Search Results (55)

Gas–liquid two-phase flow is very common in fluid machinery and has complex multiphase flow characteristics. Under the gas-containing conditions, common issues in fluid machinery include the transport of liquid, bubble variations, and pressure drop characteristics; these can be analyzed using a simplified venturi tube. In order to investigate the influence of incoming gas on the gas–liquid flow, a venturi tube with the range of inlet gas volume fraction (IGVF) from 0 to 16% was used in this experiment. The development of a two-phase flow was recorded by using high-speed photography. Under different initial liquid flow rates and gas content conditions, the evolution of the two-phase flow was similar, with the main difference being the rate of evolution. The incoming gas mainly underwent a process from column shape to expansion and then to fragmentation passing through the venturi tube. In the experimental images, the projected area of the main bubble increased linearly with the increase in IGVF. Meanwhile, the transporting ability of the venturi tube was weakened due to the blockage caused by high gas content, especially when the IGVF exceeded 10%. The pressure drop characteristics indicated an increase in losses with the increase in gas content. Full article

The efficacy of government subsidy programs in agriculture is frequently compromised by internal policy conflicts that arise between competing government departments. This challenge is addressed herein, with a focus on the policy environment in China, through the development of a game-theoretic model of an agricultural supply chain. This model explicitly incorporates two competing government bodies—the Agriculture and Rural Affairs Department (ARAD) and the Development and Reform Commission (DRC)—each with distinct objectives and performance indicators. Within this framework, the strategic interactions of four subsidy types are analyzed: production and cold-chain subsidies (ARAD), and platform operation and blockchain subsidies (DRC). The findings reveal that department-specific performance indicators can significantly distort the overall effectiveness of subsidies. While individual subsidies may achieve their intended departmental goals, their combined impact is shown to be complex and frequently suboptimal in the absence of higher-level coordination. Notably, a subsidy portfolio combining production and platform operation subsidies is found to consistently yield superior performance in maximizing social welfare. Ultimately, this research contributes a new framework for understanding subsidy policies and provides actionable insights for optimizing interdepartmental coordination to enhance supply chain performance. Full article

The Grand Canal serves as a vital water transportation route, a UNESCO World Cultural Heritage site, and an ecological corridor. It is currently undergoing coordinated transformation through infrastructure development, heritage preservation, and ecological restoration. However, existing research has primarily focused on either cultural heritage conservation or localized ecological issues, with limited attention to the spatial relationship between landscape patterns and ecological quality along the entire corridor. To address this gap, this study examines eight sections of the Grand Canal and develops a gradient analysis framework based on equidistant buffer zones. The framework integrates the Remote Sensing Ecological Index (RSEI) with landscape pattern indices to assess ecological responses across spatial gradients. A Multi-scale Geographically Weighted Regression (MGWR) model is applied to reveal the spatially heterogeneous effects of landscape patterns on ecological quality. From 2013 to 2023, landscape patterns showed a trend toward increasing agglomeration and regularity. This is indicated by a rise in the Aggregation Index (AI) from 91.24 to 91.38 and declines in both patch density (PD) from 8.45 to 8.20 and Landscape Shape Index (LSI) from 199.74 to 196.72. During the same period, ecological quality slightly declined, with RSEI decreasing from 0.66 to 0.57. The effects of PD and Shannon’s Diversity Index (SHDI) on ecological quality varied across canal sections. In highly urbanized areas such as the Tonghui River, these indices were positively correlated with ecological quality, whereas in less urbanized areas like the Huitong River, negative correlations were observed. Overall, the strength of these correlations tended to weaken with increasing buffer distance. This study provides a scientific foundation for the integrated development of ecological protection and spatial planning along the Grand Canal and offers theoretical insights for the refined management of other major inland waterways. Full article

In the context of intensifying global competition and mounting environmental pressures, understanding how firms can improve corporate sustainability through supply chain efficiency remains a pressing and underexplored issue. This study addresses this gap by investigating the relationship between supply chain efficiency and corporate sustainability, with a particular focus on the moderating roles of digitalization and internal governance. Using panel data of 8000 firm-year observations from Chinese A-share listed companies over the 2010–2022 period, we adopt a two-way fixed effects model to empirically examine how inventory turnover days and the warehousing and transportation cost ratio affect firms’ sustainable growth. Our findings indicate that improving supply chain efficiency—manifested in shorter inventory turnover cycles and lower logistics cost ratios—significantly enhances corporate sustainability. Furthermore, we find that higher levels of digitalization and stronger internal governance significantly strengthen this positive relationship. These findings extend the resource-based view and dynamic capability theory by revealing how supply chain efficiency, supported by digital and internal governance, contributes to long-term sustainability. This study offers theoretical insights and practical implications for managers and policymakers aiming to optimize supply chain strategies in support of sustainable development goals. Full article

Urban green spaces face increasing pressure to reconcile ecological conservation with rising public demand as urbanization accelerates. Yet the spatial coupling of human needs and natural provisioning in the urban–rural fringe remains insufficiently understood. Focusing on the country park cluster in Beijing’s Huitian region, this study develops an integrated assessment framework—combining ecological importance, ecological connectivity potential, construction suitability, and recreational demand—to evaluate nature suitability and pinpoint spatial mismatches in human–nature interactions. Ecological importance is quantified through ecological sensitivity analysis and InVEST-based habitat-quality modeling, while ecological connectivity potential is estimated via normalized least-cost corridor analysis. Construction suitability is derived from the proportion of artificial surfaces and road network density, and recreational demand is measured by population concentration, facility density, and transport accessibility. These metrics are synthesized to map nature-suitability patterns and reveal divergences between human demand and ecological provisioning. The results show a pronounced north–south gradient in ecological importance, with Dongxiaokou Ditch and Dongxiaokou Forest Park emerging as ecological hotspots. Nineteen ecological source patches are identified, with the strongest connectivity in the southern sector of Dongxiaokou Forest Park. Areas of high construction suitability coincide with well-developed infrastructure, whereas recreational demand clusters around Tiantongyuan and Beiqing Road. Natural and artificial elements intertwine to form an ecological core of 870.74 hm², yet 13.29% of the study area exhibits mismatches—particularly residential zones lacking green-space access. Over-development within Dongxiaokou Urban Recreation Park likewise falls short of ecological expectations. The study offers targeted recommendations—ecological protection, facility optimization, green-space enhancement, and the integration of multifunctional green infrastructure—and provides a transferable framework for coordinating human and natural systems in other urban–rural fringe contexts. Full article

Soil nutrient and fertility assessments provide a direct measure for evaluating forest management effects. In this study, we examined soil nutrient content in Chinese fir (Cunninghamia lanceolata) plantations under four reconstruction patterns: pure plantation, introduced broadleaf, introduced needleleaf, and introduced mixed broadleaf-needleleaf. The soil fertility index (SFI) evaluation model was constructed based on partial least squares path modeling (PLS-PM), revealing the influence of stand characteristics on SFI in early stand reconstruction. The results showed that, compared to pure plantations, total nutrient content increased in the introduced needleleaf pattern by 13.94% to 21.15% and available nutrient content by 18.21% to 26.91%. In contrast, both introduced broadleaf and mixed broadleaf-needleleaf exhibited a declining trend. Significant differences were observed among the reconstruction patterns (p < 0.05). In the SFI evaluation model, soil chemistry total nutrient (SCT) and soil chemistry available nutrient (SCA) made significant contributions. The weights of SCT and SCA in SFI were 0.52 and 0.48, respectively. The SFI of four patterns ranged from 0.43 to 0.58, indicating relatively low soil fertility. Compared to pure plantations, introduced trees did not enhance soil fertility in early stand reconstruction. The SFI of the introduced needleleaf was significantly higher than that of the other two reconstruction patterns (p < 0.05). Stand construction (including diameter at breast height, tree density, and tree biomass) explained 14.69% of SFI variation, with a contribution of 31.72% in the surface soil layer (0~20 cm). Tree biomass significantly influenced SFI variation, accounting for over 40% of the total stand factors. Retained tree biomass had a substantially greater effect than introduced tree biomass, contributing twice as much to SFI variation. PLS-PM could effectively reflect the soil nutrient status and accurately estimate the weight of soil fertility. In early stand reconstruction, retained tree biomass might be the major influence on soil fertility variation. We suggest determining reasonable thinning intensity to retain enough Chinese fir and promote the growth of introduced trees. This study introduces a novel approach to soil fertility assessment and provides theoretical support for formulating effective forest management strategies in the early reconstruction of Chinese fir plantations. Full article

Mycotoxins, as prevalent contaminants in the food chain, exhibit diverse toxicological effects on both animals and humans. Chronic dietary exposure to mycotoxin-contaminated foods may result in the bioaccumulation of these toxins, posing substantial public health risks. This review systematically examines the contamination patterns of mycotoxins across major food categories, including cereals and related products, animal-derived foods, fruits, and medical food materials. Furthermore, we critically evaluated two methodological frameworks for assessing mycotoxin exposure risks: (1) dietary exposure models integrating contamination levels and consumption data and (2) human biomonitoring approaches quantifying mycotoxin biomarkers in biological samples. A key contribution lies in the stratified analysis of exposure disparities among population subgroups (adults, teenagers, children, and infants). Additionally, we summarize current research on the relationship between human mycotoxin biomonitoring and associated health impacts, with a particular emphasis on vulnerable groups such as pregnant women and infants. By elucidating the challenges inherent in existing studies, this synthesis provides a roadmap for advancing risk characterization and evidence-based food safety interventions. Full article

Deoxynivalenol (DON) and Alternaria toxins (ATs) are two common types of mycotoxins in food. Although they are physiologically toxic to animals and various cell lines, data related to the exposure risks and health effects in the human population were still limited, especially for ATs. In this study, we combined food consumption data and human biomonitoring data of 200 pregnant volunteers from different districts of Shanghai to assess the exposure to DON and ATs. In addition, correlations between food consumption and urinary DON and ATs levels, urine biomarkers, and blood indexes were analyzed by regression analysis. For DON, the exposure assessment of the probable daily intake (PDI) indicated that a portion (37.5%) of all participants exceeded the Tolerable Daily Intake (TDI) proposed for DON. For ATs, the PDI values estimated based on the urinary concentrations indicated that 2–100% of all participants exceeded the threshold of toxicological concern (TTC) values for ATs. In addition, we innovatively found some associations between exposure to ATs and abnormal uric acid and high-density lipoprotein cholesterol indexes by regression analysis. Despite the inevitable uncertainties, these results make an important contribution to the understanding of DON and ATs exposure risks and potential health hazards in the pregnant women population. Full article

West Lake holds a significant position internationally. This article studies the spatial distribution, historical development, functions, and the lake–city spatial relationship of 81 West Lakes (WLs), as well as their landscape characteristics. The results indicate the following: (1) The overall spatial distribution of WLs is related to China’s history of water conservancy development. (2) The evolution of and functional changes in WLs are influenced by multiple factors such as politics, economy, and culture during different historical periods and are directly related to the will of local administrators. (3) The initial functions of WLs can be categorized into three types, primarily related to urban infrastructure. (4) In terms of spatial relationships, there are four types of spatial relationships between WLs and their water sources and three types of spatial relationships between WLs and cities, forming a common pattern of “Mountains/Hills(–Water)–WL(–Water)–Cities(–Water, River, Sea)” or “WL(–Water)–Cities(–Water, River, Sea)”. (5) The scenery of WLs comprises six elements, including natural basements, water conservancy facilities, human settlements, secularization, landscape architecture, and animal and human activities, all imbued with poetic cultural connotations. Furthermore, this study summarizes three causes of WLs’ scenery; excavates the historical wisdom of WLs in terms of a holistic approach, ecological techniques, dynamic management, and landscape esthetics; and subsequently proposes recommendations for lake ecological governance and landscape construction. Full article

Amid global environmental degradation, understanding the spatiotemporal dynamics and trade-offs of ecosystem services (ESs) under varying land-use scenarios is critical for advancing the sustainable development of social–ecological systems. This study analyzed the Chaohu Lake Basin (CLB), focusing on four scenarios: natural development (ND), economic priority (ED), ecological protection (EP), and sustainable development (SD). Using the PLUS model and multi-objective genetic algorithm (MOGA), land-use changes for 2030 were simulated, and their effects on ESs were assessed quantitatively and qualitatively. The ND scenario led to significant declines in cropland (3.73%) and forest areas (0.18%), primarily due to construction land expansion. The EP scenario curbed construction land growth, promoted ecosystem recovery, and slightly increased cropland by 0.05%. The SD scenario achieved a balance between ecological and economic goals, maintaining relative stability in ES provision. Between 2010 and 2020, construction land expansion, mainly concentrated in central Hefei City, led to a marked decline in habitat quality (HQ) and landscape aesthetics (LA), whereas water yield (WY) and soil retention (SR) improved. K-means clustering analysis identified seven ecosystem service bundles (ESBs), revealing significant spatial heterogeneity. Bundles 4 through 7, concentrated in mountainous and water regions, offered high biodiversity maintenance and ecological regulation. In contrast, critical ES areas in the ND and ED scenarios faced significant encroachment, resulting in diminished ecological functions. The SD scenario effectively mitigated these impacts, maintaining stable ES provision and ESB distribution. This study highlights the profound effects of different land-use scenarios on ESs, offering insights into sustainable planning and ecological restoration strategies in the CLB and comparable regions. Full article

Background/Objectives: Antimicrobial resistance (AMR) is a global public health concern exacerbated by inappropriate antimicrobial prescribing practices, particularly in low-resource settings such as Uganda. The research aimed to develop a culturally sensitive behavioral intervention, leveraging a “nudge” strategy, to improve healthcare provider adherence to the 2016 Uganda Clinical Guidelines (UCG 2016) in five Ugandan hospitals. This intervention formed part of broader antimicrobial stewardship initiatives led by the United States Agency for International Development Medicines, Technologies, and Pharmaceutical Services Program. Methods: This study employed a mixed-methods approach, combining formative research and behavioral intervention. Guided by the Deloitte Behavioral Insights Framework, the research team conducted key informant interviews to identify prescribing barriers and motivators and developed three suitable behavioral interventions: perceived monitoring, ward leaderboards, and educational workshops. The study evaluated the interventions’ impact through point prevalence surveys (PPS), using the World Health Organization PPS methodology at three stages: pre-intervention, immediate post-intervention, and one-month post-intervention. Results: Key behavioral themes across individual, social, environmental, and organizational elements informed the intervention design and implementation. The behavioral intervention package increased antimicrobial prescription compliance with the UCG 2016 from 27% at baseline to 50% immediately post-intervention, though these effects diminished at one-month post-intervention. Conclusions: Our study addresses an existing gap in behavioral nudges-based operational research on antimicrobial prescribing in low- and middle-income countries. These results showed an immediate improvement in adherence to the UCG 2016 among healthcare providers in Ugandan hospitals, though the effect was attenuated at one-month follow-up. Despite the attenuation, behavior change presents a feasible, cost-effective, and sustainable approach to improving antimicrobial prescribing practices and addressing AMR. Full article

Deoxynivalenol (DON) is an important mycotoxin produced by Fusarium spp., typically found in cereals, which has garnered considerable research attention. However, the risk assessment of DON exposure to muti-cereal is partial and biased, especially lacking the evaluation of different coarse grains. In this study, we synthesized and compared the presence of the total deoxynivalenol (free, acetylated, and masked) of a total of 372 grain samples (17 different types) based on high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS), as well as assessed the chronic and acute risks of total DON exposure in the Chinese population. DON was found at the highest frequency with an occurrence of 85.8% (319/372), followed by D3G at 17.2% (64/372). In total, 88.7% (330/372) of the grains were co-contaminated with mycotoxins. The DON and D3G contamination correlation coefficient was 0.68 in wheat flour. Moreover, different DON contamination levels were found in black beans (133.5 µg/kg), soybeans (128.7 µg/kg), and black rice (122.1 µg/kg). The DON/D3G/15A/tDON contamination level was significant differently among different coarse grains. Notably, the Monte Carlo model showed that 3.2–5.9% of adolescents consuming wheat flour and noodles suffered a chronic tDON risk. Full article

Agricultural white pollution is a pressing concern in China. However, the efficiency and rationality of the government’s subsidies for mulch film management remain ambiguous. To formulate reasonable policies for mulch film management and optimize fiscal resource allocation, the study employs cost–benefit analysis to evaluate the economic performance of mulch film management. Two environmentally friendly measures being primarily proposed in China, namely the application of thicker mulch film (hereinafter referred to as thicker film) and the substitution of biodegradable mulch film (hereinafter referred to as biodegradable film), are selected for analysis, with conventional mulch film (hereinafter referred to as conventional film) serving as the benchmark for comparison. Primary data obtained through field surveys, supplemented by secondary data from national statistics, industry reports, and literature reviews, are used for the study. Results show that thicker film application is cost-effective, with a net benefit of CNY 3208.8/ha (USD 449.2/ha; 1 CNY = 0.14 USD), which is CNY 253.8/ha (USD 35.5/ha) higher than that of conventional film. The net benefit for biodegradable film application is lower than that for conventional film, at CNY 2244.6/ha (USD 314.2/ha). The results reveal the significant potential of promoting the use of thicker film due to its recycling and economic advantages. Findings imply that the further promotion of its use lies in improving farmers’ cognition and optimizing subsidy dimensions to allocate government financial resources more effectively. On the contrary, biodegradable film utilization is unprofitable and relies on continuous external subsidies. The government can optimize the subsidy standard based on the cost–benefit performance of different mulch films applied and provide incentives to promote cost reductions and efficiency increases. Further analysis indicates that sustainable mulch film management entails developing mechanisms to internalize the external benefits of management and innovating a new governance landscape. Full article

Urban vitality, intricately connected to urban morphology, has long been a cornerstone of urban planning and design. The accelerated pace of urbanization has created abundant living and working spaces, but it has also brought about a series of issues such as traffic congestion, environmental pollution, insufficient public spaces, and uneven urban development, leading to a decline in urban vitality. The spatial distribution patterns of urban vitality and their influencing factors are diverse and vary across different cities, necessitating a multidimensional exploration of the relationship between urban vitality and the built environment. Utilizing the central urban area of Beijing as a case study, this research leverages multi-source urban spatial data to delineate the spatial characteristics of social, economic, cultural, and comprehensive vitality. Furthermore, a comprehensive set of built-environment indicators is developed across five dimensions to analyze their correlation with urban vitality. The results indicate: (1) There is a significant spatial clustering of various vitality types in Beijing, with a pronounced correlation between high-density population aggregation and vigorous economic activities. (2) Subdistricts exhibiting high social vitality display an “n”-shaped distribution around the Second Ring Road. In contrast, those with high economic vitality are concentrated along Chang’an Street and various district commercial centers. High cultural vitality subdistricts are distributed in a northwest–southeast trajectory from the Fourth Ring Road to the Second Ring Road, and subdistricts with high comprehensive vitality exhibit a concentric distribution radiating outwards from the center. (3) Social vitality is most closely related to comprehensive vitality, and the various vitality types in Beijing’s central urban area develop relatively evenly. (4) The built environment significantly affects all types of urban vitality. Factors such as floor area ratio, POI density, POI mixing degree, and intersection density are fundamental to enhancing urban vitality, whereas the greening rate somewhat inhibits it. (5) Future spatial planning should utilize the radiating effect of high-vitality subdistricts to optimize population distribution, enhance POI mixing, increase metro station density, and strengthen critical urban structures for synergistic economic and cultural development. This study provides a foundation and promotion strategies for optimizing the layout and enhancing vitality at the subdistrict scale within Beijing’s central urban area. Full article

Upwelling, which mixes deep and surface waters, significantly enhances the productivity of surface waters and plays a critical role in marine ecosystems, especially in key fishing areas like Zhoushan. This study utilized merged sea surface temperature data and an upwelling edge detection algorithm based on temperature gradients to analyze the characteristics of upwelling in Zhoushan and the Yangtze River Estuary over the past 28 years. The results indicate that upwelling in Zhoushan begins in April, peaks in July, gradually weakens, and disappears by October. The phenomenon is most pronounced during the summer months (June to August), with significant spatial distribution differences in April and September. Notably, high probability values of upwelling centers and core areas are mainly concentrated near Ma’an Island, Zhongjieshan Island, and Taohua Island. In these areas, upwelling remains stable during the summer, forming a unique “footprint” distribution pattern, and these are also the locations of the Zhoushan National Marine Ranch. From April to August, the extent of the upwelling area gradually decreases and stabilizes. These findings emphasize the frequent upwelling activity around Zhoushan and its significant contribution to the formation of local fisheries. Additionally, considering that the formation of natural upwelling in the East China Sea depends on the southern monsoon, the study suggests establishing artificial upwelling systems during periods unfavorable for natural upwelling, based on high probability areas, to enhance fishery yields and support the development of local fisheries. Full article