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| 1 | Identification of long-range transport pathways and potential sources of PM2.5 and PM10 in Beijing from 2014 to 2015显示文摘Trajectory clustering, potential source contribution function(PSCF) and concentration-weighted trajectory(CWT) methods were applied to investigate the transport pathways and identify potential sources of PM_(2.5)and PM_(10) in different seasons from June 2014 to May 2015 in Beijing.The cluster analyses showed that Beijing was affected by trajectories from the south and southeast in summer and autumn. In winter and spring, Beijing was not only affected by the trajectories from the south and southeast, but was also affected by trajectories from the north and northwest. In addition, the analyses of the pressure profile of backward trajectories showed that backward trajectories, which have important influence on Beijing, were mainly distributed above 970 h Pa in summer and autumn and below 950 h Pa in spring and winter. This indicates that PM_(2.5)and PM_(10) were strongly affected by the near surface air masses in summer and autumn and by high altitude air masses in winter and spring. Results of PSCF and CWT analyses showed that the largest potential source areas were identified in spring, followed by winter and autumn,then summer. In addition, potential source regions of PM_(10) were similar to those of PM_(2.5). There were a clear seasonal and spatial variation of the potential source areas of Beijing and the airflow in the horizontal and vertical directions. Therefore, more effective regional emission reduction measures in Beijing's surrounding provinces should be implemented to reduce emissions of regional sources in different seasons. | Deping Li Jianguo Liu Jiaoshi Zhang Huaqiao Gui Peng Du Tongzhu Yu Jie Wang Yihuai Lu Wenqing Liu Yin Cheng | 2017 | Journal of Environmental Sciences2017，29，6： | 22 |
| 2 | Haze observations by simultaneous lidar and WPS in Beijing before and during APEC, 2014显示文摘We present combined Mie lidar, ozone lidar and wide-range particle spectrometer observations which were carried out in Beijing, north China during two periods—one haze period before the Asia-Pacific Economic Cooperation(APEC) meeting and one moderate pollution period during the meeting in 2014. High extinction coefficient, moderate ozone concentration and variable particle number concentration were obtained throughout the first haze observation period. The mean extinction coefficients in the two pollution periods were 0.52 and 0.23 km?1, respectively, at 532 nm. The ozone concentration during the first haze phase was more various with a higher average value of 49 ppb compared with that in the second pollution observations(32 ppb). Compared with the same metrological condition occurring at the end of October, the sharply decreased aerosol extinction coefficient and ozone concentration show the effectiveness of the emission-cutting measures implemented during APEC in November. The comparison of aerosols and ozone in different heights indicate different pollution sources and the complicated ozone process of generation and disappearance. The correlation between the scattering coefficient and particle number concentrations of various diameter depended on the ambient humidity. Especially the particle number concentration(500 nm–1 ?m) contributed most to PM2.5 concentration. The four-day back trajectories from a Hybrid Single-particle Lagrangian Integrated Trajectory(HYSPLIT) model indicate that the air masses in the lower boundary layer before and during APEC were advected from the densely populated south regions of China and the long pollution transportation passing through northern China. | Zhenyi Chen Jiaoshi Zhang Tianshu Zhang Wenqing Liu Jianguo Liu | 2015 | Science China Chemistry2015，58，9： | 14 |
| 3 | Development of a static test apparatus for evaluating the performance of three PM2.5 separators commonly used in China显示文摘PM2.5 separator directly affects the accuracy of PM2.5 sampling.The specification testing and evaluation for PM2.5 separator is particularly important,especially under China’s wide variation of terrain and climate.In this study,first a static test apparatus based on polydisperse aerosol was established and calibrated to evaluate the performance of the PM2.5 separators.A uniform mixing chamber was developed to make particles mix completely.The aerosol concentration relative standard deviations of three test points at the same horizontal chamber position were less than 0.57%,and the particle size distribution obeyed logarithmic normal distribution with an R2 of 0.996.The flow rate deviation between the measurement and the set point flow rate agreed to within±1.0%in the range of-40 to 50℃.Secondly,the separation,flow and loading characteristics of three cyclone separators(VSCC-A,SCC-A and SCC112)were evaluated using this system.The results showed that the 50%cutoff sizes(D50)of the three cyclones were 2.48,2.47 and 2.44μm when worked at the manufacturer’s recommended flow rates,respectively.The geometric standard deviation(GSD)of the capture efficiency of VSCCA was 1.23,showed a slightly sharper than SCC-A(GSD=1.27),while the SCC112 did not meet the relevant indicator(GSD=1.2±0.1)with a GSD=1.44.The flow rate and loading test had a great effect on D50,while the GSD remained almost the same as before.In addition,the maintenance frequency under different air pollution conditions of the cyclones was summarized according to the loading test. | Peng Du Jianguo Liu Huaqiao Gui Jiaoshi Zhang Tongzhu Yu Jie Wang Yin Cheng Yihuai Lu Yawei Yao Qiang Fu ChihChieh Chen | 2020 | Journal of Environmental Sciences2020，32，1： | 9 |
| 4 | Great saphenous vein high ligation joint bubble hardener in the treatment of varicose ulcer 50 cases clinical observation 显示文摘 | Kang Chaowen YanPeng Zhang Zhiming Liu Jiaoshi to China | 2014 | Journal of medical information2014，27，12： | 1 |
| 5 | Investigating the effect of volatility on the hygroscopicities of acetate nanoparticle aerosols by surface plasmon resonance microscopy显示文摘Under high relative humidity(RH)conditions,the release of volatile components(such as acetate)has a significant impact on the aerosol hygroscopicity.In this work,one surface plasmon resonance microscopy(SPRM)measurement system was introduced to determine the hygroscopic growth factors(GFs)of three acetate aerosols separately or mixed with glucose at different RHs.For Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) aerosols,the hygroscopic growth trend of each time was lower than that of the previous time in three cyclic humidification from 70% RH to 90% RH,which may be due to the volatility of acetic acid leading to the formation of insoluble hydroxide(Ca(OH)_(2) or Mg(OH)_(2))under high RH conditions.Then the third calculated GF(using the Zdanovskii-Stokes-Robinson method)for Ca(CH_(3)COO)_(2) or Mg(CH_(3)COO)_(2) in bicomponent aerosols with 1:1 mass ratio were 3.20% or 5.33% lower than that of the first calculated GF at 90% RH.The calculated results also showed that the hygroscopicity change of bicomponent aerosol was negatively correlated with glucose content,especially when the mass ratio of Mg(CH_(3)COO)_(2) to glucose was 1:2,the GF at 90% RH only decreased by4.67% after three cyclic humidification.Inductively coupled plasma atomic emission spectrum(ICP-AES)based measurements also indicated that the changes of Mg^(2+)concentration in bicomponent was lower than that of the single-component.The results of this study reveal thatduring the efflorescence transitions of atmospheric nanoparticles,the organic acids diffusion rate may be inhibited by the coating effect of neutral organic components,and the particles aging cycle will be prolonged. | Bo Yang Zhibo Xie Jianguo Liu Huaqiao Gui Jiaoshi Zhang Xiuli Wei Zetao Fan Douguo Zhang | 2024 | Journal of Environmental Sciences2024，，4： | 0 |
| 6 | Retrieval of refractive index of ultrafine single particle using hygroscopic growth factor obtained by high sensitive surface plasmon resonance microscopy显示文摘When exposed to different relative humidities (RHs),the optical properties of atmospheric aerosols will change because of changes in the aerosol particle size and complex refractive index (RI),which will affect haze formation and global climate change.The potential contributions of ultrafine particles to the atmospheric optical characteristics and to haze spreading cannot be ignored because of their high particle number concentrations and strong diffusibility;measurement of the optical properties of wet ultrafine particles is thus highly important for environmental assessment.Therefore,a surface plasmon resonance microscopy with azimuthal rotation illumination (SPRM-ARI) system is designed to determine the RIs of single particle aerosols with diameters of less than 100 nm in the hygroscopic growth process.Measurements are taken using mixed single particles with different mass ratios.The RIs of mixed single aerosols at different RHs are retrieved by measuring the scattering light intensity using the SPRM-ARI system and almost all the RIs of the bicomponent particles with different mass ratios decrease with increasing water content under high RH conditions.Finally,for each of the bicomponent particles,the maximum standard deviations for the retrieved RI values are only 2.06×10^(-3),3.08×10^(-3)and 3.83×10^(-3),corresponding to the NaCl and NaNO_(3)bicomponent particles with a 3:1 mass ratio at 76.0%RH,the NaCl and glucose particles with a 1:3 mass ratio at 89.0%RH,and the NaCl and OA particles with a 1:1 mass ratio at 78.0%RH,respectively;these results indicate that the high-sensitivity SPRM-ARI system can measure the RI effectively and accurately. | Bo Yang Jianguo Liu Zhibo Xie Jiaoshi Zhang Xiuli Wei Yixin Yang DexiaWu Huaqiao Gui | 2023 | Journal of Environmental Sciences2023，，4： | 0 |
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