Ambient PM2.5 samples were collected in five midwestern United States cities throughout 2004: East St. Louis, Illinois; Detroit Michigan; Cincinnati, Ohio; Bondville, Illinois; and Northbrook, Illinois. Monthly composites were analyzed using chemical derivatization coupled with GC-MS analysis to estimate the contributions of several sources to the total ambient organic carbon. A chemical mass balance (CMB) approach was used to estimate contributions from several primary sources. An additional, organic tracer-based technique was employed to estimate secondary contributions, including secondary organic carbon derived from isoprene, alpha-pinene, beta-caryophyllene, and toluene. The sum of these contributions was compared with the total organic carbon measured at each sampling site, and reasonable carbon mass balances were observed for four of the five sites. In Bondville, Northbrook, Cincinnati, and Detroit a strong correlation was observed between the sum of the estimated primary and secondary contributions and the measured organic carbon (R2 = 0.73). The estimated secondary organic carbon concentrations were observed to vary considerably with season, with the strongest contributions coming from isoprene and alpha-pinene during the summer. While further research is required, there is some evidence that the contribution estimates for alpha-pinene, beta-caryophyllene, and toluene SOC may to some degree represent the contributions from the broader classes of monoterpenes, sesquiterpenes, and aromatics.
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http://dx.doi.org/10.1021/es0720412 | DOI Listing |
Nat Commun
January 2025
School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.
Stereocontrolled construction of tetrasubstituted olefins has been an attractive issue yet remains challenging for synthetic chemists. In this manuscript, alkynyl selenides, when treated with ArBCl, are subject to an exclusive 1,1-carboboration, affording tetrasubstituted alkenes with excellent levels of E-selectivity. Detailed mechanistic studies, supported by DFT calculations, elucidates the role of selenium in this 1,1-addition process.
View Article and Find Full Text PDFSci Bull (Beijing)
January 2025
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China; Macao Institute of Materials Science and Engineering (MIMSE), MUST-SUDA Joint Research Center for Advanced Functional Materials, Zhuhai MUST Science and Technology Research Institute, Macau University of Science and Technology, Macao 999078, China; Institute of Organic Optoelectronics (IOO), Jiangsu Industrial Technology Research Institute (JITRI), Suzhou 215200, China. Electronic address:
High-quality quantum dots (QDs) possess superior electroluminescent efficiencies and ultra-narrow emission linewidths are essential for realizing ultra-high definition QD light-emitting diodes (QLEDs). However, the synthesis of such QDs remains challenging. In this study, we present a facile high-temperature successive ion layer adsorption and reaction (HT-SILAR) strategy for the growth of precisely tailored ZnCdSe/ZnSe shells, and the consequent production of high-quality, large-particle, alloyed red CdZnSe/ZnCdSe/ZnSe/ZnS/CdZnS QDs.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China. Electronic address:
Rational regulation of interface structure in photocatalysts is a promising strategy to improve the photocatalytic performance of carbon dioxide (CO) reduction. However, it remains a challenge to modulate the interface structure of multi-component heterojunctions. Herein, a strategy integrating heterojunction with facet engineering is developed to modulate the interface structure of metal-organic frameworks (MOF)-based heterojunctions.
View Article and Find Full Text PDFJ Environ Manage
January 2025
School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, PR China. Electronic address:
Thiocyanate (SCN) is a highly toxic reducing inorganic compound commonly found in various nitrogen-rich wastewater and is also a promising electron donor for mixotrophic denitrification. However, its extent of involvement in mixotrophic denitrification under conditions of carbon limitation or excess remains unclear. In this study, five reactors were constructed to investigate the participation and microbial mechanisms of SCN in mixotrophic denitrification under high C/N and low C/N conditions.
View Article and Find Full Text PDFJ Environ Manage
January 2025
College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, China; International Science and Technology Cooperation Platform for Low-Carbon Recycling of Waste and Green Development, Zhejiang Gongshang University, Hangzhou, China. Electronic address:
The treatment of landfill leachate using anaerobic membrane bioreactors (AnMBRs) often faces challenges such as poor removal efficiency, low methane yield and membrane fouling. This study applied AnMBRs with incrementally adding conductive materials to enhance the treatment of landfill leachate under high organic loading rates(35 kg COD/(m∙d)). With 50 g/L activated carbon, COD removal percentages and methane yield increased to 81.
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