Publications by authors named "Yuan-xun Zhang"

As one of the air pollution transmission channels around the beijing-Tianjin-Hebei region, Puyang frequently suffer from severe airpollution in autumn and winter. In order to study the characteristics and main sources of fine particulate matter during these periods, manual membrane sampling of PM was conducted at three national control sites from October 15, 2017, to January 13, 2018. Chemical composition analysis was conducted and, combined with a PMF receptor model, source analysis of the fine particles was also undertaken.

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In order to investigate the chemical characteristics and sources of atmospheric heavy metals, PM samples were collected every three days during the summer of 2011 and summer of 2012. The samples were analyzed for Li, V, Cr, Mn, Co, Cu, Zn, As, Se, Ti, Ga, Ni, Sr, Cd, In, Ba, Tl, Pb, Bi, and U by ICP-MS, with an emphasis on seven major heavy metal elements (Zn, Pb, Mn, Cu, As, V, and Cr). The concentrations of Zn, Pb, Mn, Cu, As, V, and Cr were (331.

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Chemical mass balance (CMB) modeling and radiocarbon measurements were combined to evaluate the sources of carbonaceous fine particulate matter (PM) in Shenzhen, China during and after the 2011 summer Universiade games when air pollution control measurements were implemented to achieve air quality targets. Ambient PM filter samples were collected daily at two sampling sites (Peking University Shenzhen campus and Longgang) over 24 consecutive days, covering the controlled and uncontrolled periods. During the controlled period, the average PM concentration was less than half of what it was after the controls were lifted.

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Haplocladium was cultivated in a special prepared nutrient medium containing different concentrations of Pb, Fe and Cr in laboratory. The sulfur content in moss was measured by synchrotron radiation X-ray fluorescence (SRXRF), and the percentage of various oxidation states of sulfur was analyzed by X-ray absorption near-edge structure (XANES) spectrum. The results show that the sulfur absorption increases under exposure to heavy metal ions of Pb and Fe, but it decreases under exposure to 400 mg/L Pb and 200 mg/L Fe.

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Cereal straw is one of the most abundant biomass burned in China but its contribution to fine particulates is not adequately understood. In this study, three main kinds of cereal straws were collected from five grain producing areas in China. Fine particulate matters (PM2.

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The lead contamination, lead species and source assignment were studied by a combination of several analytical techniques such as Proton-induced X-ray emission analysis (PIXE), Proton microprobe (micro-PIXE), Inductively coupled plasma-mass spectrometry (ICP-MS) and extended X-ray absorption fine structure (EXAFS) techniques. The results indicate that the lead concentration in the air of Shanghai gradually decreased over the last years. The atmospheric lead concentration of PM10 in the winter of 2002 was 369 ng x m(-3), which had declined by 28% in 2001, and in the winter of 2003 it decreased further to 237 ng x m(-3).

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