra Mc Clure-Begley Irina Petropavlovskikh Meinrat O.Andreae Congbin Fu Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric SciencesNanjing University Jiangsu Provincial Collaborative Innovation Center for Climate Change Cooperative Institute for Research in Environmental Sciences University of Colorado Chemical Sciences Division NOAA Earth System Research Laboratory Department of Earth Ocean and Atmospheric SciencesFlorida State University Global Monitoring Division NOAA Earth System Research Laboratory Max Planck Institute for Chemistry Scripps Institution of Oceanography University of California

Trans-Pacific transport of enhanced ozone plumes has been mainly attributed to fossil fuel combustion in Asia in spring, but less attention has been paid to vegetation fires in Asia. Here we show that the El Ni?noSouthern Oscillation(ENSO)-modulated fires in Southeast Asia, rather than Asian fossil fuel plumes,dominate the interannual variability of springtime trans-Pacific transport of ozone across the entire North Pacific Ocean. During El Ni?no springs, the intensified fires from both the Indochinese Peninsula and Indonesia, together with large-scale circulation anomalies, result in enhanced ozone plumes that stretch over 15 000 km in both the lower-middle and upper troposphere. This enhancement is also observed in the in situ measurements of ozone concentration, with an almost 10% increase at Mauna Loa Observatory,Hawaii, a unique site to monitor the long-distance transport over the North Pacific. This study reports an unexpectedly strong influence of vegetation fires, linked with climate variability, on global tropospheric chemistry and proves once more how complex the interactions in the climate system are.

关键词： El Niño-Southern Oscillation (ENSO) climate biomass burning tropospheric ozone long-range transport Southeast Asia

Aerosol and boundary-layer interactions and impact on air quality

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2017年第6期4卷 810-833页

作者： Zhanqing Li Jianping Guo aijun ding Hong Liao Jianjun Liu Yele Sun Tijian Wang Huiwen Xue Hongsheng Zhang Bin Zhu State Key Laboratory of Earth Surface Processes and Resource Ecology GCESS Beijing Normal University Department of Atmospheric and Oceanic Sciences University of Maryland State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences School of Atmospheric Sciences Nanjing University School of Environmental Science and Engineering Nanjing University of Information Science and Technology State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences Center for Excellence in Regional Atmospheric Environment Institute Chinese Academy of Sciences Department of Atmospheric and Oceanic Sciences Peking University School of Atmospheric Physics Nanjing University of Information Science and Technology

Air quality is concerned with pollutants in both the gas phase and solid or liquid phases. The latter are referred to as aerosols, which are multifaceted agents affecting air quality, weather and climate through many mechanisms. Unlike gas pollutants, aerosols interact strongly with meteorological variables with the strongest interactions taking place in the planetary boundary layer(PBL). The PBL hosting the bulk of aerosols in the lower atmosphere is affected by aerosol radiative effects. Both aerosol scattering and absorption reduce the amount of solar radiation reaching the ground and thus reduce the sensible heat fluxes that drive the diurnal evolution of the PBL. Moreover, aerosols can increase atmospheric stability by inducing a temperature inversion as a result of both scattering and absorption of solar radiation, which suppresses dispersion of pollutants and leads to further increases in aerosol concentration in the lower PBL.Such positive feedback is especially strong during severe pollution events. Knowledge of the PBL is thus crucial for understanding the interactions between air pollution and meteorology. A key question is how the diurnal evolution of the PBL interacts with aerosols, especially in vertical directions, and affects air quality.We review the major advances in aerosol measurements, PBL processes and their interactions with each other through complex feedback mechanisms, and highlight the priorities for future studies.

关键词： aerosol PBL radiation aerosol-PBL interaction climate change

Long-term observation of air pollution-weather/climate interactions at the SORPES station： a review and outlook

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2016年第5期10卷 9-23页

作者： aijun ding Wei Nie Xin Huang Xuguang Chi Jianning Sun Veli-Matti Kerminen Zheng Xu Weidong Guo Tuukka Petaja Xiuqun Yang Markku Kulmala Congbin Fu Joint International Research Laboratory of Atmospheric and Earth System Sciences (JirLATEST) Nanjing University Nanjing 210023 China Institute for Climate and Global Change Research School of Atmospheric Sciences Nanjing University Nanjing 210023 China Collaborative Innovation Center of Climate Change Jiangsu Province Nanjing 210023 China Department of Physics University of Helsinki Helsinki 00014 Finland

This work presents an overall introduction to the Station for Observing Regional Processes of the EarthSystem - SORPES in Nanjing, East China, and gives an overview about main scientific findings instudies of air pollution-weather/climate interactions obtained since 2011. The main results summarizedin this paper include overall characteristics of trace gases and aerosols, chemical transformationmechanisms for secondary pollutants like O3, HONO andsecondary ingrganic aerosols, and the airpollution- weather/climate interactions and feedbacks in mixed air pollution plumes from sources likefossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.

关键词： Secondary pollution Ground-based measurement Planetary boundary layer meteorology Earth system processes

疫情期间全球空气质量变化:臭氧响应的区域间差异

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2021年第4期14卷 45-51页

作者： Rong Tang Xin Huang Derong Zhou Haikun Wang Jiawei Xu aijun ding School of Atmospheric Sciences Nanjing UniversityNanjingChina Collaborative Innovation Center of Climate Change NanjingJiangsu ProvinceChina

疫情期间全球各地一次排放大幅削减,而臭氧等二次污染的响应则存在着区域间差异.结合地面和卫星观测发现,同在氮氧化物大幅下降的情况下,臭氧在东亚和欧洲呈现出可达14ppb的上升信号,而北美则下降为主(约2–4ppb).我们结合气象分析和臭... 详细信息

疫情期间全球各地一次排放大幅削减,而臭氧等二次污染的响应则存在着区域间差异.结合地面和卫星观测发现,同在氮氧化物大幅下降的情况下,臭氧在东亚和欧洲呈现出可达14ppb的上升信号,而北美则下降为主(约2–4ppb).我们结合气象分析和臭氧敏感性进一步讨论了臭氧响应差异性的原因,一方面受臭氧与前体物间关系的影响;另一方面来自于气象,尤其是温度.研究明晰了人为排放,化学和气象三者的内在关联,强调了在臭氧控制过程中考虑前体物削减和气象条件协同的重要性.

关键词：空气质量 COVID-19 臭氧二氧化氮气象条件

Cloning,Expression and Activity Analysis of a Bacterial Serine Protease

在线全文

学校读者我要写书评

暂无评论

Agricultural Biotechnology 2015年第1期4卷 48-51页

作者： Jinhui HOU Jishuang CHEN Bosong LUO aijun ding Yanhua HU Jiangsu Dafeng Harbor Holdings Limited Nanjing University of Technology Xuzhou Institute of Technology

In the study, a serine protease gene from Pantoea ananatis was cloned and expressed in prokaryotic cells. The activity of recombinant serine protease was analyzed. The results showed that the recombinant serine protease gene was 1 062 bp, encoding 352 amino acids ; the optimal reaction temperature for recombinant serine protease was 50 ℃, and the optimal pH was 5. 0. The serine protease could be developed into a new tool enzyme in biological engineering and food processing.

关键词： Serine protease Cloning Prokaryotic expression