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The objective of this paper is to recommend an adjusted Susceptible-Exposed-Infectious-Removed (SEIR) model that characterizes the temporal patterns of various individuals affected by the omicron variant in an epidemic. This model considers factors such as vaccination, asymptomatic cases, indoor and outdoor air, hospitalizations, and deaths, as well as the impact of immunization and memory trace. While many recent studies overlook the complexities of multiple strains, including their diverse transmission rates and reaction to vaccines, this study introduces a new fractional derivative model to examine the spread of the omicron variant of COVID-19 and the implementation of a vaccination campaign. A thorough theoretical analysis is conducted, and the critical factor (R c r n z) is calculated using the model equations. It is demonstrated that when R c r n z is less than 1, the disease-free state is globally asymptotically stable, meaning that the epidemic diminishes. Moreover, the stability of both global and local equilibrium points is examined. Numerical simulations are employed to demonstrate the alignment between the numerical findings and theoretical characteristics. The model is adjusted to experimental data that reflect the progression of the omicron variant of COVID-19 in Guangzhou, exhibiting a satisfactory performance in predicting the number of infected individuals, thereby suggesting its capability to accurately estimate asymptomatic cases. Furthermore, to emphasize the benefits of employing fractional differential equations, the paper provides examples related to memory trace and hereditary characteristics. Moreover, the examined models are expected to be applied and expanded upon in order to contribute to the formulation of policies for disease control during times of limited vaccine availability. To summarize, the model appears to be a sufficient tool for researching and managing infectious diseases. It is projected that as the Omicron variant's prevalence declines, there will be a reduced need for respiratory-focused precautions. • An SVEIAOPHRD model is put forward to mathematically analyze the spread of the omicron variation of COVID-19. • Mathematical criteria for determining the stability of the equilibria are established. • An efficient nonstandard approach for resolving the continuous problem is suggested and examined. • The numerical simulations validate the analytical and numerical outcomes depicted in this study. [ABSTRACT FROM AUTHOR]

As high-speed rail (HSR) and air transportation developed rapidly in the last decade, their coopetition and interactional relationship has reshaped China's urban networks. Based on HSR and flight schedule data from 2009 to 2019, this paper constructs a weighted network to compare China's urban networks and their evolution, and employs machine learning to investigate the potential determinants. The results indicated that both networks tend toward polarization in the overall distribution and that the structure of urban networks under HSR networks is more hierarchical. That of HSR networks gradually forms a corridor structure along the trunk lines, while that of airline networks mainly shows a diamond spatial structure with Beijing, Shanghai, Guangzhou, and Chengdu as the cores. As for the evolution of urban networks, geographical factors, per capita GDP, and the tourism function of cities have more important impacts on that of HSR networks, while the network's topological structure and education resources have a greater impact on that of airline networks. Some socioeconomic attributes, such as urban administrative level, population, and the proportion of tertiary industry, have similar and limited influences on the two networks. • The paper constructed a comparative analysis on the evolution of China's urban networks during the last decade. • Employing machine learning to investigate the potential determinants. • The study examined the distinct attributes of the evolution and structure of high-speed rail and airline networks. • The study contrasts the determinants influencing the evolution of high-speed rail and airline networks at the city level. [ABSTRACT FROM AUTHOR]

• ON particles increased as NO x enhancement at night. • ON particles were mainly produced via heterogeneous reactions between NO x and organics. • The decrease of ON particles was associated with photo-bleaching effect. Organic nitrogen (ON) compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols, however, the mixing state, secondary formation processes, and influencing factors of ON compounds are still unclear. This paper reports on the mixing state of ON-containing particles based on measurements obtained using a high-performance single particle aerosol mass spectrometer in January 2020 in Guangzhou. The ON-containing particles accounted for 21% of the total detected single particles, and the particle count and number fraction of the ON-containing particles were two times higher at night than during the day. The prominent increase in the content of ON-containing particles with the enhancement of NO x mainly occurred at night, and accompanied by high relative humidity and nitrate, which were associated with heterogeneous reactions between organics and gaseous NO x and/or NO 3 radical. The synchronous decreases in ON-containing particles and the mass absorption coefficient of water-soluble extracts at 365 nm in the afternoon may be associated with photo-bleaching of the ON species in the particles. In addition, the positive matrix factorization analysis found five factors dominated the formation processes of ON particles, and the nitrate factor (33%) mainly contributed to the production of ON particles at night. The results of this study provide unique insights into the mixing states and secondary formation processes of the ON-containing particles. [Display omitted] [ABSTRACT FROM AUTHOR]

Alternative food networks (AFNs) have been viewed as being more deeply embedded in the fabric of places and the social relations of their food systems than conventional food networks, and have been regarded as 'spaces of hope' for addressing sustainability challenges associated with global food systems. This paper argues that embeddedness, however, is contingent and shifting rather than an intrinsic quality, and is shaped by the cultures of production, trade, and consumption in particular places. This paper evaluates challenges that emerging AFNs in Guangzhou, China, are confronting relating to their embeddedness in place. The paper is underpinned by research involving interviews and focus groups with key food system actors and stakeholders in Guangzhou, including government officials, organic farmers, retailers, and non-governmental organizations. It demonstrates that AFNs in Guangzhou achieve only 'fragmentary embeddedness' in local cultures and systems of production, retail, and consumption. Despite strong social relationships established by a few successful farms and their loyal consumer groups, AFNs more broadly have struggled to embed themselves in the social and cultural fabric of the city and its commercial foodscapes. In terms of territorial embeddedness, the association of AFNs with western values, which do not always translate into Guangzhou's production and retail systems, can limit their embeddedness and scaling up in this context. The split between 'new' farmers (i.e., educated and urban-rooted producers 'returning to the land') and common farmers (i.e., local peasants) further exacerbates the difficulty of integrating AFNs in rural communities. Regarding social embeddedness, AFNs struggle to meet local consumer preferences regarding food appearances, quality, and taste, and therefore consumer trust in them is limited. In terms of institutional embeddedness, AFNs lack government policy support, despite the alignment of their missions with national strategies. More efforts are needed to deepen the embeddedness of AFNs in Guangzhou's food system and cultures if they are to respond effectively to China's food crisis and wider sustainability issues. • The embeddedness of Alternative Food Networks (AFNs) is not given, but rather is constantly generated and changing. • AFNs in Guangzhou achieve only 'fragmentary embeddedness' in local cultures and systems of production, retail, and consumption. • The split between 'new' farmers and common farmers exacerbates the difficulty of integrating AFNs in rural communities. • Different food values between AFN initiators and general consumers limit the mutual trust. [ABSTRACT FROM AUTHOR]

Industrial branching proposed by evolutionary economic geographers exhibits robustness in illustrating the spatial emergence of new industries in regions. However, extant studies are primarily confined to a single type of industrial branching mechanism, such as spin-off or firm diversification, and biasedly equate them as regional endogenous and firm-centric processes, regardless of wider contextual embeddedness. Therefore, this paper seeks to take into account the contribution of multiple and multiscalar industrial branching mechanisms embedded in industrial nature and territorial contexts to emerging industries in regions, with a particular case study of biotechnology industries in Guangzhou, China. The emergence of biotechnology industries in Guangzhou during 1978–2019 is characterized by an overall fluctuating trend and recent remarkable expansion in the 2010s. The emerging process is driven by the combination of spin-off, start-up, and firm diversification, sourcing from actors across multilevel geographical scales (e.g., urban, regional, national, global). Multiple and multiscalar industrial branching mechanisms are rendered by the spatiotemporally contingent articulations among micro-level firm motivations, meso-level industrial nature, and macro-level territorial contexts, which is encapsulated in Guangzhou's strategic position in China's economic reform and opening-up in a gradual manner and Guangzhou's latecomer position in biotechnology development and industrialization. With an emphasis on moving beyond regional endogenous and firm-centric accounts, this paper aims to articulate actor-specific motivations with industrial and territorial embeddedness to gain a multilayered and context-sensitive understanding of the emergence of new industries in regions. • Industrial branching mechanisms operate for transferring knowledge to new industries. • Industrial branching mechanisms cover multiple types across geographical scales. • Micro-level firm-centric industrial branching mechanisms have contextual embeddedness. • A more context-sensitive understanding of regional industrial dynamics is needed. • The emergence of biotechnology industries in Guangzhou is by multilayered dynamics. [ABSTRACT FROM AUTHOR]

• A special design of new berm reinforced with geotextile layers is reported. • Field tests conduct to show the performance of the berm with special design method. • Results explore the failure mechanism of the berm with special design method. This paper reports a case study of an extension design of an existing municipal solid waste (MSW) earth berm in Guangzhou, China. The berm has limited space for extension and was constructed during a rainy season. Due to the space constraint, the extended berm was designed with a steep slope 1.1 horizontal to 1.0 vertical (1.1 H :1.0 V). Due to the rainy season, the new extended earth berm was built with a mix of gravel and sandy clay (i.e. V gravel / V clay = 50:50). To make the new berm design satisfies the stability requirement, it has been reinforced with geotextile layers within the berm and piles at the toe of the berm. A 2D finite-element analysis has been conducted to demonstrate the rationality of the design. The performance of the new berm was monitored using field sensors, which include the vertical and lateral displacements of the berm, vertical earth pressure of the berm, and tensile strain of the geotextile layers during and after the berm construction. Numerical and field tests results show that the failure surface appears along the interface between the old berm and the horizonal displacements are mainly observed in the new berm. The results of this study proven that a steep slope berm with geotextiles reinforcement can resistant the load from extended MSW landfill, which can provide a guidance for the design and construction of the extension of MSW landfill. [ABSTRACT FROM AUTHOR]

Reducing building energy consumption and increasing the use of renewable energy are essential to energy conservation. Photovoltaic thermoelectric heat pumps have been considered as a sustainable measure to supply detached houses with hot water, especially those that even do not have access to the power grid. This paper investigates a stand-alone photovoltaic/thermal integrated thermoelectric water heating system (PV/T-TEWH). A dynamic model of PV/T-TEWH is developed and validated. The performance of the system in Lhasa, Beijing, Changsha and Guangzhou is simulated and analyzed respectively, and the economics of the system are compared. Results show that PV/T-TEWH can rely on the electric energy it generates without additional power supply when the current is less than or equal to 1.4 A in Lhasa and 1.0 A in Beijing, Changsha and Guangzhou. The annual total heat gain of the PV/T-TEWH system increases as the operating current increases, but the COP of the system falls with the rise of operating current. When the system is operating at the currents of 0.6 A, 1.0 A, 1.4 A, and 1.8 A, the payback period shortens with the increase of current. Lhasa has the shortest payback period among four cities and it is only 2.2 years when the working current is 1.8 A. The PV/T-TEWH system provides a new method for building hot water supply, especially for detached houses in remote areas. • This paper proposes and investigates a photovoltaic/thermal integrated thermoelectric water heating system (PV/T-TEWH). • A dynamic model suitable for simulating the PV/T-TEWH system is developed and validated. • The annual performance of the system in Lhasa, Beijing, Changsha and Guangzhou is simulated and analyzed. • The economics of the system in different cities are compared. [ABSTRACT FROM AUTHOR]

• A new structure of desiccant fixed bed was proposed and tested. • Dehumidification capacity of double-stage box could reach 1.6 g•kg−1 on average. • Maximum dehumidification efficiency of double-stage box could peak 27.8% in given condition. • 97% of the adsorption heat was directed to heat storage of the desiccant. Desiccant fixed bed is a prospective alternative for conventional vapor compression refrigeration system. In this paper, a novel structure of fixed bed, desiccant dehumidification box, was constructed and experimented at a sub-tropical city, Guangzhou. Dehumidification performance of the new structure was evaluated by several indicators. Mathematical models were established concerning moisture adsorption rate and moisture ratio. The adsorption heat generated was analyzed by testing sensible heat gain of the process air and heat storage of the desiccant. The result shows that the double-stage desiccant dehumidification box could perform better generally. The maximum dehumidification capacity could reach 3.9 g•kg−1 and 1.6 g•kg−1 on average in condition 4. Maximum dehumidification efficiency (27.8%) was obtained in the same condition when applying the double-stage box. The desiccant saturated at about 6 h in experiments, of which variation in the double-stage box was more stable and lasting, though moisture adsorption rate presents only a little difference in comparison boxes. Exponential models fit the practical curves within 10% relative error. Maximum average temperature rise of the desiccant and process air was 4.3°C and 3.8°C respectively in the double-stage box, which was 0.4°C and 0.9°C higher than the single-stage box. Around 97% of the adsorption heat was directed to heat storage of the desiccant and only left 3% directed to sensible heat gain of the process air. [ABSTRACT FROM AUTHOR]

• This paper ranks the important logistics nodes across the complex China Railway Express (CR express) network from the Belt and Road Initiative perspective. • Moscow ranks the first in the node's importance in the CR express transport network; Guangzhou and Beihai rank the top two seaport nodes. • This paper confirms the accuracy and practicability of the structural hole theory in the importance ranking of nodes in the complex network. • This paper contributes to optimising the structure of CR express transport network and improving the network stability. China Railway Express (CR express) refers to the regular container trains transporting between China and European countries under the Belt and Road Initiative (BRI). This paper aims to conduct the systematic and in-depth research on the importance ranking of logistics nodes across the complex CR express network from China's national plan of the BRI perspective, with consideration of the connectivity between the 21st-Century Maritime Silk Road (MSR) and the Silk Road Economic Belt (SREB). In doing so, first, it sets up the complex network in the CR express transport. Second, based on the restraint coefficients in the theory of structural hole such as network scale, efficiency, grading and clustering co-efficiency, this paper applies the Multiple Attribute Decision Making (MADM) model in association with algorithm development in calculating the importance of the CR express nodes including both inland nodes and seaport nodes. The paper has three-fold contributions. In theory, it confirms the accuracy and practicability of the structural hole theory in the importance ranking of nodes in the complex network. In practice, it identifies important logistics nodes of CR express network across the BRI. Further, the findings in the paper contribute to optimising the structure of CR express transport and improving its network stability. [ABSTRACT FROM AUTHOR]

In tandem with rapid urbanization in China, the loss of farmland has become a critical problem, as farmland is related to food security and urban ecological system. The local governments of Guangzhou have adopted transfer of development rights (TDR) to protect the Ecological Fruit Park (EFP) of Guangzhou city from destruction by local farmers. The TDR programmes in China are often driven by economic development in the name of ecological protection, however lacking attention to individual development demands and benefits leads to respective implementation failure. This paper examines the TDR programme of EFP in Guangzhou and argues that the TDR of EFP have prioritized ecological concerns and social stability, and especially individual benefit is crucial for the implementation. Based on an in-depth study of the EFP, this paper argues that the core principle of the TDR on collective-owned farmland is the realization of landowners' development rights. This paper also finds that there are three main factors leading to the successful implementation of conservation projects: strong public subsidies, core location of the farmland and strong motivation of the government. This paper thus suggests that local governments should seek an alternative approach of TDR to protect farmland lacking the above-mentioned three main factors. • Since the loss of farmlands has become a national problem of China, the government of Guangzhou have adopted transfer of development rights (TDR) to protect farmlands. While many scholars have considered that TDR in China is driven by economic development in the name of ecological protection, lacking attention to individual development demands and benefits, this paper examines the TDR programme of the Guangzhou Ecological Fruit Park (EFP) and argues that certain TDR efforts in China have prioritized ecological concerns and social stability, and that individual benefit is crucial to the implementation. The core principle of TDR on collective-owned farmland is the realization of landowners' development rights. and the three main factors of the successful implementation of conservation projects are strong public subsidies, core location of the farmland and strong motivation of the government. [ABSTRACT FROM AUTHOR]

Abstract The current generation of millennial university students is more accustomed to searching reference information online than visiting the physical library facility, compared to the previous generations of students. Studies have shown that the role of the physical library facilities as a mere collection point of reading and reference materials is being threatened by the availability of free and high-speed online search engines. University libraries have always been an integral part in higher education learning activities, and they are not exempted from this threat. Based on a structural equation modelling framework, we analysed empirically the importance of different library design features that help enhance students' learning satisfaction, and found that lighting environment, acoustic environment as well as location of the library building were the main determinants impacting on the use of the university library by students in a major university in China. We conclude the paper with our suggestions in modifying library design to accommodate students' learning needs, and more importantly in recon uring the spatial and functional role of university libraries in this age of digital information from a mere provider of reference materials to a physical space of learning commons on campus. [ABSTRACT FROM AUTHOR]

In recent years, promoting regional synergistic development has become the shared objective in city-regions during the new stages of development. This paper aims to uncover the dynamics of synergistic development in urban agglomerations by constructing an index measurement system based on four dimensions: industrial synergy, innovation synergy, infrastructure synergy, and institutional synergy. By comprehensively employing theories and methods such as "space of flow" big data analysis, network analysis, and interlocking network models, this study examines patterns and capacities of synergistic development in the Guangdong-Hong Kong-Macao Greater Bay Area. The main instances of industrial cooperation between cities are observed in Hong Kong-Shenzhen and Guangzhou-Shenzhen; capital flows primarily concentrate in Guangzhou-Shenzhen and Hong Kong-Shenzhen. Research paper and patent collaborations between cities are predominantly concentrated in Hong Kong-Shenzhen; joint laboratories are mainly established in Hong Kong-Macao and Hong Kong-Guangzhou; inter-city co-construction of higher education institutions is mainly focused on Guangzhou-Foshan and Shenzhen-Hong Kong. Infrastructure synergistic development performs best in Guangzhou-Shenzhen, Guangzhou-Foshan, and Shenzhen-Dongguan. Cross-border collaboration benefits from institutional advantages held by Hong Kong and Macao. Urban interactions with outstanding performance include Guangzhou-Shenzhen, Hong Kong-Shenzhen, Guangzhou-Foshan, Shenzhen-Dongguan. Additionally, increasing interaction trends can be observed between Guangzhou-Dongguan as well as Shenzhen-Zhuhai/Shenzen-Foshan partnerships. Understanding the typical characteristics and potential trends of synergetic development within the GBA holds significant practical value for establishing a first-class bay area along with a world-class urban agglomeration. • Concept and connotation of synergistic development in urban agglomeration area was examined. • Indicators and methods for evaluation of synergistic development in the GBA were conducted. • Patterns and capacities of synergistic development at urban scale in the GBA were explained. • Urban interaction with highest synergistic development level is Guangzhou-Shenzhen. [ABSTRACT FROM AUTHOR]

As Chinese cities are issuing talent attraction policies for foreign-educated professionals, there have been waves of Chinese academic migrants returning to the homeland. By using the transnationalism/trans-locality framework and based on 30 in-depth interviews in Guangzhou, this paper studies the identity (re)construction process of skilled Chinese returnees and their integration into destination cities after returning. First, the identity negotiation of academic returnees from the time when they were overseas is investigated, and how their reconstructed identities affect their return destination choice is explored. Meanwhile, the academic returnees' dual place selection rationale is analyzed, how a globalizing city and intellectual gateway like Guangzhou in a developing country acts to attract talents is revealed, and whether its sociocultural environment facilitates or hinders returnees' integration and attachment to the city of residence is uncovered. This paper contributes to the broader migration literature by providing a micro-level detailed analysis of skilled migrants' professional and daily experience after they return to their home country in the Global South. Also, it provides some talent policy implications for higher-education administrations and local governments. • Explores the identity negotiation of academic returnees from the time when they were overseas, and how their reconstructed identities impact their return destination choice. • Extends our knowledge of academic return migrants by focusing on their return destination selection and place attachment to an emerging global city of Guangzhou. • Uncovers how a globalizing city and intellectual gateway in a developing country attracts talent and how its socio-cultural environment affects returnees' place attachment. • Provides policy implications for helping returnees adjust to the socio-cultural environment in higher education institutions and local society. [ABSTRACT FROM AUTHOR]

While urban redevelopment has been a global phenomenon for many decades, the redevelopment of urban villages (villages-in-the-city or c hengzhongcun) in China has attracted increasing scholarly attention in recent years. However, few studies focus on urban planning forces and their impacts on the redevelopment of urban villages, especially the transformation of open spaces. This paper therefore examines how urban planning transforms the space of urban villages through a case study of Yangji Village in Guangzhou City, Guangdong Province. The large increase in public spaces related to the transformation of Yangji results from collaborative governance driven by trends in urbanization and the work of urban planners. The latter are empowered by their strategic use of state support, professional knowledge and public interest incentives. However, in the Yangji redevelopment, as a state-hegemonic project, such planner-led collaborative governance remains limited in scope amid the exclusion of migrant tenants from decision-making. Although rarely regarded in the literature as playing a key role in redeveloping urban villages, this paper highlights urban planners as a salient force in the morphology of urban villages. Without challenging the hegemonic substance of urban village redevelopment, planners can coordinate with and occasionally manipulate other stakeholders to legitimate and facilitate negotiation during physical planning. Hence, redeveloped urban forms, rather than stakeholders' economic profits in short-term redevelopment, may influence urban lives in the long term due to planners' efforts. • Multiple stakeholders form collaborative governance in the physical planning of Yangji Village redevelopment to increase much open space. • The collaborative dynamics in the physical planning are built upon stakeholders' trust, fostered through informal meetings, led by planners, and fundamentally driven by urbanization. • Such collaborative governance is limited, largely due to the exclusion of migrant tenants. • Planners define the field of urban form beyond economic profit to improve redevelopment without challenging neoliberal and authoritarian hegemony. • State support, professional knowledge, and public interest ensure planners' leading role in collaboration. [ABSTRACT FROM AUTHOR]

Reasonable road design can not only improve traffic efficiency, ensure driving safety, reduce construction costs, but also reduce the energy consumption of road transportation. However, existing road design research mainly focuses on safety, efficiency, and economic factors, with few studies considering the actual construction difficulty as well as energy saving and emission reduction of transportation. To fill the research gap, this paper proposes a longitudinal slope design method for highway sections that considers both vehicle fuel consumption minimization and construction feasibility. First, the passenger car trajectory data and fuel consumption data from the Beihuan Highway in Guangzhou, Guangdong Province, China were collected, and the optimal combination features of the random forest algorithm were extracted using parameters such as vehicle operating conditions and road grades, thus establishing a fuel consumption estimation model for passenger cars on highways. Second, by combining the fuel consumption estimation model with dynamic programming algorithm, an ecological speed planning model for passenger cars on highways was developed. Finally, for the scenario of ecological driving of intelligent vehicles, a fuel-efficient slope design (FSD) method was proposed based on the Nested Monte Carlo Tree Search algorithm, and the best fuel-efficient slope design was selected considering the balance of cut and fill factors. The results show that FSD can reduce the fuel consumption of passenger cars on the section by about 4.50%–6.52%; the fuel-efficient slope design considering the balance of cut and fill not only can reduce the fuel consumption of passenger cars on the section by about 5.21%, but also has the advantage of lower engineering volume. The research results conduce to establish a theory and standards for fuel-efficient slope design of highways suitable for ecological driving scenarios of intelligent vehicles, which can reduce the trip fuel consumption of highway traffic flow in the long run while considering traffic efficiency, and have great significance for reducing carbon emissions, saving travel costs, and protecting non-renewable resources. • The study proposes a fuel-efficient longitudinal slope design method for highway. • The method can reduce the fuel consumption of a passenger car by about 4.50%–6.52%. • The concave curve is effective in reducing fuel consumption for passenger cars. • Considering the balance of cut and fill makes the slope scheme more fuel-efficient. [ABSTRACT FROM AUTHOR]

Abstract The rising fluidity of the society in contemporary China has led to a restructuring of people's cognition and emotion toward their place of residence. Although a growing body of literature has attempted to identify place-based factors that influence residents' attachment to their neighborhoods in Chinese large cities, little effort has been devoted to unraveling the migrant-local distinction regarding the meaning and mechanism of neighborhood attachment. Using both questionnaire survey data and in-depth interview data collected in 23 neighborhoods of Guangzhou, China, this paper aims to explore the meaning and mechanism of neighborhood attachment through the combination of both structure equation modelling and qualitative analysis. The novelties of this study relate to the focus of migrant-local distinction and to the breakdown of place attachment into its social and functional dimensions. Results from structure equation modelling show that local residents have stronger attachment to their neighborhoods than migrants. Migrants' neighborhood attachment is more related to its social dimension, as measured by social contact and social trust, and locals' neighborhood attachment is more linked to its functional dimension, as measured by satisfaction with living environment of the neighborhood. This paper enhances our understanding of the nature of place attachment by taking into account the effects of institutional constraints and migration experiences. Highlights • Social dimension and functional dimension contribute to place attachment. • Social dimension interacts with functional dimension. • Social dimension is an important predictor of place attachment for the migrant group. [ABSTRACT FROM AUTHOR]

Drawing upon recent post-political critiques on ineffective participation and urban planning, this paper reflects on the challenges facing participatory and collaborative planning in China's latest neighborhood regeneration practices. In 2017, Guangzhou launched a new micro-scale neighborhood regeneration program that shifted the discursive emphasis on participatory planning while China strives to create a new national image of a "people's city". This paper critically examines the implementation of old community renovation policies in 32 Chinese provinces and 776 neighborhood regeneration projects in Guangzhou. By examining the objectives and outcomes of legitimate power over participation, we uncover institutional conditions, implementation issues, and local responses in different participatory planning configurations. We found that a "co-production" model emerged in China, highlighting the role of institutionalized participatory planning activities. The conclusion is threefold: 1) Shared objectives in the emerging neighborhood regeneration discourse constitute legitimate power over participation in China's neighborhood regeneration; 2) The outcomes of legitimate power over participation are reflected in the local responses to the "co-production" activities; and 3) The "co-production" model—to produce planning schemes through co-design and joint-negotiation among multi-scalar actors including planners and residents—performs as an alternative to immature collaborative planning in China. Local governments can skillfully avoid direct confrontations with residents by introducing the function of community planners. These institutional arrangements of "co-production" have profoundly impacted the reshuffling of the state-society relationship in post-political China. While the implementation of China's latest neighborhood regeneration policy shows post-political risks in terms of depoliticized narratives, instrumentalized planning strategies, and technicized planning tools, we find "co-production" to be fruitful in promoting substantive participation and stimulating the accumulation of local knowledge. • An analytical framework to conceptualize the legitimate power of participation in China's emerging small-scale neighborhood regeneration program. • A response to the debate between two currents in the post-political context—consensus-oriented and conflict-based. • Critically examines the implementation of old community renovation policies in 32 Chinese provinces and the participatory planning practices of 776 projects in Guangzhou. • "Co-production" reflects both the objective and the outcome of legitimate power embodied in the neighborhood regeneration process. [ABSTRACT FROM AUTHOR]

With the rising urge to mitigate the green house effect, reducing the energy consumption of the freight train attracts much attention. Multiple constraints should be taken into account to solve the energy-efficient control problem, which can be reformulated as the multi-objective optimization. This paper proposes a Reinforcement Learning (RL) method for the multi-objective speed trajectory optimization with the goal of the energy-efficiency, punctuality and accurate parking simultaneously. Since the solution space for the optimization problem in this paper is large and discrete, a Gated Recurrent Unit (GRU)-based network is proposed to achieve the fast approximation of the optimal value function instead of the lookup Q-table. Meanwhile, a new architecture, including the embedding matrix, is used to model the control sequence that generates the speed trajectory. Besides, this paper constructs a Deep Q-Network (DQN) framework to train the GRU network without relying on the prior knowledge of the freight train model. Finally, the Intelligent Train Operation (ITO) algorithm is proposed and verified, using the data of Beijing–Guangzhou Railway Line and HXD1B electric locomotive. The case studies indicate that the reward function for the ITO algorithm converges rapidly and the energy consumption monotonically decreases with the trip time, which satisfies the multiple optimization objectives. In terms of saving the energy consumption, the ITO algorithm performs better than Fuzzy Predictive Control (FPC), Genetic Algorithm (GA) and the field test data. The computation time of different speed trajectories demonstrates that the ITO algorithm is applicable to generating the optimal speed trajectory off-line. • A novel multi-objective optimization model based on the reinforcement learning is proposed to search for the optimal control sequence. The embedding matrix is used to formulate the control sequence. • An intelligent train operation algorithm based on the gated recurrent unit network is proposed to compute the optimal speed trajectory without the precise train dynamics or the prior knowledge from the experienced drivers. • The energy consumption is reduced by 3.17%, 0.71% and 6.77% respectively comparing with fuzzy predictive control, genetic algorithm and field test data. [ABSTRACT FROM AUTHOR]

Urban village regeneration has been considered an effective way to achieve the vision of transforming the arrival cities in China to affordable cities. However, the existing research into urban village regeneration does not pay enough attention to the group of rural migrants, and the dynamic process of their participation is indistinct. With a theoretical underpinning of the conception of Arrival City and Affordable City and the ladder theory of participation, this paper attempts to understand the practices of rural migrants' participation in urban village regeneration and, more importantly, to unpack the underlying mysteries of the transition process from arrival cities to affordable cities in China. The paper finds that rural migrants are involved in urban village regeneration indirectly, as opposed to directly or not participating at all. Before a regeneration project take places, they are expelled and ostracised by the alliance of "government-developer-villager" because of their informal identities. After the project, middle-class migrants lived in the regenerated urban villages but suffered from social exclusion. Most of the migrants gather in the newer urban villages or form new arrival cities in the urban periphery, resulting in potential social conflicts and a vicious cycle of "regeneration – migration – regeneration – migration". The vision is realised only in the environment and discourses from the alliance, but not in terms of rural migrants. China's urban transition from arrival cities to affordable cities is incomplete and one-sided. This transition, guided as it is by the existing mechanism of urban village regeneration, undermines social equity and causes social conflicts, which is not sustainable. These findings and proposed corresponding suggestions can serve as valuable references for the practices of public participation in urban regeneration that are underway in developing countries or where there is eagerness to transition effectively from arrival cities to affordable cities. [ABSTRACT FROM AUTHOR]

The objective and automated detection of pneumonia represents a serious challenge in medical imaging, because the signs of the illness are not obvious in CT or X-ray scans. Further on, it is also an important task, since millions of people die of pneumonia every year. The main goal of this paper is to propose a solution for the above mentioned problem, using a novel deep neural network architecture. The proposed novelty consists in the use of dropout in the convolutional part of the network. The proposed method was trained and tested on a set of 5856 labeled images available at one of Kaggle's many medical imaging challenges. The chest X-ray images (anterior-posterior) were selected from retrospective cohorts of pediatric patients, aged between one and five years, from Guangzhou Women and Children's Medical Center, Guangzhou, China. Results achieved by our network would have placed first in the Kaggle competition with the following metrics: 97.2% accuracy, 97.3% recall, 97.4% precision and AUC = 0.982 , and they are competitive with current state-of-the-art solutions. [ABSTRACT FROM AUTHOR]

In the context of rapid urbanization, land has become the most valuable scarce resource, and the regeneration of urban villages is related to urban land supply for urban redevelopment. The redevelopment of urban villages can promote the efficient use of land resources and contribute to the sustainable development of the city. This paper examines the redevelopment of an urban village in Guangzhou from the perspective of territorialization and finds that urban villages ultimately become territories dominated by the coalition formed by the market developers and the rural collective organization of the urban village. When the local government attempts to redevelop the village, the coalition fights against the government and defends the territory, leading to the predicament of urban redevelopment. By exploring the territorialization process and the dynamics of spatial production, this paper argues that territorialization is a means of reifying and reinforcing power in a geographical space and represents a significant attempt to achieve urban redevelopment. Both the local government and the coalition can contribute to the redevelopment of urban villages. Although territorialization is an efficient way to achieve urban redevelopment, it may solidify an area and cause the straitened circumstances of city government to implement the new city strategy. This paper thus calls for a focus on the value of bottom-up territorialization and the ingenious combination of city planning and territorialization to achieve effective urban redevelopment. [ABSTRACT FROM AUTHOR]

• Propose a stratal slicing method to reflect the actual cutter working conditions. • The stratal slicing method has stronger geological information processing ability. • It can improve the prediction accuracy and has real-time prediction capability. • The error of combined method in real-time predictions is close to that of the manual measure. • It is expected to demonstrate excellent performance in more complex geological conditions and larger shield diameters. Monitoring the wear status of cutters is important for safe and sustainable shield construction and cost management. In this paper, an innovative stratal slicing method is proposed to convert segmented and discrete uniaxial compressive strength (UCS) test data into a sequential dataset by combining it with a geological profile. The sequential dataset not only accurately represents the changing strata conditions but also differentiates the working conditions of the disc cutters in various cutterhead areas on the excavation face. Its sequence characteristics can be better combined with shield operational parameters and time-series models for real-time prediction. Furthermore, the particle swarm optimization (PSO) algorithm was improved by adding variable inertia weights and elimination mechanisms, which effectively optimised the hyperparameters of the long short-term memory (LSTM) model. The proposed method was applied to a field tunnelling case with data collected from the Guangzhou Metro Line 18 railway. The results show that the UCS data obtained using the proposed stratal slicing method can improve the prediction accuracy compared to traditional methods and models. In particular, the combined IPSO + LSTM + horizontal summation method can obtain the most accurate prediction results and has real-time prediction capability. With the proposed stratal slicing method, the IPSO + LSTM modelling approach is generally applicable to more complex ground conditions and larger shield diameters. [ABSTRACT FROM AUTHOR]

Prior research on urban form typologies has largely relied on qualitative classification methods, resulting in subjective and limited analyses. Recently, the emerging data-intensive studies often use a single clustering algorithm and parameter setting, raising concerns about the reliability of the findings. This paper introduces a novel clustering analytical framework for conducting typological studies on urban form that yield stable and reliable results. We employ clustering ensembles, which can combine multiple clustering algorithms to further provide a comprehensible output that facilitates interpretation and knowledge generation. By applying the new framework using 3D building data in Guangzhou, we identify eight typologies of urban built forms and reveal a consistent polycentric pattern across different clustering algorithms and parameter settings. The findings have implications for urban land use planning and regulations by integrating 3D representations of urban form. • A novel clustering analytical framework for studying urban built form is developed. • The proposed framework utilizes clustering ensembles to yield stable results. • The results identified eight distinct typologies of built forms of Guangzhou. • The proposed clustering analytical framework can be applied to other urban research settings. [ABSTRACT FROM AUTHOR]

• A GIS-based two-stage assessment method for DCS implementation is proposed. • Three novel DCS evaluation indicators to build GIS layers are proposed. • The distribution of cooling demand in China at a resolution of 1 km² is mapped. • The potential zones for DCS implementation in Guangzhou are assessed. • The impact of population changes on potential zones assessment is investigated. The district cooling system (DCS) is seen as a promising cooling solution for its flexibility and high efficiency. Identifying suitable zones for DCS construction is one of the major challenges in implementing DCS, as the characteristics of the selected zones significantly impact the performance and benefits of DCS. This paper presents a geographic information system (GIS) based two-stage assessment method to rapidly determine potential zones for DCS from a large-scale. Firstly, employing a top-down method to spatially assess cooling demand. Secondly, three novel indicators (R C I , R d a y , R c a p) for DCS cooling intensity, cooling duration, and capacity utilization rate evaluation are proposed, and a multi-criteria decision-making method is applied to identify potential zones for DCS implementation. Based on the proposed method, the cooling demand in China is mapped. Shanghai, Guangzhou, Chongqing, and Shenzhen are identified as the four cities with the highest cooling demand. Furthermore, the potential zones for DCS in Guangzhou are assessed. The results indicate that zones with the highest potential exhibit high robustness against weight uncertainty and are primarily concentrated in densely populated areas. The proposed indicators and method could provide support for macro-level planning of DCS to effectively improve the decision-making efficiency. [Display omitted] [ABSTRACT FROM AUTHOR]

The new millennium signified a new phase in the development zone-oriented suburbanization of China. Spurred by a new round of urban development strategies, development zones in many large cities face a need for enormous transformations and re-development. These areas have often been compared with the Western concept of “edge cities”, although in this paper we argue that this “imported” concept, in practice, bears little resemblance to the actual development tendencies in China. Taking a comparative approach, this paper presents a critical examination of edge urban formations in the Chinese context, and identifies the major differences between the concept in China and the United States. Drawing upon a case study of Nansha in Guangzhou, the unique paths and underlying dynamics driving these transformations are revealed. It is concluded that Chinese edge urban areas are being transformed from mono-function development zones into new fully functional cities. A city in China like Nansha reveals the dynamics of both state interventions and local actions in boosting the polycentric economies of large city regions. [ABSTRACT FROM AUTHOR]

An energy-efficiency train schedule greatly contributes to alleviating some environmental issues such as carbon emissions. However, the pursuit of reducing train energy consumption often leads to passengers' longer travel time, and more operation cost of rolling stocks. Thus, it is necessary to consider costs of passengers and rolling stocks when optimizing the energy-efficiency schedule for better satisfying passenger demand and reducing trains' total operating cost. In this paper, a mixed integer nonlinear programming model of energy-efficiency train schedule considering passenger demand and rolling stock circulation plan is established for minimizing passengers' travel cost and trains' operating cost. More specifically, this model devotes to simultaneously optimizing: (1) passengers' travel choices to reduce passengers' waiting time and travel time, (2) the selection of train traction strategy in the section to reduce the traction energy consumption, and (3) the train connection scheme to ensure the economy of the rolling stock circulation plan. This paper designs a variable neighborhood search algorithm combined with CPLEX solver to solve the model efficiently. Based on the data of Guangzhou Metro Line 9, the optimization method proposed in this paper can reduce the train operation cost by 9.73% and the total passenger travel cost by 18.11%. • Integrate rolling stock circulation planning with energy-efficient train scheduling. • Consider the passengers' travel cost to ensure the quality of passenger service. • Optimize trains' traction strategies to reduce traction energy consumption. • The effectiveness is demonstrated in a real-word case. [ABSTRACT FROM AUTHOR]

The effective resistance and rapid recovery from external environmental risks has risen to be a social challenge in the accelerated urbanization process of China. However, the current measures for urban high-rise and high-density core area with high-volume pedestrians and high pollution are often focused on one-dimensional means, which cannot meet the multi-objective demands simultaneously. Therefore, this paper is aimed to explore a prevention-oriented route - a vertical pedestrian system for high-rise buildings based on scheme phase, with multiple objectives optimization of strengthening the ability of ecological order restoration and assisting occupants in recovering psychological and physiological injury from high-density environment in a relative fast speed. The feasibility and effectiveness have been verified by a complete technology route of scheme selection, numerical simulation and field measurements. The results show that, first, after the integration of secondary ground pedestrian system (SGPS) basic unit, the average predicted mean vote (PMV) improves 75.45%, the average air temperature declines 2.75 °C, and the average spatial integration increases 35.35%. Second, the optimal range of unit height difference in SGPS under hot-humid climate condition is suggested to be 6–9 storeys. Third, compared with single-sided "E-type" connection, the thermal comfort improves 70.49% and the indoor average PMV is optimized by 2.56%, with a more stable wind speed by using bilateral alternating "S-type" connection. Finally, compared with connections among low-integrated secondary ground units, the average integration is up to 6.98% with visual and path links of high-integrated-orientation. This paper objectively answers the question of whether and to what extent the combination of vertical greening and walking system contributes to ecological order restoration, which provides a new orientation for exploring the routes of maintaining urban ecological stability and optimizing environmental structure. • It evaluates the effect of SGPS on the high-rise and high-density environment. • It analyzes SGPS's effects from a multi-objective perspective. • The SPGS plays a positive role in environmental regulation and health promotion. • The union of walking system and ventilating shaft effectively integrate resources. [ABSTRACT FROM AUTHOR]

• Adapted four asymmetric models to route choice by parameterization. • Tested the asymmetric models by GPS data collected from taxis and bicycles. • Revealed and compared the route choice patterns of driving and cycling. Among the discrete choice contexts discussed in the transportation literature, route choice is particularly challenging, for which several model structures with different assumptions were developed. Recently, a group of closed-form multinomial models with asymmetric choice probability functions have been proposed to resolve the class imbalance problem in mode choice. However, these asymmetric models can hardly be estimated when the choice sets vary with observations. This paper fills the gap between the asymmetric models and the existing literature, and also adapt the models to route choice by proposing three approaches to further parameterize the shape parameter. This paper also tests the asymmetric models by two independent GPS datasets: taxi data collected in Guangzhou as well as bicycle data collected in Tel Aviv. Comparative analysis is conducted between taxi drivers and cyclists on their route choice behavior. The results indicate the existence of class imbalance in both cases. Moreover, the asymmetric models have case-dependent performance, and different parameterizations correspond to different interpretations of the asymmetry in route choice. [ABSTRACT FROM AUTHOR]

• A bi-objective multi-depot electric transit vehicle scheduling problem. • Time-of-use electricity tariffs and peak load risk for power grids are explicitly considered. • A lexicographic method to reformulate the bi-objective optimization model to achieve win-win situations. • A tailored branch-and-price algorithm that embeds heuristics and a trip chain pool strategy. • Higher solution quality and computation efficiency compared to the off-the-shelf solver. Electric buses can bring significant environmental and social benefits in the future public transportation systems. However, the large-scale adoption of electric buses faces major technical challenges caused by not only the limited running range and long charging time, but also the complex power grid characteristics, such as time-of-use (TOU) electricity tariffs and peak load risk. On one hand, the operation cost is determined by the TOU pricing and vehicle schedule. On the other hand, the unbalanced charging demand resulting from the vehicle schedule will cause peak load risk and pose a potential threat to the power grid safety. With the increasing penetration of electric buses, there is a real need to carefully design and manage electric bus scheduling to not only reduce the system costs but also ensure power grid safety. In this paper, we introduce a bi-objective multi-depot electric vehicle scheduling problem, a new generalization to the vehicle scheduling problem where the effects of TOU pricing and peak load risk are explicitly considered. The dual objectives are to minimize the total operation cost and to minimize the peak load resulting from concurrent recharging activities, as constrained by the running range of the electric buses and the capacity of charging depots/stations. A time-expanded network model is devised to represent this problem, while the bi-objective optimization model is reformulated by the lexicographic method. We propose a tailored branch-and-price method to solve the problem. Heuristics and a trip chain pool strategy are embedded into the branch-and-price method to expedite the computation time. Our method is validated through a benchmark network and a real-world bus network in Guangzhou, China. The results demonstrate that our method is effective in cost savings and peak load leveling, and far outperforms the off-the-shelf solver with respect to solution quality and computation efficiency. The real-world application results show that compared to state-of-the-practice, the peak load can be significantly reduced, on top of cost and fleet size savings. [ABSTRACT FROM AUTHOR]

The fine particulate matter, generally known as PM 2.5 , has great impact on the air quality and human health. Although closing external windows can help prevent outdoor PM 2.5 going into indoors, many studies have shown that a significant number of particles can still pass the building façade through the cracks around the window. In order to quantify the influence of the external window crack structure and some relevant parameters, such as room dimension, on the indoor PM 2.5 mass concentration, this paper introduces an updated model from a previously published paper by the authors [18]. The model was developed based on two-month field measured data from five unoccupied offices located in the central area of Beijing (capital city located in northern China), and then was validated against a new dataset measured in Guangzhou (a major city located in southern China). The model can be used to quantify the indoor PM 2.5 mass concentration based on the instant outdoor PM 2.5 level, considering influences from external window crack structure, room dimension and outdoor meteorological conditions, i.e. outdoor wind speed and relative humidity. [ABSTRACT FROM AUTHOR]

The train generates regenerative braking energy (RBE) during braking. When the RBE generated by the braking train is too large to be absorbed and utilized, the OCS voltage will rise rapidly. It may even exceed the rated voltage threshold, resulting in hidden dangers for driving safety. How to use RBE efficiently and reasonably has become a hot issue in recent years. This paper presents a metro timetable optimization method for multi-train operation to improve the RBE utilization efficiency of trains. Firstly, an energy-saving multi-objective model for multi-train operation is established, which takes the total energy consumption and travel time as the objective functions and the dwell time and departure interval as the constraints. Then, the genetic algorithm (GA) is used to generate the composition sequence of dwell time and departure interval, and the multi-node nonlinear model is used to calculate the total energy consumption of the metro line. Finally, Guangzhou metro line 7 is selected as an example to illustrate the effectiveness of the developed optimization model. The results show that the energy consumption of the whole line can be effectively reduced by adjusting the dwell time and departure interval. Meanwhile, the timetable optimization model with GA has better energy-saving effects by comparative analysis. • A metro timetable optimization method based on improved genetic algorithm is developed. • The multi-node nonlinear model is developed to calculate the total energy consumption. • The developed optimization model has better energy-saving effects than previous methods. [ABSTRACT FROM AUTHOR]

Commute time is an important determinant of commute satisfaction. However, commuters may perceive the same length of commute differently and adopt different standards (reference points) to evaluate their commute time. This paper explores the effects of commute time discrepancies relative to four reference points on commute satisfaction based on a survey in Guangzhou, China. The reference points include ideal commute time (ICT), acceptable commute time (ACT), comparison other's commute time (COCT), and non-congested commute time (NCCT). We find that the gaps between actual commute time and the four reference points are all important for commute satisfaction, though ICT and ACT seem to be more salient reference points in evaluating commute satisfaction. Our analysis also confirms the loss aversion phenomenon, as the effect sizes of loss variables tend to be larger than those of gain variables. The effects on satisfaction with commute to and from work are also different. [ABSTRACT FROM AUTHOR]

Urban planning exhibitions have been a long-standing element in planning culture, on a worldwide level. Until now, there has been a considerable gap in researching the efficiency of urban planning exhibitions in communication, especially from a quantitative perspective. Rooted in communicative planning and built on Generic Learning Outcomes and Contextual Model of Learning theory, this paper aims to explore the role of urban planning exhibitions in communication and the factors that influence their efficiency, using the recently opened Guangzhou Urban Planning Exhibition Hall (UPEH) as an example. The 115 participants in this study were divided into two groups (experimental and control) and asked to answer a series of urban planning questions before and after visiting the Guangzhou UPEH. Results showed that except for the level of education, the personal and sociocultural factors had no significant effect on changes in participants' knowledge on the subject. However, the physical factors of participants' visits, including the length of the visit, the number of exhibits seen by participants and the degree of engagement with the top-rated exhibits, significantly influenced learning about urban planning. The results demonstrated that urban planning exhibitions can provide inclusive platforms in facilitating planning communication and public engagement. • Measurement of public learning in a permanent urban planning exhibition • Participants significantly gain knowledge about urban planning after their visits. • Physical attributes of participants' visits significantly influence their learning. • Socio-cultural background of participants generally does not affect their learning. [ABSTRACT FROM AUTHOR]

The inefficient operation of cooling equipment is a significant impact factor to the high energy consumption of cooling system in data center. This study proposes an advanced model predictive control (MPC) strategy for a hybrid cooling with water storage system to improve energy efficiency and reduce the accumulation of cold storage losses. Mixed integer linear programming (MILP) in MPC strategy is used to optimize the operating parameters under free cooling, hybrid cooling, and mechanical cooling modes, further solving the problem of precise optimization for different modes. Taking Guangzhou city as an example, the equipment scheduling and the appropriate volume of cold water storage tank for MPC strategy are analyzed. The results indicate that, the emergency cold water storage tank 500 m3 only supports the efficient operation of cooling system under the maximum 60 % IT load rate, meanwhile, the optimal tank volume 1400 m3 could meet the 60–100 % IT load rate. Compared to Baseline strategy, the biggest reduction of annual energy consumption using MPC strategy would be attained by 12.19 % under free cooling mode, by 4.04 % under hybrid cooling mode, and by 22.15 % under mechanical cooling conditions at the 55 % IT load rate. Therefore, the MPC strategy proposed in this paper has important guiding significance for energy conservation and carbon reduction in global data centers. • A novel advanced MPC strategy and MILP solver is developed for hybrid cooling system of data center. • The energy consumption of MPC strategy decreases by 12.19 % under free cooling mode at 55 % IT load. • The relationship between the water tank volume and IT load rate under MPC strategy is studied. [ABSTRACT FROM AUTHOR]

The public participation process in the renovation of urban villages should not only ensure procedural justice but also guide the affective integration of residents. This paper explores the public's perception of the participation space and the process of affective construction based on a visual study of the Luofeng village renovation in Guangzhou. The aim is to elucidate how the space can be employed to create an affective atmosphere as a strategy for the renovation. The study reveals that participants focused on visual symbols carrying the narrative of daily life, evoking a positive emotional response to these elements. The public participation space successfully establishes a homey atmosphere and achieves the affective reproduction of residents through the creation of its physical environment, residents' embodied practices within it, and negotiated interactions among different subjects. Drawing on the case study, we advocate for the public participation process in urban village renovation to consider residents' embodied affective experiences. It provides a practical model that surpasses mere representation, with the intention of offering a reference for sustainable urban renewal. • The renovation of urban villages needs the affective integration of the residents. • Affective atmosphere creation provides a strategy for public participation. • Residents focus on the visual symbols that carry the narrative of everyday life. • To provide a practical pattern of public participation for urban renewal. [ABSTRACT FROM AUTHOR]

Antibiotics are causing widespread concern as one of the emerging contaminants. There is the abuse of antibiotics in high-density open aquaculture, and the tailwater is often discharged into surrounding rivers. At the same time, the water replenishment of open aquaculture ponds from nearby rivers containing antibiotic contamination from different sources may result in cross-contamination. However, it is still unclear which pollution intensity is greater in rivers or in open aquaculture. So in this paper, the levels of 20 antibiotics (i.e., Fluoroquinolones (FQs), Sulfonamides (SAs), Tetracyclines (TCs), Macrolides (MLs) and Lincosamides (LCs)) in rivers and high-density open aquaculture ponds were investigated in the Baini River basin in the suburbs of Guangzhou, China. The results showed that norfloxacin (NFX) was the predominant antibiotic in river and aquaculture water, with concentrations ranging from 6.12 to 156.04 ng/L and from 7.47 to 82.62 ng/L in both aquatic systems, respectively. As for the pollution intensity of antibiotics, the annual pollution contribution (28.64 kg/a) of the river water supply to open aquaculture is higher than that (10.81 kg/a) of open aquaculture to the river, which means river pollution has a greater impact on aquaculture ponds. The risk quotient (RQ) showed that the ecological risk of lincomycin (LIN), erythromycin (ERY), sulfamethoxazole (SMX), norfloxacin (NFX), ciprofloxacin (CFX) and chlortetracycline (CTC) in rivers and aquaculture environments had high ecological risks from 1.21 to 1.81. Water interactions with contaminated rivers will result in a corresponding increase in the ecological risk of antibiotics in the aquaculture environment. Overall, according to the results, the risk of polluted rivers to open aquaculture cannot be ignored, and it is recommended that open aquaculture should use these water sources with caution, and that the water quality evaluation of aquaculture water should be increased with monitoring indicators for emerging contaminants such as antibiotics. [Display omitted] • Twenty antibiotics in a suburban river and aquaculture ponds were investigated. • Fluoroquinolones were the predominant antibiotics in all water samples. • The impact of river water supply on open aquaculture cannot be underestimated. • All five antibiotics pose ecological risks to the aquatic environment. [ABSTRACT FROM AUTHOR]

The energy crisis caused by climate change is the most significant challenge of the 21st century. Single-objective and multi-objective optimization studies for buildings often only consider the building itself, without considering the impacts of climate change. However, in the future, energy-efficient design and appropriate operating parameters will be crucial considerations in the face of global climate change. This paper aims to discuss the impact of climate change in the humid-hot region over the past 60 years on the energy consumption of office buildings and propose countermeasures. Firstly, the meteorological data of Guangzhou from 1960 to 2020 is statistically analyzed, and four typical meteorological years and corresponding air conditioning design days are established. Secondly, Energyplus is used to simulate the building's energy consumption, and the energy consumption factors are analyzed for sensitivity using jEplus. Finally, a multi-objective optimization is performed using jEPlus + EA with the Non-dominated Sorting Genetic Algorithm (NSGA-II). The results found that climate change led to a significant increase in the duration of high outdoor temperatures during summer. Specifically, the daily dry-bulb temperature for air conditioning design increased by 0.4–0.7 °C, and due to climate change, the energy consumption of the office building increased by about 4.6 %. The main factor affecting the cooling energy consumption in summer was the indoor cooling set point (8.29%–30%), infiltration air volume (1.0%–8.6%), fresh air volume (3.2%–16.06%), the glazing solar transmission rate (1.25%–9.0%), building orientation (0%–1.43%), and relatively small influence of envelope insulation performance. The operation scheme determined by multi-objective optimization can reduce the cooling energy consumption of the building by 10.6%–16.8%, which can mitigate the rise in energy consumption resulting from climate change to a greater extent. [Display omitted] • Discuss the impact of climate change over the past 60 years on the energy consumption of office buildings. • There was a significant increase in the duration of high outdoor temperatures during the summer. • Multi-objective optimization is performed using jEPlus + EA. • Climate change caused energy consumption to increase by about 4.6 %. • Optimal solutions can reduce the cooling energy consumption of the building by 10.6%–16.8%. [ABSTRACT FROM AUTHOR]

Natural cooling energy and high-efficient radiant cooling techniques are essential to mitigate energy resources shortage crisis, breakthrough on traditional convective air-conditioning systems in isolation between indoor and outdoor environment with high indoor air quality. In this paper, a polyethylene aerogel (PEA) and phase change material (PCM) integrated novel Trombe wall was proposed, involving natural cooling energy harvesting, cooling energy storage, indoor ventilation and radiant cooling. A two-dimensional unsteady numerical model based on surface-to surface (S2S) radiation model and effective specific heat capacity method was developed in the commercial software Ansys Fluent to evaluate the cooling performance and dynamic heat-transfer mechanism of the novel Trombe wall. Subsequently, climate-responsive operation strategies on ventilation modes were proposed to maximize natural cooling energy utilization and fresh air supply. Parametrical and comparative studies were conducted on optimal structural design and robust operation. Our results showed that, with the novel design and advanced operation strategies, passive cooling capacity of 0.64 kWh/m2·day can be provided, together with fresh air supply of 2705.2 kg/day (1.4 m2 Trombe wall), corresponding to air change rate per hour (ACH) of 1.15. In terms of active cooling system, the integration of PEA and PCM can effectively prevent moisture condensation and shift peak cooling load. Hence, radiant cooling capacity of 0.99 kWh/m2·day and radiant cooling ratio of 47 % can be achieved by the novel Trombe wall, with electricity consumption only at valley period. Moreover, economic saving of 55.0 CNY/day and decarbonization potential of 23.8 kg CO 2,e /day can be achieved when the novel Trombe wall is integrated into a typical office building in subtropical climate Guangzhou. This study provides a novel structural design and optimal operation strategies on a Trombe wall, together with guidelines on techno-economic-environmental performance improvement, promoting effective natural cooling energy utilization and energy-flexible/efficient radiant cooling for decarbonization of buildings in cooling-dominant regions. • A novel Trombe wall for natural cooling energy harvesting and radiant cooling. • An unsteady numerical model for thermodynamic analysis. • Passive cooling capacity of 0.64 kWh/m2.day and fresh air supply of 2705.2 kg/day. • Radiant cooling capacity of 0.99 kWh/m2·day and radiant cooling ratio of 47 %. • Daily CO 2 reduction of 23.8 kg and economic saving of 55.0 CNY in a typical office building. [ABSTRACT FROM AUTHOR]

Energy poverty occurs when a household cannot fulfill its energy needs. Despite its widespread occurrence, Chinese cities have yet to formally recognize energy poverty as distinct from general poverty at the national level, thereby limiting the effectiveness of countermeasures. Guangzhou, a subtropical first-tier city in China, has a complex population comprising diverse migrants and locals of all ages. This age diversity greatly affects energy demand and poverty sensitivity, so analyzing age's impact on energy poverty is crucial. Thus, this paper surveyed 1072 households in 2020 to measure the extent of energy poverty. The energy poverty rate was found to be 13.85 %. Additionally, a U-shaped relationship was discovered between age and energy poverty, with a turning point at age 44. The adults in Guangzhou who are in energy poverty are not in income poverty. Higher education levels were found to impact energy consumption in households of both younger and older adults. For individuals older than 42—or 46 with a higher education level—the likelihood of experiencing energy poverty gradually decreases with age. Our findings indicate a unique pattern in which both younger and older individuals are susceptible to energy poverty in a humid subtropical climate. To achieve the UN's 2030 clean energy goals, policymakers must focus on tailored skill training, enhanced social welfare, and effective affordable housing policies to alleviate energy poverty. • We use survey datato measure Guangzhou household energy poverty. The LIHC indicator is 13.86%. • The relationship between age and energy poverty in the household is U-shaped. • Younger and older residents are vulnerable to energy poverty. • Younger and older highly educated individuals are more vulnerable to energy poverty than those without higher education. [ABSTRACT FROM AUTHOR]

Urban agglomeration is identified as the important geographic units of country development while contributing immensely to carbon emission. This paper explored energy-related carbon emission characteristics of the Pearl River Delta (PRD) - the typical urban agglomeration in China, from cities and sectors perspectives. By conducting LMDI model, this paper decomposed carbon emission by sector and by cities to illustrate the key impact factors in the PRD, explored the reasons for the change of driving effects in urban agglomeration in view of regional difference. It concludes that, most cities carbon emission rebound around 2017, while carbon emission sharply decreased. There are differences in key reduction industries in different cities, while production and supply of electric power and transport sector had negative impact on reduction processes in most cities. The significant inhibition effect of energy intensity is mainly attributed to the great decrease of energy intensity in main industries reduction cities, such as Shenzhen, Guangzhou, Dongguan and Foshan. Based on the characteristics of carbon emission and social and economic development of the PRD, this paper puts forward specific suggestions and measures for differentiated emission reduction in urban agglomeration, and provides a new idea for the governance of carbon emission in urban agglomeration. • The carbon emission inventory of typical urban agglomeration was built. • Carbon emission characteristics were diagnosed from cities and sectors perspectives. • Great disparities in contribution of carbon emission variation exists sectors and cities. • Energy intensity and economic growth were key drives of PRD region carbon emission. [ABSTRACT FROM AUTHOR]

Despite the seriousness of the problem, the city government does not wield much power in its attempt to reduce exhaust gases. While vehicle emissions are the main source of local pollution, they have regional environmental consequences. So far, localized measures to address regional smog are far from effective. This paper explains that local efforts are confined by economic interests and priorities that lie within the jurisdictional boundaries which find addressing local air pollution through limiting car ownership and use as politically unacceptable. Also, incomplete pollution data in China in general makes it difficult for city officials to come up with targeted and innovative approaches that can bring additional emission reductions. The paper further argues that without a strong and direct commitment to radically reducing current levels of vehicle-based pollution through a set of complementary behavioral modification measures, continued reliance on temporary technical fixes is likely to exacerbate the urban air pollution problem. [ABSTRACT FROM AUTHOR]

The Internet of Vehicles (IoV) can obtain traffic information through a large number of data collected by sensors. However, the lack of data, abnormal data, and other low-quality problems have seriously restricted the development and application of the IoV. To solve the problem of missing data in a large-scale road network, the previous research achievements show that tensor decomposition method has the advantages in solving multi-dimensional data imputation problems, so we adopt this tensor mode to model traffic velocity data. A new method of data missing estimation with tensor heterogeneous ensemble learning based on FNN (Fuzzy Neural Network) named FNNTEL is proposed in this paper. The performance of this method is evaluated by our experiments and analysis. The proposed method is applied to be tested by the real data captured in Guangzhou and Tianjin of China respectively. A large number of experimental tests show that the performance of the new method is better than other commonly used technologies and different missing data generation models. [ABSTRACT FROM AUTHOR]

The social and spatial patterns of ageing population in urban China illuminate the influence of the socioeconomic transformation associated with the dual economic system. Guangzhou, one of China's megacities, is used as a case study in this paper. Data from the 2010 National Census were used to examine the spatial differentiation and the related factors of ageing communities in Guangzhou. Using social area analysis, the study identified six categories of ageing communities: traditional inner-city communities, traditional danwei residential communities, commercial housing ageing communities, danwei compound ageing communities, immigrant ageing communities, and rural ageing communities. The paper analyses the reasons and processes leading to the clustering of the elderly population in each category of areas associated with distinctive spatial patterns of ageing differentiation. These patterns suggest that the socio-spatial differentiation of ageing communities is a joint outcome of urban development, housing policies, personal status and family relationships. The dynamics of both ageing in place and ageing with migration had a dual impact on the spatial, social and ecological patterns of ageing communities. The spatial differentiation of ageing communities in the study area should be taken into account when formulating urban planning and public policies. In addition, a dynamic public facility and service allocation system is also necessary to meet the needs associated with evolving socio-spatial urban restructuring. [ABSTRACT FROM AUTHOR]

With China’s rapid urbanisation driving its growing economy, the enlarging socio-spatial inequalities in the cities have received wide attention. Rather than following the largely studied residential spaces, this paper focuses on socio-spatial differentiation based on the spaces of one’s out-of-home activities. Using data of 1006 individuals collected by door to door questionnaires, this paper sets up the spatial and temporal autocorrelation GT coefficient to examine the spatial heterogeneity characteristics of high- and low income groups’ out-of-home activities in a continuous spatiotemporal framework. The factors and different mechanisms influencing the clustering of the activities are discussed to better understand social diversity in post-reform urban China. The results suggest that there is obvious spatial and temporal variation in high- and low income groups’ out-of-home activities, indicating that differing social spaces are not just limited to the macro-static residence-based living space, but also exist in the individual’s daily-activities space. Both high- and low income people have drastically different activity spaces and they may not interact much with each other. This is socially very significant because it means that there is considerable social isolation or segregation for both groups. The results also show that within the same income group there exists a divisive cluster with different formation mechanisms, including the job–housing relationship, the correlation of activity opportunities with those surrounding residential areas and the individual’s ability to access activities (that is, space–time accessibility). Structural transition can also impact on activities choices of various social groups. [ABSTRACT FROM AUTHOR]

It is argued that the competition for land rent gap or surplus is inclined to incur redevelopment. However, there exist various models of redevelopment due to different relationships among stakeholders. In this research, we introduce the framework of collective retention constituted by "power relations" and "path-dependence." We do so in order to explain why collective retention emerged within the scope of collective land redevelopment in the Pearl River Delta, an area where the state began granting collectives land redevelopment rights via a land profit-sharing scheme in 2009. Taking the Panyu district of Guangzhou as a case study, this paper examines how collective retention affects land transformation from rural to urban use in peri-urban areas. It finds that preference discrepancy in land-use change among local state, collectives, and villagers generates significant conflicts in rural renewal process, making the cost to achieve consensus significantly high. Moreover, collectives' path dependence on the rental economy hinders their incentives to engage in village redevelopment. The retention of collective ownership has slowed the process of land use transformation and strengthened landholding within the rentier class. • Collectives retain collective ownership during the process of rural land use transformation. • Preference discrepancy of stakeholders generates significant conflicts of interest in rural renewal. • Collectives' path-dependence on rental economy hinders them to engage in redevelopment. [ABSTRACT FROM AUTHOR]

In this paper, the prospect of low-GWP refrigerants used in solar-driven ejector-compression hybrid refrigeration system was analyzed and evaluated based on the solar radiation data in summer of Beijing and Guangzhou. Prominent environmental friendly alternative refrigerants, including HCFO-1233zd(E), HFO-1336mzz(Z), HFO-1234ze(Z), HCFO-1224yd(Z) and HC-600 were chosen as the working fluids to address the environmental concerns, while HFC-245fa was used as the baseline refrigerant. The hybrid refrigeration system composed of an ejector refrigeration system as the upper stage and a vapor compression system as the bottom stage, respectively. The results indicated that the system with HFO-1234ze(Z) showed the highest COP. HFO-1234ze(Z) was followed by HCFO-1233zd(E) and HC-600, and all of them showed higher COP than that of HFC-245fa. The system with HC-600 needed more electric energy than any other systems, while HFO-1336mzz(Z) consumed the lowest electric power. Meanwhile, the performances of HFO-1234ze(Z) and HFC-245fa systems were further compared. It was found that for both working fluids, the heat load of the condenser (Q e,c), total electric energy consumption (W e) and electric energy of compressor (W com) in August were the highest in Beijing, while in Guangzhou, the highest of them was achieved in September. It was also suggested that the solar radiation had no influence on the relative magnitude of the Q e,c , W e and W com between HFO-1234ze(Z) and HFC-245fa systems. The Q e,c , W e and W com of the system with HFO-1234ze(Z) were higher than those of HFC-245fa by 0.8%, 4.44%, and 3.55%, respectively. [ABSTRACT FROM AUTHOR]

• Deposition reduction of different dust on solar cells by super-hydrophobic coatings was investigated. • The self-cleaning coatings are effective to improve the transmittance and the PV efficiency. • The self-cleaning coating has the best power efficiency improvement performance for the dust C. • The coatings are effective to decrease deposition density of dust from the southern China. This paper aims to examine deposition reduction performance of different types of dust on solar PV cells by the self-cleaning coatings. Four types of dust were obtained from the Powder Technology Inc. USA (Dust A), the Henan province in the central China (Dust B), the Guangzhou city in the Southern China (Dust C) and the sand in the construction site (Dust D), respectively. The micro and macro patterns of particles, the particle deposition density, the transmittance and the output power reduction of PV system after dust deposition were investigated carefully. It was found that the particle deposition density on the solar cell covering glass is obviously decreased by the coating. The deposition density of the sand particles is 36.77% of that on the uncoated glass case, which is the minimum among the four types of dust because of the high Young's modulus and low surface energy of the sand. The self-cleaning coating has the best power efficiency improvement performance for the dust C (about 24.35%), followed by the dust B (about 19.83%) and dust D (about 18.21%). The dust A has the minimum efficiency improvement (about 12.47%) by the super-hydrophobic coating. [ABSTRACT FROM AUTHOR]

For better airport planning and air traffic management, local airport authority in a multi-airport region (MAR) often needs to consider the impacts of competition and collaboration with nearby airports on its own airport traffic. This paper proposed a dynamic spatial panel regression model to test the regional effects on airports in a MAR. The proposed model is applied to four closely situated airports in the Pearl River Delta region (PRD), China, to analyze their interactions, identify the determining factors, and evaluate the impact of these factors on airport capacity. PRD is one of the most prosperous areas in Asia, and competition among the four airports has intensified, due, in part, to the rapid growth of Guangzhou airport and Shenzhen airport. Together with the fact that Hong Kong airport reached 98% of its runway capacity in 2016, it is of great interest to understand the interactions among the airports in this region. The findings show that airport degree, flight frequency, airport capacity utilization, income, population, GDP, and fuel price are significant factors affecting airport's capacity. Furthermore, there is a spatially lagged effect in income and population, and a time-lagged effect in airport capacity, GDP, and fuel price. [ABSTRACT FROM AUTHOR]

• A novel method to examine competition of High-Speed Trains and flights is proposed. • We propose a time window method to examine the competition at a city-pair scale. • We find that HTSs and flights are scheduled differently within one-day circle. • Four markets are identified based on HSTs' and flights' spatiotemporal differences. Scheduling strategies are important to improve network efficiency and optimize time slots for both high-speed train (HST) and air travel. Although many scholars have studied HST and air travel competition from the perspectives of the spatial patterns and travel costs of the two transportation modes, few studies have investigated their potential temporal competition. To fill this research gap, this paper uses a time window method to examine the relationship between HSTs and flights operating between city-pairs. From the perspective of departure time, an analysis was conducted in the overlapping network of HSTs and flights at the city-pair level in China, based on one-day schedules. The results show that (1) HSTs and flights were temporally scheduled differently according to their within-day dynamics, and (2) HSTs and flights experienced fierce competition from 7 am to 9 am on average. Furthermore, the proposed classification method identifies city-pairs in a single-mode dominant market, full competition market, partial competition market, and complementary coordination market. Spatially, 24 city-pairs operating 343 flights with 533 train competitors in one day formed the full competition market with high-frequency schedules, including such city-pairs as Beijing-Shanghai, Guangzhou-Shanghai, and Shanghai-Xi'an. The method to classify city-pairs according to the similarity and diversity of HST and flight schedules may be generalized for allocating time slots for two modes. This work may help to schedule HSTs and flights in future transportation management. [ABSTRACT FROM AUTHOR]

• The aggregated median value of on-road PM2.5 in the morning rush hours was lower than those in the evening. • The influence factors and their spatial patterns in the morning are different from those in the evening. • The spatial-temporal heterogeneity of leading factors will be beneficial to the targeted policies and interventions. Research on the relationship between built environment and PM2.5 has attracted notable attention during the past decades. However, previous studies were less to test the spatial-temporal heterogeneity of on-road PM2.5 and its related factors at micro scale. To this end, collecting high-resolution PM2.5 data by mobile monitoring along different roads in Guangzhou, China, this paper explored the spatial-temporal heterogeneity of the relationship between built environment and on-road PM2.5 during the morning (7–9 am) and evening (7–9 pm) rush hours. Semi-variogram method and geographically weighted regression (GWR) model were utilized to reveal the non-stationarity associations among the large spatial dataset. In terms of temporal heterogeneity, the results showed that the spatial independent radii of on-road PM2.5 were 17 m and 21 m for morning and evening rush hours respectively. The aggregated median value of PM2.5 in the morning rush hours was 34.95 μg/m3, while the evening was up to 55.49 μg/m3. There were more significant factors of street conditions impact on on-road PM2.5 in the morning while more significant factors of land use and centrality that reflecting the cumulative effect of daily human activities with smaller buffer thresholds in the evening. In terms of spatial heterogeneity, GWR models achieved much better performance than the global ones of multivariate regression models with lower AICc, RMSE and higher adjusted R2 , explaining 10–69% of variance across different roads and rush hours. There was a high degree of spatial heterogeneity that the leading factors were different along various roads on rush hours. The results indicated that the policies and interventions should be more targeted to improve the on-road air environment and reduce personal exposure according to the spatial-temporal geographical context. It can be adopted to provide more realistic and practical guides for urban planning and environmental pollution control. [ABSTRACT FROM AUTHOR]