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Chinese Physics Letters 2014年第4期31卷 76-80页

作者： WANG Ding WANG Li-Ji zhang mei-gen Key Laboratory of Petroleum Resources Research Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of sciences Beijing 100029 Ur~iversity of Chinese Academy of Sciences Beijing 100049

A theoretical model is presented to describe the elastic wave propagation characteristics in porous media of periodically arranged fractures. The effects of fracture geometric parameters on a compressional wave （p-wave） are considered through analysis of the wave induced fluid flow （WIFF） process between the fractures and the background media. The diffusion equation in porous media is used to reveal how the entire diffusion process affects the wave propagation. When the thickness proportion of fractures tends to 0 and 1, the WIFF does not take place almost between fractures and background matrix porosity, and therefore the media elasticity modulus is perfectly elastic. When the fracture thickness fraction achieves a certain value, the peak of the attenuation curve reaches the maximum value at a particular frequency, which is controlled by the fluid mass conservation and stress continuity conditions on each fracture boundary. That is, the inter-coupling of fluid diffusion between the adjacent layers is important for waves attenuation. Physically speaking, the dissipation of a wave is associated with the fluid flux essentially.

关键词： Media Analysis elastic

Assessment of the regional source contributions to PM_(2.5) mass concentration in Beijing

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Atmospheric and Oceanic Science Letters 2018年第2期11卷 143-149页

作者： HAN Xiao zhang mei-gen State Key Laboratory of Atmospheric Boundary Layer physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences College of Earth Science University of Chinese Academy of Sciences

A source apportionment tool,ISAM （Integrated Source Apportionment Method）,coupled with a regional air quality modeling system,RAMS-CMAQ （Regional Atmospheric Modeling System and Community Multiscale Air Quality）,was applied to simulate the major aerosol components （sulfate,nitrate,ammonium,black carbon,organic carbon,dust,and sea salt） and investigate the impact of local and regional sources on the PM2.5 （particulate matter with an aerodynamic diameter less than 2.5 μm） mass concentration over the North China Plain （NCP） in July *** simulation results indicated that the high mass burden of PM2.5 mainly appeared in the south part of Hebei and west part of *** PM2.5 particles emitted from Beijing and Tianjin were just concentrated in the local area,but Hebei and Shandong were the dominant source over the *** on Beijing,the local contribution was just 20%-30% due to the emissions control strategies executed in recent years in *** pollutants derived from Hebei and Shandong were major contributors,providing more than 25% and 10% to the PM2.5 mass concentration in Beijing,***,the surrounding regions showed larger contributions against the pollution *** contribution percentage from Hebei and Shandong increased in both cases when the air quality became ***,it is suggested that comprehensive control strategies should be implemented based on coordinated control of emissions at the regional scale in Beijing,especially during pollution periods.

关键词： Emissions control PM2.5 source apportionmentmodel CMAQ

Assessment of Individual Direct Radiative Effects of Major Aerosol Species in East Asia

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Atmospheric and Oceanic Science Letters 2012年第1期5卷 8-14页

作者： HAN Xiao zhang mei-gen State Key Laboratory of Atmospheric Boundary Layer Physics and Atmo spheric ChemistryInstitute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

To assess individual direct radiative effects of diverse aerosol species on a regional scale, the air quality modeling system RAMS-CMAQ （Regional Atmospheric Modeling System and Community Multiscale Air Quality） coupled with an aerosol optical properties/radiative transfer module was used to simulate the temporal and spatial distributions of their optical and radiative properties over East Asia throughout 2005. Annual and seasonal averaged aerosol direct radiative forcing （ADRF） of all important aerosols and individual components, such as sulfate, nitrate, ammonium, black carbon （BC）, organic carbon （OC）, and dust at top-of-atmosphere （TOA） in clear sky are analyzed. Analysis of the model results shows that the annual average ADRF of all important aerosols was in the range of 0 to -18 W m-z, with the maximum values mainly distributed over the Sichuan Basin. The direct radiative effects of sulfate, nitrate, and ammonium make up most of the total ADRF in East Asia, being concentrated mainly over North and Southeast China. The model domain is also divided into seven regions based on different administrative regions or countries to investigate detailed information about regional ADRF variations over East Asia. The model results show that the ADRFs of sulfate, ammonium, BC, and OC were stronger in summer and weaker in winter over most regions of East Asia, except over Southeast Asia. The seasonal variation in the ADRF of nitrate exhibited the opposite trend. A strong ADRF of dust mainly appeared in spring over Northwest China and Mongolia.

关键词： CMAQ aerosol direct forcing region radiative effect

Simulated seasonal variations in nitrogen wet deposition over East Asia

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Atmospheric and Oceanic Science Letters 2016年第2期9卷 99-106页

作者： YU Jin-Hai zhang mei-gen LI Jia-Lin State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences

The regional air quality modeling system Regional Atmospheric Modeling System–Community Multiscale Air Quality was applied to estimate the spatial distribution and seasonal variation in nitrogen wet deposition over East Asia in 2010. The simulated results were evaluated by comparing modeled precipitation rates and ion concentrations, such as ammonium（NH_4~＋）, nitrate（NO_3^-）, and sulfate, in rainwater, against observations obtained from Acid Deposition Monitoring Network in East Asia and meteorological stations in China. Comparison of simulated and observed precipitation showed that the modeling system can reproduce seasonal precipitation patterns reasonably well. For major ion species, the simulated results in most cases were in good agreement with those observed. Analysis of the modeled wet deposition distributions indicated that China experiences noticeable variation in wet deposition patterns throughout the year. Nitrogen wet deposition（NH_4~＋＋ NO_3^-） during summer and spring accounted for 71% of the annual total（3.9 Tg N yr^（-1））, including 42.7% in summer. Precipitation plays a larger role in the seasonal variation of wet deposition; whereas, aerosol concentrations affect its distribution patterns. In China, the amount of annual nitrogen wet deposition ranged from 1 to 18 kg N ha^（-1）. Nitrogen in wet deposition was mainly in the form of NH_4~＋, accounting for 65.76% of the total amount, and the molar ratio of NH_4~＋∕NO_3^- was mostly more than 1, indicating a relatively larger effect from agricultural activities.

关键词： Nitrogen wet deposition CMAQ NH+4∕NO-3 ratio precipitation aerosol concentration

Numerical Simulation of CO_2 Concentrations in East Asia with RAMS-CMAQ

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Atmospheric and Oceanic Science Letters 2013年第4期6卷 179-184页

作者： KOU Xing-Xia zhang mei-gen PENG Zhen State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences School of Atmospheric Sciences Nanjing University

The regional air quality modeling system RAMS-CMAQ(Regional Atmospheric Modeling System and Models-3 Community Multi-scale Air Quality) was developed by incorporating a vegetation photosynthesis and respiration module(VPRM) and used to simulate temporal-spatial variations in atmospheric CO2 concentrations in East Asia,with prescribed surface CO2 fluxes(i.e.,fossil fuel emission,biomass burning,sea-air CO2 exchange,and terrestrial biosphere CO2 flux).Comparison of modeled CO2 mixing ratios with eight ground-based in-situ measurements demonstrated that the model was able to capture most observed CO2 temporal-spatial *** CO2 concentrations were generally in good agreement with observed *** indicated that the accumulated impacts of anthropogenic emissions contributed more to increased CO2 concentrations in urban regions relative to remote ***,RAMS-CMAQ analysis demonstrates that surface CO2 concentrations in East Asia are strongly influenced by terrestrial ecosystems.

关键词： CO2 concentration biospheric CO2 flux carbon flux regional chemical transport model

Model analysis of secondary organic aerosol over China with a regional air quality modeling system(RAMS-CMAQ)

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Atmospheric and Oceanic Science Letters 2016年第6期9卷 443-450页

作者： LI Jia-Lin zhang mei-gen GAO Yi CHEN Lei State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC) Institute of Atmospheric Physics(IAP)Chinese Academy of Sciences(CAS) College of Earth Science University of Chinese Academy of Sciences Center for Excellence in Urban Atmospheric Environment Institute of Urban EnvironmentChinese Academy of Sciences

The regional air quality modeling system RAMS-CMAQ was updated to incorporate secondary organic aerosol （SOA） production from isoprene and sesquiterpene and to account for the SOA production rate dependence on NOx and SOA aging. The system was then used to simulate spatiotemporal distributions of SOA concentration and its major constituents over China in winter. Modeled monthly mean SOA concentrations were high in central and eastern China and low in western regions. The highest SOA appeared in regions from Beijing-Tianjin-Hebei （BTH） to the middle reaches of the Yangtze River and areas from Sichuan Basin to the southwest border of China, where SOA contributions were less than 10% of the organic aerosol （OA）. The lowest concentration was in the Qinghai-Tibet Plateau, accounting for 20%-30% of OA. It is notable that contributions from anthropogenic precursors to SOA were significant in winter, especially the wide areas of central and eastern China with contributions generally varying from 50% to 80% of the total SOA. Beijing was used as an example location representative of the heavily polluted BTH area for analysis of major components of SOA. Though the modeled concentration of SOA was still underestimated compared to the observations, it still showed that xylene and toluene were the two greatest contributors to anthropogenic SOA, which was in agreement with the observations. SOA produced from monoterpene was the greatest contributor to biogenic SOA due to the high mass yield of monoterpene, followed by isoprene. More than 57% of SOAs were aged, which may increase the extinction effect of SOA.

关键词： Organic aerosol haze Beijing-Tianjin-Hebei VOCs

Model Analysis of the Anthropogenic Aerosol Effect on Clouds over East Asia

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Atmospheric and Oceanic Science Letters 2012年第1期5卷 1-7页

作者： GAO Yi zhang mei-gen LIU Xiao-Hong ZHAO Chun State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Pacific Northwest National Laboratory Richland Washington 99352 USA

A coupled meteorology and aerosol/chemistry model WRF-Chem （Weather Research and Forecast model coupled with Chemistry） was used to conduct a pair of simulations with present-day （PD） and preindustrial （P1） emissions over East Asia to examine the aerosol indirect effect on clouds. As a result of an increase in aerosols in January, the cloud droplet number increased by 650 cm-3 over the ocean and East China, 400 cm-3 over Central and Southwest China, and less than 200 cm-3 over North China. The cloud liquid water path （LWP） increased by 40-60 g m-2 over the ocean and Southeast China and 30 g m-2 over Central China; the LWP in- creased less than 5 g m-2 or decreased by 5 g m2 over North China. The effective radius （Re） decreased by more than 4 pm over Southwest, Central, and Southeast China and 2 pm over North China. In July, variations in cloud properties were more uniform; the cloud droplet number increased by approximately 250400 cm-3, the LWP increased by approximately 30-50 g m 2, and Re decreased by approximately 3 μm over most regions of China. In response to cloud property changes from PI to PD, shortwave （SW） cloud radiative m-2 over the ocean and 10 forcing strengthened by 30 W W m-2 over Southeast China, and it weakened slightly by approximately 2-10 W m-2 over Central and Southwest China in January. In July, SW cloud radiative forcing strengthened by 15 W m-2 over Southeast and North China and weakened by l0 W m-2 over Central China. The different responses of SW cloud radiative forcing in different regions was related to cloud feedbacks and natural variability.

关键词： WRF-Chem aerosol indirect effect cloud properties cloud radiative forcing

Elemental Composition of Atmospheric Particles in Winter at Datong City, Shanxi Province, China, and Its Impact on Beijing

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Atmospheric and Oceanic Science Letters 2009年第6期2卷 345-349页

作者： zhang Ren-Jian zhang mei-gen ZHU Ling-Yun HU Liang-Wen Key Laboratory of Regional Climate-Environment Research .for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China LAPC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Meteorological Science Institute of Shanxi Taiyuan 030002 China

Atmospheric particle samples were collected at an urban site of Datong, Shanxi Province, during December 2004 and their element concentrations at different sizes were analyzed by particle-induced X-ray emission (PIXE). Analysis of the observation data showed that particle pollution was heavy in winter at Datong and that concentrations of most elements were high in the coarse range. Factor analysis (FA) results indicated that the soil and dust, coal combustion dust, and industry dust are main sources for atmospheric particles in winter at Datong. The enrichment factors of element concentrations showed that particle pollution at Datong impacts the down-wind region-Beijing-in the dust season.

关键词： particles elemental concentration factor analysis

Possibility of reaching the predicted center of the“island of stability”via the radioactive beam-induced fusion reactions

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Nuclear Science and Techniques 2024年第9期35卷 186-195页

作者： Ming-Hao zhang Ying Zou mei-Chen Wang gen zhang Qing-Lin Niu Feng-Shou zhang The Key Laboratory of Beam Technology of Ministry of Education School of Physics and AstronomyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China School of Physical Science and Technology Guangxi UniversityNanning 530004China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of LanzhouLanzhou 730000China

Based on the dinuclear system model,the synthesis of the predicted double-magic nuclei^(298)Fl and 304120 was investigated via neutron-rich radioactive beam-induced fusion *** reaction^(58)Ca+^(244)Pu is predicted to be favorable for producing^(298)Fl with a maximal ER cross section of 0.301 *** of the entrance channel effect reveal that the^(244)Pu target is more promising for synthesizing^(298)Fl than the neutron-rich targets^(248)Cm and^(249)Bk,because of the influence of the Coulomb *** the synthesis of 304120,the maximal ER cross section of 0.046 fb emerges in the reaction^(58)V+^(249)Bk,indicating the need for further advancements in both experimental facilities and reaction mechanisms.

关键词： Superheavy nuclei Dinuclear system model Fusion reaction Double-magic nucleus Radioactive beam

Development of RAMS-CMAQ to Simulate Aerosol Optical Depth and Aerosol Direct Radiative Forcing and Its Application to East Asia

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Atmospheric and Oceanic Science Letters 2009年第6期2卷 368-375页

作者： HAN Xiao zhang mei-gen LIU Xiao-Hong Steven GHAN XIN Jin-Yuan WANG Li-Li State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Pacific Northwest National Laboratory Richland Washington 99352 USA

The air quality modeling system RAMS (Regional Atmospheric Modeling System)-CMAQ (Models-3 Community Multi-scale Air Quality) is developed to simulate the aerosol optical depth (AOD) and aerosol direct forcing (DF). The aerosol-specific extinction, single scattering albedo, and asymmetry factor are parameterized based on Mie theory taking into account the aerosol size distribution, composition, refractive index, and water uptake of solution particles. A two-stream solar radiative model considers all gaseous molecular absorption, Rayleigh scattering, and aerosols and clouds. RAMSCMAQ is applied to simulate all major aerosol concentrations (e.g., sulfate, nitrate, ammonium, organic carbon, black carbon, fine soil, and sea salt) and AOD and DF over East Asia in 2005. To evaluate its performance, the simulated AOD values were compared with ground-based in situ measurements. The comparison shows that RAMSCMAQ performed well in most of the model domain and generally captured the observed variations. High AOD values (0.2 1.0) mainly appear in the Sichuan Basin as well as in central and southeastern China. The geographic distribution of DF generally follows the AOD distribution patterns, and the DF at the top-of-the-atmosphere is less than 25 and 20 W m 2 in clear-sky and all-sky over the Sichuan Basin. Both AOD and DF exhibit seasonal variations with lower values in July and higher ones in January The DF could obviously be impacted by high cloud fractions.

关键词： CMAQ AOD aerosol direct forcing model development