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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ACP</journal-id>
<journal-title-group>
<journal-title>Atmospheric Chemistry and Physics</journal-title>
<abbrev-journal-title abbrev-type="publisher">ACP</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1680-7324</issn>
<publisher><publisher-name>Copernicus GmbH</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/acp-11-7755-2011</article-id>
<title-group>
<article-title>Measurements of gaseous H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; by AP-ID-CIMS during CAREBeijing 2008 Campaign</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zheng</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Hu</surname>
<given-names>M.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhang</surname>
<given-names>R.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Yue</surname>
<given-names>D.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wang</surname>
<given-names>Z.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Guo</surname>
<given-names>S.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Li</surname>
<given-names>X.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Bohn</surname>
<given-names>B.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Shao</surname>
<given-names>M.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>He</surname>
<given-names>L.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Huang</surname>
<given-names>X.</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wiedensohler</surname>
<given-names>A.</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zhu</surname>
<given-names>T.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Atmospheric Sciences, Texas A&amp;M University, College Station, TX 77843-3150, USA</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Key Laboratory for Urban Habitat Environmental Science and Technology, Shenzhen Graduate School of Peking University, Shenzhen 518055, China</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Leibniz Institute for Tropospheric Research, Permoserstrasse 15, Leipzig 04318, Germany</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Institute für Energie- und Klimaforschung Troposphäre (IEK-8), Forschungszentrum Jülich, 52425 Jülich, Germany</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>now at: Guangdong Environmental Monitoring Center, Guangdong, 510308, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>03</day>
<month>08</month>
<year>2011</year>
</pub-date>
<volume>11</volume>
<issue>15</issue>
<fpage>7755</fpage>
<lpage>7765</lpage>
<permissions>
<license xlink:type="simple">
<license-p>This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
</license>
</permissions>
<self-uri xlink:href="http://www.atmos-chem-phys.net/11/7755/2011/acp-11-7755-2011.html">This article is available from http://www.atmos-chem-phys.net/11/7755/2011/acp-11-7755-2011.html</self-uri>
<self-uri xlink:href="http://www.atmos-chem-phys.net/11/7755/2011/acp-11-7755-2011.pdf">The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/7755/2011/acp-11-7755-2011.pdf</self-uri>
<abstract>
<p>As part of the 2008 Campaign of Air Quality Research in
Beijing and Surrounding Regions (CAREBeijing 2008), measurements of gaseous
sulfuric acid (H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;) have been conducted at an urban site in
Beijing, China from 7 July to 25 September 2008 using atmospheric pressure
ion drift – chemical ionization mass spectrometry (AP-ID-CIMS). This
represents the first gaseous H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; measurements in China. Diurnal
profile of sulfuric acid is strongly dependent on the actinic flux, reaching
a daily maximum around noontime and with an hourly average concentration of
5 &amp;times; 10&lt;sup&gt;6&lt;/sup&gt; molecules cm&lt;sup&gt;−3&lt;/sup&gt;. Simulation of sulfuric acid on the
basis of the measured sulfur dioxide concentration, photolysis rates of
ozone and nitrogen dioxide, and aerosol surface areas captures the trend of
the measured H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; diurnal variation within the uncertainties,
indicating that photochemical production and condensation onto preexisting
particle surface dominate the observed diurnal H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; profile. The
frequency of the peak H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; concentration exceeding
5 &amp;times; 10&lt;sup&gt;6&lt;/sup&gt; molecules cm&lt;sup&gt;−3&lt;/sup&gt; increases by 16 % during the period of the
summer Olympic Games (8–24 August 2008), because of the implementation of
air quality control regulations. Using a multivariate statistical method,
the critical nucleus during nucleation events is inferred, containing two
H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; molecules (&lt;i&gt;R&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt; = 0.85). The calculated condensation rate
of H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; can only account for 10–25  % of PM&lt;sub&gt;1&lt;/sub&gt; sulfate
formation, indicating that either much stronger sulfate production exists at
the SO&lt;sub&gt;2&lt;/sub&gt; source region or other sulfate production mechanisms are
responsible for the sulfate production.</p>
</abstract>
<counts><page-count count="11"/></counts>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple"> % vor jede Referenz Anderson, K. E., Siepmann, J. I., McMurry, P. H., and VandeVondele, J.: Importance of the number of acid molecules and the strength of the base for double-ion formation in (H&lt;sub&gt;2&lt;/sub&gt;SO$_4)_m\cdot $Base$\cdot $(H&lt;sub&gt;2&lt;/sub&gt;O)$_6 $Clusters, J. Am. Chem. Soc., 130, 14144–14147, http://dx.doi.org/10.1021/ja8019774doi:10.1021/ja8019774, 2008. </mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple"> Arnold, F.: Atmospheric aerosol and cloud condensation nuclei formation: A possible influence of cosmic rays?, Space Sci. Rev., 125, 169–186, 2006. </mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple"> Arnold, J. R., Hartsell, B. E., Luke, W. T., Ullah, S. M. R., Dasgupta, P. K., Huey, L. G., and Tate, P.: Field test of four methods for gas-phase ambient nitric acid, Atmos. Environ., 41, 4210–4226, http://dx.doi.org/10.1016/j.atmosenv.2006.07.058doi:10.1016/j.atmosenv.2006.07.058, 2007. </mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple"> Birmili, W. and Wiedensohler, A.: New particle formation in the continental boundary layer: Meteorological and gas phase parameter influence, Geophys. Res. Lett., 27, 3325–3328, 2000. </mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple"> Biskos, G., Buseck, P. R., and Martin, S. T.: Hygroscopic growth of nucleation-mode acidic sulfate particles, J. Aerosol Sci., 40, 338–347, http://dx.doi.org/10.1016/j.jaerosci.2008.12.003doi:10.1016/j.jaerosci.2008.12.003, 2009. </mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple"> Bohn, B., Corlett, G. K., Gillmann, M., Sanghavi, S., Stange, G., Tensing, E., Vrekoussis, M., Bloss, W. J., Clapp, L. J., Kortner, M., Dorn, H.-P., Monks, P. S., Platt, U., Plass-Dülmer, C., Mihalopoulos, N., Heard, D. E., Clemitshaw, K. C., Meixner, F. X., Prevot, A. S. H., and Schmitt, R.: Photolysis frequency measurement techniques: results of a comparison within the ACCENT project, Atmos. Chem. Phys., 8, 5373–5391, http://dx.doi.org/10.5194/acp-8-5373-2008doi:10.5194/acp-8-5373-2008, 2008. </mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple"> Chan, C. K. and Yao, X.: Air pollution in mega cities in China, Atmos. Environ., 42, 1–42, http://dx.doi.org/10.1016/j.atmosenv.2007.09.003doi:10.1016/j.atmosenv.2007.09.003, 2008. </mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple"> Cheng, Y. F., Wiedensohler, A., Eichler, H., Su, H., Gnauk, T., Brueggemann, E., Herrmann, H., Heintzenberg, J., Slanina, J., Tuch, T., Hu, M., and Zhang, Y. H.: Aerosol optical properties and related chemical apportionment at Xinken in Pearl River Delta of China, Atmos. Environ., 42, 6351–6372, http://dx.doi.org/10.1016/j.atmosenv.2008.02.034doi:10.1016/j.atmosenv.2008.02.034, 2008. </mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple"> Cheng, Y. F., Berghof, M., Garland, R. M., Wiedensohler, A., Wehner, B., Muller, T., Su, H., Zhang, Y. H., Achtert, P., Nowak, A., Poschl, U., Zhu, T., Hu, M., and Zeng, L. M.: Influence of soot mixing state on aerosol light absorption and single scattering albedo during air mass aging at a polluted regional site in northeastern China, J. Geophys. Res., 114, D00G10, http://dx.doi.org/10.1029/2008jd010883doi:10.1029/2008jd010883, 2009. </mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple"> DeCarlo, P. F., Kimmel, J. R., Trimborn, A., Northway, M. J., Jayne, J. T., Aiken, A. C., Gonin, M., Fuhrer, K., Horvath, T., Docherty, K. S., Worsnop, D. R., and Jimenez, J. L.: Field-deployable, high-resolution, time-of-flight aerosol mass spectrometer, Anal. Chem., 78, 8281–8289, 2006. </mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple"> Ehhalt, D. H. and Rohrer, F.: Dependence of the OH concentration on solar UV, J. Geophys. Res., 105, 3565–3571, 2000. </mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple"> Fan, J. W. and Zhang, R. Y.: Atmospheric Oxidation Mechanism of Isoprene, Environ. Chem., 1, 140–149, http://dx.doi.org/10.1071/en04045doi:10.1071/en04045, 2004. </mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple"> Finlayson-Pitts, B. J. and Pitts, J. N.: Chemistry of the upper and lower atmosphere : theory, experiments and applications, Academic Press, San Diego, Calif., 969 pp., 1999. </mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple"> Ford, I. J.: Nucleation theorems, the statistical mechanics of molecular clusters, and a revision of classical nucleation theory, Phys. Rev. E, 56, 5615–5629, 1997. </mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple"> Fortner, E. C., Zhao, J., and Zhang, R. Y.: Development of ion drift-chemical ionization mass spectrometry, Anal. Chem., 76, 5436–5440, http://dx.doi.org/10.1021/Ac0493222doi:10.1021/Ac0493222, 2004. </mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple"> Freiberg, J. E. and Schwartz, S. E.: Oxidation of SO&lt;sub&gt;2&lt;/sub&gt; in aqueous droplets – mass-transport limitation in laboratory studies and the ambient atmosphere, Atmos. Environ., 15, 1145–1154, 1981. </mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple"> Guo, S., Hu, M., Wang, Z. B., Slanina, J., and Zhao, Y. L.: Size-resolved aerosol water-soluble ionic compositions in the summer of Beijing: implication of regional secondary formation, Atmos. Chem. Phys., 10, 947–959, http://dx.doi.org/10.5194/acp-10-947-2010doi:10.5194/acp-10-947-2010, 2010. </mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple"> He, S. Z., Chen, Z. M., Zhang, X., Zhao, Y., Huang, D. M., Zhao, J. N., Zhu, T., Hu, M., and Zeng, L. M.: Measurement of atmospheric hydrogen peroxide and organic peroxides in Beijing before and during the 2008 Olympic Games: chemical and physical factors influencing their concentrations, J. Geophys. Res., 115, D17307, http://dx.doi.org/10.1029/2009JD013544doi:10.1029/2009JD013544, 2010. </mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple"> Huang, X.-F., He, L.-Y., Hu, M., Canagaratna, M. R., Sun, Y., Zhang, Q., Zhu, T., Xue, L., Zeng, L.-W., Liu, X.-G., Zhang, Y.-H., Jayne, J. T., Ng, N. L., and Worsnop, D. R.: Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer, Atmos. Chem. Phys., 10, 8933–8945, http://dx.doi.org/10.5194/acp-10-8933-2010doi:10.5194/acp-10-8933-2010, 2010. </mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple"> IPCC: IPCC Fourth Assessment Report: Climate change 2007: the physical science basis, edited by: Solomon, S., Qin, D., Manning, M., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge Univ. Press, United Kingdom and New York, 996 pp., 2007. </mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple"> Jefferson, A., Eisele, F. L., Ziemann, P. J., Weber, R. J., Marti, J. J., and McMurry, P. H.: Measurements of the H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt; mass accommodation coefficient onto polydisperse aerosol, J. Geophys. Res., 102, 19021–19028, 1997. </mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple"> JPL: Chemical kinetics and photochemical data for use in atmospheric studies Evaluation 15, NASA, JPL, Caltech, Pasadena, Calif., 523 pp., 2006. </mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple"> Khalizov, A. F., Xue, H. X., Wang, L., Zheng, J., and Zhang, R. Y.: Enhanced light absorption and scattering by carbon soot aerosol internally mixed with sulfuric acid, J. Phys. Chem. A, 113, 1066–1074, http://dx.doi.org/10.1021/jp807531ndoi:10.1021/jp807531n, 2009a. </mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple"> Khalizov, A. F., Zhang, R. Y., Zhang, D., Xue, H. X., Pagels, J., and McMurry, P. H.: Formation of highly hygroscopic soot aerosols upon internal mixing with sulfuric acid vapor, J. Geophys. Res., 114, D05208, http://dx.doi.org/10.1029/2008jd010595doi:10.1029/2008jd010595, 2009b. </mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple"> Kulmala, M., Vehkamaki, H., Petaja, T., Dal Maso, M., Lauri, A., Kerminen, V. M., Birmili, W., and McMurry, P. H.: Formation and growth rates of ultrafine atmospheric particles: a review of observations, J. Aerosol Sci., 35, 143–176, 2004. </mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple"> Laakso, L., Petäjä, T., Lehtinen, K. E. J., Kulmala, M., Paatero, J., Hõrrak, U., Tammet, H., and Joutsensaari, J.: Ion production rate in a boreal forest based on ion, particle and radiation measurements, Atmos. Chem. Phys., 4, 1933–1943, http://dx.doi.org/10.5194/acp-4-1933-2004doi:10.5194/acp-4-1933-2004, 2004. </mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple"> Liu, Y. and Shao, M.: Estimation and prediction of black carbon emissions in Beijing City, Chin. Sci. Bull., 52, 1274–1281, http://dx.doi.org/10.1007/s11434-007-0162-8doi:10.1007/s11434-007-0162-8, 2007. </mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple"> Lu, K. D., Rohrer, F., Holland, F., Fuchs, H., Bohn, B., Brauers, T., Chang, C. C., Häseler, R., Hu, M., Kita, K., Kondo, Y., Li, X., Lou, S. R., Nehr, S., Shao, M., Zeng, L. M., Wahner, A., Zhang, Y. H., and Hofzumahaus, A.: Observation and modelling of OH and HO&lt;sub&gt;2&lt;/sub&gt; concentrations in the Pearl River Delta 2006: a missing OH source in a VOC rich atmosphere, Atmos. Chem. Phys. Discuss., 11, 11311–11378, http://dx.doi.org/10.5194/acpd-11-11311-2011doi:10.5194/acpd-11-11311-2011, 2011. </mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple"> McGraw, R. and Zhang, R. Y.: Multivariate analysis of homogeneous nucleation rate measurements. Nucleation in the p-toluic acid/sulfuric acid/water system, J. Chem. Phys., 128, 064508, http://dx.doi.org/10.1063/1.2830030doi:10.1063/1.2830030, 2008. </mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple"> Metzger, A., Verheggen, B., Dommen, J., Duplissy, J., Prevot, A. S. H., Weingartner, E., Riipinen, I., Kulmala, M., Spracklen, D. V., Carslaw, K. S., and Baltensperger, U.: Evidence for the role of organics in aerosol particle formation under atmospheric conditions, P. Natl. Acad. Sci. USA, 107, 6646–6651, http://dx.doi.org/10.1073/pnas.0911330107doi:10.1073/pnas.0911330107, 2010. </mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple"> Molina, M. J., Molina, L. T., Zhang, R. Y., Meads, R. F., and Spencer, D. D.: The reaction of ClONO&lt;sub&gt;2&lt;/sub&gt; with HCl on aluminum oxide, Geophys. Res. Letts., 24, 1619–1622, 1997. </mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple"> Nadykto, A. B. and Yu, F. Q.: Strong hydrogen bonding between atmospheric nucleation precursors and common organics, Chem. Phys. Lett., 435, 14–18, http://dx.doi.org/10.1016/j.cplett.2006.12.050doi:10.1016/j.cplett.2006.12.050, 2007. </mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple"> Seeley, J. V., Jayne, J. T., and Molina, M. J.: High-pressure fast-flow technique for gas-phase kinetics studies, Int. J. Chem. Kinet., 25, 571–594, 1993. </mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple"> Seinfeld, J. H. and Pandis, S. N.: Atmospheric chemistry and physics: from air pollution to climate change, Wiley, New York, 1326~pp., 1998. </mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple"> Sipila, M., Berndt, T., Petaja, T., Brus, D., Vanhanen, J., Stratmann, F., Patokoski, J., Mauldin, R. L., Hyvarinen, A. P., Lihavainen, H., and Kulmala, M.: The role of sulfuric acid in atmospheric nucleation, Science, 327, 1243–1246, http://dx.doi.org/10.1126/science.1180315doi:10.1126/science.1180315, 2010. </mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple"> Suh, I., Lei, W. F., and Zhang, R. Y.: Experimental and theoretical studies of isoprene reaction with NO&lt;sub&gt;3&lt;/sub&gt;, J. Phys. Chem. A, 105, 6471–6478, 2001. </mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple"> Wang, L., Khalizov, A. F., Zheng, J., Xu, W., Ma, Y., Lal, V., and Zhang, R.: Atmospheric nanoparticles formed from heterogeneous reactions of organics, Nat. Geosci., 3, 238–242, http://dx.doi.org/10.1038/ngeo778doi:10.1038/ngeo778, 2010. </mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple"> Wang, M., Zhu, T., Zheng, J., Zhang, R. Y., Zhang, S. Q., Xie, X. X., Han, Y. Q., and Li, Y.: Use of a mobile laboratory to evaluate changes in on-road air pollutants during the Beijing 2008 Summer Olympics, Atmos. Chem. Phys., 9, 8247–8263, http://dx.doi.org/10.5194/acp-9-8247-2009doi:10.5194/acp-9-8247-2009, 2009. </mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple"> Wang, T., Nie, W., Gao, J., Xue, L. K., Gao, X. M., Wang, X. F., Qiu, J., Poon, C. N., Meinardi, S., Blake, D., Wang, S. L., Ding, A. J., Chai, F. H., Zhang, Q. Z., and Wang, W. X.: Air quality during the 2008 Beijing Olympics: secondary pollutants and regional impact, Atmos. Chem. Phys., 10, 7603–7615, http://dx.doi.org/10.5194/acp-10-7603-2010doi:10.5194/acp-10-7603-2010, 2010. </mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple"> Yue, D. L., Hu, M., Zhang, R. Y., Wang, Z. B., Zheng, J., Wu, Z. J., Wiedensohler, A., He, L. Y., Huang, X. F., and Zhu, T.: The roles of sulfuric acid in new particle formation and growth in the mega-city of Beijing, Atmos. Chem. Phys., 10, 4953–4960, http://dx.doi.org/10.5194/acp-10-4953-2010doi:10.5194/acp-10-4953-2010, 2010. </mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple"> Young, L. H., Benson, D. R., Kameel, F. R., Pierce, J. R., Junninen, H., Kulmala, M., and Lee, S.-H.: Laboratory studies of H2SO4/H2O binary homogeneous nucleation from the SO&lt;sub&gt;2&lt;/sub&gt;+OH reaction: evaluation of the experimental setup and preliminary results, Atmos. Chem. Phys., 8, 4997–5016, http://dx.doi.org/10.5194/acp-8-4997-2008doi:10.5194/acp-8-4997-2008, 2008. </mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, D. and Zhang, R. Y.: Laboratory investigation of heterogeneous interaction of sulfuric acid with soot, Environ. Sci. Technol., 39, 5722–5728, 2005. </mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, D., Lei, W. F., and Zhang, R. Y.: Mechanism of OH formation from ozonolysis of isoprene: kinetics and product yields, Chem. Phys. Lett., 358, 171–179, 2002a. </mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, D., Zhang, R. Y., Park, J., and North, S. W.: Hydroxy peroxy nitrites and nitrates from OH initiated reactions of isoprene, J. Am. Chem. Soc., 124, 9600–9605, http://dx.doi.org/10.1021/ja0255195doi:10.1021/ja0255195, 2002b. </mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, Q. H., Zhang, J. P., and Xue, H. W.: The challenge of improving visibility in Beijing, Atmos. Chem. Phys., 10, 7821–7827, http://dx.doi.org/10.5194/acp-10-7821-2010doi:10.5194/acp-10-7821-2010, 2010. </mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y.: Getting to the critical nucleus of aerosol formation, Science, 328, 1366–1367, http://dx.doi.org/10.1126/science.1189732doi:10.1126/science.1189732, 2010. </mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Wooldridge, P. J., Abbatt, J. P. D., and Molina, M. J.: Physical-chemistry of the H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/H&lt;sub&gt;2&lt;/sub&gt;O binary-system at low-temperatures – stratospheric implications, J. Phys. Chem., 97, 7351–7358, 1993a. </mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Wooldridge, P. J., and Molina, M. J.: Vapor-pressure measurements for the H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/HNO&lt;sub&gt;3&lt;/sub&gt;/H&lt;sub&gt;2&lt;/sub&gt;O and H&lt;sub&gt;2&lt;/sub&gt;SO&lt;sub&gt;4&lt;/sub&gt;/HCl/H&lt;sub&gt;2&lt;/sub&gt;O systems - incorporation of stratospheric acids into background sulfate aerosols, J. Phys. Chem., 97, 8541–8548, 1993b. </mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Leu, M. T., and Molina, M. J.: Formation of polar stratospheric clouds on preactivated background aerosols, Geophys. Res. Letts., 23, 1669–1672, http://dx.doi.org/10.1029/96gl01133doi:10.1029/96gl01133, 1996. </mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Suh, I., Zhao, J., Zhang, D., Fortner, E. C., Tie, X. X., Molina, L. T., and Molina, M. J.: Atmospheric new particle formation enhanced by organic acids, Science, 304, 1487–1490, 2004. </mixed-citation>
</ref>
<ref id="ref51">
<label>51</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Li, G. H., Fan, J. W., Wu, D. L., and Molina, M. J.: Intensification of Pacific storm track linked to Asian pollution, P. Natl. Acad. Sci. USA, 104, 5295–5299, http://dx.doi.org/10.1073/pnas.0700618104doi:10.1073/pnas.0700618104, 2007. </mixed-citation>
</ref>
<ref id="ref52">
<label>52</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Khalizov, A. F., Pagels, J., Zhang, D., Xue, H. X., and McMurry, P. H.: Variability in morphology, hygroscopicity, and optical properties of soot aerosols during atmospheric processing, P. Natl. Acad. Sci. USA, 105, 10291–10296, http://dx.doi.org/10.1073/pnas.0804860105doi:10.1073/pnas.0804860105, 2008. </mixed-citation>
</ref>
<ref id="ref53">
<label>53</label><mixed-citation publication-type="other" xlink:type="simple"> Zhang, R. Y., Wang, L., Khalizov, A. F., Zhao, J., Zheng, J., McGraw, R. L., and Molina, L. T.: Formation of nanoparticles of blue haze enhanced by anthropogenic pollution, P. Natl. Acad. Sci. USA, 106, 17650–17654, http://dx.doi.org/10.1073/pnas.0910125106doi:10.1073/pnas.0910125106, 2009. </mixed-citation>
</ref>
<ref id="ref54">
<label>54</label><mixed-citation publication-type="other" xlink:type="simple"> Zhao, J., Levitt, N. P., and Zhang, R. Y.: Heterogeneous chemistry of octanal and 2,4-hexadienal with sulfuric acid, Geophys. Res. Lett., 32, L09802, http://dx.doi.org/10.1029/2004gl022200doi:10.1029/2004gl022200, 2005. </mixed-citation>
</ref>
<ref id="ref55">
<label>55</label><mixed-citation publication-type="other" xlink:type="simple"> Zhao, J., Levitt, N. P., Zhang, R. Y., and Chen, J. M.: Heterogeneous reactions of methylglyoxal in acidic media: Implications for secondary organic aerosol formation, Environ. Sci. Technol., 40, 7682–7687, http://dx.doi.org/10.1021/es060610kdoi:10.1021/es060610k, 2006. </mixed-citation>
</ref>
<ref id="ref56">
<label>56</label><mixed-citation publication-type="other" xlink:type="simple"> Zhao, J., Khalizov, A., Zhang, R. Y., and McGraw, R.: Hydrogen-bonding interaction in molecular complexes and clusters of aerosol nucleation precursors, J. Phys. Chem. A, 113, 680–689, http://dx.doi.org/10.1021/jp806693rdoi:10.1021/jp806693r, 2009. </mixed-citation>
</ref>
<ref id="ref57">
<label>57</label><mixed-citation publication-type="other" xlink:type="simple"> Zheng, J., Khalizov, A., Wang, L., and Zhang, R.: Atmospheric pressure-ion drift chemical ionization mass spectrometry for detection of trace gas species, Anal. Chem., 82, 7302–7308, http://dx.doi.org/10.1021/ac101253ndoi:10.1021/ac101253n, 2010. </mixed-citation>
</ref>
</ref-list>
</back>
</article>