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Atmospheric peroxides, especially hydrogen peroxide (H2O2), are essential oxidants. The peroxide concentration is closely related to the extent of OH radicals and the O3 cycle in the tropospheric atmospheric chemistry. However, only a few studies have investigated their atmospheric concentrations in China because of inadequacies in the measurement techniques or higher costs of analytical instruments. Therefore, it is essential to design a suitable analysis method of peroxides with higher sensitivity, lower detection limit, and low cost. In view of that, this study investigated the optimum analysis conditions of two H2O2 analytical techniques: the high-performance liquid chromatography (HPLC) with fluorescence detection using two-enzyme catalysis of horseradishperoxidase (HRP method) and Hemin (Hemin method). Furthermore, these two analysis methods were systematically compared in terms of detection limit, calibration curve, precision, accuracy, and applicability for the first time. The findings showed that the HRP method had a lower detection limit, higher sensitivity, and better applicability for detecting H2O2 and methyl hydroperoxide (MHP) than the Hemin method. Moreover, the HRP method is better suitable for H2O2 and MHP detection, which requires low detection limits and high sensitivity. Besides this, the Hemin method is inexpensive and is more suitable for detecting hydroxyl alkyl peroxides (C ≥ 3). The atmospheric concentrations (average) of H2O2 and MHP were 0.60 ± 0.37 ppb and 0.081 ± 0.039 ppb, respectively, as determined by the HRP method. Importantly, atmospheric peroxide concentrations were higher on sunny days than on cloudy days in Beijing in September 2016. H2O2 concentrations showed a diurnal variation with the lowest value in the morning and two peaks at 13:00–17:00. In contrast, MHP concentrations were lowest in the morning and highest after 17:00. Photochemical reactions were responsible for the production of H2O2 and MHP. The reactions of O3 and olefins emitted by motor vehicles also caused H2O2 concentration to increase during the evening rush hour. [ABSTRACT FROM AUTHOR]

Existing studies have explored the causal effect of social capital on harmful drinking, while the effect of drinking habits on trust is scant. In China, drinking rituals and drinking culture are considered important ways of promoting social interaction and trust, especially in rural areas where traditional culture is stronger. Based on a field survey in rural China in 2019, this paper explores the relationship between drinking habits and trust. First, we found a negative relationship between drinking habits and trust, indicating that those people who drink alcohol are more likely to have a lower trust. Second, we found significant heterogeneity in the effect of alcohol consumption on social trust across various groups. Specifically, the negative effects of alcohol consumption on trust were stronger for the females than for males; drinking alcohol did not reduce the level of trust among the Chinese Communist Party (CCP) in rural China; compared with the Han nationality, we found that the effect of drinking on trust was not significant for the ethnic minority. Third, we observed that the negative effects of alcohol consumption on trust had thresholds across age and income. Among people under 51, the risk of trust from drinking was greater than for those over 51; the negative effect of drinking on residents' trust was more obvious in low-income families, but not significant in the group with an annual household income of more than CNY 40,000. Our empirical study provides a deeper understanding of drinking culture in rural China from a dialectical perspective.

Childhood and adolescence overweight and obesity have implications for both health consequences and economic burden. Although it has been an emerging public health problem for primary school children in rural China and the importance of the diet-health link has been stressed for many years, rigorous analysis of the dietary diversity and obesity among children is rare. To clarify this issue, this study provides a better understanding of the functional linkage between dietary diversity and obesity by analyzing data from nearly 8500 rural primary students (aged from 10 to 13 years old) covering three provinces in China. Our estimation results show that there is a significantly negative correlation between dietary diversity and the probability of being overweight among primary students. In particular, for subgroups with higher dietary diversity, the negative correlation between dietary diversity and the incidence of overweight or obesity is stronger, and the absolute value of the coefficient is greater. The results also suggest that the increase in the consumption frequency of all dietary categories can significantly lead to a lower proportion of overweight. Thus, we conclude that higher dietary diversity can help to lower the risk of overweight and obesity among primary school children, presumably through increasing the daily frequency of food intakes and developing a more diverse dietary pattern.