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With a large number of new energy vehicles being put into use, it is the general trend for traditional fuel vehicles to withdraw from the market in an orderly manner. Determining the optimal ratio between them in this process is of great significance to the low-carbon sustainable development of cities. Therefore, considering the constraints of urban automobile development planning and air pollution prevention and control policies, a multi-objective model to minimize pollutants and costs is constructed in this paper. Through model calculation and sensitivity analysis of dynamic impact relationship of different types of vehicles, it is determined that when new energy vehicles account for around 36% in Beijing, 57% in Shanghai and 46% in Guangzhou, the pollutant emissions can be minimized without causing a significant increase in social costs. Additionally, compared with 2030, Beijing, Shanghai and Guangzhou can achieve emission reductions of 320,000 tons, 200,000 tons and 250,000 tons, respectively, in 2050 if they implement the policy of banning the sale and delisting of fuel vehicles, which could provide suggestions for the guidance of the low-carbon development plan of the automobile industry. [ABSTRACT FROM AUTHOR]

Given the complex interplay between economic and cultural–historical factors, this paper explores scene perception and its mechanism in individual and collective cognition of historical commercial streets. Based on a perception model constructed from scene theory, the study utilizes user scene experience feedback from Beijing Road, a commercial pedestrian street in Guangzhou. It conducts a systematic assessment using hierarchical analysis (AHP) across three dimensions: authenticity, theatricality, and legitimacy. The findings reveal the following: (1) according to visitors, traditional cuisine, cultural and creative arts, and Lingnan's intangible cultural heritage received low ratings; (2) historical relics and traditional cuisine are dominant factors, highlighting public attention to cultural heritage, but the role of historical–cultural characteristics and festival activities is relatively marginalized; (3) cultural–historical relics and traditional cuisine are the leading factors that contribute to an authentic experience, while historical context and festival activities constitute secondary factors; (4) cultural landscapes and arts are central to theatrical experiences, with modern visual elements playing a lesser role; (5) diversified commercial formats and public services are the core factors influencing legitimacy experience, reflecting the role of market diversity and policy orientation in building consumer trust. The design of historical and cultural streets should prioritize the preferences of those experiencing them to promote cultural identity and historical continuity. Additionally, the synergy between commercial diversity and policy orientation should be strategically emphasized to form a business ecosystem supporting sustainable development. Future commercial street renewals should focus on the key role of visual narrative in shaping brand culture. This paper offers insights into the dynamic process of constructing scene experience from perspectives of spatial materialization and emotional empowerment to cultural identity, providing references for strategies in historical place renewal. [ABSTRACT FROM AUTHOR]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To study urban air quality, this paper proposes a novel categorical time series model, which is based on a linear combination of bounded Poisson distribution and discrete distribution to describe the dynamic and systemic features of air quality, respectively. Daily air quality level data of three major cities in China, including Beijing, Shanghai and Guangzhou, are analyzed. It is concluded that the air quality in Beijing is the worst among the three cities but is gradually improving, and its dynamics is also the most pronounced. Theoretically, the design of our model increases the flexibility of the probabilistic structure while ensuring a dynamic feedback mechanism without high computational stress. We estimate the parameters through an adaptive Bayesian Markov chain Monte Carlo sampling scheme and show the satisfactory finite sample performance of the model through simulation studies. [ABSTRACT FROM AUTHOR]

High-speed rail (HSR) is one of the essential innovations in the field of transportation in the latter half of the twentieth century. In China, the rapid development of HSR has received increasing attention and resulted in a boost of tourism, with significant impact on the development of cities that operates HSR. To accurately comprehend how will the operation of HSR influence the regional CO2 emissions, this paper applies the modified STIRPAT model, combining with real data on high-speed rail passenger flow volume of the Beijing-Guangzhou high-speed rail Hunan section. The results show that (1) the high-speed rail operation is also a significant impact factor for regional CO2 emissions. (2) Considering the operation of HSR, the ranking of contribution rate of driving factors for regional CO2 emissions is as follows: GDP per capita, energy consumption per unit of GDP, arrival volume of high-speed rail, originated volume of high-speed rail, the proportion of coal in the energy mix, proportion of the tertiary industry, and population. (3) Surprisingly, the numerical research result shows that the operation of HSR for the cities may promote regional CO2 emissions, while the increase in urban population and the optimization of energy structure have a reducing effect on regional carbon emissions. There is a transfer effect of the operation of HSR and region development, which results in the rising of regional CO2 emissions. Thus, it is urgent to research on the decoupling of economic growth from CO2 emissions. The findings could be conducive for the government and railway company to evaluate and administrate the operation of high-speed rail and adequately deal with the relationships between the high-speed railway and regional development. [ABSTRACT FROM AUTHOR]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Taking Liangxiang Pagoda built in Liao Dynasty in Beijing as the research object, the vibration responses of the pagoda in the east-west direction and south-north direction under the action of trains on the Beijing–Guangzhou Railway Line and microseism were tested. On this basis, a numerical model was established by using ANSYS to further calculate the dynamic response of the pagoda, and the safety and integrity of the pagoda were evaluated based on existing standards. Cumulative fatigue damage theory was introduced to predict the remaining fatigue life of Liangxiang Pagoda. The following conclusions have been drawn: in the two directions mentioned above, the natural vibration frequencies of the pagoda of the first three orders are similar; the 1st-order vibration modes in the plane are bending, and the vibration modes of the 2nd and 3rd orders are shear-bending; under the action of trains, the peak vibration value of Liangxiang Pagoda at the position that bears the maximum load is 0.053 mm/s, which has a little impact on the safety and integrity of the pagoda; under the combined action of gravity and trains, the remaining fatigue life of Liangxiang Pagoda is 5.26 × 10 7 times. The research method used in this paper can provide data and scientific support for the protection of historical buildings, as well as the basis for the follow-up research of the studied ancient pagoda. [ABSTRACT FROM AUTHOR]

The condition-based maintenance of high-speed railway catenary is an important task to ensure the continuous availability of train power supply. To improve the condition monitoring of catenary, this paper presents a novel scheme to detect catenary local irregularities using pantograph head acceleration measurements. First, a series of experimental inspections is carried out in a section of the Beijing–Guangzhou high-speed line in China. The time intervals between the inspections are shortened from the traditional six months to about 40 days, which enables monitoring the short-term degradation of local irregularities. Then, based on the wavelet packet entropy, an approach is proposed to detect local irregularities with different scales in length. Criteria for identifying and verifying the local irregularities are established based on the gradient and repeatability of entropy from multiple measurements. Results from the experimental inspections show that different scales of local irregularities can be detected by the proposed scheme. By using frequent inspections, local irregularities can be effectively verified after about seven inspections. The spatial distribution of local irregularities is found to be closely related to the catenary structure. These findings provide valuable information to deploy the scheme for a railway network. [ABSTRACT FROM AUTHOR]

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

Understanding human movement patterns is crucial for comprehending how a city functions. It is also important for city planners and policymakers to create more efficient plans and policies for urban areas. Traditionally, human movement patterns were analyzed using origin–destination surveys, travel diaries, and other methods. Now, these patterns can be identified from various geospatial big data sources, such as mobile phone data, floating car data, and location-based social media (LBSM) data. These extensive datasets primarily identify individual or collective human movement patterns. However, the impact of spatial scale on the analysis of human movement patterns from these large geospatial data sources has not been sufficiently studied. Changes in spatial scale can significantly affect the results when calculating human movement patterns from these data. In this study, we utilized Weibo datasets for three different cities in China including Beijing, Guangzhou, and Shanghai. We aimed to identify the effect of different spatial scales on individual human movement patterns as calculated from LBSM data. For our analysis, we employed two indicators as follows: an external activity space indicator, the radius of gyration (ROG), and an internal activity space indicator, entropy. These indicators were chosen based on previous studies demonstrating their efficiency in analyzing sparse datasets like LBSM data. Additionally, we used two different ranges of spatial scales—10–100 m and 100–3000 m—to illustrate changes in individual activity space at both fine and coarse spatial scales. Our results indicate that although the ROG values show an overall increasing trend and the entropy values show an overall decreasing trend with the increase in spatial scale size, different local factors influence the ROG and entropy values at both finer and coarser scales. These findings will help to comprehend the dynamics of human movement across different scales. Such insights are invaluable for enhancing overall urban mobility and optimizing transportation systems. [ABSTRACT FROM AUTHOR]

Purpose: Retailers have recently leveraged store-loyal customers' store attachment to maintain customer relationships and motivate patronage intentions. However, the COVID-19 outbreak has driven customer migration from offline to mobile channels. Mobile retail applications (APPs) have been used by numerous retailers to reach their customers. Nonetheless, it has yet to be determined (1) whether store attachment can facilitate (or impede) the adoption of mobile retail APPs and (2) whether store-loyal customers will continue visiting offline stores in the post-pandemic era. To address these questions, we propose a theoretical account using integrated theories on trust transfer and store attachment. Design/methodology/approach: We conducted multi-stage, longitudinal field surveys in two cities of mainland China: Beijing and Guangzhou. From two rounds of data collection, 237 and 103 responses were obtained in March 2022. Hypotheses were tested by partial least squares – structural equation modelling (PLS–SEM). Findings: Results showed that customer trust in an offline retailer can be transferred to the retailer's mobile APP at the pre-adoption stage, facilitating APP adoption. Notably, store-loyal customers who exhibited a strong attachment to the physical store of a retailer were more inclined to transfer their trust to the mobile APP of the retailer. This occurrence leads to an increased adoption rate, enhanced post-adoption satisfaction and increased inclination to continue (rather than discontinue) usage. Originality/value: This study is the first to investigate the changes in store-loyal customers' shopping behaviour in the mobile retail era and in the post-COVID-19 pandemic recovery. Our findings elucidate the role of physical store attachment in the trust-transfer mechanism. Furthermore, store attachment may not prevent customers' channel migration behaviour. Retailers may have to re-consider how to manage channel cannibalisation issues in the post-pandemic recovery. [ABSTRACT FROM AUTHOR]

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

In this paper, energy performance of a loop-heat-pipe (LHP) type solar photovoltaic/thermal (PV/T) heat pump water heating system is studied to evaluate its feasibility in three different climatic regions. A mathematic model of this system in our former study is built and validated using outdoor test data. On the basis of this model, influences of main structural design parameters including the installation angle and the orientation of the PV/T collector/evaporator are discussed and main parameters are optimized to further improve system operation performance. Based on optimal design parameters, economic feasibility of the proposed system under different weather conditions is analyzed using the life cycle cost (LCC) method. The system is integrated with solar PV/T, loop heat pipe and solar assisted air source heat pump technologies. This combined approach is benefit for improving solar energy comprehensive application efficiency of conventional solar PV/T systems. Moreover, it enlarges the application region of traditional air source heat pump water heating systems. Depending on different solar radiation conditions, this system can operate in different modes including solar photovoltaic LHP mode, solar assisted air source heat pump mode and the only air source heat pump mode. In this study, Beijing, Shanghai and Guangzhou were selected as typical representative cities in cold area, hot summer and cold winter area, hot summer and warm winter area. Typical meteorological year (TMY) data of three cities were extracted from TRNSYS. Based on TMY data, annual operation performance of the proposed system is calculated through the validated dynamic mathematic model. Firstly, PV/T collector/evaporators of three systems are all fixed in the south direction and the same installation angle (35°) was chosen. In this case, annual net power consumptions and solar heating fractions of three systems are calculated and compared. Then installation angles and orientations are optimized to ensure maximum solar energy application. The investigation results show that, among three cities, the solar heating fraction in Guangzhou is the largest. And the least electricity is consumed in Guangzhou, which is decreased by 43.9% and 44.7% respectively compared with those in Beijing and Shanghai. The comprehensive photothermal efficiency in Guangzhou is 8.19%, 5.58% higher than those in Beijing and Shanghai. Therefore, from the view of solar energy comprehensive efficient utilization, the application of the system is most proposed in Guangzhou, and then followed by Shanghai and Beijing. Considering impacts of installation angles and orientations, the ideal installation inclination of the system in Beijing, Shanghai and Guangzhou are 35°, 25°, and 35°, and the optimal installation directions of Beijing and Shanghai are facing the south, while that of Guangzhou is 30°east to the south. With the optimal parameters, it is found that solar heating fractions in Beijing and Guangzhou (i.e. 57.42% and 58.45%) are slightly higher than that in Shanghai. It is concluded that influences of two structural parameters are different for such system in different climatic areas. To ensure maximal solar energy application, it was necessary to optimize these two parameters. For the life cycle cost analysis, a traditional air source heat pump hot water heating system is chosen as the base system. The analysis results indicate that the initial investment of the system increases significantly, which is 2.5 times of that of the base system. However, the annual power consumption of the system is about half of that of the traditional system. Besides, solar power supply fractions in Beijing, Shanghai and Guangzhou are 53%, 51% and 66% respectively. As a result, the total operation and maintenance fees in the life cycle drop significantly, which are reduced by 67.86%, 59.00%, and 62.21% in Beijing, Shanghai and Guangzhou. The life cycle cost is correspondingly reduced by 58.75%, 49.83% and 53.09% in three cities. In conclusion, the application of this system is feasible for considered weather conditions in terms of both the operating performance and economic benefits. [ABSTRACT FROM AUTHOR]

Presently, robotaxi is being tested in cities such as Beijing, Changsha, Guangzhou, etc., and it remains a relatively new mode of transportation for consumers. Considering that robotaxi is a new mobility model, its popularity has an immediate impact on the function and efficiency of urban traffic, so further research on consumers' perceptions is necessary in order to improve their acceptance of robotaxi. In this study, we explored the behavioral intention of current users of robotaxi based on their performance expectancy, effort expectation, and perceived risk. Based on the results, it appears that performance expectations and effort expectations positively influence usage intentions, which indicates that improving travel efficiency and lowering the threshold for robotaxi use will assist consumers in accepting it. In terms of consumer behavior, perceived risk negatively impacts usage intention, meaning that personal safety, service quality, and travel experience are important factors. Performance expectancy and effort expectancy are positively correlated, indicating that improving travel efficiency and lowering thresholds are complementary. [ABSTRACT FROM AUTHOR]

Spatiotemporal fusion technology effectively improves the spatial and temporal resolution of remote sensing data by fusing data from different sources. Based on the strong time-series correlation of pixels at different scales (average Pearson correlation coefficients > 0.95), a new long time-series spatiotemporal fusion model (LOTSFM) is proposed for land surface temperature data. The model is distinguished by the following attributes: it employs an extended input framework to sidestep selection biases and enhance result stability while also integrating Julian Day for estimating sensor difference term variations at each pixel location. From 2013 to 2022, 79 pairs of Landsat8/9 and MODIS images were collected as extended inputs. Multiple rounds of cross-validation were conducted in Beijing, Shanghai, and Guangzhou with an all-round performance assessment (APA), and the average root-mean-square error (RMSE) was 1.60 °C, 2.16 °C and 1.71 °C, respectively, which proved the regional versatility of LOTSFM. The validity of the sensor difference estimation based on Julian days was verified, and the RMSE accuracy significantly improved (p < 0.05). The accuracy and time consumption of five different fusion models were compared, which proved that LOTSFM has stable accuracy performance and a fast fusion process. Therefore, LOTSFM can provide higher spatiotemporal resolution (30 m) land surface temperature research data for the evolution of urban thermal environments and has great application potential in monitoring anthropogenic heat pollution and extreme thermal phenomena. [ABSTRACT FROM AUTHOR]

The Beijing Olympics were a global media event that marked China's arrival on international political and economic stages. The Chinese authorities made great efforts, and with much success, to present to the world the face of a strong, competent, efficient, welcoming and unified China. Political dissent was suppressed, although not eliminated, Beijing residents and taxi drivers were issued with guidelines of acceptable behaviour and dress, and broadcasters throughout the country celebrated the country's outstanding sporting achievements in the Games. However, although centripetal forces of national unification behind the spirit of the Games were undeniably strong, there were nonetheless countless centrifugal forces arising through media practices that disturbed this sense of imagined national unity. With new media in particular, audience fragmentation has become an established feature of China's media landscape. This paper draws on fieldwork conducted before and during the Beijing Olympics to demonstrate the tension between these two opposing sets of forces. Through discussion of various media examples it suggests that both the notion of a China unified behind the forceful media representations of the Games and the notion of straightforward audience fragmentation need careful rethinking to take account of the complex interrelations between pressures encouraging national identification on the one hand and those of social, technological and mediated division and diversification on the other hand. [ABSTRACT FROM AUTHOR]

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]

Decades ago, bicycles used to play an important role in urban transportation in Chinese cities, but they have been gradually replaced by private cars, metro, buses, and some other modes, owning to the fast-growing mobility demand as a result of urban expansion and motorization. However, in recent years, with the development of Information and Communication Technologies (ICT) and the initiative of the sharing economy, bike-sharing systems (BSSs) have been implemented extensively in Chinese cities. Their usage patterns can be revealed via system-generated data, yet less is known about users' attitudes towards and preferences for these systems. In this study, we draw on two surveys conducted in Guangzhou and Beijing on the perceptions of travelers using BSSs to estimate the effect of demographic factors, bicycle ownership, and trip-level factors on the willingness and potential frequency of BSS usage. In addition, a latent class model is built to analyze the different aspects of theses systems concerned with different types of urban travelers. It is found that respondents' age, occupation, income, mode combination, and the proximity of origin or destination to the docking station, etc., influence the willingness and frequency of using BSSs. In addition, respondents generally value features such as the proximity of docking stations to trip destinations, safety to ride, and appropriate level of fare. However, different latent classes show a different preference for other features of BSSs. According to the model results, proposals are given for the improvement of the existing systems in Chinese cities. [ABSTRACT FROM AUTHOR]

With the intensification of anthropogenic warming and urbanization, high‐temperature weather poses an enormous threat to socio‐economic and human healthy. However, the studies on annual high‐temperature days forecasting based on machine learning are relatively deficient. This study proposes a support vector machine (SVM) ensemble model based on grey wolf optimization (GWO) to predict annual high‐temperature days in Guangzhou, Shanghai and Beijing of China. Atmospheric circulation indices during 1959–2013 were utilized as inputs to train and validate models. The fivefold cross validation was used to expand the sample data and evaluate the performance of the member and ensemble models. The optimal ensemble model for Guangzhou has the highest average R (0.8939) and the lowest average root mean square error (RMSE; 3.3771), followed by the optimal ensemble models for Beijing (0.8871 and 3.6059) and Shanghai (0.7578 and 3.9968). Furthermore, compared with the typical SVM and optimal member models, the average validation RMSE of the optimal ensemble model was improved by 32.6 and 10.0% for Guangzhou, by 29.8 and 9.1% for Shanghai, and by 41.3 and 15.1% for Beijing, respectively. This study demonstrates that the GWO‐based SVM ensemble model can be a promising tool for annual high‐temperature days forecasting due to the nonlinear fitting power of the SVM, the hyperparameters tuning capability of the GWO algorithm, and the integration ability of ensemble learning. [ABSTRACT FROM AUTHOR]

As one of the largest civil engineering systems in China, the network of high-speed railway expanded fast in the last decade. The safety of railway operation is of great concern for the whole country. Railway track irregularity is a potential threat to safety of operation and comfort of passengers, and remains a challenging issue for researchers and engineers. Currently, track irregularity data are recorded by various sensors in the comprehensive inspection cars in China. To reveal relations between the operation of high-speed trains and the track geometry, the data mining and random modeling of track irregularity are needed. In this paper, different methods to evaluate the track irregularities are presented at first. A case study of a section in Beijing-Guangzhou high-speed railway is studied using the Karhunen-Loève expansion. Track geometries that are a representation of this railway network are generated along with statistical and frequency validations. As an application based on generated random track geometries, accelerations of train body under different traveling velocities are calculated and analyzed using a simulation model. [ABSTRACT FROM AUTHOR]

In 1814, Li Huaiyuan, alias Li Yao, Ayao (Ayew), a linguist (tongshi) in Guangzhou, was arrested and thrown into jail by the Chinese authorities, apparently for his service to the British traders in bringing letters and presents to a senior minister in Beijing. The British made various attempts to rescue him, including suspending trade with the Chinese. Ayew was ultimately sent to exile to Xinjiang. The present paper examines this so-called "Ayew Incident" in the history of East India Company trade in China. It analyses the real causes for the arrest of Ayew and explains how and why the British would want to rescue him at the risk of great loss in revenue. It hopes to demonstrate the significant role and position played by the linguists in the Canton System and Sino-British relationship in the eighteenth and nineteenth centuries. [ABSTRACT FROM AUTHOR]

English second language learners often experience difficulties in producing native-like English lexical stress. It is unknown which acoustic correlates, such as fundamental frequency (F0), duration, and intensity, are the most problematic for Chinese dialect speakers. The present study investigated the prosodic transfer effects of first language (L1) regional dialects on the production of English stress contrasts. Native English speakers (N = 20) and Chinese learners (N = 60) with different dialect backgrounds (Beijing, Changsha, and Guangzhou dialects) produced the same stimulus including both trochaic and iambic patterns. Results showed that (a) all participants produced the stressed syllable with greater values of F0, duration, and intensity; (b) Native speakers of English employed an exquisite combination of F0, duration, and intensity, while the dialect groups transfer their native prosody into their production of English lexical stress, resulting in the deviation or abnormality of acoustic cues. Results suggest that L1 native dialect background is considered as a potentially influential factor which may transfer in L2 speech encoding and decoding process. [ABSTRACT FROM AUTHOR]

Abstract: External wall insulation plays an important role in building energy consumption through affecting cooling and heating energy uses. In this paper, a study on the effects of external wall insulation thickness on annual cooling and heating energy uses under different Chinese climates is reported. Firstly, two indexes: Energy Gain Ratio (EGR) and Relative Variation Ratio (RVR) of the sum of annual cooling and heating energy uses, to assess the effects of external wall insulation thickness on energy saving potential are introduced. Secondly, a model space having four different exterior zones facing four different orientations in an office building is presented and the settings of the model space described. Lastly, the simulated annual cooling and heating energy uses for the four different exterior zones at different external wall insulation thicknesses under three different climates in China, Guangzhou, Shanghai and Beijing, are reported. The results suggested that energy saving was significant by increasing the external wall insulation thickness in exterior zones facing all orientations under Beijing’s climate, since the heating energy use was dominant and can be reduced remarkably with the increase in insulation thickness. Under Shanghai’s climate, increasing external wall insulation thickness to over 26mm would not reduce the sum of annual heating and cooling energy uses in the south-facing exterior zone, but would help save energy in exterior zones facing the other three orientations. For all exterior zones under Guangzhou’s climate, it was, however, hardly possible to reduce the sum of annual heating and cooling energy uses by increasing the external wall insulation thickness. [Copyright &y& Elsevier]

Multiyear inventories of vehicular emissions in Beijing, Shanghai and Guangzhou from 1995 through 2005 have been developed in this paper to study the vehicle emissions trends in China''s mega cities during the past decade. The results show that the vehicular emissions of CO, HC, NO x and PM10 have begun to slow their growth rates and perhaps even to decline in recent years due to the implementation of measures to control vehicular emissions in these cities. However, vehicular CO2 emissions have substantially increased and still continue to grow due to little fuel economy improvement. Passenger cars and large vehicles (including heavy duty trucks and buses) are the major sources of vehicular CO2 and CO emissions while large vehicles were responsible for nearly 70% and 80% of the vehicular NO x and PM10 emissions in these mega cities. Motorcycles are also important contributors to vehicular emissions in Guangzhou and Shanghai. [Copyright &y& Elsevier]

With the boom of big data, the Internet contains more and more personal behavior information, but it is difficult to extract effectively. A model involving multivariate processing capability must be constructed to deal with these time series with complex characteristics. In this paper, a novel hybrid model embedding Baidu Search Index is therefore proposed to implement multi-step ahead subway passenger flow forecasting. Firstly, we collect data from informative Baidu Search Index, reduce dimensionality, and screen out the powerful predictors by statistical analysis. Secondly, we extract matching common modes at similar time scales between the subway passenger flow and screened Baidu Search Index via multivariate mode decomposition being optimized by multi-objective algorithm. Furthermore, to eliminate pseudo statistical causality, we select the optimal combination of modal components between subway passenger flow and its corresponding Baidu Search Index at each time scale by an innovative multi–modal analysis strategy. Thirdly, we reconstruct the forecasting values of each selected optimal combination as the final results. The empirical results of Beijing, Shanghai and Guangzhou show that the proposed model can significantly outperform six benchmark models in both the level and directional accuracy. So introducing Baidu Search Index creates a sound opportunity to enhance the subway passenger flow forecasting ability. [ABSTRACT FROM AUTHOR]

• Passengers' behavioural responses toward passenger flow control strategies. • NL model for departure time and mode shift decisions. • Mathematical programming with NL-based SUE constraints. • Trade-off between operational efficiency and service fairness. • Empirical case studies of Guangzhou and Beijing metros. This paper presents a methodology for developing demand-responsive passenger flow control strategies for oversaturated metro networks. A stated preference-off-revealed preference survey was conducted to capture passengers' behavioural responses to the passenger flow control strategies, and revealed significant behavioural change intentions in terms of departure times and mode choices. Currently, such behavioural responses are often ignored, leading to deviations in estimating the size of a target group and performance of a proposed strategy. To address this issue, in this study, a mathematical programming with equilibrium constraints (MPEC) approach was developed to optimise demand-responsive passenger flow control strategies. The proposed MPEC model highlights the importance of balancing the operational efficiency of a metro system with service fairness perceived by passengers. In particular, a nested logit-based stochastic user equilibrium problem was included to accommodate potential changes in demand patterns driven by candidate passenger flow control strategies. Two empirical cases based on the Guangzhou and Beijing metros were used to demonstrate the effectiveness of the proposed model and solution algorithm. The results show that the inclusion of service fairness considerations does not contradict the pursuit of efficiency. Instead, dual emphases on service fairness and passengers' behavioural responses help create a win–win situation for both metro operators and passengers. In the Guangzhou and Beijing metros, the highest section load rate decreased from 126.6% to 105.7% and from 122.98% to 106.87%, respectively, under the optimal passenger flow control strategies. The corresponding network load Gini coefficients improved from 0.278 to 0.259 and from 0.269 to 0.248, demonstrating the remarkable performance of this approach in regards to peak cutting and load balancing. [ABSTRACT FROM AUTHOR]

With the continuous advancement of global urbanization and increasingly serious ecological problems, ecological space protection has gradually become one of the concerns of urban planning. Although some cities worldwide have relatively robust urban planning implementation systems, due to the different planning means and methods of ecological space protection, there lacks a set of standards for the evaluation and inspection of ecological spatial planning implementation, and the traditional evaluation method has some obvious shortcomings, such as low efficiency, poor accuracy, and one-sided comparison. Therefore, the content of this paper includes the following. (1) An evaluation framework for the implementation of ecological spatial planning is proposed, and was constructed from the following four dimensions: ecological index control, spatial form evolution, ecological reserve control, and policy implementation. (2) To verify the operability of the framework, the implementations of the ecological spatial planning of Beijing, Shanghai, and Guangzhou, three cities in China characterized by rapid urbanization processes, were analyzed and compared. The results show that Guangzhou has the best implementation performance, followed by Beijing with a small gap, while Shanghai lags behind the former two with a large gap. The proposed evaluation framework provides a multi-dimensional and comprehensive evaluation method for the implementation of ecological spatial planning, as well as a certain reference for the evaluation of rapidly urbanizing areas worldwide. [ABSTRACT FROM AUTHOR]

Biomonitoring provides direct evidence of the bioavailability and accumulation of toxic elements in the environment, and homing pigeons have been proposed as a biomonitor of atmospheric pollution. We evaluated metal concentrations in homing pigeon feather tissue as a biomonitoring tool. We measured cadmium, lead, and mercury concentrations in feathers collected from 5–6-yo homing pigeons from Guangzhou, Beijing, and Harbin, China during 2011, and feathers of 1, 5, and 10-yo homing pigeons collected from Guangzhou, Beijing, and Harbin, China during 2015–16. We compared metal concentrations in feathers between sexes and among ages and evaluated spatio-temporal differences. Correlations between feather metal concentrations and previously evaluated kidney and liver metal concentrations are reported. There were no significant differences in feather metal concentrations between male and female pigeons or among 1, 5, and 10-yo pigeons. Cadmium, lead, and mercury concentrations in feathers of 1-yo pigeons were significantly correlated with concentrations in liver and kidney tissues, although the correlations were not consistent. Spatio-temporal differences in feather metal concentrations suggest the usefulness of feathers in identifying areas of concern and remedial effectiveness. Homing pigeon feather metal concentrations appear to be useful as a screening biomonitoring tool. [ABSTRACT FROM AUTHOR]

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Many methods have been developed to verify the correlation between meteorological conditions and air pollutants; however, all have limitations that lead to biased or incomplete conclusions. Hence, improved methods are urgently required to describe this correlation comprehensively and accurately. In this study, we demonstrated the ability of the Copula function to apply time‐varying correlations between meteorological factors and atmospheric pollutants. A mixed Copula model was constructed using meteorological monitoring data for Beijing and Guangzhou from 2014 to 2019 to dynamically analyse the correlation characteristics and tail dependence between these factors. We then performed a correlation analysis for the data from the average, lower, and upper tails to obtain a more accurate and comprehensive correlation description. Dynamic analysis results demonstrated significant seasonal fluctuations between meteorological conditions and pollutants relationships. Moreover, the correlation coefficient variations differ according to their average and tail values. High humidity is more likely to be accompanied by increased NO2 compared with average summer humidity. Our proposed model represents a novel application of the Copula function for determining the factors influencing air pollution. This model emphasizes the tail dependence between meteorological conditions and air pollutant concentrations and can be used to guide more targeted prevention and control strategies. [ABSTRACT FROM AUTHOR]

Dengue is considered non-endemic to mainland China. However, travellers frequently import the virus from overseas and local mosquito species can then spread the disease in the population. As a consequence, mainland China still experiences large dengue outbreaks. Temperature plays a key role in these outbreaks: it affects the development and survival of the vector and the replication rate of the virus. To better understand its implication in the transmission risk of dengue, we developed a delay differential equation model that explicitly simulates temperature-dependent development periods and tested it with collected field data for the Asian tiger mosquito, Aedes albopictus. The model predicts mosquito occurrence locations with a high accuracy (Cohen's κ of 0.78) and realistically replicates mosquito population dynamics. Analysing the infection dynamics during the 2014 dengue outbreak that occurred in Guangzhou showed that the outbreak could have lasted for another four weeks if mosquito control interventions had not been undertaken. Finally, we analyse the dengue transmission risk in mainland China. We find that southern China, including Guangzhou, can have more than seven months of dengue transmission per year while even Beijing, in the temperate north, can have dengue transmission during hot summer months. The results demonstrate the importance of using detailed vector and infection ecology, especially when vector-borne disease transmission risk is modelled over a broad range of climatic zones. Author summary: Dengue is a mosquito-borne disease and the transmission of its virus depends on four factors: The presence of 1) the virus, 2) the human host, 3) the mosquito vector, and 4) the suitability of environmental conditions. Mainland China faces regular dengue outbreaks. Because the virus is constantly imported by infected travellers into the susceptible populations of Chinese metropolises, factors 1) and 2) are almost always met. We now investigate factors 3) and 4) to see when and where the risk for outbreaks is greatest. We use a novel model that considers the development of both the mosquitoes and the viruses under different climate conditions. Our findings suggest that the Asian tiger mosquito (Aedes albopictus) can potentially transmit dengue virus over large parts of mainland China; the biggest transmission risk is simulated over southern China where large outbreaks have occurred historically, but also over the temperate north, as far as Beijing, where smaller dengue outbreaks could occur during hot summer months. [ABSTRACT FROM AUTHOR]

This study examines Chinese consumer's demand for yogurt and evaluates the effect of advertising on yogurt demand in four first‐tier cities in China. An almost ideal demand system augmented with advertising is estimated, and advertising on local media channels is distinguished from that on national media channels. The main findings are that Chinese demand for yogurt is generally elastic, yet local brands tend to have smallest own‐price elasticities. More importantly, while local advertising has generally a positive effect on yogurt demand, national advertising is found to decrease demand in Beijing and Guangzhou. This may be due to households' distinct media preference across cities, as well as advertising cannibalisation within brand. Lastly, advertising one yogurt brand may function similarly as generic advertising in promoting demand for yogurt with other brands. Corresponding marketing implications are drawn for yogurt manufacturers and marketers. [ABSTRACT FROM AUTHOR]

Globalization can promote the flow of production factors across countries and regions. Developing "global cities" in China is conducive to enhancing China's international competitiveness and participation in the world's economic activities. Relevant theories reveal that globalization is of great significance to urban socio-spatial restructuring, and the social polarization or professionalization issues brought by "global cities" have been controversial. Based on the data from the statistical yearbooks of Beijing, Shanghai, and Guangzhou, this study tries to test the global city hypothesis through the analysis on these three "global cities" in China. The study finds that Beijing and Shanghai have shown certain social polarization characteristics in the process of social differentiation, while Guangzhou has not. The results can provide scientific support for the formulation of urban management and household registration policies in China. [ABSTRACT FROM AUTHOR]

Understanding the level of indoor air quality is very important to improve the quality of air that people breathe indoors. In this paper, a comprehensive evaluation method combining rough sets and a wavelet neural network is proposed to evaluate the indoor air quality of buildings. Through on-site inspections of the indoor air in six large shopping malls in Beijing, Wuhan and Guangzhou, raw data of the environmental parameters affecting the indoor air quality of large shopping malls are obtained. First, rough sets are used to reduce the dimension of features that affect indoor air quality by removing unimportant features, and important environmental parameters that affect indoor air quality are obtained. These important environmental parameters are used as input parameters of the wavelet neural network. Then, the structure of the wavelet neural network is determined, and an evaluation model of the indoor air quality of buildings based on rough sets and the wavelet neural network is established. Finally, the model is applied to the evaluation of indoor air quality in large shopping malls, and the back propagation neural network, fuzzy neural network and Elman neural network are introduced for comparison of the testing accuracy of the wavelet neural network in the sample testing stage. The results show that the structure of the wavelet neural network is optimized by using a rough set to reduce the redundant attributes of the data, and that the comprehensive evaluation method based on rough sets and a wavelet neural network can accurately evaluate the indoor air quality level of buildings. The results of this study have significance for and can guide the evaluation of the indoor air quality of buildings. • A new comprehensive evaluation method is proposed for indoor air quality of buildings. • The combination of rough sets and a wavelet neural network is analyzed. • The genetic algorithm in RS theory is applied to perform attribute reduction. • The accuracy comparison of several evaluation models based on rough sets and different neural networks is made. [ABSTRACT FROM AUTHOR]

Estimation of the Same Frequency Test and Recurrence Level of Rainstorm and Flood in the Design of Medium and Small Watersheds in South ChinaZHAO Lingling1,2*，LIU Changming2，CHEN Zishen3(1.Guangzhou Institute of Geography, Guangzhou 510002, China: 2.Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101；3. College of Water Sciences, Beijing Normal University, Beijing,100875，4. School of Geography and Planning, Sun Yat-Sen University, Guangzhou,510275)Abstract: The rationality of design flood has a direct impact on the safety of people's lives and property in flood protection zones.The design flood is deduced from the design storm based on the assumption that the rainstorm flood has the same frequency in the current flood design of small and medium-sized basins. Therefore, the assumption of the same frequency of rainstorm flood and the probability distribution of rainstorm flood encounter have become the key to verify the rationality of design flood in small and medium watersheds. Based on the hourly rainstorm and flood observation data from 1967 to 2013 in the typical heavy rainfall basin of Caojiang River in the upper reaches of Jianjiang River, this paper firstly analyzes the marginal distribution of the maximum surface rainfall and the maximum flood peak discharge of corresponding fields, then analyzes the encounter probability of the joint distribution of rainstorm and flood peak, and calculates the design recurrence level. The main conclusions are as follows: 1) the probability of the same frequency of rainstorm and flood is small in the basin; more rainstorm and flood appear in the same frequency in the corresponding period of rainstorm and flood field; 2) the condition that the peak discharge is greater than or equal to the design value of a certain frequency when the rainfall is greater than or equal to the design value of a certain frequency in the basin. The probability decreases with the decrease of the probability of excess value; 3) The probability of rainfall and flood peak discharge encountering conditions shows that there are many flood control design criteria; 4) Compared with the "or" joint recurrence period and the "and" recurrence period, the Kendall recurrence period more accurately reflects the risk rate of R-Q combination, and the maximum probability principle does not predict the risk. The Kendall recurrence period design value, which combines the probability of surfacerainfall and flood peak discharge encountering in the same basin, can provide more reference for the selection of flood control standards and risk management. Key words: design storm flood; hydrologic excerpt table; encounter probability; Kendall recurrence period; small and medium watershed [ABSTRACT FROM AUTHOR]

Atmospheric oxidation capacity is the basis for converting freshly emitted substances into secondary products and is dominated by reactions involving hydroxyl radicals (OH) during daytime. In this study, we present in situ measurements of ROx radical (hydroxy OH, hydroperoxy HO2 , and organic peroxy RO2) precursors and products; the measurements are carried out in four Chinese megacities (Beijing, Shanghai, Guangzhou, and Chongqing) during photochemically polluted seasons. The atmospheric oxidation capacity is evaluated using an observation-based model and radical chemistry precursor measurements as input. The radical budget analysis illustrates the importance of HONO and HCHO photolysis, which account for ∼50 % of the total primary radical sources. The radical propagation is efficient due to abundant NO in urban environments. Hence, the production rate of secondary pollutants, that is, ozone (and fine-particle precursors (H2SO4 , HNO3 , and extremely low volatility organic compounds, ELVOCs) is rapid, resulting in secondary air pollution. The ozone budget demonstrates its high production in urban areas; also, its rapid transport to downwind areas results in rapid increase in local ozone concentrations. The O3 – NOx –VOC (volatile organic compound) sensitivity tests show that ozone production is VOC-limited and that alkenes and aromatics should be mitigated first for ozone pollution control in the four studied megacities. In contrast, NOx emission control (that is, a decrease in NOx) leads to more severe ozone pollution. With respect to fine-particle pollution, the role of the HNO3 – NO3 partitioning system is investigated using a thermal dynamic model (ISORROPIA 2). Under high relative humidity (RH) and ammonia-rich conditions, nitric acid converts into nitrates. This study highlights the efficient radical chemistry that maintains the atmospheric oxidation capacity in Chinese megacities and results in secondary pollution characterized by ozone and fine particles. [ABSTRACT FROM AUTHOR]

This study is committed to understanding the tremendous changes that have occurred in China's media ecology due to economic reform and the growth of technology. Based on 146 in-depth interviews with journalists from 79 media outlets in four main cities, the current study provides a sufficient understanding of contemporary journalists in Mainland China. The authors summarise the social profiles, work conditions, political values and professional orientations of both traditional and online journalists, and examine how differences between journalists are contingent on the organisational form and geographical location of the media where they work. [ABSTRACT FROM AUTHOR]

This article draws on interview and documentary data from three anti-incinerator campaigns in Beijing and Guangzhou to examine how urban middle-class homeowners respond to potential local health hazards. It illustrates how and why campaigners shifted from a heavily localized “not-in-my-backyard” (NIMBY) approach that opposed incinerators based on their siting towards a much broader critique of incineration that exploited weaknesses in waste management policy. Although public health concerns remained central during the course of the three campaigns, how they were presented changed as campaigners developed expertise through self-study. This enabled them to construct an alternative narrative about incineration and present their arguments from a public interest perspective, thus deflecting the pejorative NIMBY label. [ABSTRACT FROM PUBLISHER]

The article discusses the possibilities for scholarly research concerning mass media and the Olympic Games and other major sporting events as of October 2012. It examines the opportunities offered by studying China's administration of the 2008 Summer Olympic Games in Beijing, China, and the 2010 Asian Games held in Guangzhou, China. It also discusses what the author identifies as the Olympic communication complex of television, radio, and social media as an area of possible research. The article also examines the balance between the East and West in sports media and its relationship to shifts in global power.

Accompany with the growth of homeownership, China has also witnessed a sweeping increase of homeowners' protests in the urban grassroots. When these actions are read from the meaning for civil society, action features per se are ignored. Many scholars agreed that the grassroots protests in rural China follow the logic of rightful resistance. But there is little attention paid to the urban neighborhood activism. Do the homeowners employ the rightful resistance for their protests? Is there any difference between the rural and urban rightful resistance? And what factors influence homeowners' action choice? When the proactive claims emerged in countryside, have the homeowners shown some requirement beyond the existing rules and regulations? The study is is to explore these questions and further the understanding on the characteristics and substance of grassroots resistances in urban China. [ABSTRACT FROM AUTHOR]

This cross-cultural study of international tourists' main destination choices (MDCs) within China's three major gateway cities – Beijing, Shanghai and Guangzhou – adds to the literature in two respects. First, a cognitive ‘cultural distance’ variable, formed from cultural constructs perceived by the respondents was used to underpin the comparative framework in addition to usually applied cultural proxies, such as nationality, in cross-cultural studies. A discreet choice modelling approach is used to address the operational challenges of incorporating behavioural elements in choice analysis. The research findings support the international gateway positions of Beijing and Shanghai, but that of Guangzhou is questioned. The research also revealed that, although both of the two types of cultural variables are related to the MDCs of the tourists, the level of significance of ‘cultural distance’ and ‘cultural proxies’ at expressing the differences of tourists' MDCs within a destination country are not parallel. The former appeared to be a more sensitive element in determining the behavioural patterns of international tourists than the latter. Geographical distance and demographic characteristics show no significant interrelationship with the MDCs of international tourists within a destination country. [ABSTRACT FROM AUTHOR]

New urban and economic development are transforming the fundamental nature and structure of China's cities. The distinctive patterns wrought by overlaying socialist ideals on the pre-1949 city are giving way to new forms reflecting the country's dynamic economic, social and political conditions. This article provides an analysis of the patterns and processes of change in urban form in contemporary Beijing, Shanghai and Guangzhou. Analysis of these rapidly changing cities highlights both the regional variation in urban development in China and the emergence of common trends in development and form. The article focuses on patterns of land-use specialisation, circulation and building height, and processes of planning, urban renewal and privatisation of the real estate market. [ABSTRACT FROM AUTHOR]

Ozone (O3) pollution has become an increasing concern in China since elevated surface O3 concentrations were observed in recent years. In this study, five provincial cities (Beijing, Shanghai, Guangzhou, Xi'an, and Hefei) located in different regions of China were selected to study the spatiotemporal variations and affecting factors of O3 concentrations during 2014–2015. Beijing, Shanghai, and Guangzhou had suffered more severe O3 pollution, yet Beijing had the highest number of days that exceeded the Chinese MDA8 (maximum daily 8 h average) standard of 160 µg m−3. MDA8 O3 exhibited different seasonal patterns among the five cities. In Beijing and Xi'an, MDA8 O3 showed the highest in summer and lowest in winter. Guangzhou also had the highest O3 concentration in summer, but had similar levels in other three seasons. The O3 levels were similarly high in Shanghai during spring, summer, and autumn, while in Hefei, O3 concentration peaked in autumn. No significant difference between weekend and weekday O3 levels was observed in all the five cities. The diurnal cycle reached a maximum in the afternoon and a minimum in the early morning, which was consistent in the five cities. Correlation analyses showed that the associations between O3 and the other five criteria air pollutants, as well as meteorological parameters, were substantially different among the five cities. Air mass cluster analyses during episodic days revealed that the short-distance transport of O3 and its precursors had a greater impact for high O3 pollution in the five cities. Overall, our results demonstrate that O3 pollution exhibited great divergence among different regions and thus region-oriented control measures are suggested to reduce O3 pollution in China. [ABSTRACT FROM AUTHOR]