Scale Effects Research Articles

Analysis of landscape pattern and ecological risk change characteristics in Bosten Lake basin based on optimal scale

Amidst swift socioeconomic progress, urbanization is intensifying, necessitating robust methodologies for environmental quality monitoring. Landscape Ecological Risk (LER) has emerged as a pivotal tool in this context. Extensive research has focused on the land utilization rates within watersheds, scrutinizing them through the lens of land use/land cover (LULC) dynamics. This study delves into the LULC attributes of the Bosten Lake Basin (BLB) across three temporal snapshots: 2000, 2010, and 2020. Grasslands and bare ground made up the vast majority area of the BLB. Selected twelve landscape pattern indices, analyzed their response curves with respect to grain size, determined the optimal grain size to be 150 m, and analysed its optimum amplitude of 10 km × 10 km on the basis of the semi-variance function, thus determined the optimal scale for analyzing the landscape pattern. Exploring scale effect facilitates a nuanced examination of the landscape patterns and land use efficacy within BLB. From 2000 to 2020, the landscape pattern showed less fragmented, less aggregated, and more spatially heterogeneous. The landscape ecological risk index model has been constructed for the investigation of the LER change characteristics of the BLB. Lowest-risk zones and lower-risk zones of LER predominate in BLB. In 2000, 2010 and 2020 the combined lower and lowest risk zones represent 62.02 %, 59.37 % and 58.44 % of the catchment area respectively. Finally, analyzed the spatial autocorrelation variation characteristics of LER. The global Moran' I index of BLB for the three periods from 2000 to 2020 exceeded 0.7. This study establishes theoretical and practical foundation for future multi-scale landscape ecological risk studies in eco-fragile regions.

Effects of Pressure and Characteristic Scales on the Structural and Statistical Features of Methane/Air Turbulent Premixed Flames

AbstractIn this study, the highly nonlinear and multi-scale flame-turbulence interactions prevalent in turbulent premixed flames are examined by using direct numerical simulation (DNS) datasets to understand the effects of increase in pressure and changes in the characteristic scale ratios at high pressure. Such flames are characterized by length-scale ratio (ratio of integral length scale and laminar thermal flame thickness) and velocity-scale ratio (ratio of turbulence intensity and laminar flame speed). A canonical test configuration corresponding to an initially laminar methane/air lean premixed flame interacting with decaying isotropic turbulence is considered. We consider five cases with the initial Karlovitz number of 18, 37, 126, and 260 to examine the effects of an increase in pressure from 1 to 10 atm with fixed turbulence characteristics and at a fixed Karlovitz number, and the changes to characteristic scale ratios at the pressure of 10 atm. The increase in pressure for fixed turbulence characteristics leads to enhanced flame broadening and wrinkling due to an increase in the range of energetic scales of motion. This further manifests into affecting the spatial and state-space variation of thermo-chemical quantities, single point statistics, and the relationship of heat-release rate to the flame curvature and tangential strain rate. Although these results can be inferred in terms of an increase in Karlovitz number, the effect of an increase in pressure at a fixed Karlovitz number shows differences in the spatial and state-space variations of thermo-chemical quantities and the relationship of the heat release rate with the curvature and tangential strain rate. This is due to a higher turbulent kinetic energy associated with the wide range of scales of motion at atmospheric pressure. In particular, the magnitude of the correlation of the heat release rate with the curvature and the tangential strain rate tend to decrease and increase, respectively, with an increase in pressure. Furthermore, the statistics of the flame-turbulence interactions at high pressure also show sensitivity to the changes in the characteristic length- and velocity-scale ratios. The results from this study highlight the need to accurately account for the effects of pressure and characteristic scales for improved modeling of such flames.

Farmland transfer contract performance and green production technology adoption among farmers: evidence from a survey of four provinces in China.

The popularization and use of green production technology is the key to promoting the sustainable development of agriculture. Exploring the path of promoting farmers' adoption of green production technology has important theoretical and practical significance for promoting the green transformation of agriculture and realizing the high-quality development of agriculture. This study examined the impact of contract performance on the adoption of green production technology in the farmland transfer market based on the characteristics of green production technology. An empirical test was conducted using survey data from Heilongjiang, Henan, Zhejiang, and Sichuan Provinces, which differ in agricultural resource endowment and economic development. The results demonstrated that farmland area was positively associated with the number of green production technologies adopted by farmers and use of straw returning, subsoiling, and soil testing for formula fertilization technology. Moreover, improving the performance rates of farmland transfer contracts strengthened the promotional effect of operation scale on green production technology adoption. Using either contract execution or dispute resolution rates to measure contract performance promoted the adoption of green production technology, particularly for large-scale farmers. Therefore, in the publicity and promotion of agricultural green production technology, the government should not only formulate differentiated promotion strategies and support policies based on resource endowment, but also focus on the construction of rural legal systems, which are helpful for building and maintaining a good farmland market order and performance environment, and create conditions for the durability and stability of technology adoption.

CLIMATE-SMART CITY: CAN CHINA’S SMART CITY POLICY LEAD TO LOW-CARBON DEVELOPMENT OF CITIES?

As an intensive mode of urbanization, a smart city may be conducive to achieving a win–win situation of regulating the urban economy and the environment. Based on a quasi-natural experiment in three batches of smart pilot cities, we use the difference-in-differences (DID) method to examine the impact of the smart city policy on CO2 emissions by adopting city panel data in China during the period 2003–2017. This study also explores the influence mechanism and heterogeneous effects of smart city policy. The empirical results indicate that China’s smart city policy effectively lowered CO2 emissions by approximately 1.83%. This primary finding remains reliable using the propensity score matching (PSM)-DID method for robustness check. Moreover, the smart city policy not only directly inhibits CO2 emissions, but also indirectly influences CO2 emissions through scale, structure, and technology effects. Regarding city heterogeneity, the first-tier cities in the eastern area, which have larger population scale and more resource endowments, tend to have stronger negative impacts on CO2 emissions. Based on these conclusions, we highlight several specific policy measures for reducing CO2 emissions and achieving dual carbon targets in China.

Two-sided dynamic pricing and value-added service investment strategies of competitive platforms considering indirect network effects

In recent years, many platforms have realized that relying on subsidies and low-price strategies may result in limited access to users. To expand the market scale and realize the second growth in user scale, some platforms have started adding value-added service (VAS) investment. In this study, we focus on two competing platforms whose bilateral users can be multi-homed. Considering that the users' scale and indirect network effects (INEs) at the initial stage affect their willingness to access and the platforms’ VAS investment in the next stage, we build a two-stage game model to study the two-sided dynamic pricing decisions of competitive platforms when VAS is offered. The results indicate that the platforms should formulate different pricing strategies at two stages. In the first stage, the platforms can adopt a strategy of subsidizing or charging. Particularly, under certain conditions, it will be more beneficial for the platforms to subsidize the side users with the weaker strength of INE. Differently, in the second stage, the platforms should always charge bilateral users. Moreover, at this stage, the platforms will implement differentiated VAS and pricing combination strategies for both sides; they can offer a lower VAS level to one side of users but charge them a higher access fee, while offering a higher VAS level to the other side of users but charge them a lower access fee.

Vinterutfodring av renar - effekter på renarnas beteende, renskötseln och miljön

This report is based on the results from a Nordic network project funded by The Nordic Joint Committee for Agricultural and Food Research (NKJ) during the years 2021-2022. This network was created to encourage further cross-border discussions about the prospects of winter feeding of reindeer. In reindeer husbandry winter feeding has increased during the last decades due to competing land use activities and climate change. Herders in Norway, Sweden and Finland have previously raised concerns about the benefits and risks associated to the increasing need of winter feeding of reindeer in all three countries. The report, published in Swedish, Norwegian, Finnish and North Sámi, and covers the main findings from a series of preparatory workshops within each country and a main workshop in Arvidsjaur 8-9 June 2022. During the network activities, reindeer herders, researchers and managers discussed the effects of feeding on reindeer behaviour, herding practices and the environment. The two main topics discussed at the preparatory workshops were 1) the short- and long-term effects of winter feeding on reindeer behaviour, and 2) local to large scale effects of feeding on the environment and the natural pastures. During the main workshop, discussions were held about reasons for feeding of reindeer, the preconditions of feeding in the three countries, how winter feeding is usually performed, and best practices in relation to reindeer behaviour and the environment. The work aimed at promoting knowledge exchange on winter feeding of reindeer among all participants to help find solutions and mitigation actions to avoid changes in reindeer behaviour and negative effects of feeding on reindeer, reindeer herding and the environment. The report is aimed at herders, managers, as well as other land users, authorities and policymakers to give information on what was discussed and a summary of the challenges related to winter feeding and effects on reindeer behaviour and reindeer husbandry, and the environment. Rangifer Report No 18 is the Swedish version of the report. Reports in Norwegian, Finnish and North Sámi are published as following numbers of Rangifer Report.

Is the digital economy empowering high-quality tourism development? A theoretical and empirical research from China.

How digital economy (DE) empowers high-quality development of tourism (HQDT) has become a common concern among scholars. Given this, this study clarifies the theoretical connotation of DE enabling HQDT,and finds that: Micro, DE promotes efficiency improvements in tourism enterprises, with its economies of scale and Matthew effect reducing average costs, its economies of scope meeting diversified demand, and its long-tail effect improving supply-demand matching mechanism. Meso, DE can transform and upgrade tourism industry structure through industrial digitization and digital industrialization, and also form a new tourist industry form and value chain through cross-border integration. Macro, DE can stimulate innovation and flexibility of market players, increase new factor inputs in tourism, improve factor allocation efficiency, and advance macro regulation of the tourism market. Accordingly, the study conducts an empirical test based on panel data for 31 provinces in mainland China during 2011-2020. Results show that: ① DE positively influences HQDT, and the sub-dimensions all positively influence HQDT. ② DE has a heterogeneous impact on HQDT and shows spatial spillover effects. Finally, the study concludes with effective paths for DE promoting HQDT: "Promote digital infrastructure construction, accelerate tourism digital transformation, strengthen integration and innovation development, and overcome the challenges of tourism enterprises".

Examining the scale effect of nearby residential green space on residents’ BMI: A case study of Guangzhou, China

Green spaces are closely related to the quality of the urban environment and public health. However, studies have rarely paid attention to nearby residential green space which is more closely connected to residents’ daily lives. Does nearby residential green space have a scale effect on the body mass index (BMI) of residents? What type of green space has a more significant effect? Does this effect differ for residents living in central urban areas and suburban areas? To answer these questions, this study first measured three scales of nearby residential green space accessibility of 1398 samples of 18 neighborhoods’ survey data in Guangzhou, China, combined with the application of the TIQS (Travel O-D point Intelligent Query System). And then, multilevel mixed-effects models were developed to examine the scale effect of nearby residential green space accessibility on residents’ BMI. The results show that nearby residential green space has a scale effect on individual BMI and the effect of the 10-minute walking scale is the most significant. Within a 10-minute walking distance from the residence, the larger the green space and the more accessible it is, the lower the individual’s BMI. Parks are the green spaces that are most correlated to residents’ BMI, but their effect is somewhat different between the central urban areas and suburban areas. These findings give us a better understanding of the association between nearby residential green space and public health, as well as providing implications for the improvement of the urban green space system and policy development for healthy cities.

Impact of digital economy on urban land green use efficiency: evidence from Chinese cities

Abstract Improving urban land green use efficiency (ULGUE) is essential for achieving the sustainable use of land resources and the high-quality economic development of cities. The digital economy has overcome spatial and locational constraints, blurred the boundaries between industries, and created a collaborative and open economic model, inevitably affecting urban land utilization. However, whether the digital economy will affect ULGUE and how such an effect would take place are still unclear. This study evaluates the digital economy and ULGUE of Chinese cities from 2011 to 2019 and systematically analyzes both the direct and indirect impact mechanisms through which the digital economy affects ULGUE. The results show that the digital economy can significantly enhance ULGUE, and these results prove to be reliable, as shown by various endogeneity treatments and robustness tests. The digital economy enhances ULGUE by optimizing the industrial structure (structural effect), increasing green technology innovation (technical effect), and agglomerating digital talent (scale effect). Moreover, land finance dependency plays an adverse moderating role in the relationship between the digital economy and ULGUE. Further heterogeneity analysis shows that the promoting effect of the digital economy on ULGUE takes full effect in the eastern cities, larger cities, and cities with high levels of digital economy development and land marketization. This paper presents recommendations for supporting the balanced and integrated development of the digital economy across regions and provides differentiated development strategies to enhance ULGUE in the context of digitization.

Shadow banking and loan pricing of commercial banks: Evidence from China

We examine the role of regulatory arbitrage via wealth management products (WMPs) in the determination of lending rates in China. We find WMP yields are positively associated with lending rates whereas the effect of WMP scale varies across bank size. For the big-5 state-owned banks, the negative “transfer-effect” of high-risk high-yield loans into shadow bank credit dominates the positive “funding-cost-effect” of banks becoming more dependent on wholesale funding. For smaller banks, the positive funding-cost effect dominates. Our study provides insights into the role of regulatory arbitrage on asset structure and profit margins in the interest of banks and the regulators.

Multiscale structural understanding of plasma spraying anti-ablation coating: an example of Ta-Hf-W-C ultrahigh temperature ceramics

The coating formation and structural design of ultra-high temperature ceramics (UHTCs) for aerospace vehicle anti-ablation coatings through plasma spraying remain uncertain despite extensive engineering applications. In this study, (Ta,Hf,W)C/HfC micro-composite, (Ta,Hf,W)C single-phase, and (Ta,Hf,C)/W nanocomposite coatings were successfully prepared using induction plasma spheroidization (IPS), vacuum plasma spraying (VPS), and spark plasma sintering (SPS). Density functional theory (DFT) was employed to capture the electronic structure of (Ta,Hf,W)Cy (y = 1, 0.875, 0.75, 0.5), confirming the influence of carbon vacancies and ceramic metallicity on the plastic forming behavior of sprayed coatings. Additionally, the contribution of HfC to structural stability and WC to the metallicity of carbon-based rock salt-structured UHTCs was elucidated. The pivotal role of carbon vacancies in inducing metastable phase formation and metal phase precipitation for (Ta,Hf,W)C was identified. Ablation behavior variations resulted from differences in multi-scale coating structures, where transverse cracks exhibited more detrimental effects than vertical cracks. Notably, a scale effect of oxidation related to the uniformity of metal elements in the multicomponent ceramic coating was uncovered. It was determined that components capable of forming high melting point oxides should not be uniformly dissolved in the matrix.

Circular Economy and Entrepreneurship in Europe: an analysis of the impact of cultural factors, regulatory framework and rate of entrepreneurship

The aim of this work is to delve into the phenomenon of the circular economy (CE) to enhance understanding of the contextual factors that foster its development. We study how countries’ cultural values, regulatory frameworks and rates of entrepreneurship, affect the transition to more circular economies. The model proposed and tested through a binomial logistic regression analysis of a sample of European small and medium-sized enterprises (SMEs), shows that such firms are more likely to adopt CE actions when located in more entrepreneurial societies, with more individualistic and feminine values, and with less stringent environmental regulations. Additionally, the study evidences a scale effect, but not an experience effect, in the transition to CE. Several practical and political implications are outlined.

Evolution of rates, patterns, and driving forces of green eco-spaces in a subtropical hilly region

Monitoring ecological resource change in mountainous and hilly areas (MHAs) is vital for theoretical and practical advancements of ecological resource utilization and management in complex ecosystems. The factors driving structural and functional changes in green eco-spaces (GES) in these areas are complex and uncertain, with notable spatial scale effects. However, analyzing the multi-scale driving mechanisms of ecological and socioeconomic factors at a fine spatiotemporal scale presents significant challenges. To address these challenges, we analyzed dynamic changes in GES and eco-socio-economic development in Shanghang County, a typical mountainous region in southern China. We used multiple linear regression and multi-scale geographically weighted regression model to identify key factors driving GES changes and their multi-scale effects at both global and local levels. Over the past two decades, the GES area in the study area has exhibited a consistent pattern of decline, characterized by phases of gradual decline (2000–2005), sharp decline (2005–2009), slow decline (2009–2019). Key global factors driving GES changes included elevation (ELE), slope (SLOPE), population density (PD), distance to settlements (SETTLE), and distance to administrative centers (ADMIN). These factors exhibited significant spatial heterogeneity and multi-scale effects on GES changes. Specifically, SETTLE, PD, SLOPE, and ELE consistently drove GES changes at the local level, while ADMIN only showed significant localized effects during 2005–2009. The synergy between SETTLE and SLOPE had a considerable impact on GES changes, increasing over time, whereas ELE and PD demonstrated a consistent trade-off effect. These findings provide detailed spatiotemporal insights into the driving mechanisms of natural ecological resources, offering crucial guidance for environmental management, land source management, regional economic development, and biodiversity conservation in Shanghang and analogous subtropical hilly regions worldwide.

Continuous design and technoeconomic assessment of commercial‐scale biorefinery processes for the production of succinic acid

AbstractSuccinic acid is recognized as a key component in the production of various commercially important chemical commodities. Technical‐economic analysis can provide valuable insights into the feasibility of large‐scale biochemical production of succinic acid. In this study, the effects of scale on the design of a biorefinery using sugarcane bagasse were evaluated using a detailed process modeling methodology. Four processes were simulated and compared, three based on patents from biosuccinic acid (bio‐SA) manufacturing companies and one based on a process economic program report (PEP). This methodology allowed for the analysis of scale benefits for each technological route. A comprehensive economic evaluation was conducted by comparing the biochemical processes in terms of investment and production costs, as well as the minimum selling price (MSP) of bio‐SA. Results show that the MSP of more promising process designs ranged from 3105 to 2095 $ t−1, which is compatible with the cost of petrochemical‐based succinic acid. Moreover, for capacities above 90 kt year−1, the MSP remains virtually constant, and every process evaluated revealed a breakdown in the project economy of scale. A sensitivity and risk analysis was carried out to evaluate the impacts of several process parameters on the project's technoeconomic analysis, resulting in bio‐SA selling price and investment costs as parameters with the highest impact on economic viability.

Enhanced toughness and ductility of T91 steel after exposure to liquid LBE saturated by oxygen at 350–500 °C

The mechanical tensile properties of T91 steel after being oxidized in liquid LBE saturated by oxygen at 350–500 °C for up to 1000 h are studied. Duplex oxide scales are found on T91 steels after the LBE exposure, and the thickness evolution is revealed. Oxidized T91 steels with surface oxide scale yield enhanced toughness and ductility, which is mainly attributed to the inner oxide layer. We show that the enhancing effect relies on the presence of the oxide scale, not its thickness. The possible enhancing effect of the oxide scale on the toughness of T91 steel by impeding the dislocation from emitting out of the steel surfaces is discussed and qualitatively verified by micro-scale elastoplastic simulations based on a newly proposed discrete dislocation dynamics and peridynamics superposition scheme.

Spatial difference on nitrogen removal in the water based on different resolutions for Sanhuanpao wetland, Northeast China.

The research on the deviations caused by different resolutions is relevant to the study of spatial scale effects. In 2018, spatial interpolations were performed using the removal ratios of the TN, NH4-N, and NO3-N of the layers of different resolutions, respectively. Based on the mean and the standard deviation, the area, shape, and position were obtained for four levels related to the removal ratios of the three nitrogen forms. The linear and 6th function fitting methods were used to reveal the differences in nitrogen removal in wetland water at different spatial resolutions. The results showed that a resolution of 25 times the original was the key scale of the spatial effects. Due to the fact that 52 of the 72 functions did not reach a significant level (P < 0.05), the spatial scale effect of the nitrogen removal was mainly characterized by disorderly fluctuations. The results have a certain extrapolation value for the analysis of spatial scale effects. PRACTITIONER POINTS: The resolution difference was not sufficient to change the spatial pattern of the geographic phenomena. The resolution of 25 times the original was the important scale for determining spatial effects. When studying the spatial scale effects caused by differences in resolution, it was necessary to comprehensively consider various resolutions.

Destination transitions and resilience following trigger events and transformative moments

ABSTRACT Disasters and crises are increasingly seen as opportunities for transformation of the tourism system at various scales. From a resilience perspective, crises and disasters may act as trigger events for system change, sometimes described as the “disaster-reform hypothesis”. An integrative framework informed by different fields is used to analyse the destination development pathways following the Kaikōura earthquake in New Zealand. In addition to policy documents and media, the study draws on semi-structured interviews with 21 business owners and managers in the Kaikōura region, an internationally recognised ecotourism destination. The findings show pathway competition, experimentation, scale effects and lock-in influencing transitions. The research identifies interactions between different actors at different levels of governance in shaping destination pathways post-disaster, with external political and economic actors having the most influence. Multiple levels of resilience chart a potentially more resilient destination. The study concludes that the range of potential destination pathways is constrained by decision-making at other scales, e.g. national policy settings and insurance coverage, that affect tourism businesses and destination decision-making. As a result, the notion of transformation should be understood as an essentially contested concept both within a destination and between destination stakeholders and those that operate at a national scale.

Deformation behavior and scale effects in microchannel hydroforming in ultra-thin TA1/CFRP fuel cell bipolar plates

Microchannels of fuel cell bipolar plates have complex shapes and dimensions at the microscale level, posing significant challenges for manufacturing. Additionally, for traditional bipolar plate materials, mainly based on graphite composites and metals, make it difficult to meet the increasing performance requirements. As the latest fourth-generation fiber-reinforced metal composites, Ti/CFRP laminates exhibit high impact resistance and stiffness after solidification and are electrically conductive, presenting broad prospects for application in bipolar plates. In this study, the metallic layer of the traditional Ti /CFRP laminate was miniaturized to microscale, and a new method for ultra-thin TA1/CFRP laminate low-constraint hydro-microforming was proposed. By combining theoretical modeling, numerical simulation, and process experiments, the deformation behavior and scale effects of the laminate, during the microchannel hydroforming process, were investigated under different process and structural parameters. A single-channel deformation mode was used to study the forming process and examine the impact of hydraulic pressure loading paths and temperature. Additionally, multi-channel and curved channel deformation modes were employed to elucidate the influence of section inclination, channel width, ridge width, and bending angle on the forming process. By varying the laminate thickness, grain size and friction status, the geometric, grain and friction scale effects, as well as the microscale mechanisms of ultra-thin TA1/CFRP laminates in microchannel forming, were explored. This study explores new avenues for the precise microforming of lightweight laminate structures and their application in fuel cell bipolar plates. It provides a theoretical foundation to address the challenges in the microchannel forming of laminates and improve forming accuracy and performance quality.

Extracting Features from Satellite Imagery to Understand the Size and Scale of Housing Sub-Markets in Madrid

The following paper proposes a novel machine learning approach to the segmentation of urban housing markets. We extract features from globally available satellite imagery using an unsupervised machine learning model called MOSAIKS, and apply a k-means clustering algorithm to the extracted features to identify sub-markets at multiple intra-urban scales within a case study of Madrid (Spain). To systematically explore scale effects on the resulting clusters, the analysis is repeated with varying sizes of satellite image patches. We assess the resulting clusters across scales using several internal cluster-evaluation metrics. Additionally, we use data from online listings portal Idealista to measure the homogeneity of housing prices within the clusters, to understand how well sub-markets can be differentiated by the image features. This paper evaluates the strengths and weakness of the method to identify urban housing sub-markets, a task which is important for planners and policy makers and is often limited by a lack of data. We conclude that the approach seems useful to divide large urban housing markets according to different attributes and scales.

Quantifying high-resolution carbon emissions driven by land use change in the Guangdong-Hong Kong-Macao Greater Bay Area

Accurate research on carbon emission spatial distribution is vital for achieving carbon neutrality. Previous studies suffered from scale effects, demanding enhanced resolution. This study collected and computed land use carbon emission data for the Guangdong-Hong Kong-Macao Greater Bay Area (GBA). It also introduced a novel method to downscale this data into 30 m raster format using night light and NDVI data. The study showed a consistent annual rise in GBA land use carbon emissions, accompanied by increasing disparities. At the city level, emissions in the highest-ranking cities were 58 times higher than those in the lowest-ranking ones. Impervious land carbon emissions held over 90% sway over total carbon emissions, making them the primary driver of land use-related carbon emissions. Remarkably, high-emission zones, such as coastal cities Guangzhou, Foshan, Dongguan, and Hong Kong, expanded outward, forming multi-tiered, high-density carbon areas, giving rise to an “∩” shape pattern. Carbon emission change rates from cropland were modest, characterized by a pattern of fluctuation. Moreover, spatial autocorrelation and K-means cluster analyses uncovered a noticeable spatial correlation among urban land use carbon emissions in the GBA. Consequently, a compelling case exists for enhancing inter-city cooperation to collectively pursue regional emission reduction objectives.