Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 197
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 197
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 271
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3165
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 597
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 511
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 317
Function: require_once
98%
921
2 minutes
20
In recent years, the central plains urban agglomeration has been facing air pollution problems, of which the ozone (O) pollution in Hebi City has been particularly prominent, for up to five months, with the most serious pollution situation occurring in June. In this study, the period from June 20-27, 2023, which had the longest O duration (8d) and high O hourly average concentration of 256 μg·m, was selected as a typical O pollution process for characterization and analysis. Various methods, such as the positive definite matrix factor decomposition (PMF) model, air pollutant source emission inventory, and ozone formation potential (OFP), were used to resolve ozone sources. The Meteoinfo model potential source contribution factor method (PSCF) and concentration weighting trajectory (CWT) method were used to explore the regional transport of O. The results showed that: ① O was more strongly correlated with VOCs and became significantly negatively correlated with aromatic, alkane, and halogenated hydrocarbons, followed by NO. ② Based on the local traceability of VOCs, the reactive species such as isoprene, /-xylene, ethylene, 1,2,4-trimethylbenzene, hexanal, and toluene contributed the most to the O generation, and the results of the local emission inventories and PMF modelling showed that the main sources of VOCs included solvent use sources (25.7%), process sources (23.1%), mobile sources (20.4%), fossil fuel stationary combustion sources (9.9%), biomass combustion sources (8.9%), and natural sources (12.15%). ③ In addition, fossil fuel stationary combustion sources and mobile sources also contributed the most to NO emissions. ④ In response to the pollution process, man-made sources of O pollution were influenced by air masses from different directions in the surrounding cities of Xinxiang, Anyang, and Zhengzhou. Natural sources were mainly influenced by a southeastern air mass dominated by Zhoukou and Chuzhou. In summary, O pollution prevention and control should focus on cutting down the enterprises with high VOCs emissions such as the coal chemical industry in Baoshan Park and the fine chemical industry in Jijishan Park in Hebi, as well as electric power enterprises mainly based on Heqi and Fenghe Power Generation Limited Liability Company, and timely checking the standards for the use of machinery at construction sites and agricultural machinery, while it is crucial to strengthen the regional joint prevention and control.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.13227/j.hjkx.202405328 | DOI Listing |