Mega-events such as the Olympic Games, the World Cup, the World Expos, and the G20 Summit play important roles in international political economy in the age of globalization. But we know little about how they shape domestic politics and policy processes in their host countries. China has emerged as the leading host of various sports, cultural, economic, and political mega-events in the past decades. Employing an original panel dataset of Chinese cities from 2001 to 2019, we find that cities that host mega-events gain an advantage in bargaining with central bureaucracies for policy resources. Using subway investments as an example, we demonstrate that host cities not only obtained centrally regulated infrastructure investments that directly serve the needs of the events, but also achieve development that they otherwise could not. The result is robust with two-way fixed effects models and after accounting for various alternative explanations. We show that host cities gain advantage because the events capture the attention of national leaders. National leaders have power over central bureaucrats’ careers and thus steer their decisions, and they see the success of mega-events as an opportunity to project national strengths. Our findings highlight the domestic policy consequences of international events in the age of China’s rapid rise and integration with the world.
Populism has recently enjoyed success in Europe, the US, and beyond. Populist leaders and their supporters have accused “mainstream” media of being part of a “corrupt” elite that misrepresents the will of the virtuous “people.” Distrust of the media has also prompted the rejection of traditional media sources for political information and given prominence to alternative and hyperpartisan sources such as Breitbart. However, limited research exists concerning who consumes hyperpartisan media, how the websites of hyperpartisan media are interconnected, and what content is presented in hyperpartisan news. By combining cross-national surveys with large-scale digital trace datasets of website visits, this paper demonstrates the link between populist party support and hyperpartisan media visits. It also identifies influential sources of hyperpartisan news by analyzing the audience similarity networks of these websites and reveals country-level variations in hyperpartisan news and the dominance of US politics among the identified hyperpartisan news topics.
Financial inclusion and energy poverty have an interactive relationship; however, this two-way relationship lacks sufficient research. This study investigates the two-way mechanisms of financial inclusion, energy poverty, and neighborhood spillover effects. Using a spatial simultaneous equation model, this study examines 2615 Chinese rural households in 2020. Results reveal a statistically significant positive interaction between financial inclusion and energy poverty. In addition, the neighborhood spillover effects of financial inclusion and energy poverty are both significantly positive, whereas their neighborhood interaction spillover effects are significantly negative.
The COVID-19 pandemic, characterized by its highly contagious nature and devastating death toll, posed a dual threat to both physical and psychological well-being. As a potential intervention to alleviate the psychological impact, values-affirmation involves individuals engaging in the activity of writing about their core values. While its effectiveness in non-WEIRD (i.e. Western, Educated, Industrialized, Rich, Democratic) populations, notably among Chinese adults, has been confirmed, it remains largely unexplored whether the intervention can promote mental health in Chinese adolescents, especially in the context of the COVID-19 pandemic. The purpose of this study thus is to provide the first empirical evaluation of this intervention in promoting well-being and alleviating psychological distress among Chinese adolescents during the COVID-19 pandemic. A total of 2,234 students from 112 secondary schools in China were randomly assigned to an affirmation or control condition. The study found that self-affirmation intervention improved students' life satisfaction, mental health, and self-esteem, as well as buffered a decline of their purpose in life; however, no effects were found for clinical measures of depression, anxiety, and loneliness. The results suggest that self-affirmation interventions, while having limited effects on clinically relevant outcomes, can be an effective approach to boost well-being in adolescents during a major crisis, including in a more historically collectivist culture. Implications for self-affirmation theory and cultural psychology, as well as avenues for future research, are discussed.
Using 13,584 observations of 4772 undergraduate students enrolled in 523 online classes offered synchronously at a research university in China, and using online-learning platform data and administrative data, this paper examines the impacts of class attendance on academic performance. Based on student-level and course-level fixed effects models with a unique set of student-course level control variables, this paper finds class attendance to have a significantly positive impact on academic performance. This effect is larger for low-performing students and smaller for students in courses with larger class sizes. The above findings survive a number of robustness checks, including a bounding technique, restricting sample to compulsory courses and limiting variation in attendance caused by whole day absence.
The successful implementation of in-situ bioremediation of nonaqueous-phase liquid (NAPL) contamination in soil-groundwater systems is greatly influenced by the migration performance of NAPL-degrading bacteria. However, the impact and mechanisms of NAPL on the migration/retention of pollutant-degrading bacteria remain unclear. This study investigated the migration/retention performance of A. lwoffii U1091, a strain capable of degrading diesel while producing surfactants, in porous media without and with the presence of mono- and multicomponent NAPL (n-dodecane and diesel) under environmentally relevant conditions. The results showed that under all examined conditions (5 and 50 mM NaCl solution at flow rates of 4 and 8 m/d), the presence of n-dodecane/diesel in porous media could reduce the migration and enhance retention of A. lwoffii in quartz sand columns. Moreover, comparing with mutlicomponent NAPLs of n-dodecane, the monocomponent NAPLs (diesel) exhibited a greater reduction effect on the retention of A. lwoffii in porous media. Through systemically investigating the potential mechanisms via tracer experiment, visible chamber experiment, and theoretical calculation, we found that the reduction in porosity, repulsive forces and movement speeds, the presence of stagnant flow zones in porous media, particularly the biosurfactants generated by A. lwoffii contributed to the enhanced retention of bacteria in NAPL-contaminated porous media. Moreover, owing to presence of the greater amount of hydrophilic components in diesel than in n-dodecane, the available binding sites for the adsorption of bacteria were lower in diesel, resulting in the slightly decreased retention of A. lwoffii in porous media containing diesel than n-dodecane. This study demonstrated that comparing with porous media without NAPL contamination, the retention of strain capable of degrading NAPL in porous media with NAPL contamination was enhanced, beneficial for the subsequent biodegradation of NAPL.
The mitigating effects of straw burning bans on air pollution are widely known; however, their effects on indoor air pollution are generally ignored. Cooking fuel use is an important factor that affects indoor air quality. However, the debate over the pros and cons of a province-wide ban on straw burning has been a major issue in environmental economics. By utilizing household survey data, this study investigates the role of straw burning bans on cooking fuel use in households. To infer causal relationships, difference-in-difference models that compare households in provinces with and without a complete ban on open straw burning (COSB) are employed. The results show that COSBs promote the use of clean cooking fuels and discourage the use of firewood for cooking by households. These results hold true after a series of robustness tests, such as parallel trends and placebo tests. However, the results show that the effect of COSBs on the household use of coal as a cooking fuel is not significant. Further analysis shows heterogeneity in the effects of COSBs on the use of household cooking fuels. Thus, COSBs promote the conversion to cleaner cooking fuels in rural households, but the implementation of these policies needs to be contextualized.
Abstract The insufficient exciton (e−-h+ pair) separation/transfer and sluggish two-electron water oxidation are two main factors limiting the H2O2 photosynthetic efficiency of covalent organic frameworks (COFs) photocatalysts. Herein, we present an alternative strategy to simultaneously facilitate exciton separation/transfer and reduce the energy barrier of two-electron water oxidation in COFs via a dicyano functionalization. The in situ characterization and theoretical calculations reveal that the dicyano functionalization improves the amount of charge transfer channels between donor and acceptor units from two in COF-0CN without cyano functionalization to three in COF-1CN with mono-cyano functionalization and four in COF-2CN with dicyano functionalization, leading to the highest separation/transfer efficiency in COF-2CN. More importantly, the dicyano group activates the neighbouring C atom to produce the key *OH intermediate for effectively reducing the energy barrier of rate-determining two-electron water oxidation in H2O2 photosynthesis. The simultaneously enhanced exciton separation/transfer and two-electron water oxidation in COF-2CN result in high H2O2 yield (1601 μmol g−1 h−1) from water and oxygen without using sacrificial reagent under visible-light irradiation. COF-2CN can effectively yield H2O2 in water with wide pH range, in different real water samples, in scaled-up reactor under natural sunlight irradiation, and in continuous-flow reactor for consecutively producing H2O2 solution for water decontamination.
Human occupants themselves constitute an important source of volatile organic compounds (VOCs) in indoor environments through breath and dermal emissions. In order to quantify VOC emissions from occupants under real-world settings, previous indoor observational studies often determined emission factors (i.e., average emission rates per person). However, the values obtained across these studies exhibited large variability, and the causes of this variability still need to be understood. Herein we report 10-day real-time VOC measurements in a university student office, using a proton transfer reaction-quadrupole interface-time-of-flight mass spectrometer. A method was developed to identify VOCs of primary human origin and to quantify the corresponding emission factors, accounting for the dynamically changing occupancy level and ventilation rate in the assessed office. We found that the emission factors of many dermally emitted VOCs strongly increased as the ozone concentration increased from <3 to 10–15 ppb. These VOCs include geranyl acetone, 6-methyl-5-hepten-2-one (6-MHO), and C10-C12 saturated aldehydes, which align with characteristic first-generation ozonolysis products of skin oil. The strongest increase occurred for 6-MHO, from 113 to 337 μg/h/p. In comparison, acetone and isoprene, which are primarily emitted from human breath, varied little with the ozone level. In light of this finding, we conducted an integrated analysis of emission factors reported in the literature for two frequently reported species, namely, 6-MHO and decanal. Ozone concentration alone can explain 94–97% of the variation in their emission factors across previous studies, and the best-estimated ozone dependence obtained using the literature data is consistent with those obtained in the current study. These results suggest that the ozone concentration is a key factor regulating emission factors of many dermally emitted VOCs in real indoor environments, which has to be considered when reporting or using the emission factors.
Quorum sensing (QS)-based manipulations emerge as a promising solution for biofilm reactors to overcome challenges from inefficient biofilm formation and lengthy start-ups. However, the ecological mechanisms underlying how QS regulates microbial behaviors and community assembly remain elusive. Herein, by introducing different levels of N-acyl-homoserine lactones, we manipulated the strength of QS during the start-up of moving bed biofilm reactors and compared the dynamics of bacterial communities. We found that enhanced QS elevated the fitness of fast-growing bacteria with high ribosomal RNA operon (rrn) copy numbers in their genomes in both the sludge and biofilm communities. This led to notably increased extracellular substance production, as evidenced by strong positive correlations between community-level rrn copy numbers and extracellular proteins and polysaccharides (Pearson's r = 0.529−0.830, P < 0.001). Network analyses demonstrated that enhanced QS significantly promoted the ecological interactions among taxa, particularly cooperative interactions. Bacterial taxa with higher network degrees were more strongly correlated with extracellular substances, suggesting their crucial roles as public goods in regulating bacterial interactions and shaping network structures. However, the assembly of more cooperative communities in QS-enhanced reactors came at the cost of decreased network stability and modularity. Null model and dissimilarity-overlap curve analysis revealed that enhanced QS strengthened stochastic processes in community assembly and rendered the universal population dynamics more convergent. Additionally, these shaping effects were consistent for both the sludge and biofilm communities, underpinning the planktonic-to-biofilm transition. This work highlights that QS manipulations efficiently drive community assembly and confer specialized functional traits to communities by recruiting taxa with specific life strategies and regulating interspecific interactions. These ecological insights deepen our understanding of the rules governing microbial societies and provide guidance for managing engineering ecosystems.
The speedy raise of residential buildings' carbon emissions is a hindrance to achieving China's 2030 carbon peak goal. This study constructs an assessment framework for comprehensive consideration of 30 Chinese provinces' socioeconomic circumstances, energy demand, and emissions reduction technology to meet the consistent coupling degree of equity and efficiency (CDEE). This study is the first to propose an allocation scheme for equilibrating provincial carbon increments for rural and urban residential buildings in 2030 under carbon peaking constraints. The relevant results are fourfold. (1) Residential building's floor area per capita and energy carbon emissions coefficients are the soliddest drivers to facilitate and inhibit the raise of carbon emissions during 2010–2020. (2) Through dynamic Monte Carlo simulation from 2021 to 2030, we demonstrate that provinces with the most gamey carbon emissions in urban and rural areas include Shandong, at 121.52 (± 5.50) Mt. and Hebei, at 61.34 (± 3.08) Mt. in 2030, respectively. (3) A CDEE of 52.3% (biased equity) in urban areas and 34.5% (biased efficiency) in rural areas indicates equilibrated allocation of provincial carbon increment. (4) In the final 2030 allocation scheme, the greatest carbon mitigation pressures are in Beijing (11.34 Mt) and Heilongjiang (3.23 Mt), and the provinces with the largest carbon increment in urban areas include Hebei, Henan, and Guangdong, while the largest carbon increments in rural areas are in Hebei, Henan, and Guangdong. Overall, this study furnishes a targeted and valuable decision making reference for the government to determine provincial carbon peak goals for Chinese residential buildings.
