City In Southern China Research Articles

Geovisualizing the recovery pattern of intercity mobility during the Covid-19 outbreak in China

ABSTRACT This paper visualizes variations in the recovery patterns of intercity mobility during the Covid-19 outbreak in China using cartogram mapping. We found large regional disparities in intercity mobility recovery, with lower recovery ratios and speeds primarily concentrated in megacities and provincial capitals. Conversely, the recovery of intercity mobility was relatively high in other cities, especially in some labour-exporting cities of central and south-western China. In addition, cities in southern China showed a relatively higher recovery ratio and speed in intercity mobility than those in northern China.

School Bullying Victimization and Associated Factors Among School-Aged Adolescents in China.

There has been a significant amount of research on correlates of bullying victimization, but most prior studies are descriptive and do not distinguish between different types of bullying. The current study used a case-control study design to explore factors related to different types of bullying victimization, including physical, relational, verbal, sexual, property, and poly-bullying victimization. This study was conducted in a southern city in China, including 3054 cases who self-reported being victims of school bullying and 3054 controls who reported not being involved in any school bullying in the past 12months. Each victim case was matched with a control on gender, school, and grade level. Univariate logistic analyses and multivariate conditional logistic regression analyses were used to identify factors associated with being a victim of school bullying. Results suggest physical bullying victimization was only associated with a family-level characteristic (parenting style) while the other four types of bullying victimization (relational, verbal, sexual, and property bullying) and poly-bullying victimization were associated with multiple social domain variables at individual, family, and school levels. Findings from this study provide evidence of factors for different types of bullying victimization and have implications for potential measures to prevent bullying. Measures from multiple social domains, including individual, family and school (e.g., developing healthy behaviors, improving social skills, positive parent-child interactions, building trust between teachers and peers, and forming strong friendships), should be considered in order to effectively prevent adolescent victimization from bullying.

GM(1,1) based improved seasonal index model for monthly electricity consumption forecasting

Accurate monthly electric load forecasting plays an important role in the development of a smart grid. Although many algorithms have been proposed for load forecasting, these algorithms suffer from poor prediction accuracy or high computational complexity; moreover, they require a large amount of data for training. To address these challenges, in this study, a new seasonal-index model based on grey model optimisation is proposed. First, three trend equations, i.e., linear, exponential, and logarithmic equations, are adopted in the proposed model to fit the development law of electricity consumption. We then use a grey model to predict the seasonal index (SI). Finally, the forecast is obtained by combining the trend forecast value with the SI. To completely evaluate the performance of the proposed algorithm, monthly electric load data from some typical industries of a city in southern China were used in the test. On comparing with some benchmark models, the results indicate that, if the electric-load data of the industries shows the characteristics of trends and (or) seasonality, the proposed algorithm can significantly improve the forecast accuracy even with a small monthly electric load dataset, otherwise, its performance will degrade in a certain level. In particular, we can obtain a mean absolute percentage error (MAPE) of 3.6%, 2.6% and 2.9% for three typical datasets, respectively, and each with only 54 data points. Moreover, the proposed algorithm has the lowest execution complexity, which confirms its advantages over the benchmark schemes.

Measurement report: Characterization and source apportionment of coarse particulate matter in Hong Kong: insights into the constituents of unidentified mass and source origins in a coastal city in southern China

Abstract. Coarse particulate matter (i.e. PM with an aerodynamic diameter between 2.5 and 10 µm – PM2.5 and PM10 – or PMcoarse) has been increasingly recognized for its importance in PM10 regulation because of its growing proportion in PM10 and the accumulative evidence for its adverse health impact. In this work, we present comprehensive PMcoarse speciation results obtained through a 1-year-long (January 2020–February 2021) joint PM10 and PM2.5 chemical speciation study in Hong Kong, a coastal and highly urbanized city in southern China. The annual average concentration of PMcoarse is 14.9 ± 8.6 µg m−3 (± standard deviation), accounting for 45 % of PM10 (32.9 ± 18.5 µg m−3). The measured chemical components explain ∼75 % of the PMcoarse mass. The unexplained part is contributed by unmeasured geological components and residue liquid water content, supported through analyses by positive matrix factorization (PMF) and the thermodynamic equilibrium model ISORROPIA II. The PMcoarse mass is apportioned to four sources resolved by PMF, namely soil dust/industrial and coal combustion, construction dust/copper-rich emissions, fresh sea salt, and an aged sea salt factor containing secondary inorganic aerosols (mostly nitrate). The PMcoarse concentration and source composition exhibit a distinct seasonal variation, a result mainly driven by the source areas the air masses have travelled through as revealed by back-trajectory analysis. In summer when the site is dominated by marine air mass, PMcoarse is the lowest (average = 8.1 µg m−3) and sea salt the largest contributor (47 %), followed by the two dust factors (36 % in total). In winter when the site receives air mass mainly from the northern continental region, PMcoarse concentration triples (24.8 µg m−3), with the two dust factors contributing three quarters of the aerosol mass. The potential dust source areas are mapped using the concentration-weighted trajectory technique, showing either the Greater Bay Area or the greater part of southern China as the origin of fugitive dust emissions leading to elevated ambient PMcoarse loadings in Hong Kong. This study, the first of this kind in our region, provides highly relevant guidance for other locations with similar monitoring needs. Additionally, the study findings point to the need for further research on the sources, transport, aerosol processes, and health effects of PMcoarse.

Memory Behaviors of Air Pollutions and Their Spatial Patterns in China

Particulate matter (PM2.5 and PM10) and ozone (O3) are the two major air pollutants in China in recent years. The fluctuations of PM2.5, PM10 and O3 strongly depend on the weather processes and anthropogenic emission. These processes may lead to the existence of short- and long-term memory behaviors in air pollutants. Hence, here we use the autoregressive parameter a of the first-order autoregressive process [AR (1)] to characterize the short-term memory effects of pollutants. We estimate the scaling exponent α using detrended fluctuation analysis (DFA) for the long-term memory effects of air pollutants (PM2.5, PM10, and O3) in summer and winter for different cities in China. Our results show that PM2.5, PM10, and O3 have strong short-term and long-term memory characteristics both in summer and winter. Furthermore, both the short- and long-term memory effects are stronger in winter than summer for most cities associated with stronger and longer persistent weather systems in winter. In general, the scaling exponent α of PM2.5 and PM10 are smaller for northern cities than those of southern cities in China. The long-term memory patterns of O3 are stronger in northern cities and weaker in southern cities in relative to those of PM2.5 and PM10 in winter. Our results show that the short- and long-term memory behaviors of air pollutions are dominated by the weather systems with different time scales.

Comparing cooling efficiency of shading strategies for pedestrian thermal comfort in street canyons of traditional shophouse neighbourhoods in Guangzhou, China

In the context of climate change, the outdoor thermal environment is essential for urban health, particularly in hot and humid climate zones. In most cities in southern China, traditional shophouse neighbourhoods are regarded as a reference for climate-responsive urban morphology because multiple shading strategies are integrated, including deep canyons, semi-open arcades, and vegetation. In total, four shading strategies, namely, the height-to-width ratio of canyons and arcades, tree coverage area, and orientation, are employed in this study to compare their cooling efficiency in street canyons during summer daytime. The ENVI-met is employed for the microclimatic simulations and validated by site measurement data. The impact of varying sky view factor on the physiologically equivalent temperature was quantified to assess the cooling efficiency of each shading strategy. Our results demonstrate that the cooling efficiency of orientations varies significantly with sky view factor and is negatively associated with pedestrian thermal comfort in alleys, but positive in street canyons with arcades and trees. Varying the height-to-width ratio of canyons in arcade streets presents the best cooling efficiency, except in the east-west orientation. Shading by arcades shows a slightly higher cooling efficiency than tree coverage.

Synchronous Online Learning During COVID-19: Chinese University EFL Students’ Perspectives

The outbreak of COVID-19 in late 2019 had soon become a pandemic, leading to the lockdown of schools all around the world. To mitigate the negative impacts brought by COVID-19, the educational institutions of all levels have inevitably shifted from face-to-face teaching to online teaching. For English language teaching, fully synchronous online learning has been implemented worldwide, posing a great challenge for both instructors and learners. This study reports on findings of Chinese university English as a foreign language students’ perspectives’ on synchronous online language learning during the pandemic, with a special focus on their encountered difficulties. Drawing on the qualitative interview method, the study investigated 14 EFL learners at a public comprehensive university in a coastal city in southern China. Using thematic analysis, there are four main difficulties identified in the interviews, namely the lack of learning climate, the cultivation of learner autonomy, changes of interaction patterns, and the adaptation to remote assessment. The paper ends with a discussion of findings and implications for English learning and teaching in the “new normal.”

Association of Infants Small for Gestational Age with Anemia under Five Years Old in Two Large Longitudinal Chinese Birth Cohorts.

Babies who are born small for their gestational age (SGA) have low iron reserves, thus probably increasing the risk of offspring anemia. We studied two longitudinal birth cohorts to evaluate the association of SGA with the risk of anemia during early childhood. Cohort 1 was recruited from five counties in northern China involving 17,180 singleton infants born during 2006–2009 and cohort 2 from 21 counties or cities in southern China involving 180,619 children born during 1993–1996. Anemia was diagnosed by hemoglobin at 6 and 12 months in cohort 1 and at 55 months in cohort 2. The overall incidences of SGA were 7.07% and 5.73% in cohort 1 and cohort 2, respectively. SGA was associated with increased anemia at 6 months (adjusted odds ratio (OR): 1.52; 95% confidence interval (CI): 1.24, 1.86) and 12 months (adjusted OR: 1.42; 95% CI: 1.13, 1.79) in cohort 1 and at 55 months (adjusted OR: 1.11; 95% CI: 1.05, 1.17) in cohort 2. The positive associations for anemia at 6, 12, and 55 months persisted in both logistics and multiple linear models. Our results support a gradually decreased association between SGA and the increased risk of childhood anemia with a longer follow-up time in infants and children.

Comprehensive Detoxification Mechanism Assessment of Red Imported Fire Ant (Solenopsis invicta) against Indoxacarb.

The red imported fire ant (Solenopsis invicta) is one of the deadliest invasive ant species that threatens the world by disrupting biodiversity, important functions within a natural ecosystem, and community structure. They are responsible for huge economic losses in the infested countries every year. Synthetic insecticides, especially indoxacarb, have been broadly used to control S. invicta for many years. However, the biochemical response of S. invicta to indoxacarb remains largely undiscovered. Here, we used the sublethal doses of indoxacarb on the S. invicta collected from the eight different cities of Southern China. The alteration in the transcriptome profile of S. invicta following sublethal dosages of indoxacarb was characterized using high-throughput RNA-seq technology. We created 2 libraries, with 50.93 million and 47.44 million clean reads for indoxacarb treatment and control, respectively. A total of 2018 unigenes were regulated after insecticide treatment. Results indicated that a total of 158 differentially expressed genes (DEGs) were identified in the indoxacarb-treated group, of which 100 were significantly upregulated and 58 were downregulated, mostly belonging to the detoxification enzymes, such as AChE, CarE, and GSTs. Furthermore, results showed that most of these DEGs were found in several KEGG pathways, including steroid biosynthesis, other drug metabolizing enzymes, glycerolipid metabolism, chemical carcinogenesis, drug-metabolizing cytochrome P450, glutathione metabolism, glycerophospholipid metabolism, glycolysis/gluconeogenesis, and metabolism of xenobiotics. Together, these findings indicated that indoxacarb causes significant alteration in the transcriptome profile and signaling pathways of S. invicta, providing a foundation for further molecular inquiry.

Transcultural Adaptation and Psychometric Evaluation of the Chinese Version of the Family Caregiver ICU Delirium Knowledge Questionnaire

Objective: To test the reliability and validity of the Chinese version of the family caregiver ICU delirium knowledge questionnaire (C-CIDKQ) in mainland China. Methods: The Brislin translation model was used for standard translation and back-translation; cross-cultural adjustment of the translated scale was carried out through expert group discussion, communication with the original author and pre-investigation; convenience sampling method was used to study 214 family caregivers of ICU patients in a tertiary first-class general university hospital in Guangzhou city in southern China. Results: C-CIDKQ included three dimensions and 21 items: risk factor dimension (10 items), action dimension (6 items), and symptom dimension (5 items). The Cronbach’s alpha coefficients of the three dimensions of risk factor dimension, action dimension and symptom dimension were 0.713, 0.213 and 0.839, respectively, and the internal consistency reliability of the total scale was 0.777. Conclusion: C-CIDKQ has good reliability and validity and can be used as an ICU delirium knowledge evaluation tool for family caregivers of ICU patients in China. If the items of the action dimension are appropriately modified, the reliability and validity of the scale can be further improved.

Numerical Simulation of radon migration influenced by heat-moisture coupled transfer in aerated concrete wall under different outdoor temperature and humidity conditions

It is of great significance for indoor radon radiation protection to study the mechanism of radon migration systematically caused by heat-moisture coupled transfer in building walls. The radon migration model of porous building walls under the influence of the heat-moisture coupled model is built. On the base of it, four types of different temperature and humidity conditions, including high temperature and high humidity, high temperature and low humidity, low temperature and high humidity and low temperature and low humidity, and the real ambient temperature, relative humidity conditions in a southern city of China in July, are set for the numerical simulation. The migration mechanism of the radon through the wall influenced by outdoor temperature and humidity conditions, including its emanation, diffusion and condensation, is studied by numerical simulation, and the main factors leading the results are analyzed, which provides some reference for indoor radon radiation protection.

Mineralogical and elemental data for soil discriminating and geolocation tracing

One of the key tasks of soil analysis in forensic sciences is to provide information about its diversities and geolocation. In fact, soil analysis is relevant for forensic geologists. In this study, a total of 80 soil samples were collected from eight Chinese cities (10 samples per city). Different minerals and their relative percentages were analyzed by the X-ray diffraction (XRD) method. In addition, the relative amounts of montmorillonite, kaolinite, amphibole, feldspar, calcite, and dolomite provided information about the origin of a soil, either if it came from a northern or southern city of China. The oxide weight percentages of 10 elements of Al2O3, SiO2, Fe2O3, K2O, Na2O, MgO, CaO, P2O5, MnO, and TiO2 were also obtained by using X-ray fluorescence (XRF) from the 80 soil samples. Moreover, principal component analysis (PCA) and hierarchical clustering analysis (HCA) methods were performed for dimensionality reduction, elemental marker identification and soils classification to the city they came from purposes. The eighty soils analyzed in this study could be tracked correctly to their city of origin. The K-Nearest Neighbors (KNN) model was done to evaluate the prediction ability based on the soil elemental composition, and it was confirmed by cross validation methods. The results demonstrated that mineralogical and elemental composition can provide powerful information for soil discrimination and source tracing.

Self-regulation mediates the relations between family factors and preschool readiness

This study examined the role of selfregulation in the path from family factors to preschool readiness in China. Altogether 661 preschool children (M = 43.30 months, SD = 3.6) were sampled from 5 preschools in a coastal city of Southern China. Their parents reported on the family routines, parenting styles, and the child's selfregulation. And their teachers rated each child's preschool readiness. The structural equation modeling results suggested that: (1) selfregulation could significantly predict children's preschool readiness, including abilities to follow classroom rules, learning dispositions, and social competence; (2) selfregulation mediated the path from family routines to children's preschool readiness; (3) selfregulation also mediated the relationships between authoritative parenting and children's preschool readiness; (4) authoritarian parenting directly influenced children's social competence; and (5) family SES only correlated with young children's selfcare and emotional maturity. These findings underscore the importance of considering the joint influences of children's selfregulation, family routines, parenting styles, and family SES in shaping children's readiness for preschool.

Hospital response to a case-based payment scheme under regional global budget: The case of Guangzhou in China

Both developed and developing countries have been searching for effective provider payment methods to control health expenditure inflation. In January 2018, Guangzhou city in Southern China initiated an innovative case-based payment method for inpatient care under the framework of the regional global budget, called the Diagnosis-Intervention Packet (DIP). Contrary to the usual practice of the case-based payment, the DIP payment scheme includes a price adjustment mechanism through which the actual reimbursement for each case is determined ex post. By employing the difference-in-difference method and data from Beijing and Guangzhou, we evaluate the effects of the DIP payment on medical expenditures and provider behaviors. We find that total health expenditures per case have decreased by 3.5%, which is mainly driven by a substantial decrease in drug expenditures. It suggests that the DIP payment reform achieved a short-term success in slowing down the growth of health expenditures. However, the average point volume per case for local inpatients with social health insurance coverage has increased by more than 3%, primarily due to an increasing likelihood of performing at least one procedure. We also find suggestive evidence of up-coding. All these results suggest that healthcare providers have taken strategic behaviors in response to the DIP payment. These findings hold lessons for the ongoing payment reforms in China and other countries.

Ozone control strategies for local formation- and regional transport-dominant scenarios in a manufacturing city in southern China

Given the leveling off of fine particulate matter (PM2.5), ground-level ozone (O3) pollution has become one of the most significant atmospheric pollution issues in the Pearl River Delta (PRD) region in China, especially in the manufacturing city of Dongguan, which faces more severe O3 pollution. The development of strategies to control O3 precursor emissions, including volatile organic compounds (VOCs) and nitrogen oxide (NOx), depends to a large extent on the source region of the O3 pollution. In this study, by combining the Weather Research and Forecasting model coupled with chemistry (WRF-Chem), the Empirical Kinetic Modeling Approach (EKMA), and the Flexible Particle model (FLEXPART), more effective strategies of controlling O3 precursor emissions were identified under two typical types of O3 pollution episodes: local formation (LF)-dominant (8–12 September 2019) and regional transport (RT)-dominant (23–27 October 2017) episodes, distinguished by the WRF-FLEXPART model. During the LF-dominant episode, the EKMA revealed that the O3 formation in Dongguan was in a transitional regime, and the abatement of solvent use-VOCs emissions in the key area of Dongguan was more effective in reducing O3 levels, with an emission reduction benefit 1.7 times that of total VOCs emission sources throughout Dongguan. With respect to the RT-dominant episode, the reduction in VOCs emissions in the local region did not effectively curb O3 pollution, although the photochemical regime of the O3 formation in Dongguan was VOCs-limited. A 50% reduction in NOx emissions in the upwind regions (parts of Guangzhou and Huizhou) effectively decreased the O3 concentration in Dongguan by 17%. The results of this study emphasize the importance of the source region of O3 pollution in the implementation of effective O3 control strategies and provide valuable insights for region-specific precursor emission policy formulation, not only in Dongguan, but also in other regions facing severe O3 pollution.

An analytical method to determine typical residential district models for predicting the urban heat island effect in residential areas

Residential areas play an important role in the formation of the urban heat island (UHI). Many studies adopted hypothetical or simplified models to analyze UHI in residential areas based on numerical simulation. Nevertheless there is still a lack of an accurate and efficient method to obtain typical residential district models with regional characteristics. This paper presented an analytical method to determine the typical residential district model which can provide a baseline model for analyzing the relationship between residential planning indicators and UHI. Using a case study approach, this study collected residential information (including site size, layout type, building size, building orientation, building density, average building height and building interval) from 97 residential districts constructed in Nanning (a southern city of China), and obtained four typical residential district models. The applicability of the proposed method was discussed in terms of heat island intensity (HII) for the typical residential district models with actual residential districts using a numerical simulation tool (ENVI-met). The simulation results showed that the average difference of HII values was less than 0.1 °C. It was found that the proposed method can provide a baseline model for predicting the residential thermal environment at the scheme design stage.

The Relationship between Bullying Victimization and Suicidal Ideation among Chinese Adolescents: The Role of Depressive Symptoms and Gender Differences

ABSTRACT Both traditional school bullying and cyber bullying among adolescents have become international concerns across many countries including China. The role of depressive symptoms in the relationship between various forms of bullying victimization and suicidal ideation has not been adequately studied in the Chinese context. This study aims to explore this issue using self-report data collected from 1,814 high school students in a city in southern China. The results of the structural equation modeling analyses showed that, after controlling for a set of bullying-related variables and demographic information, depressive symptoms played a mediating role in the relationship between certain forms of bullying victimization and suicidal ideation. The effects also differed by gender. Specifically, depressive symptoms mediated the relationship between verbal victimization and suicidal ideation for boys and girls alike. However, depressive symptoms mediated the effects of relational and cyber bullying victimization on suicidal ideation among girls only. In addition, both the effects of cyber bullying victimization and depressive symptoms on suicidal ideation were stronger for girls than boys. Policy implications were then discussed in the Discussion and Conclusion section.

Work–family conflict, family well-being and organizational citizenship behavior: a moderated mediation model

PurposeThis study aims to examine the consequences of work–family conflict and explore the mechanism by which it influences organizational citizenship behavior from the perspective of changes in and preservation of family well-being (emotional resources).Design/methodology/approachWork–family conflict has always been an important research topic in the field of organizational behavior; scholars have studied the relationship between it and organizational citizenship behavior from different perspectives. To better understand the mechanism of work–family conflict on organizational citizenship behavior, we use a longitudinal design and analyze the multi-stage matching data of 209 employees and their superiors from six cities in southern China. The authors construct a theoretical model based on the conservation of resources theory to explore the mechanism by which work–family conflict influences organizational citizenship behavior when taking employees’ family well-being as a mediator and work–family segmentation preference as the boundary condition.FindingsWork–family conflict has a significant negative effect on family well-being and this effect is moderated by work–home segmentation preferences. Work–family conflict also has a significant indirect effect on organizational citizenship behavior through family well-being and this indirect effect is enhanced by an increase in the level of preference for work–home segmentation.Originality/valueThis study enriches our knowledge of the moderating variables in the study of work–family relationships from the perspective of individual personality traits. It also provides a new perspective for the study of such relationships in the context of Chinese family culture.

Data-driven method based on deep learning algorithm for detecting fat, oil, and grease (FOG) of sewer networks in urban commercial areas

The content of fat, oil and grease (FOG) in the sewer network sediments is the key indicator for diagnosing sewer blockage and overflow. However, the traditional FOG detection is time-consuming and costly, and the establishment of mathematical models based on statistical methods to predict the content of FOG fail to provide satisfactory accuracy. Herein, a deep learning algorithm used a data-driven FOG content prediction model is proposed to achieve a more accurate prediction of FOG content. Meanwhile, global sensitivity analysis (GSA) is exploited to evaluate the contribution of input indicators to the output indicator (FOG) in the model, so that some input indicators that have less impact on the prediction performance can be screened out, the best combination of input indicators can be determined, and the operation cost of the model can be reduced. To evaluate the effectiveness of the proposed model, a case study was conducted in a city in southern China. The experimental results indicate that the prediction model obtains good FOG estimations and performs well from a single site to multiple sites with a mean R2 of 0.922, showing a good generalization performance. Through GSA, the key input indicators in the model were identified as pH, water temperature (T), relative humidity (RH), sewage flow (Flow), drinking water supply (DWS), velocity (V) and conductivity (σ), and the input indicators such as air pressure (AP), population (Pop.), and liquid level (LV) can be reduced without affecting the prediction accuracy of the model.

The Aldehyde Dehydrogenase ALDH2*2 Allele, Associated with Alcohol Drinking Behavior, Dates Back to Prehistoric Times.

Human alcohol-consumption behavior is partly genetically encoded. The alcohol consumption of 987 residents in Keelung, Taiwan, was evaluated by using the Alcohol Use Disorder Identification Test (AUDIT). We assessed ~750,000 genomic variants of 71 residents who drank hazardously (AUDIT score ≥ 8) and 126 residents who did not drink in their daily lives (AUDIT score = 0), using high-density single nucleotide polymorphism (SNP) arrays. The rs671 G > A manifests the highest significance of the association with drinking behavior (Fisher’s exact P = 8.75 × 10−9). It is a pleiotropic, non-synonymous variant in the aldehyde dehydrogenase 2 (ALDH2) gene. The minor allele “A”, commonly known as ALDH2*2, is associated with non-drinkers. Intriguingly, identity-by-descent haplotypes encompassing genomic regions with a median length of 1.6 (0.6–2.0) million nucleotide bases were found in all study participants with either heterozygous or homozygous ALDH2*2 (n = 81 and 13, respectively). We also analyzed a public-domain dataset with genome-wide genotypes of 2000 participants in Guangzhou, a coastal city in Southern China. Among them, 175 participants have homozygous ALDH2*2 genotype, and again, long ALDH2*2-carrying haplotypes were found in all 175 participants without exceptions. The median length of the ALDH2*2-carrying haplotype is 1.7 (0.5–2.8) million nucleotide bases. The haplotype lengths in the Keelung and Guangzhou cohorts combined indicate that the origin of the ALDH2*2 allele dates back to 7935 (7014–9381) years ago. In conclusion, the rs671 G > A is the leading genomic variant associated with the long-term drinking behavior among residents of Keelung, Taiwan. The ALDH2*2 allele has been in Asian populations since prehistoric times.