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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]

The Chinese government aims to balance employment stabilization and emissions reduction when it initiates an emissions trading scheme (ETS) to control carbon emissions. However, the policymakers should not neglect the role of imperfectly competitive market structure and market power from incumbent firms. In view of this, classical framework of Berman and Bui's (2001) is extended in this paper to clarify the theoretical mechanism of employment effect of the ETS considering firm-level market power. In addition, based on the firm-level panel data from 2008 to 2019 of China, the employment effect of each pilot ETS is measured with the method of difference-in-difference-in-differences. Then a moderating effect model is established to verify the role of firm-level market power on the heterogeneous employment effect among the pilot ETSs. Moreover, the employment effect is further decomposed to evaluate the influential mechanism from the perspective of firms' strategic behavior. It is found that there is negative employment effect of China's ETS policy, due to the significant moderating role of firm-level market power. This decrease in labor demand is mainly dominated by a negative output effect rather than a positive substitution effect because strategic allowance sellers with stronger market power tend to hire fewer employees to reduce carbon emissions by controlling production scale. However, the heterogeneity of policy effects resulted by market structure is also identified in different pilot regions. Employment dividend has been found in Beijing and Tianjin where strategic allowance buyers manipulate the carbon market and hire more employees to consolidate their market power. Therefore, policymakers should improve the design of the ETS to overcome the adverse employment effect duo to the region-specific market structure. [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]

• Chinese dam export industry connects actors in China and outside, but loosely. • Beijing played a key role in formalizing Chinese dam actors and "go out" policies. • Chinese government facilitates dam export through events gathering interest groups. • Chinese players' capacities to export dams result from international collaboration. • New form of relations between Chinese and "international" dam actors emerge. The world has witnessed a recent increase of Chinese involvement in foreign dam building, frequently interpreting it as a result of implementing the Chinese government's "going out" policy. However, the Chinese dam industry's interweaving with its government and external forces remains unclear, blurring the nature of the "Chinese export" of dams overseas. The theory of the Chinese water machine has uncovered the existence of a network of actors interacting on water issues in China, and framed an assemblage approach to interpret the formation, maintenance and operation of this machine. Following the assemblage approach, this paper investigates the emergence and operation of a Chinese dam export industry, which is conceptually the consequence of a network of actors, including members of the Chinese water machine. In so doing, the interaction between the Chinese government, corporations and international forces is examined. Based on fieldwork and open-source data, this paper argues that the Chinese turn to overseas dam building not only follows the Chinese government's going out and state-owned enterprise reform policies and the self-interest of industrial players for profit, but also reflects a Chinese response to international politics on dams at the turn of the century, which is technically and politically influenced by the activities of international players in and outside China. [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]

• 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]

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]

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]

As the primary source sector of carbon emissions, the power industry's green innovation is an indispensable component of China's low-carbon transformation. This paper took China's Carbon Emission Trading Scheme as a quasi-natural experience and adopted the synthetic control method to evaluate the impact of Carbon Emission Trading Scheme pilot policy on power industry's green innovation based on the provincial industrial level data. Furthermore, this paper examined the impact mechanisms of Carbon Emission Trading Scheme on the power industry's green innovation through policy comparison, moderating and mediating effect analyses. The research findings show that: 1) there is heterogeneity in Carbon Emission Trading Scheme's effectiveness in inducing green innovation in China, the power industry only in Beijing and Guangdong has been significantly promoted, while other pilots have not; 2) the success of Beijing and Guangdong can be attributed to distinctive features of their carbon market and power industry, including the refined quota accounting mechanism, the application of paid quota allocation, the larger enterprise scale and more research and development investment; 3) enterprise scale and research and development investment have positive moderating effect and mediating effect in the promotional effect of the Carbon Emission Trading Scheme on green innovation respectively. Finally, some policy recommendations are put forward to promote the power industry's green innovation and carbon market construction. • Evaluate the impact of China's CETS on the power industry's green innovation in each pilot. • The CETS effects among pilots are heterogeneous, only significant in Beijing and Guangdong. • Rational CETS mechanism design could improve the power industry's green innovation. • Enterprise scale and R&D investment positively moderate and mediate the CETS effect. [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]

[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]

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]

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]

• 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]

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]

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]

With the rapid development of China's industrialization, the air pollution is becoming more and more serious. It is vital for us to predict the air quality for determining the further prevention measures of avoiding the brought disasters. In this paper, we are going to propose an approach of predicting the air quality based on the multiple data features through fusing the multiple machine learning models. The approach takes the meteorological data and air quality data for the past six days as one batch of input (the whole data set is for 46 days) and employs a multi-model fusion to provide an improved 24-hour prediction of PM2.5 pollutant concentration all over Beijing. During the above process, two focal feature groups are composed. The first focal feature group contains the historical meteorological data, while the second group includes the statistical information, the date information and the polynomial variations. Besides the two groups, we complement one million more data items by employing the time sliding means. Among the supplementary data, we select the most critical 500 features with Light Gradient Boosting Machine (LightGBM) model and send the features as the input to Gradient Boosting Decision Tree (GBDT) and LightGBM models. Meanwhile, we screen the most critical 300 features with eXtreme Gradient Boosting (XGBoost) model and send them as the input to the three prediction models. Referring to each of the models, we respectively gain the optimal parameters through grid search methods and then fuse the models' contribution with the linear weighting. The experiments indicate that the proposed approach based on the weighting fusion is better than that provided by a single modeling scheme, and the loss value is 0.4158 under the SMAPE index. • An approach of predicting air quality with fusing the multiple machine learning models. • The machine learning solutions to model PM2.5 pollutant concentration distribution feature. • The time sliding means for developing one million more data items. • The fusion of multiple models under linear weighting strategy. The experiments indicate that the approach based on the weighting fusion is better than that provided by the single modeling scheme, and the loss value is 0.4158 under the SMAPE index. [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]

Abstract: In this paper, we first analyze the 5 most cited papers with the title containing “Urban ecosystem health” in Chinese academic journals, and 5 newer papers retrieved from the CSSCI (Chinese Social Sciences Citation Index). The results show that the number of indicators to be used together in more than three papers is 28, and then we select 27 of them to assess Beijing and Shanghai's urban ecosystem health from 2000 to 2011. Secondly, when we standardize the original data, the worst value adjustment coefficient is introduced innovatively. Thirdly, using the entropy method, the weights of concrete indicators of Beijing and Shanghai in the different adjustment coefficients are calculated respectively. Fourthly, based on the fuzzy matter-element method, using the Hamming approach degree, the two cities' ecosystem health index and the contribution value to overall health index from each component are calculated. Lastly, using gray prediction model, the evolutionary time response sequence function of Beijing and Shanghai's urban ecosystem health index is identified, and thus both cities' urban ecosystem health is predicted. [Copyright &y& Elsevier]

Abstract: Much like other post-socialist cities, Chinese cities experienced dramatic changes after economic reform. The danwei, or state-owned work unit, was once a fundamental building block of Chinese cities. In addition to being the basic form of economic and social organization, danwei communities defined Chinese urban development before reform, taking the form of gated, walled-off combined factory and residential areas. This paper focuses on spatial changes at the neighborhood scale in danwei, by selecting the Tongrentang pharmaceutical factory in Beijing, China during the time period between 1973 and 2006 as a case study. Through archival material and interviews, this paper describes how the community changed from gated, boring, solidified and strictly constrained work units to un-gated, vibrant, mixed-use and flexible urban neighborhoods. This case study in urban China provides implications for planning professionals and policy makers. By properly redeveloping these brownfield, traditional danwei communities many change to become un-gated, livable, accessible, integrated, and sustainable in the post-socialist era. The implication for current transition theory is that despite the similarity to Central and East European countries, urban China has a local context and unique spatial changes that should be embraced in future transition studies. [Copyright &y& Elsevier]

The existing literature on migrants' place attachment tends to focus on neighbourhoods. Migrants' sense of belonging to the host city may vary in different residential neighbourhoods. Utilising a survey of selected peri-urban neighbourhoods in Beijing, this paper reveals that migrants with similar socio-economic attributes are grouped in their neighbourhoods. It also demonstrates a spatial dimension of migrants' sense of belonging to the host city. Such variation is created not only by the socio-economic achievement, institutional attainment and social networks; but also because these neighbourhoods are distinctive residential environments for different pathways of social integration. This research contributes to the theoretical debate on the (im)migrant enclave and mixed neighbourhood. Qualitative analysis shows that a low sense of belonging is not necessarily a result of homogenous tenure and residential population, but of living with uncertainty, exclusion from the formal urban economy, and a poor neighbourhood environment. The findings also support the positive role of the social-ethnic mix and tenure heterogeneity in terms of reduced stigmatisation and a sense of privilege and privacy in mixed neighbourhoods. • This paper explores migrants' sense of belonging to the city and its determinants from a neighbourhood perspective. • Migrants with similar socioeconomic attributes are grouped in their neighbourhoods. • Through the lens of neighbourhood, we demonstrate a spatial dimension of migrants' sense of belonging to the host city. • A low sense of belonging results from uncertainty, exclusion from the formaleconomy, and a poor neighbourhood environment. • Social-ethnic mix and tenure heterogeneity reduce stigmatisation, and provide a sense of privilege and privacy. [ABSTRACT FROM AUTHOR]

The aggressive industrial upgrade in China's first-tier cities has caused a shift in scholarly attention from peasant migrant workers to skilled migrants. Contrasting with a few elite migrants who are entitled special settlement policies, there is a large group of skilled migrants struggling for permanent homes and settlement amidst the rapid property inflation in the first-tier cities. However, these new floaters' housing experiences and settlement intention have not been studied. This paper fills this gap with a specific focus on skilled migrants' initiatives in expanding access to homeownership from the informal sector and showing how informal homeownership reshapes their settlement intention. Using a structural equation model on a dataset collected from Beijing and Shenzhen, this paper reveals the sorting and enabling effects of informal homeownership (small property rights housing, SPRH) on skilled migrants' settlement intention. The modelling results showed skilled migrants with an intention to settle down in Beijing/Shenzhen tend to buy an informal house as a residence instead of renting a home. Living in owned SPRH encourages migrants' intention to settle down because informal homeownership enables them to offset their structural disadvantages in the formal housing system. Therefore, SPRH serves as a stepping-stone for skilled migrants towards formal homeownership and permanent settlement in China's first-tier cities. Our empirical findings substantiate the socially inclusive nature of SPRH and contributes a new justification to tenure pluralism. • Skilled migrants are struggling for settlement in China's first tier cities. • Their housing experiences and settlement intention have not been studied. • Sorting effects of SPRH: Those with settlement intention tend to buy a SPRH. • Enabling effects of SPRH: Living in owned SPRH encourages settlement intention. • SPRH serves as a stepping-stone for skilled migrants to settle down. [ABSTRACT FROM AUTHOR]

Abstract: It is not feasible to apply the traditional prediction method to predict hourly building cooling load at the urban energy planning stage because of the limited building information and complexity of energy prediction. This paper presents a simplified prediction model: Hourly Cooling Load Factor Method (HCLFM) that can provide quick and fair estimate of building cooling load for large-scale urban energy planning. The paper introduces the assumptions and principles of the proposed method, as well as discussing the implication and limitation of the approach. As a verification and demonstration, the method is applied to an office building in Beijing. The predicted results show that the dynamical trend of the cooling load is reasonable. The study further analyzes the potential causes of prediction errors and the significance of various cooling load influence factors. [Copyright &y& Elsevier]

Abstract: With the urban rail transit network in Beijing becoming gradually intensive, the passenger flow organization also develops towards the type of the network mode. This paper analyzes the development trend of the urban rail transit network in Beijing. On the basis of a reasonable classification of emergencies occurred in urban rail transit, this paper puts forward the passenger organization model of rail transit network under emergency conditions, and then set a certain train accident of Beijing Metro Line 1 as an example to illustrate the practical application of the passenger emergency organization mode. [Copyright &y& Elsevier]

Abstract: During the summer of 2008 China’s biggest food crisis struck when it was discovered that milk suppliers were adding melamine, a colorless crystalline compound, to artificially boost the protein readings of their milk. While there was a lot of attention on the criminal investigations and post scandal industrial shake up, less is known about the impact of the Milk Scandal and policy response on the dairy farmer. The main objectives of this study are to describe the policies that were implemented by the government in response to the Milk Scandal and analyze the effect of the policies on dairy producers. To meet the objectives of the study, the paper uses a primary data set collected by the authors in 25 dairy producing villages, including 231 households, in the Greater Beijing area. The data set documents the policies that were implemented by the government as well as the response of the dairy farmers—both their participation in the dairy sector (stay in or drop out) and their herd size. Using descriptive and multivariate analyses on the changes in dairy production in the sample villages, the paper finds that, although dairy participation fell and herd sizes were reduced after the Milk Scandal, government policies did matter. Specifically, Marketing Management Policies were shown to have limited the fall in both participation and herd size. Production Management Policies had less of an effect in keeping dairy producers participating in the production of milk. The implementation of Crisis Income Management was correlated with a stronger decline in participation and herd size. [Copyright &y& Elsevier]

Abstract: The focus of the current study is the wind loads on a 11.92m section of parabolic trough collector with an aperture of 5.76m, located in Beijing, PR China. This paper presents selected results of full-scale field measurements of wind loads and wind pressure on the solar collector. The field data such as wind speed, wind direction and wind pressures are simultaneously measured from the solar collector. The measured data are analyzed to obtain the information on boundary layer wind characteristics, wind pressures and wind loads on the solar collector. The results presented in this paper are expected to be of considerable interest and of use to researchers and engineers involved in analysis and design of parabolic trough solar collectors. [Copyright &y& Elsevier]

Abstract: This paper provides an in-depth illustration of the shallow tunnelling method (STM) used for tunnelling in shallowly buried soft ground. Limited arching effect and limited ground strength mobilization are the two mechanical characteristics of the STM. The stability of the cutting face and the dry tunnelling condition are the two preconditions that should be satisfied for the STM. Some “necessary” auxiliary methods mainly served to guarantee these two preconditions are highlighted. Five principles, namely proper auxiliary methods, sequential excavation with short advance length, rigid support with quick installation, short ring closure time and systematic deformation monitoring, which are required to follow when using the STM are summarized. The state-of-art of the STM is classified into five different construction approaches according to tunnelling sequences, which are adopted in the construction of the nine subway stations in Beijing. The tunnelling procedures, support measures and settlement characteristics associated with excavation are demonstrated. Statistical analyses of the settlement data of 342 ground surface monitoring points above these nine stations are performed to illustrate the ground deformation characteristics of the STM. Numerical simulations are also employed to study the ground deformation characteristics of different construction approaches under the same geological conditions. This paper systematically demonstrates the applicability of STM in theory and practice. It is helpful in updating the database of the world tunnel projects and serving as a practical reference for future similar projects. [Copyright &y& Elsevier]

Abstract: This paper is the second in a series of three papers aimed at understanding the emissions of vehicles in China by conducting on-board emission measurements. This paper focuses on light-duty gasoline vehicles. In this study, we measured 57 light-duty gasoline vehicles (LDGVs) in three Chinese mega-cites (Beijing, Guangzhou, and Shenzhen), covering Euro 0 through Euro IV technologies, and generated CO, HC, and NOx emission factors and deterioration rates for each vehicle technology. The results show that the vehicle emission standards have played a significant role in reducing vehicle emission levels in China. The vehicle emission factors are reduced by 47–81%, 53–64%, 46–71%, and 78–82% for each phase from Euro I to Euro IV. Euro 0 vehicles have a considerably high emission level, which is hundreds of times larger than that of Euro IV vehicles. Three old taxis and four other Euro I and Euro II LDGVs are also identified as super emitters with equivalent emission levels to Euro 0 vehicles. Of the measured fleet, 23% super emitters were estimated to contribute 50–80% to total emissions. Besides vehicle emission standards, measures for restricting super emitters are equally important to reduce vehicle emissions. This study is intended to improve the understanding of the vehicle emission levels in China, but some key issues such as emission deterioration rates are yet to be addressed with the presence of a sufficient amount of vehicle emission measurements. [Copyright &y& Elsevier]

Abstract: This paper describes the development of a forecasting model, named the emergy-based urban dynamic model capable of accurately simulating the observed resource consumption, economic growth and environmental impact of Beijing. This model differs from previous urban emergy models by monitoring the negative effects to human well-being and ecosystem integrity in the developing urban system. A fresh perspective focuses on urban comprehensive performance linking such impacts to a supply-side environmental cost evaluation (including ecological service supply, ecological and economic losses and investment for treatment). In this introductory paper, we present the conceptual considerations of the most important components of the emergy-based urban dynamic model: the urban assets, lands, capitals, population, water resources, economic and environmental loss. Each subsystem in this model will enrich the feedback dynamics, policy levers and post-scenario analyses. Statistical Information and calibration are also considered in this dynamic emergy accounting. This study advances the temporal dynamic principles of emergy accounting through integrating upstream and downstream evaluation methods to quantify the environmental impact by addressing specific damages to human health and ecosystem''s integrity and by linking such impacts to a supply-side environmental cost evaluation. [Copyright &y& Elsevier]

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]