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This paper utilizes an improved undesirable output DEA model to measure the eco-efficiency of cities in five major urban agglomerations in China during 2006–2020. It employs the Theil Index and Geodetector to investigate the spatial-temporal distribution differentiation characteristics and driving factors of urban eco-efficiency. The main findings are as follows. Firstly, the eco-efficiency of all urban agglomerations showed a fluctuating upward trend, but the eco-efficiency performance of different urban agglomerations in China shows a stratification characteristic. Specifically, the Pearl River Delta urban agglomeration consistently ranks first in China, while the mean values of the Yangtze River Delta urban agglomeration, Beijing-Tianjin-Hebei urban agglomeration, and Chengdu-Chongqing urban agglomeration are lower than the national average. Secondly, the overall differences in the urban eco-efficiency of all sample cities show a consistently fluctuating downward trend. The factor that affects the level differences of eco-efficiency in different cities is the intra-regional differences. Last but not least, the top three factors affecting the spatial distribution difference of urban eco-efficiency in the whole sample are environmental pollution control investments, innovation level, and environmental infrastructure investments. In the end, this paper proposes that reducing the intra-regional differences is the primary task to achieve the coordinated improvement of urban eco-efficiency in urban agglomerations, and then puts forward some policy suggestions to improve eco-efficiency for the five major urban agglomerations. [ABSTRACT FROM AUTHOR]

With the advent of the era of Industry 4.0, big data and the Internet of Things came into being. The rise of big data and the Internet of Things has had an impact on all walks of life. The development of big data and the Internet of Things provides an opportunity for the evolution of street form. With the rapid development of smart cities, the street shape is also changing more and more towards the direction of intelligence. Taking Chunxi Road in Chengdu as an example, this paper studies the generation mechanism of street morphology. The factors influencing the generation of street form are divided into two categories: (1) legal factors. (2) Architectural design factors. By building a model, the article quantitatively analyzes the impact of these two types of factors on street form. At the same time, the article conducts an in-depth study on the evolution of ancient Chinese street morphology. The ancient Chinese street form is divided into four stages, namely the Tang and Song Dynasties, the Yuan, Ming and Qing Dynasties, the Late Qing Dynasty, and the founding of New China. The influencing factors of street shape are divided into four categories, namely, the influence of commodity economy, the influence of foreign culture, the influence of building materials, and the influence of traffic. This paper elaborates the influence mechanism of these four factors on the street form in China. The article finally puts forward the development trend of my country's future street form, and points out that the evolution of my country's street form will develop in the direction of intelligence, and intelligent transportation, intelligent garbage classification system, etc. will be applied. The number of brick-and-mortar stores in my country's street layout may decrease. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of digital reading during educational disruption on science and engineering students' learning experience. Before the pandemic, some studies explored whether university students preferred using printed or digital resources for their academic readings. Amidst the pandemic, online learning became essential. Several studies showed students' preference for printed text. This paper extends a pilot study that was conducted during the first COVID-19 wave in China. A survey consisting of Likert questions and open questions was designed using MS-Forms. The survey was shared with the science and engineering students in Years 2–4 (Levels 1–3) of their study at SWJTU-Leeds Joint School, Southwest Jiaotong University in Chengdu, China. This covered students from four undergraduate programs: Civil Engineering with Transport, Electronic and Electrical Engineering, Mechanical Engineering, and Computer Science. In total, 223 students participated in this study. The survey was anonymous and was made available to students for a month. The participation rate is nearly 27%. Findings indicate that the behavior of science and engineering students toward digital reading was different than other majors, and it is generally favorable. The necessity for online learning during educational disruption has encouraged some students to develop their digital reading skills. [ABSTRACT FROM AUTHOR]

Early work on China's Two-Child Policy identified cost as a major disincentive to having a second child, but financial constraints may work in tandem with cultural factors to shape childbearing desire. In addition, most research has excluded men from the sample. This paper develops Yan's (2003) concepts of 'new' and 'traditional' fertility cultures to childbearing desire, a key component of fertility decision-making that is poorly understood (Hayford & Agadjanian, 2017). In particular, we focus on how differing conceptions of children's needs relate to perceptions of cost. This paper reports on semi-structured interviews with 29 men and women in Chengdu, the capital of Sichuan province. We found that interviewees who espoused views consistent with a traditional fertility framework were more interested in having a second child, and were less concerned about cost. In addition, men were more likely to espouse views consistent with a traditional fertility cultural framework. [ABSTRACT FROM AUTHOR]

China's foreign capital R&D network has become a core component of the high-quality development of the national innovation ecosystem. Narrowing the spatial difference in the foreign R&D network is considered an essential strategy to improve China's holistic innovation capability. Previous studies only examined the internal factors of the system while mostly ignoring the quantitative analysis of the spatial differences diffusion. Based on the dissipative structure theory, the current paper demonstrates the construction of positive and negative entropy indexes of foreign capital R&D networks in China. Rested on a survey dataset of 340 foreign R&D institutions in 21 Chinese provinces from 2016 to 2017, this paper analyzes the spatial differences and driving factors of the innovation development of foreign capital R&D networks across the country using the Brusselator model. The results show that China's entire deviation degree of foreign capital R&D networks is small. Still, there are significant spatial differences in the deviation between the entropy value and the ideal status of dissipative structure in foreign R&D networks, with the minor deviation-value areas located in the eastern regions. In addition, the central and western regions where the late-mover layout of the foreign R&D network deviates are far from the ideal status. Among them, the western (i.e., Xi'an and Chengdu) foreign R&D network is significantly better than the central innovation performance. It is found that policy traction of talent advantage and intellectual property rights protection positively impact the negative entropy flow of foreign R&D networks in China, which becomes an influential driving force for the future system equilibrium. The paper concludes with several policy implications to guide China's innovation and ecological optimization of foreign capital R&D networks. [ABSTRACT FROM AUTHOR]

One of the most important archaeological finds excavated from the Tianhui Laoguanshan Han tombs in 2012–13 was a manuscript on horse medicine, dated around the third century BCE. Prior to the discovery of this highly specialized veterinary text, only a handful of horse recipes from the Qin and Han periods had been found, and a sixth-century CE agricultural treatise, Essential Techniques for the Common People , was generally regarded as the earliest surviving source of extensive veterinary material, including various medical treatments for horses. Although the Laoguanshan manuscript – given the modern title Book of Treating Horses by the Team for Collating the Medical Bamboo Slips Excavated from the Han Tombs in Tianhui Town, Chengdu – has suffered significant damage, it nevertheless gives us an insight into the knowledge and treatments for horses during the Qin and early Han periods. A variety of ways of treating horses are recorded in Treating Horses , including herbal remedies, piercing, cauterization, hot packs, bandages, massage, and bathing. The use of gold needles is also mentioned in this text, echoing the gold and silver sewing needles excavated from Liu Sheng's (d. 113 BCE) tomb in Mancheng, Hebei Province. This paper offers a short introduction to this valuable text on horse medicine by examining the content of its fragments, including names of ailments, symptoms of certain diseases, etiologies, and treatment methods. The discovery of Treating Horses challenges the established view that horse treatment methods in ancient China were predominantly herbal and that techniques of bleeding and cauterization recorded in Essential Techniques were brought to China from elsewhere, together with the introduction of Buddhism. The paper argues that the "foreign influence" had already occurred at a much earlier date, in the form of interactions with nomadic tribes such as the Scythians, the horsemen par excellence of classical antiquity. [ABSTRACT FROM AUTHOR]

Rural China is experiencing rapid socioeconomic transformations, including suburbanisation and rural gentrification. In this paper, we argue that to understand these processes, we have to take into account the changes in rural land rights. Based on an analysis of a pilot case for China's rural collective commercial construction land (RCCCL) reform policy at the edge of Chengdu City, we demonstrate how state-led rural land reform paves the way for stealthy land dispossession and rural gentrification. Our argument in this paper is threefold. First, given the entrenched collective land use rights of rural villagers in China, state-led land commodification, is a necessary condition for rural gentrification in China. Secondly, the prospect of capital accumulation through rural gentrification motivates entrepreneurial public and private actors to promote such reforms in ways that dispossess rural peasants and peasant collectives of their land (use) rights. Thirdly, the particularities of dispossession through state-led land reform result in particular experiences of displacement and displacement pressure on the side of affected rural communities. Our findings contribute to the decentring of rural gentrification theory, in that they underline the necessity to include the particular histories of land commodification and dispossession in our understanding of rural gentrification in contexts where rural land is partly or wholly shielded from market influences. In the case of China, dynamics of rural gentrification are blurring the rural-urban boundary on three dimensions: political economy (land use governance), material infrastructure (landscape and residential architecture), and socio-cultural practices (rural livelihoods and identity). • Rural land regimes structure peri-urban development in China. • Land commodification is a precondition for rural gentrification in China. • Original villagers are dispossessed and displaced. • Rural gentrification blurs the rural-urban boundary in terms of land use (rights), landscape and social relations. [ABSTRACT FROM AUTHOR]

The paper contributes to the literature on rural gentrification by incorporating empirical evidence from amenity-poor rural areas in the developing world. While current literature on rural gentrification has largely focused on the gentrification process in amenity-rich rural areas, the present study examines rural gentrification process in a historically polluted county in Chengdu, Sichuan Province, China. The gentrification process features a holistic transformation of farmland into an artificial landscape, thereby segregating gentrifiers from both polluted rural space and unwelcoming urban space. The paper attributes the rise of holistic gentrification to state-initiated farmland concentration, and to the gentrifier developers' practices of redefining rurality as immersive resort experiences. The paper concludes that the holistic gentrification was conducive to job losses in both the recreation and agricultural sectors, consequently reducing peasant households to a state of passivity and dependency, while collective actions against gentrifier developers were ineffective owing to highly skewed power dynamics. • Holistic gentrification transforms large-scale farmland into scenic rural resorts in amenity-poor rural areas in China. • Holistic gentrification is caused by national peasant relocation programs. • Gentrifier developers redefine rurality as immersive resort experience. • Holistic gentrification is conducive to local job losses in recreation and agricultural sectors. [ABSTRACT FROM AUTHOR]

With the deepening of urbanization in China, the coordinated development of cities in different regions is an important part of the sustainable development of the country, and the reasonable quantification of the unbalanced development of cities in different regions is an important issue facing the society nowadays. Previous studies usually use population data to analyze the power-law distribution law to quantify the imbalance of urban development in different regions, but China's population data span a large number of years and numerous division criteria, and the results obtained from different population data are widely disparate and have obvious limitations. The paper starts from a fractal perspective and utilizes OpenStreetMap (OSM) data to extract national road intersections from 2015 to 2022, calculates critical distance thresholds for eight years using urban expansion curves, generates urban agglomerations in China, and quantifies the imbalance of urban development in different regions by calculating the urban agglomeration power-law index. The results indicate that (1) the critical distance threshold of urban expansion curves exhibits a slight overall increase and stabilizes within the range of 120–130 m, (2) the number of urban agglomerations in China has been increasing significantly year by year, but the power-law index has been decreasing from 1.49 in 2015 to 1.36 in 2022, and (3) the number of urban agglomerations and the power–law index of the Beijing–Tianjin–Hebei, Yangtze River Delta, Pearl River Delta, and Chengdu–Chongqing regions, which is consistent with the national scale trend, indicates that the scale distribution of urban agglomerations in China at this stage does not conform to Zipf's law, and there is a certain Matthew effect among cities in different geographic areas with a large unevenness. The results of the study can provide new ideas for assessing the coordinated development of cities in different regions. It compensates for the instability of population and economic data in traditional studies. [ABSTRACT FROM AUTHOR]

Despite growing scholarly attention on the role of urban networks for understanding regional dynamics, there has been limited research examining the impact of cities' transportation network connections on regional market integration. This paper analyzes China's four major urban agglomerations: the Yangtze River Delta, the Pearl River Delta, Beijing-Tianjin-Hebei, and Chengdu-Chongqing. Applying a spatial Durbin model to cross-sectional datasets for 2019, we provide insight into the role of cities' transportation network connections in promoting regional market integration, considering both the potentially heterogeneous impact of network connections and the interplay between network and agglomeration externalities. Our results indicate that: (1) cities' transportation network connections have an inverted 'U'-shaped effect on regional market integration; (2) transportation network connections have spatial spillover effects; (3) the positive impact of transportation network connections on regional market integration becomes more pronounced as city size decreases; and (4) there are neither complementary nor substitution effects between network and agglomeration externalities. We reflect on the broader implications of our empirical findings for regional development strategies and discuss possible avenues for further research. [ABSTRACT FROM AUTHOR]

In daily operation, urban rail transit (URT) systems often experience disturbances that result in a partial reduction in transport capacity [partial disturbances (PDs)] rather than disturbances leading to a complete reduction in transport capacity. However, research that assesses the resilience of URT networks under PDs remains limited. This paper addresses this gap by proposing a passenger-oriented resilience assessment model for URT networks under PDs, considering the travel behaviors of passengers and different relations (i.e., linear, concave, and convex) between the velocity coefficient and failure severity. A simulation-based assessment approach was developed to solve the resilience assessment model. A numerical experiment was conducted on the Chengdu subway network in China. The results demonstrate that the performance indicator employed herein reflects the impact of passenger travel time distribution on network performance. Deliberate PDs cause more significant performance losses than random PDs. Moreover, the network is the least resilient under PDs considering the convex relation between the velocity coefficient and failure severity. The resilience-based critical link of each line is not fixed and varies with the failure severity and disturbance occurrence time. Increasing the failure severity of PDs results in more severe performance losses than increasing the number of PDs. Additionally, the passenger-oriented resilience of a URT network can be enhanced by improving the passengers’ tolerable delay time and disturbance duration. [ABSTRACT FROM AUTHOR]

Due to the rapid urbanization and climate change, one of the pressing problems confronting Chinese cities lies in air pollution. Especially during recent years, most cosmopolitan cities in China suffer from thick smog caused by PMs. It is reported that such air pollution has close relations with traffic-related pollutants, such as NO2. Meteorological condition contributes significantly to long-range transport sources and has remarkable influences on the distribution of the above pollutants. Thus, it is necessary to quantitatively analyze such influential patterns. In this paper, taking Chengdu as an illustrative example, the meteorological and pollutant statistics in 4947 h are collected and fitted with 8 meteorological parameters of PM2.5, PM10, and NO2 through linear regression method. And data is analyzed and compared on the hourly, daily, weekly, and monthly basis, respectively. Results show that hourly and daily data focus on fluctuations that affected by multiple interferences other than meteorological influences. When hourly values of PM2.5, PM10, and NO2 exceed 175 μg/m3, 250 μg/m3, and 125 μg/m3, respectively, discrete values that cannot be explained by meteorological influences increase notably, while weekly and monthly variations illustrate more tendencies, and communicable patterns that decisively influenced by meteorology can be extracted among 3 pollutants. By comparing the results in 4 timescales, respectively, similar principal meteorological factors are involved in fitting processes. Thirdly, visibility (V), wind speed (WS), precipitation (P), and cloud condition (CC) are the most influential factors and served as main parameters in linear regressions within 4 timescales. Air temperature (AT) and dew temperature (DT) are less influential factors by daily and weekly data but are served as main parameters when it goes to hourly and monthly data and function as variables that signify tendency variances in linear regressions, while relative humidity (RH) and barometric pressure (BP) are lest influential factors and have limited effect on fitting results. This work can provide guidance and reference for urban planning optimization and air environment protection in cities with air quality control considerations impacted by local climatic conditions. [ABSTRACT FROM AUTHOR]

In China, there is a "psy‐boom," which is understood as the rapid increase in the provision of psychological services and interest in psychological concepts since the initiation of market reforms. This is a heavily gendered phenomenon. This paper seeks to explore why women are drawn into the psy‐boom and what sustains their participation in it. Following a year of fieldwork engaging in various forms of psychotherapy training in the city of Chengdu, the provincial capital of Sichuan province, China, the paper looks in detail at three women who engage in the psy‐boom. The psy‐boom creates a space for these women to try to articulate complex and often competing desires thrown up by the gendered circumstances in which they find themselves. The paper shows how each of these three women draws on their various engagements with the psy‐boom to try to formulate and actualize their visions of the good life. [ABSTRACT FROM AUTHOR]

• Rural restructuring in China is theorized as a transition towards productivism. • China now has a productivist agricultural regime. • Uses Halfacree's three-fold model of rural space to analyse productivist space. • Residential restructuring produces spaces of productivism in new rural settlements. • Productivist residential space strengthens productivist agriculture. This paper theorizes the rural restructuring in China today as a transition towards productivism – characterized by both a productivist agricultural regime and productivist rural spaces. The rise of the productivist agricultural regime has spearheaded this transition for two decades; now the residential restructuring programs implemented under various policy schemes are also producing spaces of productivism in the new concentrated settlements. This paper, employing Halfacree's three-fold conceptual model of rural space and using the empirical case of residential restructuring in Chengdu, offers the first full analysis of the rise of productivism in all three facets of rural space. It demonstrates both how formal representations and planning practices are building spaces of productivism in a multi-scalar process and how this new spatiality is contested and modified by residents in their everyday lives, creating tensions and contradictions in the emerging productivist rural spatial regime. A key insight from this study is that the productivist transformation of residential space is constitutive of the broader transition to productivism and crucial to the rise of productivist agriculture. [ABSTRACT FROM AUTHOR]

This paper examines how the government harnesses the development of social enterprises. Drawing on an in-depth qualitative study in Chengdu City, China, we find that institution building, financial supporting, incubation developing, systematical cultivating and resource matchmaking are the main strategies employed by the municipal government to promote the development of social enterprises, whereupon we argue that besides the role as referee and sponsor which are the governments' traditional roles in western countries, the government in China also play a role of coach in harnessing the development of social enterprises. This paper contributes to the literature by theorizing how administrative forces affect the growth of hybrid organizations and also contributes to providing empirical evidence of the institutional environment of social enterprises in China. [ABSTRACT FROM AUTHOR]

• A non-linear programming model to design full-day demand-adapted timetables is proposed. • The time-dependent maximum sectional passenger flow is used as input data. • A new algorithm is proposed to match demand and services' supply. • The algorithm uses a rolling-horizon mechanism to iteratively compute departure times. • The effectiveness of the proposed algorithm is illustrated using real data of Chengdu Metro line 1. This paper focuses on the problem of designing the schedule of urban rail transit systems under dynamic passenger demand considering limited train capacity and congestion. From the point of view of operators, the goal of timetable optimization consists of using as few as possible service trains to transport the arriving passengers to their destinations securely and quickly. On the other hand, passengers want to spend the minimum time travelling to their destinations, including the time they wait on platforms until they board the first and successive trains in case of transferring between lines. Due to the variability of passenger flows and the difficulty in exactly solving full-day timetabling problems in short computation times, it is difficult in practice to use the approaches proposed in the literature. Moreover, when the capacity of trains is considered and oversaturation conditions emerge, the problem becomes even more complex, converting into a challenge the design of schedules from an operational point of view. By considering fixed train dwell times at stations and train running times between stations, we first propose a non-linear programming formulation to model the problem of determining the most convenient interdeparture times of services at the first station of a line, aiming at minimizing the waiting time of passengers. Since the dynamic behaviour of passenger demand and the maximum sectional passenger flow are approximately synchronous, an innovative method, the spatiotemporal synchronization coupling algorithm, based on working with the time-varying maximum sectional passenger flow instead of the demand patterns is proposed to quickly solve in an approximate way the demand-driven timetabling problem. The proposed approach is applied to a real case of Chengdu Metro Line 1 in China. The results show the effectiveness of the algorithm, both in terms of computational effort and in terms of reducing the waiting time currently experienced by passengers. [ABSTRACT FROM AUTHOR]

This paper draws on linguistic-ethnographic fieldwork in Chengdu, China to consider the utility of broad labels such as Chinese, Western and gay in accounting for the performance of sexual and cultural identity. I problematise work which takes such notions to be stable and self-evidently referential, arguing instead that identity is much more fluid, emergent and discourse-dependent than conventional understandings tend to imply. I focus on visibility of queer sexual identity partly because it is an especially accessible example of the role of language in identity performance, being most often achieved through verbal interaction. More broadly, however, this focus emerged through my ethnographically informed, discursive-sociocultural approach to my life and research in mainland China during the period 2008–2019. Specifically, I use spoken data from the interviews which formed part of this process to argue that social practice within related ethnic and/or social groups is best understood in terms of the situated use of sociolinguistic tools and the entailed negotiation of pertinent ideological systems. From this perspective, the ostensibly insurmountable ideological pressures that "Chinese gays" are typically seen to face, and which tend to be attributed to a taken-for-granted and monolithic "Chinese culture", are better interpreted with reference to the complex relationship between language, culture and identity. Thus, I do not assume the right to make broad claims about what Chinese gays do, or to state that they are categorically different from their presumed homogenous Western counterparts. Instead, I discuss what certain individuals say in certain conversations, noting how their performance of identity is often highly individualised, being shaped according to the interactants present and the interactional aims relevant to specific moments of communication. [ABSTRACT FROM AUTHOR]

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The Local Climate Zone (LCZ) classification scheme is a vital method of building a category dataset for high-resolution urban land. For the development of urban meteorology, air pollution and related disciplines, the high-resolution classification data of urban buildings are very important. This study aims to create LCZ datasets with detailed architectural characteristics for major cities and urban agglomerations in China, and obtain more accurate results. We constructed 120 m resolution land use datasets for 63 cities (mainly provincial capitals, municipalities directly under the Central Government, important prefecture-level cities and special administrative regions) and 4 urban agglomerations in China based on the local climate zone (LCZ) classification scheme using the World Urban Database and Access Portal Tools method (WUDAPT). Nearly 100,000 samples were used, of which 76,000 training samples were used to provide spectral signatures and 23,000 validation samples were used to ensure accuracy assessments. Compared with similar studies, the LCZ datasets in this paper were generally of good quality, with an overall accuracy of 71–93% (mean 82%), an accuracy for built classifications of 57–83% (mean 72%), and an accuracy for natural classifications of 70–99% (mean 90%). In addition, 35% of 63 Chinese cities have construction areas of more than 5%, and the plateaus northwest of Chengdu and Chongqing are covered with snow all year round. Therefore, based on the original LCZ classification system, the construction area (LZC H) and the snow cover (LCZ I) were newly added as the basic classifications of urban LCZ classification in China. Detailed architectural features of cities and urban agglomerations in China are provided by the LCZ datasets in this study. It can be applied to fine numerical models of the meteorological and atmospheric environment and improve the prediction accuracy. [ABSTRACT FROM AUTHOR]

In the era of the urban economy and service economy, the decoupling of service industry land expansion from economic growth has always been a key measure to evaluate sustainable and healthy development. Based on the decoupling model and GIS spatial analysis method, this paper conducted an empirical study of Chinese cities from 2012 to 2019. Results: (1) Increasing spatial heterogeneity, correlation and agglomeration of land expansion were found in China's urban service industry and its economic growth; (2) Most cities were in weak decoupling, with evolved, degraded and unchanged cities accounting for one-third each, and the number of cities in negative decoupling was increasing, leading to increasingly diverse and complex decoupling relationships; (3) From the perspective of changes in the urban service industry land and its decoupling from economic growth, HH cities were clustered in the Yangtze River Delta, Pearl River Delta, Beijing–Tianjin–Hebei and Chengdu–Chongqing urban agglomerations in a continuous belt pattern, while LL and HL cities were mostly in the north, especially in the northeast, creating many cluster-like agglomerations that have become problematic spaces; (4) A significant synergistic effect was identified between the factors of urban permanent population, value added of the secondary industry, per capita GDP, government financial expenditure, international trade, foreign direct investment, total retail of commodities, and authorized patents, with factor pairs formed showing nonlinear enhancement. The factor value added of the secondary industry had the largest direct impact, while urban permanent population and foreign direct investment led in terms of net synergies; (5) It is recommended to introduce classified and differentiated urban service industry land use policies, plan and build a number of national, provincial and municipal modern service industry clusters, demonstrate changes in land supply and use, build a scientific and efficient land resource allocation and management system, guard against and prevent recoupling and effectively improve the ability of cities to achieve high-quality economic development. [ABSTRACT FROM AUTHOR]

The classical multi-period inventory routing problem (MIRP) combines inventory management and vehicle routing problems, attempting to maintain customer inventory levels via autonomous deliveries, with the assumption that stock-out never occurs at the supply side. While this is no more the truth when a common third-party logistics company operates a central warehouse for a group of small and medium sized retailing companies. Procurements have to be made to refill inventory at the central warehouse. This study thus extends the traditional MIRP by incorporating procurement decisions (MIRP-PD) and tries to minimize the total cost of procurement, inventory holding and transportation. To our knowledge, this paper is among the first to formally describe MIRP-PD and model it as a mixed integer linear program. A hybrid two-level heuristic is proposed to address large-scale instances. The upper level of the algorithm determines the visiting schedule while the lower level works out procurement and routing decisions accordingly. Components from tabu search and adaptive threshold acceptance are also embedded to help escape from local optima. Extensive numerical instances are generated from a real case in Chengdu (China), based on which the computational results reveal the effectiveness and efficiency of the proposed algorithm compared with the commercial solver CPLEX. The comparison between MIRP and MIRP-PD has demonstrated the cost advantage of incorporating procurement decisions into inventory and routing plans. Impacts on costs of key factors including delivery frequency and buffer size of stores have also been examined to provide managerial implications to practitioners. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office 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.)

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. 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.)

The Yangtze River Economic Belt (YREB), an important industrial belt for food security for China, is facing the challenge of decreasing cultivated land in the process of rapid urbanization. In this case, how to improve the cultivated land use efficiency (CLUE) has become the top priority. Based on data from 108 cities of YREB from 2001 to 2019, we measured CLUE using a slack-based measure with undesirable output (SBM-Undesirable). The high-value area of CLUE shows a trend from multi-core agglomeration to two-core agglomeration, mainly concentrated in Chengdu-Chongqing urban agglomeration and the northern part of the YREB. Then the paper examines the spatial effect of urbanization on CLUE using the Spatial Error Model (SEM). The result shows that population urbanization has significantly promoted the improvement of CLUE in YREB during the sample period. With each percentage point increase in population urbanization, CLUE will increase by 2.99%. Land urbanization has a negative impact on CLUE, for each percent increase in the expansion of urban spatial scope, CLUE will decrease by 0.06%. The spatial heterogeneity analysis shows that population urbanization in the lower reaches has significantly promoted CLUE, with a coefficient of 1.053. The population urbanization level in the middle and lower reaches of the region has no obvious effect on CLUE. The coefficient of land urbanization in the downstream region is 0.35, which significantly promotes CLUE. The coefficient in the middle is −0.26, which implies the CLUE decreases by 0.26% for every one percentage point increase in land urbanization. Land urbanization in the upper has no significant impact on the CLUE. Policy implications include improving the quality of the three major urban clusters along the YREB, building an ecologic protective screen in the upper, encouraging a new agricultural management system and detailed regulations related to the cultivated land protection in YREB. [ABSTRACT FROM AUTHOR]

Earth Pressure Balance (EPB) shield machines are considered to be the most efficient tunneling method for Metro tunnels due to their adaptability to a great variety of ground conditions, higher construction efficiency, and providing a safer working environment. There are many guidelines available for EPB shield machine selection. However, these guidelines are very general and cannot be used directly for an upcoming project. This paper takes Chengdu Metro Line 6 in China as the engineering background; the studied area is typical of a water-rich sandy and cobble stratum with high content of cobble. Three types of EPBs in the two continuous intervals exhibit significant differences in performance and encounter many difficulties such as wear of the cutter disc and tools, clogging, and severe surface settlement during the operation. These difficulties prevent the construction efficiency, increase the cost of the project, and cause delays in construction period. The causes of these difficulties are summarized by recording and comparing the operational parameters of the three types of EPBs. These parameters that are summarized include the advance rate, total thrust, torque, and the rate of rotation of the cutter-head. In addition, the surface settlements are also compared. The results indicate that the opening rate, maximum opening size, and the opening position of the cutter-head are key factors that affected the geological adaptability of the shield machine in water-rich sandy and cobble strata. Among the three factors, the maximum opening size and opening position are the most important factors influencing the strata adaptability of the cutter-head. To avoid frequent jams of the cutter-head, the maximum torque should be not less than 6,500 kNm. The maximum opening size should not be less than 420 mm × 420 mm. The effect of increasing the central opening of the cutter-head is that large cobbles and boulders can be discharged through the central opening when they cannot be discharged through the opening near the original position of the cobbles and boulders. This paper provides specific guidance on the selection of cutter-head for shield machines in water-rich sandy and cobble strata. [ABSTRACT FROM AUTHOR]

The development of urbanization has changed the original land cover and exacerbated the urban heat island effect, seriously affecting the sustainable development of the ecological environment. Research on urban heat island characteristics and land cover changes in five major urban agglomerations in China to provide a reference for preventing thermal environmental risks and urban agglomeration construction planning. This paper estimates the surface urban heat island intensity (SUHII) of the five major urban agglomerations in China from 2003 to 2019 based on Google Earth Engine (GEE) through the urban–rural dichotomy, analyzes their trends through the Sen + M–K trend analysis method, and combines the detrending rate matrix to analyze the impact of land cover type shift on urban heat island change. Research shows that (1) the land cover types of the five major urban agglomerations in China have changed considerably from 2003 to 2019, and all five major urban agglomerations in China experienced varying degrees of urban expansion. (2) The annual average value of SUHII decreases in Beijing-Tianjin-Hebei, Yangtze River Delta, and middle reaches of the urban agglomerations, while the annual average value of SUHII increases in Chengdu-Chongqing and Pearl River Delta urban agglomerations. (3) The spatial composition of land cover types in the five major urban agglomerations in China is highly spatially correlated with urban heat islands, with urban land and bare land urban heat islands being the most pronounced. (4) The land cover type shift has the most significant heat island impact on Beijing-Tianjin-Hebei, Yangtze River Delta, and Chengdu-Chongqing urban agglomerations. (5) The land cover change (LCC) with an increasing trend in SUHII is mainly bare land converted to arable land, and water bodies, grassland, forest land, and arable land converted to urban land. [ABSTRACT FROM AUTHOR]

With the deepening of the implementation of the “precision poverty alleviation” strategy and the continuous development of China ’s ethnic minority characteristic industry construction, more and more characteristic agricultural industry and poverty alleviation project are receiving attention. The development of characteristic agriculture is the strategic adjustment of agricultural structure in the southwestern region. The rapid development of pillar industries in the characteristic agricultural industry will inevitably promote the scale of commodity production bases and the rational allocation of resources, realize the multi-level and multi-channel development and utilization of agricultural resources, and meet the diverse and high-quality market needs. This article aims at the current situation of the characteristic agricultural industry in the southwest mountainous area, which studies the path and related policies of poverty alleviation and welloff in southwestern China. Taking Chengdu-Chongqing Economic Zone as an example, the policy background of industrial poverty alleviation, the main methods of industrial poverty alleviation, the main problems, their causes, and countermeasures analyzed and discussed in this paper. Through the research and analysis of the Chengdu-Chongqing Economic Zone samples, this paper proposes the path of industrial poverty alleviation in ethnic areas, which has a direct role in promoting poverty alleviation in the southwest mountain area. The research of poverty alleviation problem in this area will be reference for poverty alleviation in other poverty areas and ethnic minority areas. [ABSTRACT FROM AUTHOR]

Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University 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.)

Purpose: Public–private partnerships (PPPs) have emerged in developing countries, such as China, as a ubiquitous means by which government procures needed infrastructure. In this regard, they have been much studied. However, due to their long concession period, running into decades, few have run their full course into the transfer phase (TP) in which the PPP concession reverts from the private entity back to the public. In China, this is about to change as many PPPs approach their TP. Hence, the purpose of this paper is to comprehensively investigate the TP of PPPs in China. Design/methodology/approach: A three-part methodology was undertaken to achieve the research purpose. Extensive literature review was first conducted to analyze the status quo of the transfer management regime in China, followed by the identification of critical challenges and the exploration of solutions via studying the TP of the Chengdu No. 6 Water Plant B Project – the first PPP in China's water sector to reach the TP. Research procedures and outcomes were hierarchically visualized by using Integration DEFinition language 0 (IDEF0) method. Findings: The current transfer management regime of PPPs in China's water sector is deficient in many aspects. Based on the insight into the practice, a generic transfer process model with hierarchical structure process and sub-processes serving as a dynamic framework transfer model with self-evolving nature is developed to facilitate the successful transfer of the PPP utility. Originality/value: To the authors' best knowledge, this is the first attempt to systematically probe the TP of PPPs. Hopefully, the findings of this paper are to instruct government and PPP practitioners alike on mechanisms for smoothing the TP of further PPP projects ending their concession period. [ABSTRACT FROM AUTHOR]

In China, traditional food is a significant element of culture that affects human behaviors. The point of interest (POI) of traditional food restaurants' location and their volatile organic compounds (VOCs) emissions affect the urban ecology. Rather than examine potential urban development patch (PUDP) based on land use data, the perspective of this paper is to examine the PUDP, air quality, and food culture in urban ecology in Chengdu, China. Methods: First, the research identifies three types of PUDP models (open PUDP, landscape PUDP, and conflict PUDP) with the weighted overlay of land use data, then uses machine learning to examine the relationship between PUDP, POI of traditional food restaurant, and VOCs. Results: The study generates three types of PUDP which are open PUDP, landscape PUDP, and conflict PUDP. VOCs and POI of traditional restaurant have a strong correlation, and both have a significant negative correlation with open PUDP. However, the landscape PUDP and conflict PUDP do not show an obvious relationship with food POI and VOCs. Conclusion: The results indicate that the future urban ecology should consider restaurant location, VOCs from restaurants, and their relationship to urban land use data as they have a strong relationship. [ABSTRACT FROM AUTHOR]

As the passenger railway network is expanding and improving, the internal connections and interdependence in the network are rising. Once a sudden geological hazard occurs and damages the network structure, the train service is prone to large-scale halt or delay. A geographical railway network is modeled to analyze the spatial distribution characteristics of the railway network as well as its vulnerability under typical geological hazards, such as earthquakes, collapses, landslides and debris flows. First, this paper modeled the geographical railway network in China based on the complex network method and analyzed the spatial distribution characteristics of the railway network. Then, the data of geological hazards along the railway that occurred over the years were crawled through the Internet to construct the hazard database to analyze the time–space distribution characteristics. Finally, based on the data of geological hazards along the railway and results of the susceptibility to geological hazards, the vulnerability of the geographical railway network was evaluated. Among these geological hazards, the greatest impact on railway safety operation came from earthquakes (48%), followed by landslides (28%), debris flows (17%) and collapses (7%). About 30% of the lines of the geographical railway network were exposed in the susceptibility areas. The most vulnerable railway lines included Sichuan–Guizhou Railway, Chengdu–Kunming Railway and Chengdu–Guiyang high-speed Railway in Southwest China, Lanzhou–Urumqi Railway and Southern Xinjiang Railway in Northwest China, and Beijing–Harbin Railway and Harbin–Manzhouli Railway in Northeast China. Therefore, professional railway rescue materials should be arranged at key stations in the above sections, with a view to improving the capability to respond to sudden geological hazards. [ABSTRACT FROM AUTHOR]

Taking the Chengdu Municipal Solid Waste Incineration (MSWI) Plant in China as object, totally 100 ambient soil samples from 20 sampling points were taken for experiment. This paper analysed the characteristics of Cd in soil. By analyses, the distribution and health risk assessment were taken into consideration. The results demonstrated that the Cd value in soil in the surroundings of the MSWI plant was beyond the acceptable level according to standards (GB15618-2018). The risk assessment in this experiment showed that the carcinogenic and noncarcinogenic risks via inhalation exposure were in the accessible levels. [ABSTRACT FROM AUTHOR]

Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University 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.)

The high environmental pollution load caused by the massive pollutant emissions and the accumulation of endogenous and cross-regional pollution has become an important obstacle to the current ecological civilization construction in the Yangtze River Economic Belt (YREB) in China. Taking the YREB as an example, by using four environmental pollutant emission indicators, including chemical oxygen demand (COD), ammonia nitrogen (NH3-N), sulfur dioxide (SO2), and nitrogen oxides (NOx), this paper established an environmental pollution load index (EPLI) based on the entropy-based measurement. Moreover, the Spatial Durbin Model was used to quantitatively analyze the drivers and spatial effects of environmental pollution load. Finally, specific scientific references were provided for formulating environmental regulations of pollution source control in the YREB. The results showed that: 1) During 2011–2015, the EPLI in the YREB was reduced significantly and the environmental pollution load increased from upstream to downstream. Among them, the pollution load levels in the Upper Mainstream subbasin, Taihu Lake subbasin, and Lower Mainstream subbasin were the most prominent. 2) The environmental pollution load situation in the YREB was generally stable and partially improved. High load level areas were mainly concentrated in the Yangtze River Delta Region and the provincial borders in upstream, midstream, and downstream areas. The high load level areas already formed in Chengdu and Chongqing were also the key regulatory points in the future. 3) The degree of local environmental pollution load was apparently affected by the adjacent cities. The population size, industrialization level, and the fiscal decentralization not only drove the increase of the local environmental pollution load level, but also affected the adjacent areas through the spatial spillover effects. The land development intensity mainly drove the increase in the local EPLI in the YREB. While factors such as economic development level and agricultural economic share could only act on the environmental pollution load process in adjacent cities. 4) According to the differentiation characteristics of drivers of each city, the YREB was divided into seven zones based on k-medoids cluster method, and targeted zoning control policy recommendations for alleviating environmental pollution load in the YREB were proposed. [ABSTRACT FROM AUTHOR]

The business environment is becoming a yardstick for assessment of local governments in China, and thus the question of how to evaluate the business environment of urban agglomerations has become an important new issue. This paper proposes a quantitative method for the assessment of business environments in urban agglomerations for purposes of city ranking. First, a business environment evaluation index system for urban agglomerations, including the four dimensions of market, government, law, and humanistic, was established. Second, A hybrid model combined entropy weight method (EWM), genetic algorithm (GA), and back propagation (BP) neural network was constructed to quantise the business environment. Then, the Chengdu-Chongqing and Beibu Gulf urban agglomerations in China, the two most important urban agglomerations of the new western land-sea corridor, were selected as cast study. The results are as follows: (1) The business environments of the two most important urban agglomerations of the new western land-sea corridor have been improved, but the differences between them are significant. The level of development of the business environment of Chengdu-Chongqing is higher than that of Beibu Gulf; specifically, the biggest gap is of the rule of law environment. The gap in the governmental business environment is the smallest. (2) From 2015 to 2020, the difference in business environment between the two most important urban agglomerations in the new western land-sea corridor decreased. However, intra-group differences were the largest. (3) The spatial pattern of the business environment in the new western land-sea corridor shows a "northwest-southeast" distribution, with the center of gravity of the business environment moving to the southeast from 2015 to 2020. (4) Compared with focusing on the development of the business environment in large cities, promoting the business environment in small and medium-sized cities has a more significant effect on improving the business environment in urban agglomerations. • A quantification method is proposed. • Business environment in the corridor is uneven. • Small cities should develop firstly. [ABSTRACT FROM AUTHOR]

• Present a methodology for investigating ring road investment and cordon tolling problems in a congested ring-radial city. • Establish a two-dimensional urban system equilibrium for a ring-radial city. • Develop two social welfare maximization models (a short-sighted decision and a far-sighted decision) to optimize ring road investment and cordon tolling schemes. • Carry out a case study on the city network of Chengdu China. Ring roads, as candidate cordons, provide a convenient condition for implementing cordon tolling schemes. This paper presents a methodology for investigating the ring road investment and cordon tolling problems in a congested ring-radial city. A two-dimensional urban system equilibrium for a ring-radial city is first formulated, in which interrelated equilibria among stakeholders, including the authorities, property developers, households and commuters, are explicitly considered. Two social welfare maximization models for optimizing the ring road investment and cordon tolling schemes, a short-sighted and a far-sighted one, are then proposed. In the short-sighted model, the ring road investment decision is first made, and then the cordon tolling scheme is optimized based on the determined ring road locations as candidate cordons. However, in the far-sighted model, a simultaneous decision of the ring road investment and cordon tolling is made. The proposed models explicitly incorporate the estimation of the intra-area travel. A case study applied to the city network of Chengdu China shows that ring road investment and cordon tolling can reshape the urban spatial structure as a result of the tug-of-war between the dispersion effects due to ring road investment and the concentration effects due to cordon tolling. The far-sighted solution entails building more ring roads than the short-sighted solution, and is closer to the social optimum solution. Whether all ring roads are tolled, or just one, the far-sighted solution yields an appreciably higher welfare gain. The optimal single-cordon tolling scheme performs nearly as well as the optimal multi-cordon tolling scheme in terms of the social welfare. Ignoring the household residential relocation behavior leads to underestimates of total cordon toll revenue and welfare gain. [ABSTRACT FROM AUTHOR]

Cities are currently confronted with many urban problems, such as water shortages, water quality pollution, floods, and the loss of habitats of aquatic organisms, and badly in need of a more comprehensive solution. In this context, the concept of "sponge city" is proposed. This paper, based on the theory of sponge city and low impact development, elaborated the origin, development, connotation, and construction method of "sponge city" concept. In this paper, the urban design scheme of Renbei District in Chengdu was taken for example to analyze the geographical environment and climate characteristics of Chengdu and explain the formation and verification of the scheme. It is considered that the "sponge city" is different from the traditional urban infrastructure. It is essentially an ecological approach. It's core is to build a cross-scale urban water ecological infrastructure to comprehensively solve the prominent water-related problems of urban and rural areas in China. [ABSTRACT FROM AUTHOR]

The aging and the urban development bring a great challenge to the residential facilities of the elderly community. By exploring the layout and current situation of the elderly residential facilities in Chengdu City, this paper stressed the key points in the layout of various facilities at the macro scale. Through the deep investigation of residential districts, the paper explored the community endowment mode that is between the organisation support and home-based for the aged, and proposed 3 modes on the basis of "visiting, day care and short-stay''. Considering the specific needs of the aged and the compound modes, compound community endowment mode was put forward as the future development direction of community endowment to contribute to the construction of the overall social endowment system. [ABSTRACT FROM AUTHOR]

Online dating has modernized traditional partner search methods, allowing individuals to seek a partner that aligns with their preferences for attributes such as age, height, location, or education. Yet traditional forms of partner selection still exist, with continued parental involvement in the matching process. In this paper, we exploit different matchmaking methods with varying degrees of youth autonomy versus parental involvement. We use a unique dataset collected in Chengdu, China, where profiles from the blind date market (n = 158) capture parental preferences and profiles from an online dating website (n = 500) capture individual preferences. Regarding gender, we find that men generally display a desire for women younger, shorter, and less educated than themselves, while women desire older and taller men of the same education as themselves. With regards to parental influences, we find parents specify a narrower range of accepted partner attributes. Further, we find an interaction effect between gender and generational influences: the preferences of parents advertising their daughters on the blind date market show a greater discrepancy in attribute preferences to the online daters than parents advertising their sons. [ABSTRACT FROM AUTHOR]

Purpose: To explore the relationship among leisure motivation, barriers, attitude and satisfaction of middle school students in Chengdu, Sichuan, to help students establish a positive leisure attitude and provide a reference for youth leisure counseling. Methods: Based on consulting research literature, this paper designs a survey volume of teenagers' leisure motivation, barriers, attitude, and satisfaction; 2249 valid questionnaires of middle school students in Chengdu were obtained by stratified random sampling. The data were statistically processed by the combination of exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results: (1) There are significant positive correlation effects between leisure motivation and leisure attitude, leisure attitude and leisure satisfaction, and leisure motivation and leisure satisfaction; (2) There is a low degree of positive correlation effect (r = 0.35 *) between leisure barriers and leisure motivation, which is contrary to common sense and needs to be further studied in the follow-up; (3) Leisure barriers has no significant direct impact on leisure satisfaction, but it can have a significant negative impact on leisure satisfaction with the intermediary variable of leisure attitude; (4) Leisure motivation is the most important variable in the whole leisure model structure. It not only has the greatest direct impact on leisure satisfaction but also has a great positive impact on leisure satisfaction through the intermediary of leisure attitude. Conclusion: Adolescent leisure motivation, barriers, attitude, and satisfaction are complementary and interdependent. Among them, leisure motivation is the core variable and leisure attitude is the dual intermediary variable. Through the initiation of leisure motivation, helping adolescents establish a positive leisure attitude may be the key to ensure their leisure satisfaction. [ABSTRACT FROM AUTHOR]

This paper explores the effect of government supervision on the development of FFBS by analyzing massive travel information data. Our identification strategy exploits a natural experiment focusing on Mobike in Chengdu. We find that supervision does not necessarily suppress the development of FFBS. It also allows FFBS to increase its focus on alleviating the pressure of public transport and reducing the consumption of public resources. Moreover, we identify that the impact of government supervision on weekends is considerably more significant than on weekdays given that government supervision has a significant suppression effect on the FFBS travel behavior of scattered parking, leisure, and long distance. In contrast, the effect of government supervision on the FFBS travel behavior of commuting and schooling is not significant. We finally present implications for government and operators of FFBS, especially in developing countries, on the sustainable development of FFBS. [ABSTRACT FROM AUTHOR]

Purpose: Rational location of emergency medical service (EMS) facilities could improve access to EMS, and thus assist in saving patients' lives and improving their health outcomes. A considerable amount of spatial optimization research has been devoted to the development of models to support location planning in the context of EMS, with extensive applications in policy making around the world. However, in China, studies on the location of EMS facilities have not been paid enough attention to, let alone their practical applications. This paper conducted location optimization for EMS facilities in Chengdu, one of the biggest cities in southwest China with more than 16.5 million population, aiming to optimize the EMS system by adding (upgrading) a minimum number of EMS facilities to achieve a given population coverage. Methods: Location optimization was conducted according to regional health policy goal for the EMS system in Chengdu, China, 2017. The nearest-neighbor approach was used to calculate the shortest travel time based on geographical information system (GIS). The location set covering model was used to formulate the optimization problem under China's context, and genetic algorithm (GA) was employed to determine the optimized locations. Results: The results showed that a minimum number of 55 new facilities were required to upgrade to EMS facilities to achieve the policy goal of 90% population coverage of EMS within 15 minutes. Access to EMS also improved substantially in terms of shortest travel time after facility upgrading. The weighted median shortest travel time to EMS facilities in Chengdu decreased by 14.57%, from 6.45 minutes to 5.51 minutes. Conclusion: Our study showed that the solution could effectively achieve the policy goal of population coverage with a minimum number of new EMS facilities. Our findings would support evidence-based decision-making in future EMS planning in China. [ABSTRACT FROM AUTHOR]

As low and lower-middle social groups account for a great proportion of the total population in China and their status in society is special, it is of great social and practical significance to study their housing conditions and characteristics. Based on research at home and abroad, this paper defines the basic characteristics of low and lower-middle social groups in China, and elaborates the definition and connotation of housing marginalization, thereby proposing that these residents in the Chinese city are facing a problem of housing marginalization. According to data from the fifth and sixth population census and statistical yearbooks of Chengdu, it reveals changes in housing location, housing tenure structure, and housing quality of the study group between 2000 to 2010 by means of spatial and statistical analysis, which indicates that the low and lower-middle social groups are facing the three trends of "living in outskirts," "predicament in tenure selectivity of housing," and "impoverishment of housing quality." In response to these trends, three planning suggestions are proposed: 1 to establish "housing policy areas" suitable for the group of residents to reside and work; 2 to innovate policy measures to support the low and lower-middle social groups to rent and purchase houses within these areas; 3 to guide the residents to integrate into the community life circle in these areas so as to avoid poverty concentration. [ABSTRACT FROM AUTHOR]

[ Objective) This paper aimed to the quantification of the detailed ranges and dynamics of the environmental factors of the light, temperature, air and moisture in morel cultivation. ( Methods ] Environmental factors in greenhouses for Morchella importuna cultivation were collected in Chengdu plain area using Internet of Things (IoT) technologies. Illumination intensity, air temperature, air relative humidity, oxygen percentage in the air, carbon dioxide concentration in the air, soil temperature and soil water content were recorded every ten mi nutes, in greenhouses with different layers of sunshade-net. Fluctuation models in 24-hour cycle were established for the environmental fac tors at different stages. [ Results] The sunlight in the greenhouses showed a dynamic that indirectly regulated the fluctuating features of the ox Oxygen percentage, relative humidity and temperature in the air, while the average illumination intensity in the greenhouse with the highest mo rel yield were about 2500 - 3500 ks at the noon of sunny days. Sunshade-net effectively prevented over-heating during daytime and over-chill ing during night., diminishing the occurrence of extreme values of air temperature and soil temperature, whereas the cumulative temperatures of the air and the soil, as well as the cumulative values of the relative humidity. oxygen percentage and carbon dioxide concentration in the air, and the soil water content, showed no significant difference between the regimes of different sunshade net layers. The effects of the sunshade-net layers were attenus ting the fluctuations of the environmental factors, The air tem perature was either higher than or similar to the soil temperature during the fruiting stage. (Conclusion) Field conditions ideal for morel cultivation were summarized from the analytical results of the environmental factors, for the reference of field management of morel cul tivation in plain area of southwestern China, which further provided some inspirations for the engineers hoping to develop factory-mode tech nologies of morel production. [ABSTRACT FROM AUTHOR]

• A wind-PV system for powering electrical facilities on highways is proposed. • The system is installed in the medians of highways to avoid occupying extra land. • The system is foldable for easy deployment and self-protection. • Estimation results show that the annual generation of the system reaches 356 GWh. In this paper, a portable wind-photovoltaic power generation system (WPPGS) based on the foldable umbrella mechanism is presented. The proposed WPPGS is installed in the medians of highways, and it can simultaneously capture the solar energy and wind energy produced by running vehicles. The studied system mainly consists of three submodules: a solar harvesting module, a wind-energy-harvesting module and an energy storage module. The whole system is foldable for easy deployment and self-protection. The electricity generated by the wind and solar energy harvesting modules is stored in the energy storage module, which can supply power to the electrical facilities on highways. The Chengdu-Chongqing highway is selected for case study. Theoretical and simulation results show that the annual power generation of the solar harvesting sub-module, wind collection sub-module and entire WPPGS system deployed on all highways in Mainland China can be up to 155 GWh, 201 GWh and 356 GWh, respectively. Furthermore, the wind and solar-energy-harvesting subsystems have appropriate complementarity in time, which indicates that the WPPGS has excellent technical performance throughout the entire year. [ABSTRACT FROM AUTHOR]

The Jinsha River rail–road double-deck arch bridge (bridge designed to 250 km/h) of the Chengdu–Guiyang high-speed railway (HSR) (designed to 350 km/h) is a complex system with a novel structure in China. The upper deck carries a four-track railway while the lower deck carries a six-lane urban expressway, with a height difference of 32 m. The bridge is located in the mountainous river reach of the city of Yibin. The 336 m main span adopts a high-pier, rigid steel frame, parallel tied-arch structure, built using cantilevers and temporary stay cables with the cable crane method. The 116 m and 120 m side-arches are reinforced concrete, simply-supported, basket-lifting tied-arches built by the mass cast in situ method. The rare layered structure gathers different arch types (top-bared, bottom-bared and half-through arches) into one bridge, which brought significant challenges to its design and construction. Other innovative solutions included flexible hangers passing through rigid hangers for the layered stiffening decks, ultra-high-performance concrete for the steel orthotropic deck road pavement and the use of boat shipments to overcome the scarce availability of flat land at the site. This paper describes some of the salient design and construction challenges of this landmark structure, the world's first double-deck HSR arch bridge. [ABSTRACT FROM AUTHOR]

Urban ecosystem has become a critical part of ecological security and draws much attention worldwide. It is both a result of natural ecological system development, and also an inevitable outcome of human ecological system development within a certain stage, with the objective of identifying the possible improvement space for unban ecological security evaluation from complex system perspective. Based on the brittle structure model and set pair theory, this paper firstly explored the main research methods of urban ecological security theory and its characteristics, then conducted a theory of complex system brittleness to analyze the urban ecological security brittle factors, brittle primitives, and brittle structure. Furthermore, it conducted a model of urban ecological system brittleness correlation entropy together with a set pair analysis method to discuss its brittleness. And finally, an ecological safety evaluation has been presented based on the empirical case in Chengdu City of China. The theoretical and empirical analysis shows that the brittle correlation entropy of natural subsystem in urban ecological security is the biggest one. The risks from natural subsystem collapse can easily trigger the brittleness of the entire urban system. The corresponding maximum brittle fluctuation entropy is from economic subsystem; it has a largest impact on the entropy change of urban ecosystem. The way of reducing the uncertainty of urban ecological risks is to lower difference degree coefficient in the system. Relevant decision makers should consider to reduce the increasing degree of entropy and eliminate the fluctuation of the brittle factors. Thus, the threats or risks of urban ecological system can be within the acceptable range and under control. An integrated system management combing with brittleness characters of natural, economics, and social subsystem is necessary. It is helpful for the ecological security construction. [ABSTRACT FROM AUTHOR]

Samples of hydrogen and oxygen stable isotopes in precipitation collected and analyzed during the summer monsoon in 2017 and 2018 in Chengdu are reported in this paper. Increasing (decreasing) trends of isotope values (δD and δ18O) occur from May to June (September to October), and the valleys occur from July to August. The correlation between δD and δ18O for both precipitation events and monthly average precipitation is significant, with high R² values (≥0.98). The differences in regression lines may be due to the comprehensive influence of moisture sources, transport path and sub-cloud processes. Combining the d-excess values of precipitation and air mass trajectories generated by the HYSPLIT model, precipitation with a low (high) d-excess value and a more (less) negative δ18O corresponds to moisture from ocean (inland) sources. The δ18O–temperature (T) and δ18O–precipitation (P) correlations are not significant and vary greatly among different periods, which may be attributed to the mutual masking of different effects and the influence of atmospheric circulation processes. The results imply that the negative values in biological and geological proxies may be related to warmer climate, higher precipitation and a larger contribution of oceanic monsoon precipitation, but cannot indicate the changes in temperature and precipitation quantifiably. [ABSTRACT FROM AUTHOR]

Purpose: Motivated by a problem in the context of DiDi Travel, the biggest taxi hailing platform in China, the purpose of this paper is to propose a novel facility location problem, specifically, the single source capacitated facility location problem with regional demand and time constraints, to help improve overall transportation efficiency and cost. Design/methodology/approach: This study develops a mathematical programming model, considering regional demand and time constraints. A novel two-stage neighborhood search heuristic algorithm is proposed and applied to solve instances based on data sets published by DiDi Travel. Findings: The results of this study show that the model is adequate since new characteristics of demand can be deduced from large vehicle trajectory data sets. The proposed algorithm is effective and efficient on small and medium as well as large instances. The research also solves and presents a real instance in the urban area of Chengdu, China, with up to 30 facilities and demand deduced from 16m taxi trajectory data records covering around 16,000 drivers. Research limitations/implications: This study examines an offline and single-period case of the problem. It does not consider multi-period or online cases with uncertainties, where decision makers need to dynamically remove out-of-service stations and add other stations to the selected group. Originality/value: Prior studies have been quite limited. They have not yet considered demand in the form of vehicle trajectory data in facility location problems. This study takes into account new characteristics of demand, regional and time constrained, and proposes a new variant and its solution approach. [ABSTRACT FROM AUTHOR]