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• Index of recycling sustainability for assessing waste paper recycling. • Integrating methodology of GIS and value chain model. • Historical changes of informal recyclables distribution sites in Beijing. • Value chain of waste paper recycling in Beijing may face challenges in the future. • Policy implications to improve waste paper recycling in Beijing. China established a self-organized and market-driven recycling system, which was dominated by the informal sectors. In recent years, the amount of domestically-recycled waste paper grew slower than expectation in China, which may be resulted from a decline in economic sustainability of current recycling system. For understanding the waste paper recycling system in most cities in China, the economic mechanism remains unclear and the city-level data is extremely insufficient. In this work, an index of recycling sustainability (IRS, benefit divided by cost) is analyzed with a resolution of 1 km2 grid in Beijing City, by adopting value chain and GIS methodology. Five degrees of IRS are defined, from high-degree (IRS > 1.10) to low-degree (IRS < 0.95). Different stakeholders in the informal waste paper recycling system were interviewed to fill the data gap. Results show that: (1) from 2015 to 2018, the informal recycling of waste paper accounted for approximate 80% in Beijing; (2) the number of informal recyclables distribution sites decreased from 27 to 11, and their average distance to the city-center rose from 27.5 km to 40.9 km; (3) in 2015 and 2018, the grids with high-degree IRS accounted for 99.5% and 89.2%, respectively, indicating a sustainable waste paper recycling industry in Beijing; and (4) according to the scenario analysis, if the operating cost rises by 30%, the grids with low-degree IRS accounts for 98.5%, indicating a nontrivial challenges when the recycling cost keeps increasing in the future. Policy recommendations are put forward for a more sustainable paper waste recycling system in China. [ABSTRACT FROM AUTHOR]

With large volume of passengers boarding and alighting through subway platforms, the stations are getting crowded, resulting in drops in the level of service and safety concerns, especially for subway systems operating at capacity during peak hours. Thus, it is crucial for subway agencies to sense changes in travel demand and adjust their management schemes accordingly. In this paper we propose a statistical approach to estimate dynamic passenger flows with automated data. First, we develop a dynamic logistic model for calculating passenger tap-out times, which can be employed to infer passenger flow characteristics at the aggregate level. In addition, a new passenger-to-train assignment model for any subway route is derived based on the dynamic model. Subsequently, we apply an expectation-maximization algorithm to estimate the model parameters with automated fare collection and automated vehicle location data. Finally, a cross-validation method is employed to validate our approach with data obtained from several routes in Beijing subway system in China. Results of 95% prediction intervals indicate the effectiveness of the models and the proposed estimation methods. • Propose a dynamic logistic model for inferring and predicting subway passenger tap-out times. • Apply an expectation-maximization algorithm for model parameters estimation. • Develop a novel passenger-to-train assignment strategy. • No prior distributions of parameters or additional information required in the proposed methods. • Results show good effectiveness of the models and acceptable accuracy of the prediction methods. [ABSTRACT FROM AUTHOR]

When building new airports various strategies for initiating new air routes prominently affect the overall system performance. From a perspective of disruption management, however, very little is known regarding the impacts of different strategies exerted to the resilience of airline networks in a multi-layer system configuration. In this paper, we established a multi-layer China airline network (CAN) using route data from 46 airlines in mainland China and proposed four optimization strategies for adding new routes based on service-oriented perspectives. The geographical traits of the multi-layer CAN was first explored and, taking the Daxing International Airport (a new-built airport in Beijing, China) as a demonstrative example, we then conducted both qualitative and quantitative analyses to investigate the impact of the proposed strategies and their effectiveness of improving network resilience. It is revealed that those strategies have heterogeneous effects on the network performance in terms of meeting passenger demands and balancing overall connectivity at a national strategic level, and the overall resilience of the CAN could be significantly improved under the selected strategy by 59.8% on average. Based on the findings, several managerial and policy implications are put forward and discussed. This paper sheds new lights on resilience-building strategies for service carriers and airport managers and is also of value to regional governments for offering incentives for expanding connections to new destinations. • A comprehensive multi-layer airline network is constructed. • The network consists of 46 layers of sub-networks from mainland China. • Practical strategies are proposed and tested for improving network resilience. • Optimized strategies improve the overall resilience of the multi-layer network by 59.8% on average. • Implications for managing a growing multi-layer airline network are provided. [ABSTRACT FROM AUTHOR]

• This paper is a large scale clinical studies between cytokines and prognosis of Kawasaki disease in China. • The prominent feature of this paper is the large amount of data. • The number of mediators detected in this study is large. Kawasaki disease (KD) is a type of pediatric vasculitis. Ten to twenty percent of children with KD do not respond to initial intravenous immunoglobulin (IVIG) treatment which called refractory Kawasaki disease. If untreated, approximately 15–25% of KD patients have complications. Therefore, it is important to predict whether KD is resistant to IVIG at an early stage. The aim of this study was to determine whether cytokines are predictors of refractory KD in children. We retrospectively reviewed the medical records of 265 children diagnosed with KD who received IVIG within 10 days of fever onset at Beijing Children's Hospital. Refractory Kawasaki disease was defined as persistent or recrudescent fever beyond 36 h after IVIG. Before IVIG and 3 days after temperature normalization following IVIG treatment, the concentrations of cytokines in the serum including interferon gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), interleukin-6 (IL-6), interleukin-4 (IL-4), interleukin-2 (IL-2) and other conventional inflammatory mediators including white blood cells counts (WBC), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and albumin were detected. The patients were divided into 2 groups: IVIG-sensitive group and refractory group. Of the 265 patients, 47 (17.7%) were refractory. After treatment with IVIG, the serum levels of IFN-γ, TNF-α, IL-10 and IL-6 in both groups were significantly lower than those before treatment (P < 0.05). Before treatment, the serum levels of IFN-γ, TNF-α, IL-10 and IL-6 in refractory group were significantly higher than those in IVIG-sensitive group (P < 0.05). There were no significant differences in IL-4 or IL-2 levels between the 2 groups. The results of logistic regression analysis showed that IFN-γ, IL-6, fever duration and serum albumin were independent risk factors for refractory KD. The area under the receiver operating characteristic curve (ROC curve) for IFN-γ was 0.781, and the cut-off value for refractory was 7.37 pg/ml, while the area under the ROC curve for IL-6 was 0.837, and the cut-off value for refractory was 70.13 pg/ml. IFN-γ and IL-6 were independent risk factors for refractory Kawasaki disease in children. KD patients with serum levels of IFN-γ above 7.37 pg/ml and IL-6 above 70.13 pg/ml before treatment were prone to refractory. [ABSTRACT FROM AUTHOR]

Residential mobility has become an increasingly important issue in China, where urban families participate frenetically in the commodity housing market leading to soaring property prices. Applying place dependence approach and logistic regression models, this paper examines the association between residential mobility intentions and place dependence for employment and education in Beijing. The results reveal that people's intentions to move homes are driven by place dependence on the access to high-quality schools for their children, while the dependence for employment is rather weak. The findings indicate children's education has emerged as a new driving force that shapes urban space in contemporary China and therefore should be a focal point for planners and policy makers in urban resource distribution. This paper provides evidences to further our understanding of the high premium of properties that enable access to good schools. The needs for other spatial utilities and sentimental attachment to a place also encourage residential mobility intentions, which deserves further research. • Residential mobility intention was analyzed in Zhongguancun area in Beijing. • Influences of children's education and parents' employment were measured. • Children's education has emerged as a new driving force affecting residential choices. • Place dependence provides a useful lens to comprehend housing mobility in contemporary cities. [ABSTRACT FROM AUTHOR]

In the early morning on December 17, 2020 Beijing time, China's chang'E-5 probe successfully returned to the Earth with 1731 g of lunar samples after completing drilling, shoveling, packaging of lunar soil and scientific exploration on lunar surface. It is the successful completion of the third phase of China's lunar exploration project, namely "circling, landing and returning to the moon". The scientific objectives of CE-5 mission are to carry out in situ investigation and analysis of the lunar landing region, laboratory research and analysis of lunar return samples. This paper analyzes scientific exploration tasks of CE-5 mission conducted on the lunar surface, and carries out the scientific payload system architecture design and individual scientific payload design with the scientific exploration task requirements as the target, and proposes the working mode and main technical index requirements of the scientific payloads. Based on the preliminary geological background study of the Mons Ruemker region which is the landing region of CE-5, the lunar scientific exploration and the laboratory physicochemical characterization of the return samples are of great scientific significance for our in-depth understanding of the formation and evolution of the Earth-Moon system and the chemical evolution history of the lunar surface. [ABSTRACT FROM AUTHOR]

• Proposed bundle pricing model considers unit price of landfill and incineration. • Bundling waste disposal fees can motivate the public to reduce generation of MSW. • Increase in revenue from bundling pricing model can alleviate the capital shortage. • Separate prices for landfill and incineration can promote incineration technology. Considering the various ways of Municipal Solid Waste (MSW) disposal that are currently in practice, this paper proposes a bundle pricing model of MSW disposal in Beijing, China. The bundle pricing model is set according to per capita annual disposable income, per capita annual consumption expenditure and MSW disposal cost based on the cost reimbursement principle and complementarity principle. This paper first estimates the unit costs of landfill and incineration respectively, and then designs three bundling packages according to three different income levels of households in Beijing (low-income households, middle-income households and high-income households). Specifically, based on our bundle pricing model, we propose to charge low-income households (of the average size of 3 persons) MSW fees 5.64 RMB per month, middle-income households 10.16 RMB, and high-income households 20.70 RMB per month. We also discuss and explain how the proposed mechanism can be expected to not only mitigate the capital shortage problem, but also reduce MSW quantity and improve the MSW incineration disposal technology. [ABSTRACT FROM AUTHOR]

Accurate PM 2.5 forecasting provides a possibility for establishing an early warning system to notify the public and take precautionary measures to prevent negative effects on ambient air quality and public health. Considering strong seasonal variation in meteorological conditions, in this paper, a seasonal stacked autoencoder model combining seasonal analysis and deep feature learning is proposed for forecasting the hourly PM 2.5 concentration, named DL-SSAE model. The original data are firstly decomposed into four seasonal subseries according to the Chinese calendar, and then the Kendall correlation coefficient method is employed to search inherent relationships between PM 2.5 concentrations and meteorological parameters within 1-h ahead for each seasonal time series. The inherent relationships of each seasonal subseries are finally extracted, learned, and modeled by different deep neural networks (stacked autoencoders for regression), and the hourly PM 2.5 forecasts are yielded. The addressed model is tested by the dataset collected from three environmental monitoring stations in Beijing, China. The results demonstrate that the proposed model outperforms all other considered models with/without seasonality consideration in this paper. [ABSTRACT FROM AUTHOR]

Abstract Given the ongoing "mobility turn" in social science research, a more comprehensive understanding of segregation is needed. Activity-space-based segregation studies have aroused renewed interests in geography and urban planning research. Most of the existing studies utilized the differences in spatial characteristics of people's actual activity space to identify the segregation among social groups. However, few studies have examined activity-space-based segregation in terms of individuals' potential activity space and the temporal variations in their segregation experiences. This paper aims to help fill these two research gaps by implementing an empirical study in Beijing. We examine the activity-space-based segregation of the residents of different types of housing in a Beijing suburb in terms of both actual activity space and potential activity space. We further investigate the temporal variations of the residents' segregation experiences during a week. A 7-day individual GPS tracking dataset, combined with the activity diary data and the socioeconomic attributes data of 422 participants is used for the study. The major finding is that residents of different types of housing in Beijing do experience activity-space-based segregation, while the characteristics of segregation vary with respect to actual activity space and potential activity space. Also, participants' segregation experiences varies between different days of the week. This paper offers some empirical evidence on enriching the understanding of activity-space-based segregation research as well as improving the understanding about social segregation among the residents of different types of housing in Chinese cities. It also generates some nuanced knowledge for future policy recommendations in a broad context. Highlights • Residents of different housing types in Beijing do experience activity-space-based segregation, while the characters of segregation varies in AAS and PAS. • The residents of affordable housing have both the smallest AAS and PAS on weekdays, which makes them the most isolated group. • With respect to the residents of market housing and institutional housing, they have relatively large AAS on weekdays while having relatively moderate PAS. • As for the residents of resettlement housing, their PAS are relatively large, although their AAS are small. • Significant differences in the extensity of both the AAS and PAS of the residents in different housing types can only be identified on weekdays. In weekends, differences in the extensity of the activity spaces are not significant. [ABSTRACT FROM AUTHOR]

With the development of social economy and health care technology, people are expected to live longer, and the world's population tends to be ageing. As one of the services for elderly people, the concessionary bus travel programme provides a kind of social welfare for elderly people, while peak-hour traffic pressures (e.g., traffic congestion, traffic injuries, and travel discomfort) faced by elderly people have been ignored. This paper attempts to help society create a better travel environment for elderly people by analysing their travel behaviours. Specifically, using household survey data from Beijing, the statistical analysis is used to paint a more detailed picture of daily travel experience of elderly people with regard to departure times, travel purposes, travel mode choices, etc. Then, a nested logit model is employed to interpret travel patterns of elderly people. The results show that the bus plays the most important role in motorized travel of elderly people. Furthermore, the free bus programme has induced only 4.85% of bus travel among elderly people, indicating that the programme has little effect on elderly people's bus choices. Based on the results of the analysis, several options are proposed in this paper to help society adapt to the changing demographics. [ABSTRACT FROM AUTHOR]

Highlights • Explore the self-selection issue from the perspective of households. • Examine how two partners' attitudes affect residential and car ownership decisions. • Husbands' travel attitudes have more influence in these decisions than wives'. • The travel attitudes of two household heads can affect each other's travel behaviors. Abstract Residential self-selection has been acknowledged as a key issue underlining the link between the built environment and travel behavior. Existing studies often implicitly assume that residential choice is a decision of an individual and the influence of intra-household interactions is not considered. In reality, residential choice is a decision often made at the household-level involving more than one household members. Similarly, car ownership is usually a household-level decision incorporating views of different household members. In both cases, the travel related attitudes of more than one household members may play a role in the decision making. In other words, there is an issue concerning residential self-selection (similarly car ownership self-selection): whose self-selection? This paper makes an attempt to probe into this question by examining the self-selection issues concerning residential location choice and car ownership decision from the perspective of households, by incorporating the travel attitudes and travel behaviors of two household heads into an integrated self-selection framework. Data are derived from a household sample survey involving two-day activity-travel diaries conducted in 2016 in Beijing, China. Multivariate modeling results show that household members play different roles in household decisions with travel implications: in general husbands' travel attitudes have relatively more influence in residential choice and car ownership decision than wives'. Nevertheless, wives' travel attitudes have more power than husbands' in explaining the commuting distances of both husbands and wives. Some distinct features of the residential and car ownership self-selections in the Chinese context are also identified and discussed in this paper. [ABSTRACT FROM AUTHOR]

• The Monte Carlo method is used to construct the charging load of EV in the planning area divided into four different vehicles type. • The Prim algorithm is adopted to search for the optimal network layout of energy transmission pipelines. • Proposed collaborative planning modeling promotes the time-of-use electricity price scheme to change the temporal and spatial characteristics of EV charging load. • The growth of EV charging load in the planning area has not increased the investment and operation-maintenance costs of DES equipment, and reduced carbon transaction costs as well as improved economic of system operation. • Simulations are conducted to verify the effeteness of proposed method. Under the dual-carbon goal, the number of electric vehicle (EV) has surged, and the uncertainty of the temporal and spatial characteristics of the load has become prominent, which brings the challenge for higher requirements to the equipment composition of distributed energy station (DES) and performance of station-network. This paper proposes a collaborative planning method for low-carbon DES with networks, which is focusing on the characteristics of EV charging behavior. First of all, based on the quantitative analysis of the temporal and spatial distribution of charging load of four typical types of EV, including private vehicle, public vehicle, taxi and bus, the Monte Carlo method is used to construct the charging load modeling of EV in the region area. In addition, the low-carbon DES is modeled equipped with photovoltaic (PV) and power to gas (P2G) devices, and the Prim algorithm is adopted to search for the optimal network layout of energy transmission pipelines in the region area. Under carbon trading mechanism, aiming at the lowest annualized total cost of the regional station-network, a station-network collaborative planning modeling strategy for the capacity allocation of low-carbon DES with networks is established. Finally, the case study for a project in Beijing China is implemented on MATLAB, to prove the effectiveness of the method proposed in the paper. The time-of-use electricity price scheme changes the temporal and spatial characteristics of EV load. For example, more than 2 MW the EV load can be brought into the valley price range, which reduces the carbon transaction cost and energy purchase cost of DES by 50 thousand yuan almost when peak-valley electricity price difference is close to 1.2 yuan. At the same time, the growth of EV charging load(the penetration rate of EV can reach up to 20%) in the planning area has not increased the investment and operation-maintenance costs of DES equipment. [ABSTRACT FROM AUTHOR]

[Display omitted] • A methodological framework to delineate the provision area for the wind erosion prevention service based on the carrier dynamics of ecosystem service flows; • A computational framework to determine ecosystem service transmission pathways; • Methods to calculate the realized ecosystem service value distribution within the service provision area; • Implications on urban ecological hinterland delineation and precise ecological compensation program design. Many ecosystem service (ES) items, such as the wind erosion prevention service (WEPS), have spatially separated service provision and benefit areas (SPA & SBA), which are connected by directional ecosystem services flows (ESF). Clarifying the specific spatial relationships between the SPA and SBA is of potential scientific and policy importance for such directional flow-conveyed ES. Much of the existing research has focused on the identification of SBA based on a given SPA. However, due to the asymmetry of supply-based and demand-based ESFs and geospatial heterogeneity, this relationship cannot be directly inferred backward to obtain the SPA for a given SBA. In this paper, we propose a methodological framework along with computational methods to delineate the SPA of a given SBA. Our methods feature ESF carrier dynamics-based algorithms to determine the specific path of the ESF which is enabled by an adapted Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model, as well as quantification approaches for evaluating the actual realization of ecosystem services value (RESV) with the support of the Revised Wind Erosion Equation (RWEQ) model. We demonstrate the applicability of our methods with the example of three mega-cities in northern China that are severely affected by the wind erosion problem. The results show that the spatial distribution of wind erosion source areas in the three cities are different, and the SPA based on the trajectory weights shows a decreasing trend from the city center to periphery, with those in the cities of Beijing and Taiyuan mainly concentrated in the northwestern direction, while the high RESV zones in the SPA are mainly concentrated in the desert areas. In the time series, wind erosion affecting these three cities mainly occurred in late April and May. The study provides a methodological and empirical basis for applied ecological analysis including the delineation of the ecological hinterlands of cities, or the formulation of precise ecological compensation programs. [ABSTRACT FROM AUTHOR]

Air quality prediction is a global hot issue, and PM 2.5 is an important factor affecting air quality. Due to complicated causes of formation, PM 2.5 prediction is a thorny and challenging task. In this paper, a novel deep learning model named temperature-based deep belief networks (TDBN) is proposed to predict the daily concentrations of PM 2.5 for the next day. Firstly, the location of PM 2.5 concentration prediction is Chaoyang Park in Beijing of China from January 1, 2018 to October 27, 2018. The auxiliary variables are selected as input variables of TDBN by Partial Least Square (PLS), and the corresponding data is divided into three independent sections: training samples, validating samples and testing samples. Secondly, the TDBN is composed of temperature-based restricted Boltzmann machine (RBM), where temperature is considered as an effective physical parameter in energy balance of training RBM. The structural parameters of TDBN are determined by minimizing the error in the training process, including hidden layers number, hidden neurons and value of temperature. Finally, the testing samples are used to test the performance of the proposed TDBN on PM 2.5 prediction, and the other similar models are tested by the same testing samples for convenience of comparison with TDBN. The experimental results demonstrate that TDBN performs better than its peers in root mean square error (RMSE), mean absolute error (MAE) and coefficient of determination (R2). [ABSTRACT FROM AUTHOR]

China is faced with a serve aging crisis, and the seniors’ long-distance travel is becoming more challenging with the rapid development of high-speed trains. This paper studies the transfer feasibility for elderly passengers passing through specific barriers at high-speed train stations. Questionnaires were distributed at Beijing High-Speed Train Station, with 716 valid samples involved. This paper divides the transfer procedure into seven phases, and proposes various points of interest at each phase with different barriers. These points of barriers are categorized into three major different types: Serious AND Common, Serious BUT NOT Common, and Common BUT NOT Serious. The quantitative relationships between each point of barriers and old travelers’ information have been explored using decision tree and binary logistics regression. As a conclusion, we suggest some recommendations for improving the transfer environment, long-distance mobility, as well as wellbeing of the older adults at high-speed train stations. To the best of our knowledge, we are the first to study the transfer feasibility at high speed train stations for seniors both qualitatively and quantitatively, especially dealing with the complicated transfer procedure. [ABSTRACT FROM AUTHOR]

• This study explores the multi-dimensional features of the round-trip carsharing usage pattern. • Stop time thresholds are determined by considering different rental time. • The impact of price incentives on carsharing usage is discussed. Users' usage of carsharing and parking spaces has obvious peak hours. • Hotspots in the spatial distribution of activities are identified. In recent years, the concept of carsharing is rapidly gaining popularity in China, and the round-trip carsharing has become a common mode. However, few studies have revealed the role of round-trip carsharing in users' travel. In this study, the round-trip GPS data provided by a carsharing company in Beijing, China is used to analyze the users' usage patterns based on their trip chains. Through the extraction and analysis of trip information, all trip chains are grouped into three clusters, each of which has a different usage pattern. Then the consumption features and the shared car pick-up and return time of these three patterns are discussed. Further, the Bayes' rule is used to predict the activity purpose, and the proportion and spatial distribution of different purposes are analyzed. Results reveal that the carsharing program presents multiple usage patterns to meet the different travel needs of users. Price incentives like coupons, discounts, and packages can attract more shared car trips. Users' demand for price incentives increases with longer travel distance and time. Also, users' usage of vehicles and parking spaces has obvious peak hours. The spatial distribution of user activities has distinctly different hotspots. This paper can be beneficial for operators to set a reasonable pricing plan and provide better services. [ABSTRACT FROM AUTHOR]

This study proposes a series of statistical and regression approaches to investigate city-cluster transport connectivity patterns. Three major city clusters in China are selected for this study, namely, the Beijing-Tianjin-Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD) economic zones. Our analyses examine three aspects of city-cluster connectivity patterns: (i) connectivity distribution among cities within the city cluster; (ii) dependence of the non-center city on the center city; and (iii) the impact of improved intra-city-cluster rail connectivity on air-connectivity distribution. First, it is found that the BTH has the most concentrated connectivity among the three city clusters, with Beijing clearly dominating the other cities in every kind of connectivity. The connectivity distributions are more balanced in the YRD and PRD. Second, the calculated "survival connectivity" and regression analyses suggest that non-center cities heavily rely on the center city as the hub to develop their network connectivity. Such a "hub-and-spoke system" helps a non-center city improve total connectivity but reduces its direct connectivity to other cities outside the city cluster. Finally, our regression analysis shows that improved intra-city-cluster rail connectivity further deteriorates the air-connectivity disparity within the city cluster, which occurs because the center city benefits more from the upgraded air-HSR (high speed rail) intermodal connectivity because it can attract air passengers from neighboring non-center cities. Relevant policy implications and suggestions are also discussed in the paper. We believe the proposed statistical and regression approaches can be easily applied to examine city-cluster connectivity in other contexts and countries. [ABSTRACT FROM AUTHOR]

Megacities in China are undergoing transformation in urban functional structure brought on by rapid urbanization and spatial expansion, while private motorization connects disparate functional zones with ever-longer journeys. Policies to control growth of the car fleet while investing in mass public transport, in Beijing and in many other cities, have divided city residents into car users and those dependent on public transport. This paper examines these policies from the transport equity perspective by measuring accessibility disparity between public transport and private car. Cumulative accessibility is measured for each of the two transport modes, while an accessibility equity index (AEI) is developed based on numerical and spatial computation. The recent changes in spatial distributions of population and employment in Beijing are analyzed. Accessibility and AEI are measured using network-based Geographical Information System (GIS) and analyzed quantitatively and spatially. Nine scenarios with different employment location strategies are simulated to analyze their impacts on accessibility and AEI, with clear benefits among the scenarios with regard to accessibility equity for suburban populations. Results suggest that reducing the demand for car use and ownership can be supported through employment spatial redistribution policies, which can be used to raise relative accessibility by public transport. Land use policy can form part of a larger set of spatial and transport policies that includes regulation of the car fleet and public transport development. Such integrated approaches are of particular importance for the present and future megacities of China that are expanding rapidly, with relatively high volume flows on limited movement networks. • Proposed a framework for transport equity assessment through measuring modal and spatial disparity. • Developed an accessibility equity index (AEI) based on numerical spatial computation. • Examined the transport equity of Beijing as a case study. • Applied equity assessment to spatial scenario analysis and policy with equity and efficiency improvement was suggested. [ABSTRACT FROM AUTHOR]

In order to solve the problems of atmospheric pollution and haze caused by traditional coal-fired heating, the promotion and application of clean energy heating methods is urgently needed. The air-source heat pumps are applied in the residential buildings to replace traditional coal-fired heating in Beijing and Tianjin. Limited to the cost and economic conditions, air-source heat pumps are usually installed with the traditional steel radiator. The unreasonable selection and operation of equipment can lead to low energy efficiency of partial load operation. The importance of finding an economical and efficient alternative scheme, therefore, is beyond words. The experimental research and computational fluid dynamics simulation on the performance and air distribution of air-to-air heat pump and air-to-water heat pump under the same operating conditions are done in this paper. The results demonstrate that ATAHP has bigger heating capacity than ATWHP, the decrease of the actual operation COP of ATAHP is 28.30% which is smaller than that of ATWHP by 15.45% with the ambient temperature decreasing from 7 °C to −20 °C. Thus, ATAHP is better than ATWHP at low temperature operation conditions. The temperature and velocity distribution of indoor air with ATWHP is more uniform, but the high speed air with high temperature with ATAHP blows to the head and feet directly. Consequently, the air distribution with ATAHP is more in line with the requirements of thermal comfort. To conclude, ATAHP has better performance and thermal comfort, and ATAHP is more suitable than ATWHP to be applied and popularized in northern China. • ATAHP and ATWHP heating system was tested in an environmental laboratory. • The COP degradation of ATWHP is severe than that of ATAHP in cold conditions. • ATAHP has higher average indoor temperature and better thermal comfort than ATWHP. • ATAHP is expected to be applied and popularized in northern China. [ABSTRACT FROM AUTHOR]

• Explore the land use-travel relationship from a household perspective. • Examine how residential and workplace built environments affect partners' travels. • Land use factors have varied and even contrast effects on partners' travel behaviors. • Land use factors affect husbands' travels indirectly by affecting wives' travels. The linkage between travel and the built environment has received extensive research attention over the past decades. However, the existing studies normally evaluate the built environment effect on travel from an individual-based perspective, neglecting the influence of intra-household interactions. We argue that individuals' travel behavior is derived from the allocation of household tasks and resources (e.g., household vehicles) and the travel behaviors of household members are interdependent. This suggests that the built environment may impact one member's travel behavior indirectly through its influence on others members' travel choices. Thus, examining the travel impact of the built environment needs to consider intra-household interactions. This paper proposes to analyze the land use-travel relationship from a household perspective. We simultaneously examine the effects of the built environments of residential and work locations on married couples' travel behaviors, considering the interrelations between their travels and controlling for both partners' travel attitudes. The empirical study in Beijing, China indicates that the built environment effect on travel is different between partners. Two work environment factors influence the partners' driving behaviors in opposite directions. Moreover, the wife's travel behavior mediates the association between the built environment and the husband's travel behavior. These findings highlight the importance of understanding the land use impact on travel behavior from the household perspective. [ABSTRACT FROM AUTHOR]

Within the context of climate change and population growth, the development of urban agriculture is of great environmental and economic significance in rapidly urbanizing China. Based on the primary survey data, this paper evaluated the carbon footprint (CF) and economic efficiency of urban agriculture in Beijing (China) using the life cycle assessment method (from cradle to consumption approach). Two cases were analyzed and compared considering their differences in on-farm cultivation and off-farm supply chains: a conventional small householder farm that sells its vegetables directly to consumers in a local market, and a large home-delivery agriculture (HDA) initiative that delivers its vegetables to the consumers' home directly. Both cases were equipped with greenhouses with plastic covering but no heating system. The CF of the production, transportation and distribution of 1 kg fresh vegetables was estimated at 0.318 kg CO 2 -eq kg−1 and 0.624–0.652 kg CO 2 -eq kg−1 for conventional and HDA initiative farm, respectively. However, the HDA initiative showed a better environmental performance than the conventional operation when taking economic efficiency into consideration. The CF per unit of profit of HDA initiative (0.093–0.097 kg CO 2 -eq per CNY) was lower than conventional farm (0.111 kg CO 2 -eq per CNY). The lower CF per unit of product weight of the conventional farm was largely attributed to the high yield and the lower CF per unit of profit of the HDA initiative was mainly due to the outstanding economic profitability through income optimization. The major hotspots of CF in both cases were greenhouse plastic films in the cultivation phase (from cradle to farm gate) and transportation in the supply chain (from farm gate to consumption). Simulation of a switch to biodiesel instead of gasoline and diesel in combination with the replacement of current fossil-fuel-dominated electricity by hydro-powered electricity resulted in 20.0–21.8% reduction in the total CF. By identifying the CF hotspots of two farm cases, particular inputs and activities can be targeted for adjustment in order to effectively reduce the CF of urban agriculture in Beijing. [ABSTRACT FROM AUTHOR]

From 1990 to 2017, the number of vehicles in China increased sharply from 5 million to 310 million, and vehicle emissions became one of the major sources of air pollution. Among the main sources of PM 2.5 in Beijing, the contributions from vehicle sources increased from 5.6% (2000) to 31.1% (2012) to 45% (2017). In 2010, the CO, hydrocarbon (HC), NO x , and particulate matter (PM) emissions of yellow-label vehicles (YLVs) accounted for 46.1%, 47.9%, 63.1% and 86.1% of the total emissions from on-road vehicles. In recent years, China has been implementing a YLV scrappage subsidy policy to control air pollution, and this policy has cost several hundred billion yuan nationwide. However, China has not evaluated the costs and benefits of the policy. Many people question whether the YLV scrappage subsidy policy is worthwhile, but all the stakeholders involved complicate the process of accurately evaluating the true value of the policy. In this study, we evaluated and compared the costs and benefits of the policy in the Beijing-Tianjin-Hebei (BTH) region based on 1.362 million YLVs from 2008 to 2015. Because of the implementation of the policy, the PM 2.5 , PM 10 , NO x , CO and HC emissions in the BTH region decreased by 16.46, 18.12, 174.44, 669.11, and 91.64 kt, respectively, in 2008–2015. The results show that the policy played an important role in reducing pollutant emissions and improving environmental quality in the BTH region. The costs, benefits, and net benefits of the policy were 13.69, 34.03, and 20.34 billion yuan , respectively. The cost-benefit ratio in the BTH region was 1:2.49; at the city scale, Beijing ranked first (1:7.27), and the cost-benefit ratios of Tianjin and Hebei Province were 1:2.06 and 1:1.14, respectively. Of the 13 cities in the BTH region, Beijing had the highest net benefits, amounting to 16.43 billion yuan , while Handan City has the lowest net benefits, amounting to −0.58 billion yuan. The results may provide scientific support for the promotion of older vehicle and diesel vehicle scrappage subsidy policies, the development of cost-benefit analysis (CBA), and effective environmental decision-making in China. • Based on net number of scrappage YLVs, net benefits of the policy are calculated. • This paper estimates costs and benefits of the policy based on 1.27 million YLVs. • The costs, benefits, and net benefits are 13.69, 34.03, and 20.34 billion yuan. • The results help China promote vehicle scrappage subsidy policy on a large scale. • The results promote the development of the cost-benefit analysis in China. [ABSTRACT FROM AUTHOR]

This paper examines residents' walking and biking patterns for food shopping in China and the influence of neighborhood form and market characteristics on effective walk/bike catchment areas of food markets. Based on 1417 resident surveys at 15 food markets in three neighborhoods in the city of Beijing, we found that residents rarely shop at the nearest food stores and prefer larger farmer's markets and supermarkets instead. And they travel in much shorter distance compared with residents in the western cities. An ordinary least squares regression analysis reveals that, after controlling for the effect of personal socioeconomic and trip characteristics, traditional neighborhoods with dense street networks, mixed land uses and ample tree shades present the largest walk/bike catchment area, followed by enclave neighborhoods and superblock neighborhoods. In addition, markets with larger size, ground-level and adjacency to a park are significantly associated with longer walking and biking distances. • Residents rarely shop at the nearest food stores and prefer farmer's markets and supermarkets. • Traditional neighborhoods present the largest walk/bike catchment area, followed by enclave and superblock neighborhoods. • Markets with larger size, ground-level and adjacency to a park increase the walking and biking distance for food shopping. • Some personal characteristics and trip factors also affect the walking and biking distance. [ABSTRACT FROM AUTHOR]

The urban heat island effect in Beijing is significant, which has become a serious environmental problem posed to Beijing citizens. As an important measure to alleviate the urban heat island effect, cool roof is recommended in relevant Evaluation Standard for Green Building of China. In order to elicit policy implications, this paper investigates Beijing residents' willingness to pay for promoting cold roofs to alleviate the urban heat island effect and its determinants. This research applied double-bounded discrete choice format and face to face interview to elicit public's willingness to pay. 841 Beijing households were randomly selected and interviewed. For 242 (29%) respondents refuse to pay, the spike model was introduced to process the data for it has been proved to outperform the conventional model in dealing with zero responses. The average annual willingness to pay was computed as 1510.854 Chinese Yuan, which is 220.562 US dollars per household. In addition, In terms of the determinants of residents' willingness to pay, other than conventional demographic characteristics, we added and estimated covariance with regard to environmental knowledge and the theory of planned behavior. The result indicated that social norm, perceived behavior control, and previous knowledge of urban heat island effect and cool roof are statistical significantly related with residents' willingness to pay. This research suggests that timely information disclosure with regard to urban environment management and pro-environment education are urgently needed in promoting public participation in alleviating the urban heat island effect. • Willingness to pay for cool roofs for mitigating urban heat island effect is estimated. • The annual mean willingness to pay 1510.854 Chinese Yuan. • TPB theory and environmental knowledge can greatly explain pro-environment behavior. • Government credibility and education is important in promoting public participation. [ABSTRACT FROM AUTHOR]

• The community livability evaluation is quantitative, practical and fine-grained. • The evaluation criteria span dimensions of environment, traffic and population. • Remote sensing, surface observation and geospatial big data are used. • Most communities are distributed within the central and marginal urban areas. • Communities in urban area tend to have robustly high livability. Effective evaluation of community livability is in urgent need to avoid increased livability at the expense of sustainability. However, studies concerning community livability evaluation were still conceptual, qualitative or conducted at city or regional scales. The availability of abundant, fine-grained, and multi-source data in the big data era laid the foundation for comprehensive livability evaluation at much finer scales. This paper proposed a quantitative and practical method for up-to-date livability evaluation at individual community scale in China. Nine evaluation criteria were identified spanning dimensions of environment, traffic, convenience, and population. These criteria were calculated respectively from remote sensing, surface observation and geospatial big data. The Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) was applied for community livability evaluation, and the uncertainty and sensitivity of evaluation results were assessed. The livability evaluation in the case study area of Haidian District, Beijing, China demonstrated the practicality and effectiveness of the framework. A total number of 1242 communities in Haidian District were evaluated. Communities in urban area were generally associated with higher evaluation scores and lower uncertainties than those in rural area. The careful selection of criteria weights with high sensitivity, i.e., green space coverage within community and driving time to schools, can potentially significantly reduce the uncertainty of the livability evaluation. The community scale livability evaluation is expected to bridge the gap between theoretical concepts and practical implementations of livability evaluation, and enables the development of more effective and locally specific regulations and policies to improve community livability. [ABSTRACT FROM AUTHOR]

Research has shown, that the replacement of conventional vehicles (CVs) by electric vehicles (EVs) can reduce urban heat island intensity (UHII). This leads not only to a more comfortable climate during summer but also to a reduction of carbon dioxide emissions from the vehicles themselves and to a reduction in the need for air conditioning (AC) and associated emissions. The current study examines to what extent a range of different mobility concepts, can lead to a reduction in urban heat island intensity and carbon dioxide emissions in the city of Beijing, China. For this purpose, the impact that electric vehicles fuelled with the average energy mix, hydrogen vehicles (HyVs) fuelled with hydrogen from electrolysis from the regular energy mix, HyVs fuelled with hydrogen produced through wind power, energy efficient CVs, EVs fuelled with wind power and energy efficient metro light railway (metro) travel have on summer heat island intensity (SHII) and CO 2 -emissions is analysed. The lowest SHII mitigation effect was found for a replacement of CVs with fuel efficient diesel cars while hydrogen cars that are fuelled with hydrogen generated from the average electricity mix even leads to higher SHII and higher CO 2 emissions. The largest SHII mitigation effect was found for a scenario where conventional vehicles are replaced with energy efficient metro travel. The CO 2 saving potential is highest for EVs which are powered with electricity generated from wind turbines, closely followed by HyVs that are fuelled with hydrogen generated from electrolysis of water using wind electricity. The paper helps policymakers and consumers to make the right choices when it comes to environmentally friendly mobility options. • Summer heat island intensity (SHII) is mitigated through different mobility choices. • CO 2 reduction by over 12,000 tons/day is possible through reduced usage of air conditioning. • Energy efficient public transportation leads to the highest mitigation of SHII and CO 2 levels. • Electric and hydrogen cars fuelled with renewable energies mitigate SHII and CO 2 levels. • Hydrogen cars fuelled with non-renewable energies lead to higher SHII and CO 2 levels. [ABSTRACT FROM AUTHOR]

Abstract This paper studies the potential application of ventilation systems with thermal energy storage (TES) using phase change materials (PCMs) for space cooling in air conditioned buildings during the summer. A south-facing middle office room located in Beijing, China is considered for study. To simulate the indoor thermal environment and energy consumption of the room, a dynamic computational model which consists of a building thermal model, a heat transfer model of a TES unit and the performance curve of an air conditioner (AC) is built and validated. The time lag to switch on AC, the cooling energy provided by AC, PCMs and structure elements, the runtime of AC and fan, and the overall electricity energy consumption of the TES system are calculated and compared to a base case without night ventilation (NV) and a case with conventional NV system. The results indicate that the higher the indoor temperature set point, the higher the cooling energy contributions of PCMs and structure elements and therefore the higher the potential application of the TES system. The electricity energy saving ratio (ESR) by using the TES system over the base case is found to be 16.9%–50.8%, while that against the conventional NV system is 9.2%–33.6%. Highlights • Potential of ventilation systems using PCMs in air conditioned offices is studied. • A dynamic computational model is developed and validated. • Higher indoor temperature set point has higher potential application of the system. • ESR over the base case without night ventilation is 16.9%–50.8%. • ESR against the conventional night ventilation system is 9.2%–33.6%. [ABSTRACT FROM AUTHOR]

In China, overlapped routes from multiple bus lines are widespread. Some buses are overcrowded while others have few passengers. The goal of this study is to reduce onboard passenger crowding without wasting bus capacity. This paper examines an extended multiple-depot vehicle scheduling problem (VSP) with multiple vehicle types. First, a bi-objective integer programming model was created. The trade-off between operating cost and passenger travel cost was established and the crowding cost due to different vehicle sizes was especially considered. Then, the capacity restraint incremental assignment algorithm and a vehicle scheduling method with multiple vehicle types were developed to find Pareto-optimal solutions that considered vehicle capacity constraints. Finally, the proposed methodology was validated using a real-world transit network in Beijing, China. The optimization results from about 1.18 million bus card swiping records show that our model and solution algorithm can effectively reduce the passenger crowding cost and avoid the waste of transport capacity. [ABSTRACT FROM AUTHOR]

The application of a gas-fired CCHP can effectively solve seasonal shortages of electricity and gas. To realize providing investment decision for gas-fired CCHP in Beijing, first, the paper analyses the status of gas-fired CCHP systems in Beijing; second, the technology structure and economic benefits of gas-fired CCHP systems are analyzed; third, a technical economic evaluation framework of a gas-fired CCHP is built, which analyses the cascade utilization and energy saving effects of a heat and power energy system in a gas-fired CCHP system. Analysis of the gas-fired CCHP system economy and the factors that influence the economic performance is also performed, as well as a sensitivity analysis. In addition, the paper also analyses an energy efficiency sharing model of a cooling, heating and power system that considers the grid enterprises’ economic efficiency. Finally, an empirical analysis of a trigeneration project control center in the Beijing Gas Group is carried out. Research results show that gas-fired CCHP system is good to both customers and beneficial, fuel price and electricity price will influence revenue of Gas-fired CCHP system greatly, a reasonable energy efficiency sharing ratio will help to the recovery of investment in Gas-fired CCHP. [ABSTRACT FROM AUTHOR]

Agriculture in peri-urban areas is prone to dynamic changes due to urban influences. Previous studies have explored the impact of urban growth on peri-urban agriculture (PUA), but the active responses of the agricultural sector are rarely examined. This paper investigates recent agricultural development practices in peri-urban Beijing and explores approaches to agricultural transformation in the rapid process of urbanisation. The investigation finds that high-tech precision agriculture, down-stream processing and agro-tourism have emerged as major forms of PUA in Beijing. It also uncovers that the PUA developments are not only economically appealing, but also socially inclusive and environmental friendly. The findings contribute to a better understanding of PUA progress in China. The paper suggests policy implications in facilitating integrated development between urban and rural sectors, which would help improve economic development, spatial planning and local governance in peri-urban areas. [ABSTRACT FROM AUTHOR]

The Chinese Accelerator Driven Sub-critical system (C-ADS) Injector-I is designed and constructed by the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences (CAS) in Beijing, China. The test cryomodule (TCM), housing two 325 MHz spoke cavities and two solenoids and operating at 2 K, has been designed, assembled and commissioned since the beginning of 2012. The C-ADS Injector-I linac with the TCM successfully accelerated the proton beam to 3.68 MeV with the peak current of 10.1 mA in pulse mode. It is the world's first prototype of spoke cavity cryomodule with beam, and is an important step in the qualification of the cryomodule before series productions. This paper describes the detail of the design, operation and thermal performances of the prototype cryomodule. The analysis takes into account the heat loads of the main components (support posts, multilayer insulation and cavities) at various cryogenic temperature levels. The estimated heat loads of the cryomodule have been compared with the available experimental measurements, and the cryogenic deformations by simulation is verified by the experimental measurements by the wire position monitors (WPMs). The operation experiences including the cool down, alignment and heat load measurement are reported. • The 325 MHz spoke cavity prototype cryomodule has been designed, assembled and commissioned. • The thermal performance of the bottom-supported cryomodule has been proved firstly worldwide. • The cryomodule can be in a stable operation at 2 K and 31 mbar with beam. • The operation experiences including the cool down, alignment and measurement of heat loads are reported. • The linac with cryomodule had been accelerated successfully to 3.68 MeV@10.1 mA in pulse mode. [ABSTRACT FROM AUTHOR]

This paper studies the impacts of congestion pricing and reward strategies on automobile travelers' morning commute mode shift decisions using stated preference travel mode choice data of over 1000 automobile travelers collected in Beijing inner districts. To address the complex impacts of these strategies on automobile travelers, a stage-based model framework is developed to analyze their mode shift decision-making process (whether they will shift from using automobile to public transit, biking or walking or continue using automobile) under these strategies. Four multilevel structural equation models are created for participants using automobile (personal vehicle and/or taxi) as the most common mode of transportation (hereafter referred to as "more habitual automobile travelers") and those using automobile as second most common mode (hereafter referred to as "less habitual automobile travelers") under each strategy. Model estimation results show that the impacts of latent psychological factors on mode shift decisions under congestion pricing and reward strategies are significantly different between more and less habitual automobile travelers. The results also show that congestion pricing strategies are more effective than reward strategies in promoting mode shifts among more habitual automobile travelers, while the opposite is observed for less habitual automobile travelers. This study provides insights for designing congestion pricing and reward strategies and illustrates the importance of developing complementary modules that target numerous factors in different stages of the mode shift decision-making process to effectively promote mode shifts from automobile to sustainable travel modes in China. [ABSTRACT FROM AUTHOR]

The growth curves of fractal dimension of urban form take on squashing effect and can be described by sigmoid functions. The fractal dimension growth of urban form in western countries can be modeled by Boltzmann's equation and logistic function. However, these models cannot be well applied to the fractal dimension growth curve of Beijing city, the national capital of China. In this paper, the experimental method is employed to find parametric models for the growth curves of fractal dimension of Chinese urban form. By statistical analysis, numerical analysis, and comparative analysis, we find that the quadratic Boltzmann equation and quadratic logistic function can be used to characterize how the fractal dimension of the urban land-use pattern of Beijing increases in the course of time. The models are also suitable for many cities in the north of China. In order to convert the empirical models into theoretical models, we attempt to construct a model of spatial replacement dynamics of urban evolution, from which the logistic model of urban fractal dimension growth can be derived. The models can be utilized to predict the rate and upper limitation of Chinese urban growth. In particular, the models can be employed to reveal the similarities and differences between the fractal growth of Chinese cities and that of the cities in western countries. • The squashing effect of limit values of fractal dimension leads to sigmoid curves. • Urban fractal dimension growth curves can be modeled by quadratic Boltzmann equation. • Quadratic Boltzmann equation can be reduced to a quadratic logistic function. • Fractal dimension growth curves of urban form fall into two types. • Fractal dimension growth curves indicate two types of spatial dynamics of cities. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the potential expansion and impacts of Electric Vehicle (EV) market in Beijing, China at the micro level with an agent-based integrated urban model (SelfSim-EV), considering the interactions, feedbacks and dynamics found in the complex urban system. Specifically, a calibrated and validated SelfSim-EV Beijing model was firstly used to simulate how the EV market might expand in the context of urban evolution from 2016 to 2020, based on which the potential impacts of EV market expansion on the environment, power grid system and transportation infrastructures were assessed at the multiple resolutions. The results suggest that 1) the adoption rate of Battery Electric Vehicle (BEV) increases over the period, whereas the rate of Plug-in Hybrid Electric Vehicle (PHEV) almost remains the same; Furthermore, the so-called neighbour effects appear to influence the uptake of BEVs, based on the spatial analyses of the residential locations of BEV owners; 2) the EV market expansion could eventually benefit the environment, as evident from the slight decrease in the amounts of HC, CO and CO 2 emissions after 2017; 3) Charging demand accounting for around 4% of total residential electricity demand in 2020 may put slight pressure on the power grid system; 4) the EV market expansion could influence several EV-related transport facilities, including parking lots, refuelling stations, and charging posts at parking lots, in terms of quantity, layout and usage. These results are expected to be useful for different EV-related stakeholders, such as local authorities and manufacturers, to shape polices and invest in technologies and infrastructures for EVs. [ABSTRACT FROM AUTHOR]

Abstract Agricultural nonpoint source pollution (NPS) is the main water-use impairment in the upper watershed of the Miyun Reservoir in Beijing, China. Selection and placement of best management practices (BMPs) in heterogeneous watersheds, requires a multi-objective optimization framework to identify the most cost-effective conservation strategy to achieve desired water quality goals. In this paper, a novel optimization methodology was developed, utilizing a BMP database that includes BMP reduction efficiencies and costs, using a multi-objective sorting genetic algorithm (NSGA-II, nondominated sorting genetic algorithm-II) combined with the Soil Water and Assessment Tool (SWAT) served as the NPS watershed model. Cost-effectiveness curves (optimal fronts) between pollutant reduction and total net cost input were obtained for the upper watershed of Miyun Reservoir. The optimal combination of BMP, which include a combination of conservation tillage, careful timing of 30% less fertilizer application, contour planting, and use of a 10-m edge-of-field buffer strip, indicate that the least costly scenario reduced total nitrogen (TN) and total phosphorus (TP) loads by 33% at a cost of 1.02 × 106 China Yuan. The cost-effective scenario reduced TN and TP loads 44% and 68% at a cost of 2.52 × 107 and 5.64 × 107China Yuan. The greatest reduction scenario reduced TN and TP loads 55% and 76%, respectively, at a cost of 2.01 × 108 and 2.48 × 108 China Yuan. Watershed with poultry operations, required a 30% reduction in number of birds, along with a 30% reduction in the amount of manure applied was needed to achieve water quality goals. Use of the coupled BMP optimization model can assist the policy makers achieve a cost-effective implementation of best management practices to mitigate agricultural nonpoint sources at a watershed scale. Highlights • Multi-objective optimization model for the selection and placement of BMPs for nonpoint source pollution control. • Cost-effectiveness analysis for single and combination BMPs at watershed scale. • Dynamic database were development to achieve the auto-simulation of SWAT model. [ABSTRACT FROM AUTHOR]

Abstract Public rental housing (PRH) exits exert a profound influence on turnover rates, which further impact the public housing principles of fairness and efficiency. However, very few studies have attempted to investigate the tenant's barriers to exit PRH units in Chinese studies. In this paper, using data drawn from a randomly sampled survey of tenants in Beijing during the March 2017, we employ structural equation modeling (SEM) to examine the factors influencing tenant's barriers to exit. We find that housing availability is the most influential factor in determining the tenant's barriers to leave PRH, and residential satisfaction is also considered as a motivation against PRH exits. In addition, residential satisfaction transfers the impact of tenant's perceptions of housing and neighborhood to exit barriers. Especially, the effects of housing availability on exit barriers are higher in some groups, such as elderly, high income households, large-sized families and respondents with long spell of residence. Any program aimed at getting tenants to leave public housing sector needs to reduce their barriers to access to the private rental market and take into consideration the various characteristics of the tenants. Highlights • Explored the determinants of tenants' barriers to exit public rental housing in Beijing, China. • Housing availability is the most influential factor in determining the tenant's barriers to leave public rental housing. • Residential satisfaction transfers the impact of tenant's perceptions of housing and neighborhood to exit barriers. • Effects of housing availability on exit barriers are higher in some families. [ABSTRACT FROM AUTHOR]

Abstract Chinese energy consumption structure has been dominated by coal for a long time, which makes China facing serious environmental problems. To achieve the target of CO2 emission reduction, a carbon emission trading (CET) market and promoting the development of new energy should be worthy choices. The issues of dynamic linkages and spillover effects between the CET market, the coal market and the stock market of new energy companies (NEC) are important topics for studies. The paper applies a VAR(1)-DCC-GARCH(1,1) model and a VAR(1)-BEKK-AGARCH(1,1) model to obtain the following conclusions: (1) There exists significant time-varying correlations and long-run persistence of shocks to the DCCs between Beijing CET market, the coal market and the stock market of NEC, and the coal market and the new energy stock market have higher volatility persistence; (2) There is a bi-directional spillover effects between the coal market and the stock market of NEC, which is consistent with the results of the Granger causality; (3) The optimal weight is 82.65% for new energy stock and 17.35% for coal. The optimal hedge ratio is 49.98% for coal, while the optimal hedge ratio is 17.34% for new energy stock. Highlights • There are significant time-varying correlations and long-run persistence of shocks to the DCCs between three markets. • There is a bi-directional volatility spillover between the coal market and the new energy stock market. • The optimal weight is 82.65% for new energy stock and 17.35% for coal. • The optimal hedge ratio is 17.34% for new energy stock and 49.98% for coal. [ABSTRACT FROM AUTHOR]

Highlights • We investigate the weather's impact on school commute mode choices in Beijing, China. • A large survey of middle school commutes is adopted, containing 97,427 observations. • Multinomial probit and multinomial logit models are estimated and compared. • The air quality index has a significant impact on school commute mode choices. Abstract Weather conditions have been recognized as important factors affecting school commute mode choices. This paper aims to explore the modal shift of middle school commutes with respect to the variation in weather-related variables, with empirical emphases on the situation in Beijing, China. Data from the latest Beijing School Commute Survey (2014–2015) were adopted, and multinomial probit (MNP) and multinomial logit (MNL) models were developed. The modeling results are in favor of the MNP model because it has better statistical performance. Weather-related variables, including sky condition, wind speed, highest temperature, humidity, air quality index (AQI), and some interaction terms, were found to have a significant impact on students' commute mode choices. Based on these models, an empirical sensitivity measure was defined as the expected percentage change in the probability of choosing each mode with respect to an order of magnitude change in the influential factors. Most of the results are in line with those of previous studies, and some unique results reflect features of Beijing. For example, on days with extremely poor air quality, students are more likely to turn to public transport rather than use a car from active transportation modes. This is probably due to the special urban traffic regulations that restrict household car ownership and car travel in Beijing. These findings could have implications for promoting active transportation for students and serve as references for policymakers and planners. [ABSTRACT FROM AUTHOR]

Highlights • The increases of commuting CO 2 emissions are several times larger than the urban size, population, and economics' developments. • Metro services reducing commuting CO 2 emissions near the metro stations is not statistically significant, possibly because the proportions of car users near the metro stations are similar to the two cities' average levels, which is caused by their higher household income and the longer travel time using the metro. • In Beijing, there are the smallest commuting CO 2 emissions in the outer suburbs due to job-housing balances, short distance and large percentage of non-motorized mode uses while the largest commuting CO 2 emissions in the inner sprawl suburbs due to car trips with long distance. Abstract To understand the changing relationships between commuting CO 2 emissions (CCE), travel behavior and urban forms, this paper provides a comparative study between the typical Chinese cities of Beijing (more developed) and Xi'an (rapidly developing). Further, the effects of metro services on reducing CCE were explored, and comparative analysis on CCE between the inner sprawling suburbs and outer suburbs was conducted. It was found that: (i) the increases in CCE are several times larger than the increases in urban size, population, and economic developments; (ii) metro services reducing CCE near metro stations is not statistically significant, maybe because the proportions of car users near the metro stations are similar to the two cities' average levels, which is caused by their higher household income and the longer travel time using the metro; (iii) in Beijing, there are smallest CCE in the outer suburbs due to job-housing balances, short distance and large percentage of non-motorized mode uses while largest CCE in the inner sprawl suburbs due to car trips with long distance. These findings indicate that to cope with the rapidly increasing CCE, more attention should be paid to developing strong industry and real-estate simultaneously; the improvement in the feeder bus and public bicycle systems should also be reinforced to reduce the total travel time of metro users; and satellite cities with job-housing balance are greatly needed. The implications will benefit efforts to reduce CCE and mitigate global climate change, and they also provide empirical evidence and reference values for other global cities. [ABSTRACT FROM AUTHOR]

Highlights • The relationship between commuting behaviour and congestion satisfaction are significant. • Semi-parameter model results are robust. • Heterogeneous effects on perceived satisfaction about congestion across social-spatial gradients. Abstract Megacity growth in developing countries suffers from heavy congestion, which undermines satisfaction as experienced by local residents. Drawing on a large scale individual survey in Beijing, this paper explores the social-spatial differentiation of urbanites' satisfaction perceptions about congestion by comparing residents with various motorized commuting modes including car, shuttle bus, and public transit. The results show that shuttle bus commuters are significantly associated with better satisfaction perceptions about congestion than other commuting mode users. We find that perceived wellbeing implications vary with demographic characteristics and transport accessibility characteristics. Findings from this study suggest the importance of considering neighborhood built environment into the design of land use and transport policy aiming to enhance commuters' subjective experiences towards congestion. [ABSTRACT FROM AUTHOR]

Highlights • The first city-level building energy efficiency benchmarking system for China. • A model considering the influence of operation parameters on energy consumption. • A systematic methodology of building energy benchmarking is proposed. • The model is a valuable analysis support tool for building energy managers. Abstract The city-level public building energy efficiency benchmarking system has an important guiding value for building energy-saving work, especially for Beijing, with its high energy-consumption density and both long heating and air-conditioning periods. This paper analyzed the characteristics of large-scale office buildings in Beijing and gives a detailed description of the process of establishing a public building energy efficiency benchmarking system for large-scale office buildings in Beijing, China, including data investigation and verification, Energy Usage Intensity(EUI) calculation, determining independent and dependent variables, developing and testing the benchmarking model, and deriving the benchmarking rating table. Then the first city-level public office building energy efficiency benchmarking system in China is established based on 88 large-scale office buildings in Beijing. The results showed that the model's performance index R2 is 0.667 and gives a good representation. The process has a strong potential for replication for other cities in China and even for a national energy-consumption evaluation system. [ABSTRACT FROM AUTHOR]

Active faults in urban have a potential damage to citizens, because they can induce not only earthquakes, but also damage pavements, utilities, homes, businesses, factories and other manmade structures because of the slow, secular and differential slippage. Consequently, the researches of detecting active faults are of great significance. This paper proposes a set of geophysical methods to detect active faults by an example in Beijing, including gravity, controlled source audio-frequency magnetotellurics(CSAMT), seismic reflection, DC resistivity and paleomagnetism (Natural remanent magnetization in rocks) to locate faults and discuss their activities. In proposed methods, gravity interpretation helps us obtain the distribution and characteristics of buried faults beneath the plain, the results of CSAMT, seismic reflection and DC resistivity reveal features and characteristics of faults from the deep to shallow part; paleomagnetism associated with radiocarbon dating help us analyze the fault slip rate; 3D seismic reflection interpretation shows the structure of two faults in the three-dimensional subsurface and the interaction of each other. Also, a few acquisition parameters, data processing methods and significant suggestions are mentioned. [ABSTRACT FROM AUTHOR]

Beijing, the capital of China, has experienced rapid industrialization, urbanization and motorization in recent decades. Consequently, air pollution in Beijing, especially fine particulate matter (PM 2.5 ) pollution, has gradually become a severe environmental issue, due to the continuing growth in energy consumption and the resulting multiple pollutant emissions. In response to the increasingly serious PM 2.5 pollution, Beijing's government implemented a series of policies, measures and regulations on air pollution prevention and control and took some concrete actions to improve air quality. In this paper, firstly, we summarize China's ambient air quality standards, China's policies and regulations on air pollution prevention and control. Secondly, we illustrate historical evolution and current status of air pollution in Beijing. Finally, we introduce control measures and actions in Beijing and its surrounding areas. The paper aims to help environmental scientists and policy makers around the world understand the past and current air pollution in Beijing and control strategies and actions taken by Beijing's government. [ABSTRACT FROM AUTHOR]

The development of electric vehicles (EVs) is expected to play an important role in achieving the emission reduction targets in the transportation sector by many countries and regions, including China's dual carbon goals. A bottleneck to the mass roll-out of EVs is the limited charging facilities. This paper considers the planning of charging facilities for a new developing area in a metropolis, and an optimization model for charging station planning based on the dynamic transportation system is proposed. The proposed model is developed using an objective framework that considers the spatio-temporal characteristics of EV charging demand in order to minimize the overall cost while the constraints from suppliers and drivers are met. The Voronoi diagram is used to determine the final service boundary of each charging station, and the effect is verified in the planning of charge stations for the Yizhuang new town in Beijing. The case study confirms that the proposed method can optimize the charging facilities that fit well with the traffic network conditions. Furthermore, it is shown that the charging demand varies in accordance with the population density and regional functionality in different areas. [ABSTRACT FROM AUTHOR]

Demand-side decarbonization and electrification promote a strong coupling between electric vehicles (EVs) and buildings. From a building-centric perspective, this paper established a survey-based simulation platform for charging system design, which supports annual simulations with a 15-min interval. Field survey data of private vehicles in two office buildings located in Beijing (a metropolis) and Ruicheng (a county in China) were used as inputs and for validation. The platform was applied to analyze workplace charging and give suggestions for charging system design. First, the city size greatly influences vehicle behavior and charging demands. This study indicates an unusual double-peak charging demand on weekdays in the county case due to different vehicle behavior from the urban cases. Second, slow charging at workplaces can almost meet the intra-urban travel demand of private EVs. Specifically, chargers with a rated power of 3–4 kW can achieve a guarantee level of EV use of SOC 0.999 = 20%. Third, the low solar self-consumption rate of current PV charging systems (generally 18%∼42%) mainly results from significant PV surpluses on weekends and in summer. These findings emphasize building-centric planning of EV-related infrastructures and proper charging strategies for energy interaction between EVs and buildings. [Display omitted] • Electric vehicle (EV) behavior is investigated from a building-centric perspective. • A simulation platform is developed for charging system design (τ = 1 yr, Δ τ = 15 min). • City size greatly influences vehicle behavior and charging demands. • Slow charging at workplace can meet the intra-urban travel demand of private EVs. • PV surpluses on weekends and in summer result in low solar power self-consumption. [ABSTRACT FROM AUTHOR]

Despite massive new town development in megacities in China, none of the prior studies examined commuting disparities of residents of different income groups living in various types of new towns. Based on established literature on urban structure and commuting and income disparities in commuting, this paper has examined the roles of income and new town types in commuting distance, mode, and time differences. Based on Beijing's new town development context, we categorize its six major new towns into residential, national park-driven industrial, market-based industrial, and satellite new towns. Using descriptive analysis and regressions on 595 new town residents, we find that high-income commuters tend to have longer commuting distances and times and are more likely to drive to workplaces. Those living in the residential new town tend to have longer commuting distances and times. Results also show the transportation resource differences in different types of new towns. Those living in the residential new town are more likely to commute by public transit. Results also show the transportation difficulties for low-income residents who live in satellite towns. Though high-income commuters living in those towns have significantly longer commuting distances, they do not necessarily have longer commuting times than low-income people living in these towns. This study has several implications for future research and policy implications for new town development in China and other transit-dependent cities in Asia and Global South. • This paper examines commuting disparities across different types of new towns and income groups in Beijing. • High-income commuters tend to have longer commuting distances and times and are more likely to drive. • Those living in the residential new town tend to have longer commuting distances and times. • Those living in the residential new town are more likely to commute by public transit. • Results also show the transportation difficulties for low-income commuters living in satellite towns. [ABSTRACT FROM AUTHOR]

In previous urban planning research, the fine-grained population was considered a crucial factor. However, this population, which is generated from census data, represents only the number of people who live in a region. This static figure cannot indicate the underlying number of people and their temporal variation. Therefore, any decision-making based on the static population may be separated from reality. To overcome this difficulty, in this paper, the urban crowd flux is initially proposed and defined as the number of individuals flowing into or out of a region per unit time interval. Then, the urban crowd flux is estimated using an approach of human trajectory gridding reconstruction based on mobile phone location data. This approach is divided into three steps. First, the trajectory of each individual is extracted from sparse sampling of mobile phone location data after data cleansing. Then, combining with a road network, the trajectory of each individual is reconstructed by network interpolation based on the shortest path algorithm in regular grids. Third, we use the velocities of each user's trajectory record to estimate the urban crowd flux on spatio-temporal grids at each time slice. Finally, urban crowd flux in Beijing, China were estimated using our method and the spatio-temporal characteristics of flux is analyzed. [ABSTRACT FROM AUTHOR]

In this paper, we present a formal analysis of the neighborhood vibrancy created by urban form. We use Geographic Information Systems (GIS) to develop quantitative measures of urban form and define neighborhood vibrancy based on a GPS-based activity survey in suburban Beijing. An Urban Form index was adopted to determine that our measures of urban form capture meaningful differences in the characteristics of urban neighborhoods – differences that may have direct impacts on neighborhood vibrancy. Specifically, high density and mixed land use are strongly positively correlated with neighborhood vibrancy, whereas developed external traffic systems are negative. However, a thorough inter-circulation system and convenient accessibility do not always boost neighborhood vibrancy. These factors lose efficacy when gated neighborhoods are selected and surrounding facilities are distributed far away. Our study argues that urban planners, using their professional judgment, can contribute to urban vitality at the neighborhood scale. [ABSTRACT FROM AUTHOR]

With China's rapid urbanization and industrialization, carbon emission in Chinese cities deserve special attention, and promoting low-carbon city (LCC) is considered essential for China. However, different cities present different development stages and carbon emission scenarios. This study presents the factors affecting carbon emission by introducing a city development-stage framework. The method of logarithmic mean Divisia index (LMDI) is adopted to decompose emission factors into energy structure, energy intensity, industrial structure, economic output and population scale. Beijing is chosen as the case city in this study, and four development stages for the city are identified by using the Environmental Kuznets Curve (EKC) theory, namely, S 1 (−1991), S 2 (1991–2004), S 3 (2004–2022) and S 4 (2022-). As the data collected for analysis are only available for the period of 1995–2014, this study focuses on the factor analysis for the stage S 2 and S 3 . The results show that the main driving factor for carbon emission increase in the stage S 2 is economic output, followed by population scale, while the main factor contributes to carbon emission reduction in this stage is the industrial structure. In the stage S 3 , the economic output is the top contributor to increase carbon emission, followed by population scale and energy structure, whereas energy intensity is the main influencing factor in curbing the carbon emission. Although the paper refers to the specific case of Beijing, the understanding on the driving emission factors in different development stages not only provides policy-makers and practitioners with valuable references for adopting effective measures to reduce carbon emission, but also provides other cities internationally with important lessons for accelerating the development of LCC. The innovative economic development stage framework incorporates carbon emission characteristics provides a new approach for understanding driving emission factors at city or national level. [ABSTRACT FROM AUTHOR]

In recent years, economy grows rapidly in China but it also pays a huge cost of destroy of resources and environment, and energy-saving and emission reduction has become a hot topic. This paper aims at calculating the environmental efficiency and environmental total factor productivity (TFP) of Beijing under the constraint of energy-saving and emission reduction to explore the relationship of the city’s economy and environment. We used an improved directional distance function – Biennial Directional Distance Function (BDDF) and Luenberger (L) productivity index which is corresponding to BDDF. This method can decompose the efficiency and productivity according to input and output factors and solve the problem of infeasible solution. The study found that the environmental efficiency of Beijing is different from regions and it takes on a concave distribution from the urban center to the edge of the city. Energy inputs and environmental pollution are the main influence factors of environmental inefficiency. The environmental TFP of the two central regions is higher than the two fringe regions, and through the decomposition results, we learned that the technology progress and the energy-saving emission reduction are the core of productivity growth momentum. From the change trend, the environmental efficiency of Beijing reached a high level in 2011 and followed by a slow decline. Whereas environmental TFP showed a tortuous rise trend which is down to the lowest in 2011–2012 and up to the highest in 2015. Based on our conclusions, we can say that energy-saving and emission reduction work of Beijing has made some good achievements, but with the difficulties increase we should take more reasonable measures according to the actual situation and join together to make the results of energy-saving and emission reduction work more effective. [ABSTRACT FROM AUTHOR]