<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Yu Song</style></author><author><style face="normal" font="default" size="100%">Xiaoyan Tang</style></author><author><style face="normal" font="default" size="100%">Shaodong Xie</style></author><author><style face="normal" font="default" size="100%">Yuanhang Zhang</style></author><author><style face="normal" font="default" size="100%">Yongjie Wei</style></author><author><style face="normal" font="default" size="100%">Zhang, Minsi</style></author><author><style face="normal" font="default" size="100%">Limin Zeng</style></author><author><style face="normal" font="default" size="100%">Sihua Lu</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Source apportionment of PM2. 5 in Beijing in 2004</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of hazardous materials</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2007</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.sciencedirect.com/science/article/pii/S0304389406014257?via%3Dihub</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1-2</style></number><publisher><style face="normal" font="default" size="100%">Elsevier</style></publisher><volume><style face="normal" font="default" size="100%">146</style></volume><pages><style face="normal" font="default" size="100%">124–130</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span&gt;Based on measurements of fine particulate matter (PM2.5, i.e., particles with an aerodynamic diameter of 2.5&lt;/span&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;span&gt;μm or less) in January and August 2004, serious air pollution persists in Beijing. The chemical analysis included organic and elemental carbon, water-soluble ions, and elemental compositions. The positive matrix factorization (PMF) method was used to apportion the PM2.5 sources. The sources contributing dominantly to PM2.5 mass concentrations are coal combustion in winter and the secondary products in summer. Furthermore, the contributions from motor vehicles, road dusts and biomass burning could not be neglected. The products of biomass burning for winter heating in the area around Beijing could enter the urban area during quasi-quiescent weather conditions. In conclusion, some effective control measures were proposed to reduce the PM2.5 pollution in Beijing.&lt;/span&gt;&lt;/p&gt;</style></abstract></record></records></xml>