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ABSTRACTTo study the interface friction and vibration behaviours of brake systems with wheel flat, a rigid-flexible vehicle dynamics model and a finite element model of brake system are developed. These two models are validated using experimental test data. Additionally, an analysis formula of brake system excited by wheel flat is proposed to reveal the tribological behaviours. The results indicate that the wheel flat directly induces the elastic vibration of brake disc and further affects the disc contact, resulting in a significant increase in the contact force, contact stress, friction force and vibration acceleration between the brake interfaces. Furthermore, the proposed model can be used to investigate the related tribological behaviour of brake systems under other complex wheel-rail excitations.

Brake systems are essential for the speed regulation or braking of a high-speed train. The vehicle dynamic performance under braking condition is complex and directly affects the reliability and running safety. To reveal the vehicle dynamic behaviour in braking process, a comprehensive trailer car dynamics model (TCDM) considering brake systems is established in this paper. The dynamic interactions between the brake system and the other connected components are achieved using the brake disc–pad frictions, brake suspension systems, and wheel–rail interactions. The force and motion transmission from the brake system to the wheel–rail interface is performed by the proposed TCDM excited by track irregularity. In addition, the validity of TCDM is verified by experimental test results. On this basis, the dynamic behaviour of the coupled system is simulated and discussed. The findings indicate that the braking force significantly affects vehicle dynamic behaviour including the wheel–rail forces, suspension forces, wheelset torsional vibration, etc. The dynamic interactions within the brake system are also significantly affected by the vehicle vibration due to track irregularity. Besides, the developed TCDM can be further employed to the dynamic assessment of such a coupled mechanical system under different braking conditions.

•GWQR model is applied to address the heterogeneity of ride-hailing travel demand.•Ride-hailing order data are collected in Shenzhen, China.•Socioeconomic and demographic, transport infrastructure, and land use patterns are considered as explanatory variables.•The spatial effects of key variables crossing different quantiles are discussed.

•Older pedestrians tend to be more affected by barrier and micro-factors.•Traffic related factors have 2-folds stronger impacts on older than other pedestrians.•Urban density and greenery have inverse U-patterns correlation with pedestrian volume.•Environment factors have varying effects across different spatial resolutions.

•Effects of road features on e-scooter trip volume (ETV) of the segment are studied.•The multiple membership multilevel model is used to tackle the boundary problem.•Segments with sidewalks, dedicated bicycle facilities, and slower traffic are preferred.•Density of street lights and trees are also positively related to ETV.•ETV is higher in the commercial, residential, and high-income areas.

•The real-world CO2emission reductions of ridesplitting are quantified based on observed data.•Interpretable machine learning is used to explore the determinants of CO2emission reductions of ridesplitting.•The average CO2emission reduction rate of ridesplitting is 43.15 g/km.•15% of ridesplitting trips increase CO2emissions compared with regular ridesourcing.•The overlap and detour rates of shared rides are the most important determinants.

Vibrancy is one of the most desirable outcomes of transit-oriented development (TOD). The vibrancy of a metro station area (MSA) depends partially on the MSA’s built-environment features. Predicting an MSA’s vibrancy with its built-environment features is of great interest to decision makers as these features are often modifiable by public interventions. However, little has been done on MSAs’ vibrancy in existing studies. On the one hand, seldom has the vibrancy of MSAs been explicitly explored, and measuring the vibrancy is essential. On the other hand, because MSAs are interconnected, one MSA’s vibrancy depends on the MSA’s features and those of relevant MSAs. Hence, selecting a suitable metric that quantifies spatial relationships between MSAs can better predict MSAs’ vibrancy. In this study, we identify four single-dimensional vibrancy proxies and fuse them into an integrated index. Moreover, we design a two-layer graph convolutional neural network model that accounts for both the built-environment features of MSAs and spatial relationships between MSAs. We employ the model in an empirical study in Shenzhen, China, and illustrate (1) how different metrics of spatial relationships influence the prediction of MSAs’ vibrancy; (2) how the predictability varies across single-dimensional and integrated proxies of MSAs’ vibrancy; and (3) how the findings of this study can be used to enlighten decision makers. This study enriches our understandings of spatial relationships between MSAs. Moreover, it can help decision makers with targeted policies for developing MSAs towards TOD.

The brake system is a key component of a high-speed train, which suffers intense wheel-rail interactions caused by wheel polygonal wear (WPW) in realistic working conditions. To explore the dynamic characteristics of the disc brake systems with WPW, a rigid-flexible coupled vehicle dynamics model is proposed. The developed model systematically takes into account the flexible deformation of brake components and wheelsets, measured WPW and non-linear factors such as wheel-rail interaction, disc-pad friction and non-linear damping characteristics. It allows the dynamic behaviors of the vehicle brake system in service to be accurately and effectively revealed. The model is verified using line test data, and then the dynamic characteristics of disc brake systems with WPW are investigated in details. The results show that for vehicle speed below 80 km/h and depths of WPW below 0.04 mm, the effect of WPW on the vibration of the caliper is slight. However, as vehicle speed and wear depth continue to rise, the vibration of the caliper increases noticeably. Furthermore, the effects of vehicle speed and wear depth on brake disc vibration are more obvious, and increasing vehicle speed and wear depth will steadily deteriorate the vibration of the disc. Besides, the effect of WPW is particularly pronounced on the dynamic behavior of the brake units closer to the wheels. Overall, the influence of wheel polygon cannot be neglected in the study of dynamic characteristics of brake system. At the same time, the proposed model can also be applied in the strength evaluation of brake components and the study of the tribological behaviors within the brake interface.

Awareness is amounting that understanding the people-animal-environment relationships and further considering it in city design are important to make future cities and society more resilient and sustainable. The presence of green space stimulates recreational walking behaviour. Also, animals in urban outdoor spaces have a restorative effect. However, scant attention has been paid to whether and how green space and animals have a synergistic effect on recreational walking behaviour.

•Green spaces can account for approximately 20% of the variance in active travel.•The effect of the area of green spaces on active travel is generally positive.•The green view index affects cycling in complex ways.•Synergistic effects are evident among the predictors.

•Evaluate the effectiveness of wearable fitness trackers (WFTs) and smartphone pedometer apps (SPAs) in encouraging the participation of physical activities.•Develop binary logit models to depict the significant factors affecting the mode choice decision between walking and traveling by public transport.•Analyze the variation in the choice behavior of users and non-users of WFTs and SPAs in short and long trips.•Provide policy insights and suggest improvements in the walking environment to promote walking and cultivate a healthy lifestyle.

•Migrants in Xiamen travel less and rely more on active/public transport than locals.•For locals, most sociodemographic and built-environment variables are significant determinants.•Population density, diversity, and shorter distance to commercial centers are positively related to sustainable travel modes of locals.•Trip frequency of migrants is more affected by sociodemographic variables than built environment variables.

•Three objective measuring method were used to assessed different dimensions of urban greenery.•Schools with greener surrounding areas are more likely to encourage active transport behaviour.•Children attending schools with greener surrounding areas are more likely to have a lower BMI.•Active school transport behaviour partially mediates the impact of urban greenery on BMI.

Abstract:The article investigates whether and how economic upgrading leads to social upgrading for rural migrant workers (RMWs) in the Pearl River Delta (PRD) region of China. Two cities that represent different types of economic upgrading in the PRD, namely Shenzhen and Foshan, were selected as the investigation sites. The data were mainly obtained from statistical yearbooks and interviews with 72 informants, including RMWs, scholars, employers, and officials. The article argues that two types of economic upgrading, namely reindustrialization and tertiarization, affect the social upgrading of RMWs in different ways. However, both types of economic upgrading have caused a pushing-out effect by increasing unemployment or working intensity and living costs.

Understanding the underlying behavioral mechanism of tourist destination choices is the first and foremost step in establishing effective and appropriate management measures for a scenic area. Few studies have used high-resolution and fine-grained spatio-temporal data to develop sophisticated statistical models for uncovering micro-scale tourist movements. This study combined Global Positioning Systems (GPS) and conventional questionnaire survey data of 312 respondents from Gulangyu, China, a small island with a total area of 1.87 km2, to develop multinomial logit (MNL) models for identifying factors that affect tourists’ destination choices. A market segmentation analysis for different ticket purchasers was then performed. The Watson and Westin pooling test demonstrated that destination choices vary significantly between joint- and single-ticket purchasers. Joint-ticket purchasers are shown to be a more regular group whose mobility behavior can be better predicted and modeled compared with single-ticket purchasers. Several policy implication are discussed based on the modeling results. The proposed modeling, findings, and discussions provide the basis for policy instruments and will be useful for the enhanced planning of on-site movement, improved regulation of tourist flows, and rationalized design and management of tourist destinations.

•Evaluate and compare the service quality of the fixed-route and demand-responsive public light bus services.•Interview 547 respondents for their satisfaction with the service quality of both types of services.•Propose a new methodology to rank the significantly underperforming areas that should be improved.•Find that the in-vehicle environment, waiting time, driver’s attitude, and safety hold a higher improvement priority.•Discuss novel and valuable policy implications for improving and regulating both types of services.

Ageing populations are becoming common in many cities, and their rapid growth may lead to serious transportation issues when elderly users’ mobility is compromised by their inability to access or use public transport. It is of paramount importance to provide good public transport services to the elderly to maintain their quality of lives. An interviewer-administered face-to-face interview survey was conducted in March 2015 in Hong Kong, an example of a high-density and transit-oriented city, among elderly residents aged 60 and above to evaluate their level of satisfaction with various public transport modes. In this paper, an ordered probit model is calibrated to evaluate the relative importance of the quality of nine service aspects to the overall service performance. An importance-satisfaction analysis is conducted to visualize how best to prioritize actions for improving each of the nine service aspects. The findings reveal that the interviewed elderly individuals considered seat availability as the worst performed service aspect, with which 17.8% of them were dissatisfied or very dissatisfied. The condition of stations or stops is identified as the most influential factor affecting the overall satisfaction level with public transport services. These two service aspects hold the top priority for enhancement. The drivers’ attitude is suggested to be improved additionally if resources allow. For better public transport services to the elderly and thus enhancing their mobility to more actively participate in social activities, appropriate training and guidance to public transport drivers are recommended to enhance their awareness of driving behavior and attitude; provision of seats and shelters is recommended at the bus stops typically frequented by the elderly; and the culture of offering seats to the needy should be promoted through education.

•We uncover the respondents’ travel patterns in different age cohorts and genders.•We show the spatio-temporal travel characteristics of the elderly and young adults.•We discuss policy insights to improve public transport services for the elderly.

Silver-filled polydimethylsiloxanes (PDMS) are expected to be used as various advanced materials. The role of silver particles on the reinforcement and rheological behaviors of PDMS composites has not been sufficiently investigated. In addition, the processing of highly viscous PDMS mixed Ag particles is a difficult work. In this work, uniformly dispersed filled PDMS composites with macro-nano Ag were prepared by an in-situpolymerization method. The viscoelasticity and strain amplitude (ε) dependent rheology, also known as Payne effect, of the Ag in-situfilled PDMS composites were studied in compared with those of fumed silica-filled PDMS systems, helping to comprehend the microcosmic deformation mechanisms. Bound rubber in Ag-filled PDMS was at a low level. Ag provided a reinforcement effect and introduced a rheological nonlinearity in the PDMS composites at a critical loading of 6.10 wt%. The critical strain (εc = 76.5%) of vulcanized Ag-filled PDMS was insusceptible with Ag contents in the range of 3.04 wt% to 14.70 wt%. Ag and fumed silica in the composites showed different rheological behaviors.

There is strong evidence in Western cities that neighborhood-level characteristics of the built environment are linked with a higher risk of overweight or obesity among residents. Due to the rapid urbanization during the last several decades, many types of residential community have formed and coexisted in the major cities of China. These communities provide residents with different built-environment features and lifestyles. However, it remains unclear whether the community type affects the risk of overweight and obesity among residents.

•A rule-based model was used to identify commuting trips using metro service with smart card data (SCD).•Metro usage for commuting mode share and ridership were measured at station level.•Metro commuting mode share is negatively associated with population density, while street intersection shows a positive relationship.•Office-oriented urban function and street intersection density is positively correlated with metro ridership.•Land use diversity was not found significant association with metro usage in Wuhan in 2015.

The UNESCO label of World Heritage can attract a high number of tourists to heritage properties for their Outstanding Universal Values (OUV). Although international studies have demonstrated the World Heritage system can contribute to stimulating cultural tourism and boosting the local economy, how this heritage-led development process promotes urban conservation and morphological changes in cities is yet to be explored adequately. This paper aims to explore the urban morphology of a historic Chinese city after its inscription on the UNESCO World Heritage List, taking the Old Town of Lijiang as case. The methods of spatial plan analysis and discourse analysis are used to analyse the data. The research findings have demonstrated that, theoretically, the Conzenian approach of urban morphology can be an effective framework for World Heritage OUV-monitoring. Methodologically, the analysis of spatial plans and multi-stakeholder interviews can reveal local urban morphology from macro to micro levels. Case-specifically in Lijiang, urban physical characteristics and building structures have been well maintained while traditional social fabric and neighbourhood networks have almost vanished. This research has incorporated the urban morphology approach into (world) heritage management in China, as well as worldwide, in order to maintain the balance between urban conservation and economic growth.

Protein micropatterning on microfabricated surfaces is a promising technology in applications for biochip microarrays, cell attachment, and biosensors. In the present work, a novel photoresponsive polymer based on light-triggered charge shifting bridged polysilsesquioxane (CBPS) is designed and prepared. The organic bridged units containing a photocleavable group of diethylaminocoumarin-4-yl in CBPS could be cleaved rapidly upon irradiation at 410 nm, resulting in the polymer surface switching from a positive charge to a negative charge property. The photoresponsive behavior of CBPS is studied using FTIR, UV–vis, SEM, fluorescence microscopy, and zeta potential analysis. Proteins are easily immobilized on the polymer surface via electrostatic interactions and released after irradiation as required. Combined with photopatterning techniques, accurate protein micropatterns are fabricated by covering a photomask upon irradiation. A gradient protein pattern is also spatially and temporally controlled by regulating irradiation parameters. This smart photoresponsive polymer surface provides a gentle and straightforward strategy to micropattern charged proteins. Moreover, the photoresponsive polymer holds permitting potential in biomedical applications such as conjugating biomolecules, guiding cell arrays, and resisting bacteria.