期刊文献+
共找到16篇文章
< 1 >
每页显示 20 50 100
Enrichment of carbon recovery of high ash coal fines using air fluidized vibratory deck separator 被引量:3
1
作者 Laxmikanta Sahu Shobhana Dey 《International Journal of Coal Science & Technology》 EI 2017年第3期262-273,共12页
Coal is primarily beneficiated by wet gravity methods. The wet processing of coal is an efficient practice. However, it introduces the moisture in the range of 6%-15%, depending upon the size of coal which is as detri... Coal is primarily beneficiated by wet gravity methods. The wet processing of coal is an efficient practice. However, it introduces the moisture in the range of 6%-15%, depending upon the size of coal which is as detrimental as ash content to the heating value of coal. Dry beneficiation of coal fines was carried out using an air fluidized vibrating table in which the coal particles get separated from the heavier mineral particles as a result of horizontal and vertical stratification. Two level factorial design matrix was used to optimize and assess the interactive effects of the operational parameters of a pneumatic table viz. deck eccentric, side tilt and air flow rate on the clean coal yield and its ash content. Double stage processing was found to be more effective for reducing the ash content of the clean coal. Initial stage of processing at a higher ash level generates a reject of high ash with low combustibles. Cleaning of the rougher concentrate at 34%-35% ash level shows significant improvement in the organic efficiency (88.6%) and useful heat value of clean coal (15690 kJ/kg). The performance of air fluidized vibrating deck was measured by Ep value which is 0.18. 展开更多
关键词 air flow rate · Deck eccentric · Segregation of particles ·Separation efficiency
下载PDF
CO and Particle Pollution of Indoor Air in Beijing and Its Elemental Analysis
2
作者 J.N.WANG Y.ZHANG 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1990年第2期132-138,共7页
Three representative types of houses in Beijing were selected and, in each type, smoking and nonsmoking households were compared. IP, RP. and CO concentrations in the living room and kitchen were monitored during each... Three representative types of houses in Beijing were selected and, in each type, smoking and nonsmoking households were compared. IP, RP. and CO concentrations in the living room and kitchen were monitored during each season. and the level of COHb in the heads of the households were measured. The study showed that indoor air pollution was rather severe, especially during winter. when paniculate concentrations markedly exceeded the standard and CO concentration was as high as 47 ppm. Indoor air pollution was closely related to the type of house, particularly to the mode of heating. In houses. of the same type, pollution improved greatly after central heating facilities were installed. Analysis of 30 elements revealed that pollution was typically caused by coal burning. aggravated by dusty wind, but high indoor Pb levels were probably due to the use of LPG for cooking. In our study the effect of cigarette smoking was sometimes masked by the severe indoor pollution. (C)1990 Academic Press, Inc. 展开更多
关键词 Be In CO and Particle Pollution of Indoor air in Beijing and Its Elemental Analysis COHb
下载PDF
INDOOR AIR QUALITY ASSESSMENT FOR A MULTI-STOREY UNIVERSITY OFFICE BUILDING IN MALAYSIA
3
作者 Abd Halid Abdullah Yee Yong Lee +1 位作者 Eeydzah Aminudin Yeong Huei Lee 《Journal of Green Building》 2019年第4期93-109,共17页
The indoor air quality(IAQ)in office buildings should be assessed for public health concerns as it relates to work performance and productivity.Therefore,this paper aims to assess the IAQ in a university office buildi... The indoor air quality(IAQ)in office buildings should be assessed for public health concerns as it relates to work performance and productivity.Therefore,this paper aims to assess the IAQ in a university office building.From this investigation,the level of contaminated indoor air is examined,the significant causes and contributing factors of contaminated indoor air are determined and a recommendation to improve the existing condition has been proposed.The physical parameters measured include air temperature,air velocity,relative humidity,and concentrations of carbon dioxide(CO_(2)),carbon monoxide(CO),sulphur dioxide(SO_(2)),and also air particles.It was found that the number of air particles of 0.5μm in diameter is about 197,748 particles/m^(3),while air particles of 5.0μm in diameter is around 534 particles/m^(3).The collected data were then compared with a questionnaire and IAQ standards.In conclusion,the indoor air quality within the multi-storey central office building of Universiti Tun Hussein Onn Malaysia(UTHM)is acceptable and suitable for occupation even though there were countable symptoms of Sick Building Syndrome(SBS)among its occupants. 展开更多
关键词 air particles indoor air quality university office building Sick Building Syndrome carbon dioxide carbon monoxide sulphur dioxide
下载PDF
The role of mitochondria in inflammatory syndromes
4
作者 VIRGINIA VANASCO TIMOTEO MARCHINI +6 位作者 NATALIA MAGNANI TAMARA VICO MARIANA GARCES LOURDES CACERES ALEJANDRO GUAGLIANONE PABLO EVELSON SILVIA ALVAREZ 《BIOCELL》 SCIE 2016年第1期47-50,共4页
Several authors have addressed the importance of mitochondrial function in inflammatory syn-dromes,as it may play a role in the genesis of tissue injury.Sepsis and exposition to environmental particles are examples of... Several authors have addressed the importance of mitochondrial function in inflammatory syn-dromes,as it may play a role in the genesis of tissue injury.Sepsis and exposition to environmental particles are examples of inflammatory conditions.Sepsis occurs with an exacerbated inflammatory response that damages tissue mitochondria and impairs bioenergetic processes.One of the current hypotheses for the molecular mech-anisms underlying the complex condition of sepsis is that enhanced NO production and oxidative stress lead to mitochondrial dysfunction,bioenergetic derangement and organ failure.The mechanism of particulate mat-terhealth effects are believed to involve inflammation and oxidative stress.Components in particles that elicit inflammation have been poorly investigated,although recent research points out to the contribution of composi-tional elements and particle size.Oxygen metabolism and mitochondrial function appear to be important areas of study in inflammatory conditions for clarifying molecular mechanisms involved. 展开更多
关键词 mitochondrial function BIOENERGETICS HEART ENDOTOXEMIA ambient air particles
下载PDF
INVESTIGATIONS ON MOISTURE TRANSPORTS, BUDGETS AND SOURCES RESPONSIBLE FOR THE DECADAL VARIABILITY OF PRECIPITATION IN SOUTHERN CHINA 被引量:2
5
作者 胡娅敏 司东 +1 位作者 柳艳菊 赵亮 《Journal of Tropical Meteorology》 SCIE 2016年第3期402-412,共11页
In the context of global warming,apparent decdal-interdecdal variabilities can be detected in summer precipitation in southern China.Especially around the 1990 s,precipitation in South China experienced a phase transi... In the context of global warming,apparent decdal-interdecdal variabilities can be detected in summer precipitation in southern China.Especially around the 1990 s,precipitation in South China experienced a phase transition from a deficiency regime to an abundance regime in the early 1990 s,while the Yangtze River Valley witnessed a phase shift of summer precipitation from abundance to deficiency in the late 1990 s.Pertinent analyses reveal a close relationship between such decadal precipitation shifts and moisture budgets,which is mainly modulated by the meridional component.This relationship can be attributed to large-scale moisture transport anomalies.Further,the HYSPLIT model is utilized to quantitatively evaluate relative moisture contributions from diverse sources during different regimes.It can be found that during the period with abundant precipitation in South China,the moisture contribution from the source of Indochina Peninsula-South China Sea increased significantly,while during the deficient precipitation regime in the Yangtze River Valley,moisture from local source,western Pacific and Indochina Peninsula-South China Sea contributed less to precipitation.It means some new features of relative moisture contributions from diverse sources to precipitation anomaly in southern China took shape after 1990 s. 展开更多
关键词 precipitation in southem China moisture transport moisture budget method tracing the air particle viaLagrange scheme
下载PDF
Introduction to investigations of the negative corona and EHD flow in gaseous two-phase fluids
6
作者 Jerzy MIZERACZYK Artur BERENDT 《Plasma Science and Technology》 SCIE EI CAS CSCD 2018年第5期147-156,共10页
Research interests have recently been directed towards electrical discharges in multi-phase environments.Natural electrical discharges,such as lightning and coronas,occur in the Earth's atmosphere,which is actually a... Research interests have recently been directed towards electrical discharges in multi-phase environments.Natural electrical discharges,such as lightning and coronas,occur in the Earth's atmosphere,which is actually a mixture of gaseous phase(air) and suspended solid and liquid particulate matters(PMs).An example of an anthropogenic gaseous multi-phase environment is the flow of flue gas through electrostatic precipitators(ESPs),which are generally regarded as a mixture of a post-combustion gas with solid PM and microdroplets suspended in it.Electrical discharges in multi-phase environments,the knowledge of which is scarce,are becoming an attractive research subject,offering a wide variety of possible discharges and multi-phase environments to be studied.This paper is an introduction to electrical discharges in multi-phase environments.It is focused on DC negative coronas and accompanying electrohydrodynamic(EHD) flows in a gaseous two-phase fluid formed by air(a gaseous phase) and solid PM(a solid phase),run under laboratory conditions.The introduction is based on a review of the relevant literature.Two cases will be considered:the first case is of a gaseous two-phase fluid,initially motionless in a closed chamber before being subjected to a negative corona(with the needle-toplate electrode arrangement),which afterwards induces an EHD flow in the chamber,and the second,of a gaseous two-phase fluid flowing transversely with respect to the needle-to-plate electrode axis along a chamber with a corona discharge running between the electrodes.This review-based introductory paper should be of interest to theoretical researchers and modellers in the field of negative corona discharges in single-or two-phase fluids,and for engineers who work on designing EHD devices(such as ESPs,EHD pumps,and smoke detectors). 展开更多
关键词 DC negative corona discharge Trichel pulses gaseous two-phase flow air withsuspended particle flow ESP EHD
下载PDF
Triboelectric nanogenerator enhanced multilayered antibacterial nanofiber air filters for efficient removal of ultrafine particulate matter 被引量:6
7
作者 Guang Qin Gu Chang Bao Han +7 位作者 Jing Jing Tian Tao Jiang Chuan He Cun Xin Lu Yu Bai Jin Hui Nie Zhou Li Zhong Lin Wang 《Nano Research》 SCIE EI CAS CSCD 2018年第8期4090-4101,共12页
We developed a high-efficiency rotating triboelectric nanogenerator (R-TENG)- enhanced multi.layered antibacterial polyimide (PI) nanofiber air filters for removing ultrafine particulate matter (PM) from ambient... We developed a high-efficiency rotating triboelectric nanogenerator (R-TENG)- enhanced multi.layered antibacterial polyimide (PI) nanofiber air filters for removing ultrafine particulate matter (PM) from ambient atmosphere. Compared to single- layered PI nanofiber filters, the multilayered nanofiber filter can completely remove all of the particles with diameters larger than 0.54 ffm and shows enhanced removal efficiency for smaller PM particles. After connecting with a R-TENG, the removal efficiency of the filer for ultrafine partides is further enhanced. The highest removal efficiency for ultrafine particulate matter is 94.1% at the diameter of 53.3 nm and the average removal efficiency reached 89.9%. Despite an increase in the layer number, the thickness of each individual layer of the film decreased, and hence, the total pressure drop of the filter decreased instead of increasing. Moreover, the nanofiber film exhibited high antibacterial activity because of the addition of a small amount of silver nanoparticles. This technology with zero ozone release and low pressure drop is appropriate for cleaning air, haze treatment, and bacterial control. 展开更多
关键词 triboelectricnanogenerator antibacterial property electrospinnin Ag-polyimide nanofiber air filter ultrafine particle
原文传递
Impact of emission control on regional air quality: An observational study of air pollutants before, during and after the Beijing Olympic Games 被引量:22
8
作者 Shulan Wang Jian Gao +5 位作者 Yuechong Zhang Jingqiao Zhang Fahe Cha Tao Wang Chun Ren Wenxing Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第1期175-180,共6页
An observational study on trace gases and PM2.5 was conducted at three sites in and around Beijing, during the Olympic season from 2007 to 2009. Air quality improved significantly during the Olympic Games due to the s... An observational study on trace gases and PM2.5 was conducted at three sites in and around Beijing, during the Olympic season from 2007 to 2009. Air quality improved significantly during the Olympic Games due to the special emission control measures. However, concentrations of the primary pollutants and PM were found to have risen significantly after the Games. Although the major O3 precursors (NOx and VOCs) were well controlled during the Olympic season, O3 was still found to be the highest in 2008, based on the data of ground-based observation. All this information suggests that while control of regional emissions for the Beijing Olympic Games did improved the air quality in Beijing, more efforts will be needed for the continuous improvement of regional air quality, especially for significant reductions of O3 and fine particulate pollution, and not only in Beijing, but also in the B eijing-Tianjin-Hebei region. 展开更多
关键词 Beijing Olympic Games primary pollutants ozone fine particle air
原文传递
Influence of mass air flow ratio on gas-particle flow characteristics of a swirl burner in a 29 MW pulverized coal boiler 被引量:1
9
作者 Rong YAN Zhichao CHEN +1 位作者 Shuo GUAN Zhengqi LI 《Frontiers in Energy》 SCIE CSCD 2021年第1期68-77,共10页
In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler... In a gas/particle two-phase test facility, a three-component particle-dynamics anemometer was used to measure the characteristics of gas/particle two-phase flows in a 29 megawatt (MW) pulverized coal industrial boiler equipped with a new type of swirling pulverized coal burner. The distributions of three-dimensional gas/particle velocity, particle volume flux, and particle size distribution were measured under different working conditions. The mean axial velocity and the particle volume flux in the central region of the burner outlet were found to be negative. This indicated that a central recirculation zone was formed in the center of the burner. In the central recirculation zone, the absolute value of the mean axial velocity and the particle volume flux increased when the external secondary air volume increased. The size of the central reflux zone remained stable when the air volume ratio changed. Along the direction of the jet, the peak value formed by the tertiary air gradually moved toward the center of the burner. This tertiary air was mixed with the peak value formed by the air in the adiabatic combustion chamber after the cross-section of x/d = 0.7. Large particles were concentrated near the wall area, and the particle size in the recirculation zone was small. 展开更多
关键词 industrial pulverized coal boiler swirl burner air/particle flow particle dynamic analyzer(PDA)
原文传递
Effects of supply air temperature and inlet location on particle dispersion in displacement ventilation rooms 被引量:5
10
作者 Yanming Kang Youjun Wang Ke Zhong 《Particuology》 SCIE EI CAS CSCD 2011年第6期619-625,共7页
The effects of supply temperature and vertical location of inlet air on particle dispersion in a displacement ventilated (DV) room were numerically modeled with validation by experimental data from the literature. T... The effects of supply temperature and vertical location of inlet air on particle dispersion in a displacement ventilated (DV) room were numerically modeled with validation by experimental data from the literature. The results indicate that the temperature and vertical location of inlet supply air did not greatly affect the air distribution in the upper parts of a DV room, but could significantly influence the airflow pattern in the lower parts of the room, thus affecting the indoor air quality with contaminant sources located at the lower level, such as particles from working activities in an office. The numerical results also show that the inlet location would slightly influence the relative ventilation efficiency for the same air supply volume, but particle concentration in the breathing zone would be slightly lower with a low horizontal wall slot than a rectangular diffuser. Comparison of the results for two different supply temperatures in a DV room shows that, although lower supply temperature means less incoming air volume, since the indoor flow is mainly driven by buoyancy, lower supply temperature air could more efficiently remove passive sources (such as particles released from work activities in an office). However, in the breathing zone it gives higher concentration as compared to higher supply air temperature. To obtain good indoor air quality, low supply air temperature should be avoided because concentration in the breathing zone has a stronger and more direct impact on human health. 展开更多
关键词 Displacement ventilation Particle dispersion Numerical simulation Supply air temperature Inlet location
原文传递
Removal of inhalable particles from coal and refuse combustion by agglomeration with solid nuclei 被引量:2
11
作者 Deshuai Sun Xiaodong Zhang +2 位作者 Zhongyi Zhang Long Fang Hui Du 《Particuology》 SCIE EI CAS CSCD 2018年第2期127-133,共7页
Airborne inhalable particles are a potent environmental pollutant. Formed via industrial processes, separation of these particles is difficult using conventional clean up techniques. In this work, solid nuclei particl... Airborne inhalable particles are a potent environmental pollutant. Formed via industrial processes, separation of these particles is difficult using conventional clean up techniques. In this work, solid nuclei particles of different chemical compositions were introduced into an agglomeration chamber with simulated flue gases to investigate their ability to remove these particles. Organic nuclei were able to capture more inhalable particles from coal-derived fly ash than inorganic nuclei, though these proved more effective for the agglomeration of inhalable particles in refuse-derived fly ash. Increasing the diameter of the solid nuclei benefitted the agglomeration process for both types of ash. Varying the local humidity changed adhesion between the particles and encouraged them to aggregate. Increasing the relative humidity consistently increased particle agglomeration for the refuse-derived ash. For coal-derived fly ash, the removal efficiency increased initially with relative humidity but then further increases in humidity had no impact on the relatively high efficiencies. After agglomeration in an atmosphere of 62% relative humidity, the mean mass diameter of inhalable particles in the coal-derived fly ash increased from 3.3 to 9.2 μm. For refuse-derived fly ash, agglomeration caused the percentage of particles that were less than 2μm to decrease from 40% to 15%. After treatment at a relative humidity of 61%, the mean size of inhalable particles exceeded 10 μm. 展开更多
关键词 lnhalable particle Agglomeration Solid nuclei Fly ash air pollution Relative humidity
原文传递
Occurrence,evolution and degradation of heavy haze events in Beijing traced by iodine-127 and iodine-129 in aerosols 被引量:1
12
作者 Miao Fang Xue Zhao +8 位作者 Yixuan Liu Yang Shao Ning Chen Min Luo Luyuan Zhang Qi Liu Lingling Ma Diandou Xu Xiaolin Hou 《Chinese Chemical Letters》 SCIE CAS CSCD 2022年第7期3507-3515,共9页
Heavy haze events have become a serious environment and health problem in China and many developing countries,especially in big cities,like Beijing.However,the factors and processes triggered the formation of secondar... Heavy haze events have become a serious environment and health problem in China and many developing countries,especially in big cities,like Beijing.However,the factors and processes triggered the formation of secondary particles from the gaseous pollutants are still not clear,and the processes driving evolution and degradation of heavy haze events are not well understood.Iodine isotopes(127Ⅰand129Ⅰ)as tracers were analyzed in time series aerosol samples collected from Beijing.It was observed that the127Ⅰconcentrations in aerosols peaked during the heavy haze events.The conversion of gaseous iodine to particular iodine oxides through photochemical reactions provides primary nuclei in nucleation and formation of secondary air particles,which was strengthened as the external iodine input from the fossil fuel burning in the south/southeast industrial cities and consequentially induced heavy haze events.Anthropogenic ^(129)Ⅰconcentrations peaked during clean air conditions and showed high levels in spring and later autumn compared to that in summer.^(129)Ⅰoriginated from the direct air discharges and re-emissions from contaminated seawaters by the European nuclear fuel reprocessing plants was transported to Beijing by the interaction of Westerlies and East Asian winter monsoon.Three types of mechanisms were found in the formation and evolution of heavy haze events in Beijing by the variation of ^(127)Ⅰand ^(129)Ⅰ,i.e.,iodine oxides intermediated secondary air particles,dust storm and mixed mode by both secondary air particles and dust storm induced processes. 展开更多
关键词 HAZE Iodine isotopes Aerosol Primary nuclei Secondary air particles Formation mechanism of particles
原文传递
Influence of staff number and internal constellation on surgical site infection in an operating room 被引量:11
13
作者 Sasan Sadrizadeh Ann Tammelin +1 位作者 Peter Ekolind Sture Holmberg 《Particuology》 SCIE EI CAS CSCD 2014年第2期42-51,共10页
Prediction of bacteria-carrying particle (BCP) dispersion and particle distribution released from staffmem- bers in an operating room (OR) is very important for creating and sustaining a safe indoor environment. P... Prediction of bacteria-carrying particle (BCP) dispersion and particle distribution released from staffmem- bers in an operating room (OR) is very important for creating and sustaining a safe indoor environment. Postoperative wound infections cause significant morbidity and mortality, and contribute to increased hospitalization time. Increasing the number of personnel within the OR disrupts the ventilation airflow pattern and causes enhanced contamination risk in the area of an open wound. Whether the amount of staffwithin the OR influences the BCP distribution in the surgical zone has rarely been investigated. This study was conducted to explore the influence of the number of personnel in the OR on the airflow field and the BCP distribution. This was performed by applying a numerical calculation to map the airflow field and Lagrangian particle tracking (LPT) for the BCP phase. The results are reported both for active sampling and passive monitoring approaches. Not surprisingly, a growing trend in the BCP concentration (cfu/ms) was observed as the amount of staff in the OR increased. Passive sampling shows unpredictable results due to the sedimentation rate, especially for small particles (5-10 i^m). Risk factors for surgical site infections (SSls) must be well understood to develop more effective prevention programs. 展开更多
关键词 air quality Surgical site infection airborne particle control Hospital operating room Ventilation system
原文传递
Effect of traffic restriction on atmospheric particle concentrations and their size distributions in urban Lanzhou, Northwestern China 被引量:2
14
作者 Suping Zhao Ye Yu +2 位作者 Na Liu Jianjun He Jinbei Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第2期362-370,共9页
During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect ... During the 2012 Lanzhou International Marathon, the local government made a significant effort to improve traffic conditions and air quality by implementing traffic restriction measures. To evaluate the direct effect of these measures on urban air quality, especially particle concentrations and their size distributions, atmospheric particle size distributions (0.5-20μm) obtained using an aerodynamic particle sizer (model 3321, TSI, USA) in June 2012 were analyzed. It was found that the particle number, surface area and volume concentrations for size range 0.5-10 μm were (15.0±2.1) cm-3, (11.8±2.6) μm2/cm3 and (1.9±0.6) μm2/cm3, respectively, on the traffic-restricted day (Sunday), which is 63.2%, 53.0% and 47.2% lower than those on a normal Sunday. For number and surface area concentrations, the most affected size range was 0.5-0.7 and 0.5-0.8 μm, respectively, while for volume concentration, the most affected size ranges were 0.5-0.8, 1.7-2.0 and 5.0-5.4 μm. Number and volume concentrations of particles in size range 0.5-1.0μm correlated well with the number of non-CNG (Compressed Natural Gas) powered vehicles, while their correlation with the number of CNG-powered vehicles was very low, suggesting that reasonable urban traffic controls along with vehicle technology improvements could play an important role in improving urban air quality. 展开更多
关键词 traffic restriction particle concentration size distribution urban air quality
原文传递
Six-day measurement of size-resolved indoor fluorescent bioaerosols of outdoor origin in an office 被引量:4
15
作者 Yangyang Xie Oscar A. Fajardo +2 位作者 Weizhuo Yan Bin Zhao Jingkun Jiang 《Particuology》 SCIE EI CAS CSCD 2017年第2期161-169,共9页
Indoor airborne bioaerosols of outdoor origin play an important role in determining the exposure of humans to bioaerosols because people spend most of their time indoors. However, there are few studies focusing on ind... Indoor airborne bioaerosols of outdoor origin play an important role in determining the exposure of humans to bioaerosols because people spend most of their time indoors. However, there are few studies focusing on indoor bioaerosols originating from outdoors. In this study, indoor versus outdoor size-resolved concentrations and particle asymmetry factors of airborne fluorescent bioaerosols in an office room were measured continuously for 6 days (144 h) using a fluorescent bioaerosol detector. The windows and door of this room were closed to ensure that there was only air infiltration; moreover, any human activities were ceased during sampling to inhibit effects of indoor sources. We focused on fine particles, since few coarse particles enter indoor environments, when windows and doors are closed. Both indoor and outdoor fluorescent bioaerosol size distributions were fit with two-mode lognormal distributions (indoor R2 = 0.935, outdoor R2 = 0.938). Asymmetry factor distributions were also fit with lognormal distributions (indoor R2 = 0.992, outdoor R2 = 0.992). Correlations between indoor and outdoor fluorescent bioaerosol concentrations show significant concentration-attenuation and a time lag during the study period. A two-parameter, semi-empirical model was used to predict concentrations of indoor fluorescent bioaerosols of outdoor origin. The measured and predicted concentrations had a linear relationship for the studied size fractions, with an R2 for all size fractions of larger than 0.83. 展开更多
关键词 Fluorescent bioaerosols Indoor air Outdoor air Waveband integrated bioaerosol sensor(WIBS)Particle size distributions Concentrations
原文传递
Characterization of particle number size distribution and new particle formation in Southern China 被引量:4
16
作者 Xiaofeng Huang Chuan Wang +6 位作者 Jianfei Peng Lingyan He Liming Cao Qiao Zhu Jie Cui Zhijun Wu Min Hu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2017年第1期342-351,共10页
Knowledge of particle number size distribution(PND) and new particle formation(NPF)events in Southern China is essential for mitigation strategies related to submicron particles and their effects on regional air q... Knowledge of particle number size distribution(PND) and new particle formation(NPF)events in Southern China is essential for mitigation strategies related to submicron particles and their effects on regional air quality,haze,and human health.In this study,seven field measurement campaigns were conducted from December 2013 to May 2015 using a scanning mobility particle sizer(SMPS) at four sites in Southern China,including three urban sites and one background site.Particles were measured in the size range of15-515 nm,and the median particle number concentrations(PNCs) were found to vary in the range of 0.3× 10~4-2.2 × 10~4 cn^(-3) at the urban sites and were approximately 0.2 × 10~4 cm^(-3) at the background site.The peak diameters at the different sites varied largely from 22 to 102 nm.The PNCs in the Aitken mode(25-100 nm) at the urban sites were up to 10 times higher than they were at the background site,indicating large primary emissions from traffic at the urban sites.The diurnal variations of PNCs were significantly influenced by both rush hour traffic at the urban sites and NPF events.The frequencies of NPF events at the different sites were0%-30%,with the highest frequency occurring at an urban site during autumn.With higher SO_2 concentrations and higher ambient temperatures being necessary,NPF at the urban site was found to be more influenced by atmospheric oxidizing capability,while NPF at the background site was limited by the condensation sink.This study provides a unique dataset of particle number and size information in various environments in Southern China,which can help understand the sources,formation,and the climate forcing of aerosols in this quickly developing region,as well as help constrain and validate NPF modeling. 展开更多
关键词 Scanning mobility particle sizer(SMPS) Particle number size distribution(PND) New particle formation(NPF) air pollution Southern China
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部