<?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%">Shaodong Xie</style></author><author><style face="normal" font="default" size="100%">Yuanhang Zhang</style></author><author><style face="normal" font="default" size="100%">Limin Zeng</style></author><author><style face="normal" font="default" size="100%">Lynn G. Salmon</style></author><author><style face="normal" font="default" size="100%">Mei Zheng</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Source apportionment of PM2. 5 in Beijing using principal component analysis/absolute principal component scores and UNMIX</style></title><secondary-title><style face="normal" font="default" size="100%">Science of the Total Environment</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2006</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.sciencedirect.com/science/article/pii/S0048969706006760?via%3Dihub</style></url></web-urls></urls><number><style face="normal" font="default" size="100%">1</style></number><publisher><style face="normal" font="default" size="100%">Elsevier</style></publisher><volume><style face="normal" font="default" size="100%">372</style></volume><pages><style face="normal" font="default" size="100%">278–286</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;div id=&quot;abstracts&quot; class=&quot;Abstracts&quot;&gt;
&lt;div id=&quot;aep-abstract-id8&quot; class=&quot;abstract author&quot;&gt;
&lt;div id=&quot;aep-abstract-sec-id9&quot;&gt;
&lt;p&gt;&lt;span&gt;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/source-apportionment&quot; title=&quot;Learn more about Source Apportionment&quot;&gt;Source apportionment&lt;/a&gt;&lt;span&gt;&amp;nbsp;of fine&amp;nbsp;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/particulate-matter&quot; title=&quot;Learn more about particulate matter&quot;&gt;particulate matter&lt;/a&gt;&amp;nbsp;(PM2.5, i.e., particles with an aerodynamic diameter of 2.5&amp;nbsp;μm or less) in Beijing, China, was determined using two&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/eigenvectors&quot; title=&quot;Learn more about eigenvectors&quot;&gt;eigenvector&lt;/a&gt;&lt;span&gt;&lt;span&gt;&lt;span&gt;&amp;nbsp;models, principal component analysis/absolute principal component scores (PCA/APCS) and UNMIX. The data used in this study were from the chemical analysis of 24-h samples, which were collected at 6-day intervals in January, April, July, and October 2000 in the Beijing metropolitan area. Both models identified five sources of PM2.5: secondary sulfate and secondary nitrate, a mixed source of&amp;nbsp;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/coal-combustion&quot; title=&quot;Learn more about Coal Combustion&quot;&gt;coal combustion&lt;/a&gt;&amp;nbsp;and&amp;nbsp;&lt;/span&gt;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/biomass-burning&quot; title=&quot;Learn more about biomass burning&quot;&gt;biomass burning&lt;/a&gt;&lt;span&gt;,&amp;nbsp;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/industrial-emission&quot; title=&quot;Learn more about industrial emission&quot;&gt;industrial emission&lt;/a&gt;, motor vehicles exhaust, and road dust. On average, the PCA/APCS and UNMIX models resolved 73% and 85% of the PM2.5 mass concentrations, respectively. The results were comparable to previous estimate using the positive matrix&amp;nbsp;&lt;/span&gt;&lt;/span&gt;&lt;a href=&quot;https://www.sciencedirect.com/topics/earth-and-planetary-sciences/factorization&quot; title=&quot;Learn more about factorization&quot;&gt;factorization&lt;/a&gt;&amp;nbsp;(PMF) and chemical mass balance (CMB) receptor models. Secondary products and the emissions from coal combustion and biomass burning dominated PM2.5. Such comparison among various receptor models, which contain different physical constraints, is important for better understanding PM2.5 sources.&lt;/span&gt;&lt;/p&gt;
&lt;p&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;/p&gt;
&lt;/div&gt;
&lt;/div&gt;
&lt;/div&gt;</style></abstract></record></records></xml>