Track topics on Twitter Track topics that are important to you
Regional sources of nitrogen oxides (NO) in North China during summer were explored using both a Bayesian isotopic mixing model and a positive matrix factorization (PMF) model. Results showed that the nitrogen isotope (δN) composition of particulate nitrate (NO) varied between -8.9‰ and +14.1‰, while the oxygen isotope (δO) composition ranged from +57.4‰ to +93.8‰. Based on results from the Bayesian isotopic mixing model, the contribution of the hydroxyl radical (•OH) NO conversion pathway showed clear diurnal fluctuation; values were higher during the day (0.53 ± 0.16) and lower overnight (0.42 ± 0.17). Values peaked at 06:00-12:00 and then decreased gradually until 00:00-06:00 the next day. Coal combustion (31.34 ± 9.04%) was the most significant source of NO followed by biomass burning (25.74 ± 2.58%), mobile sources (23.83 ± 3.66%), and microbial processes (19.09 ± 5.21%). PMF results indicated that the contribution from mobile sources was 19.83%, slightly lower as compared to the Bayesian model (23.83%). The PMF model also reported a lower contribution from coal combustion (28.65%) as compared to the Bayesian model (31.34%); however, the sum of biomass burning and microbial processes in the Bayesian model (44.83%) was lower than the aggregate of secondary inorganic aerosol, sea salt, and soil dust in PMF model (51.52%). Overall, differences between the two models were minor, suggesting that this study provided a reasonable source quantification for NO in North China during summer.
This article was published in the following journal.
Name: Environmental pollution (Barking, Essex : 1987)
PM samples were collected simultaneously at three urban sites including Beijing (BJ), Tianjin (TJ), Shijiazhuang (SJZ) and one background site Xinglong (XL) from June 2014 till April 2015. Typical pol...
Regional ozone (O) pollution has drawn increasing attention in China over the recent decade, but the contributions from urban pollution and biogenic emissions have not been clearly elucidated. To bett...
Halogenated flame retardants (HFRs) and water-soluble ions (WSIs) were investigated in fine particulate matter (PM) collected from an urban site, a rural e-waste recycling (e-waste) site, and a backgr...
Ambient measurements of PM-bounded polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and oxy-PAHs (OPAHs) were conducted during the summer in Jinan, China, an urban site, and at Tuoji islan...
Source identification of trace metals in the water environment is important in understanding its environmental behavior and in the prevention and remediation of further pollution. Here, the regional g...
Approximately 3000 advanced NSCLC patients, who fulfil the inclusion/exclusion criteria, will be recruited by 30 sites in North China.
A French University team (M. Jeanne, MD, and M. LOGIER, Ph D) have developed a pain assessment tool based on the analysis of the variability heart rate which evaluates the Analgesia Nocice...
This is a randomized double-blind placebo controlled trial aim to compare the efficiency of genuine regional and non-genuine regional Rhizoma Atractylodis in treating functional dyspepsia....
Lung cancer is one of the leading cause of cancer related death in China. Lung cancer screening with low-dose computed tomography was considered as a better approach than radiography. Howe...
The study is a prospective, single arm, non-blinded, multi-site study conducted in mainland China.
Radiation from sources other than the source of interest. It is due to cosmic rays and natural radioactivity in the environment.
The country is bordered by RUSSIA on the north and CHINA on the west, south, and east. The capita is Ulaanbaatar.
A country located in southern Asia, bordering the Arabian Sea, between India on the east and Iran and Afghanistan on the west and China in the north. The capital is Islamabad.
A method of delineating blood vessels by subtracting a tissue background image from an image of tissue plus intravascular contrast material that attenuates the X-ray photons. The background image is determined from a digitized image taken a few moments before injection of the contrast material. The resulting angiogram is a high-contrast image of the vessel. This subtraction technique allows extraction of a high-intensity signal from the superimposed background information. The image is thus the result of the differential absorption of X-rays by different tissues.
A plant genus of the family POACEAE. The small pointed seeds are grown for hay in North America and western Europe and important as food in China and other Asian countries.