Search Results (459)

As the key driver of economic development, sci-tech finance presents a new opportunity for China’s economic green transformation. This paper employs the difference-in-difference method to examine the influence of sci-tech finance policies on urban carbon emission efficiency. The results show the following: (1) Generally, the technology finance policy can notably enhance urban carbon emission efficiency, and this conclusion remains valid after a series of robustness checks. (2) Mechanism tests indicate that sci-tech finance can promote low-carbon development via innovation, financing, and energy structure channels. (3) Heterogeneity tests reveal that sci-tech finance has a more pronounced impact on emissions reduction in the eastern regions, areas with strict environmental regulations, regions with a higher degree of marketization, and non-resource-based cities. (4) A spatial Durbin model was employed to analyze the spatial spillover effects of science and technology finance. (5) The Double Machine Learning (DML)model was used for verification and inspection, and found that sci-tech is conducive to improving the carbon emission efficiency of cities. Finally, this study offers policy recommendations, including formulating region-specific implementation guidelines for the growth of sci-tech finance, taking into account the distinct features of each area. Full article

The development of carbon-based anode materials for high-performance lithium-ion batteries has been limited by their low theoretical capacity density, low conductivity, and high manufacturing costs. Herein, natural Si/N co-doped biomass carbon micron-tubes, derived from reed catkins, were synthesized. The as-prepared RC-Si/N anode exhibits a good discharge capacity of 761.3 mAh g⁻¹ at 100 mA g⁻¹ after 200 cycles. Moreover, it exhibits outstanding cycling stability, retaining discharge capacities of 517.7 mAh g⁻¹ at 1 A g⁻¹ after 1000 cycles. The excellent electrochemical performance is attributed to the trace Si originating from the biomass precursor, which provides high specific capacity, while N doping introduces structural defects and improves electronic conductivity. Coupled with its unique micrometer-scale tubular morphology, the material facilitates efficient lithium-ion transport and storage. Further DFT calculations corroborate enhanced Li⁺ adsorption ability, sustained structural integrity over prolonged cycling, and promoted reaction kinetics. These findings underscore the potential of natural Si/N co-doped biomass-derived carbon as an advanced lithium-ion battery anode material. Full article

Extreme heatwaves threaten public health and economies. Using multi-source data from 1964–2023 and the Excess Heat Factor (EHF), we identified heatwaves and, with a generalized linear mixed model and Hurst-based intensity forecasting, assessed drivers and future trends across Belt and Road Initiative (BRI) regions. (1) Duration, frequency, and the number of events increased by 18.7 days, 21.2 days, and 5.5 events, respectively. During the 2004–2023 period, HWD, HWF, and HWN accelerated, expanding from South Asia/Middle East to Central Asia, the Caucasus, and North Asia. In 1994–2023, centroids shifted west/south: frequency 2.54° W, 1.83° S; and intensity 1.17° W, 2.79° S. (2) Between 2000 and 2019, interaction effects exceeded single effects; dominant drivers shifted from SPEI and wind speed to shortwave radiation and NDVI. (3) Future intensification peaks in East Asia, the Iranian Plateau, and China’s east coast; with H ≥ 0.7, enhanced areas exceed 33% (max 37%), concentrated in Central and western West Asia. Full article

Lithium-ion batteries with high energy density and long cycle life have been widely used as secondary batteries in electric vehicles and energy storage systems. With the growing demand for high energy density in lithium-ion batteries, silicon-based materials, which possess a high theoretical specific capacity (4200 mAh g⁻¹), are regarded as core candidates for anode materials. However, Si-based materials undergo severe volume expansion (up to 300%), which leads to the collapse of the electrode structure, inducing pulverization of the active material and capacity loss, thereby hindering the commercial application of silicon-based materials. To address these issues, scholars from various countries have developed many silicon-based materials with different compositions and three-dimensional structures, and have made some research progress. This review first elaborates on the lithium storage mechanisms and advantages of diverse silicon-based anode materials by taking Si, SiO_x, SiN_x, and SiP_x as representative examples with distinct characteristics. Subsequently, from the two aspects of dimensional design (0D, 1D, 2D and 3D) and architecture design (core–shell, sandwich-like and network structure), the design strategies for various silicon-based anode structures and their enhancement on electrochemical performance are analyzed. Finally, this review elucidated the challenges faced by silicon-based anodes from the perspectives of mechanism elucidation, structural customization, industrialization, and full-cell applications. It also proposed future development directions for silicon anodes by combining actual challenges and focusing on aspects such as structure optimization, machine learning, advanced characterization techniques, and mechanistic analysis. Full article

This paper examines source-conditioned spillovers and tail dependence in Belt and Road Initiative equity markets under China-related equity distress and WTI oil-price-decline distress. We define source-conditioned spillovers as incremental changes in pairwise dependence relative to a median-threshold benchmark, and source-conditioned tail dependence as the nonlinear higher-order component of these changes. Using a DCC-GARCH model with multivariate generalized hyperbolic innovations, we construct a linear co-moment layer and a nonlinear tail-dependence layer for 32 equity markets from 2007 to 2025. The resulting annual country-level exposure measures are then related to macroeconomic, China-linked, and oil-linked characteristics through benchmark fixed-effects and source-matched regressions. The empirical results imply that the linear layer mainly reflects background synchronization, whereas the nonlinear layer captures selective tail-state amplification. SSEC-conditioned exposure is more visible in China-adjacent and regionally linked equity relationships, while WTI-conditioned exposure is more visible among intermediary receiving markets and in nonlinear oil-related episodes. The comparison after 2013 suggests that BRI equity markets became more vulnerable to energy driven tail risk, as WTI distress is more strongly associated with nonlinear downside amplification. SSEC distress mainly increases the common linear exposure channel, indicating broader regional synchronization rather than a persistent rise in nonlinear contagion. The framework provides a financial-stability diagnostic for sustainable-finance resilience by distinguishing routine cross-market synchronization from nonlinear downside exposure relevant to cross-border financing, infrastructure investment, and energy-transition-related capital allocation. Full article

The Ili River is a transboundary water body in Central Asia and a key region along the Belt and Road Initiative, yet antibiotic pollution in this river remains unexplored. This study investigated the occurrence, distribution, and ecological risks of 14 antibiotics in the Yining section of the Ili River and the effluent of the Huocheng Wastewater Treatment Plant (HWTP). We optimized and validated an analytical method using solid-phase extraction coupled with high-performance liquid chromatography-tandem–mass spectrometry (SPE-HPLC-MS/MS). The method achieved low detection limits (0.05–1.0 ng·L⁻¹) and good recoveries (70.0–108.3%). Results showed that HWTP removed 9.8–98.3% of detected antibiotics, with negative removal observed for several compounds due to desorption or metabolite reconversion. In the Yining river section, tetracyclines dominated (55.9% of total antibiotics), followed by fluoroquinolones (33.8%), macrolides (9.7%), and β-lactams (0.6%). Ecological risk assessment using the risk quotient method revealed that the combined risk (RQ_s) in the Yining section ranged from 1.54 to 2.74, indicating a high-risk level. Chlortetracycline exhibited the highest individual risk (RQ 0.92–0.97) and is proposed as a priority pollutant. This study provides the first baseline data on antibiotic pollution in a Central Asian transboundary river and underscores the need for international cooperation in water quality management within the Belt and Road framework. Full article

Co-channel interference (CCI) remains a critical factor affecting link reliability in narrowband wireless systems, especially in scenarios with intensive frequency reuse, overlapping coverage, and dense terminal access. Existing interference detection methods are either computationally simple but insufficiently sensitive to short-term spectral variations, or highly accurate but dependent on labeled data and nontrivial inference resources. To address this issue, this paper proposes a lightweight CCI detection method in the FFT domain based on spectrum-jump analysis. The proposed method does not rely on absolute power growth as the primary interference indicator. Instead, it tracks the temporal inconsistency of dominant spectral-bin indices across consecutive FFT frames and converts recurrent peak-bin migration into an interference decision through a short-window counting mechanism. The method is computationally efficient, interpretable, and suitable for real-time deployment without offline model training. SDR-based measurements are combined with controlled repeated experiments to assess detector performance under varying signal-to-noise ratio (SNR), interference-to-signal ratio (ISR), carrier-frequency offset (CFO), multi-peak ambiguity, and two-path Rayleigh fading conditions. On the measured SDR record, the proposed method captures all interference-positive windows after the marked onset, while the controlled SNR/ISR experiments yield an overall detection probability of 96.0% over 250 CCI trials with no false alarms over 250 normal trials. ROC and precision–recall analyses further show that the selected threshold lies within a broad validation plateau. The results also reveal clear applicability boundaries: when the CFO approaches zero, when the interference is very weak, or when multiple stationary peaks have nearly equal power, dominant-bin migration may be weak or ambiguous. Therefore, the proposed approach is a low-complexity online detector for CCI cases that induce observable FFT-bin instability, and it can also serve as a front-end trigger for more advanced interference analysis modules. Full article

Understanding how urban road network structures influence household carbon emissions is fundamental to developing low-carbon urban environments. This study examines China’s Western Valley cities (WVCs), which have distinct structural characteristics, to analyze the heterogeneous effects of road network structures on household carbon emissions. Using 2020 household carbon emissions and road network data, we employed stepwise regression and curve estimation regression models to clarify these relationships based on the distribution patterns of both variables. The following are the key findings of this study: (1) Substantial differences exist between cities in terms of total household carbon emissions, per capita emissions, and per capita land use. (2) Regarding road network structure, cities can be categorized into three types—clusters, fingers, and belts—based on the distribution of high and low values of closeness centrality (CC), with four, five, and six cities falling into each category, respectively. While compactness differences between cities are relatively small, variability exhibits large disparities, leading to different city rankings and highlighting the complexity of road network organization. (3) The three structural characteristics show significant correlations with household carbon emissions not only in terms of direction but also magnitude and influence mechanisms. (4) CC follows an inverse function pattern, initially declining sharply before gradually stabilizing. Compactness follows a positive linear growth pattern, consistently promoting household carbon emissions. Variability exhibits a positive power-law growth pattern, showing a sharp initial increase that weakens over time. Full article

Under global warming and rapid urbanization, understanding the link between residential spatial layouts and carbon emissions, considering microclimate effects, is crucial. Using the Local Climate Zone (LCZ) framework, this study selected 60 residential neighborhoods in Suzhou (hot summer and cold winter zone). A microclimate–neighborhood morphology coupling model was built by integrating the Urban Weather Generator (UWG) and Urban Metabolism-Induced Energy (UMI) model. The factor method was used to simulate energy use and carbon emissions of building clusters. The study systematically analyzed eight spatial form indicators, their influence on carbon emissions, and developed a predictive model. Main conclusions: (1) Carbon emission intensity ranks: LCZ6 > LCZ3 > LCZ5 > LCZ4 > LCZ2 > LCZ1. (2) Shape factor is positively correlated with carbon emissions across all LCZs, being the most stable and significant predictor. (3) Dominant factors vary by LCZ: sky view factor for compact high-rise (LCZ1); scattering degree for open high-rise (LCZ4); shape factor for compact mid-rise (LCZ2), open mid-rise (LCZ5) and open low-rise (LCZ6); no significant factor for compact low-rise (LCZ3). These findings can support low-carbon residential design, energy-efficient renovation of old neighborhoods, and optimization of residential evaluation standards. Full article

As a major ecological safeguard in northwestern China and an important corridor for the Belt and Road Initiative, the Hexi Corridor holds strategic significance for improving landscape structure and enhancing regional ecological security. Focusing on the Hexi Corridor, this study develops a landscape ecological risk (LER) index based on land use (LU) data from 2000, 2010, and 2020. The study employs ArcGIS spatial analysis and XGBoost-SHAP, an interpretable machine learning method, to analyze the spatiotemporal evolution of LU and LERs, as well as their driving factors. Furthermore, the Markov-FLUS model is utilized to simulate and predict LU and LER spatial patterns under multiple scenarios for 2030. The results show that: (1) The dominant land type in the Hexi Corridor is unused land, accounting for 67.33%. During the research period, the extents of unused land, grassland, and forestland showed a steady decline, while built-up land and cropland increased. (2) LERs are categorized into five types, with high risk being the most prevalent, accounting for 52.02%. Between 2000 and 2020, the total area of higher and high risks decreased by 4312 km², indicating an overall decrease in LER across the region. (3) LER is primarily influenced by annual rainfall, population density, distance to main roads, and distance to rivers. (4) Marked variations in LU patterns and LER are observed across different development scenarios projected for 2030. Full article

The countries in the Belt and Road Initiative (BRI) significantly influence global carbon emissions, and the spatial correlation and driving mechanisms of their emissions are crucial for regional emission reduction and global climate governance. This study constructs a carbon emission spatial correlation network, where links represent pairwise spatial correlations derived from a modified gravity model, using data from 54 BRI countries (2011–2020). It applies social network analysis (SNA) to examine the network structure and uses the Temporal Exponential Random Graph Model (TERGM) to identify influencing factors. The main findings are as follows: (1) The BRI carbon emission network has become more interconnected and cohesive, with stronger regional connectivity and reduced inequality. (2) The network shows a core–periphery structure with notable spatial association patterns. Countries like Qatar, Israel, India, China, and the UAE have rapidly established carbon emission links, positioning them at the core due to their high connectivity and influence. (3) The network displays temporal dependence, with reciprocity associated with stronger mutual connections and transitivity associated with more cohesive network structures. Technological innovation and industrial structure optimization are positively associated with the formation of carbon emission connections, while energy structure and foreign investment are negatively associated with it. Economic development and technological innovation are associated with a country’s greater involvement in carbon emission connections, and countries with similar urbanization rates, energy, and industrial structures, but large economic disparities are more likely to form carbon emission associations, reflecting potential complementarities in the network structure. Full article

Frequent major emergencies threaten the security of the feed grain import supply chain. Enhancing import resilience is essential for supporting a new development pattern. However, research on a dedicated system to evaluate the resilience of China’s feed grain imports remains limited. In addition, strategies to strengthen resilience based on country-specific distances are still underexplored. This study constructs a comprehensive indicator system for China’s feed grain import resilience, using data from 2000 to 2023. It empirically examines the impact of country distance on this resilience across four dimensions: geographic distance, economic distance, institutional distance, and cultural distance. The findings indicate that country distance has an inhibitory effect on China’s feed grain import resilience. This conclusion holds true even after testing various adjustments, such as changes to core explanatory and dependent variables, modifications in sample sizes, alterations in measurement methods, and the introduction of instrumental variables. Further analysis reveals that country distance undermines feed grain import resilience by significantly reducing trade efficiency. However, the Belt and Road Initiative (BRI) and Regional Trade Agreements (RTA) help mitigate the negative impact of country distance on resilience. To strengthen China’s feed grain import resilience, it is crucial to enhance cultural and institutional trust, improve trade efficiency, and optimize import distribution. This study provides empirical evidence to support the safety of China’s feed grain imports and promote efficient, mutually beneficial trade in feed grains with partner countries. Full article

The advancement of green and low-carbon transition in the steel industry has increased the demand for high-quality direct reduced iron (DRI) as a premium feedstock for electric arc furnace steelmaking. This imposes stricter quality requirements for fired pellets utilized in gas-based shaft furnace processes. To address the poor low-temperature reduction degradation (LTD) of fired pellets produced from a single high-grade magnetite concentrate during gas-based direct reduction. This study investigates the effects of blending hematite concentrates into a magnetite concentrate base (with additions of 0, 20 wt.%, 30 wt.%, and 40 wt.%) on the characteristics of the mixed concentrates, green ball properties, firing performance, and the metallurgical performance of the resulting fired pellets under conditions simulating an HYL shaft furnace. The results indicate that the incorporation of hematite concentrate optimizes the overall particle size distribution and green ball properties. As the hematite proportion increases, the optimal preheating temperature for green balls rises, while the required roasting temperature decreases. The most significant reduction in roasting temperature, from 1225 °C to 1175 °C, is achieved with a 20 wt.% hematite addition. Regarding metallurgical properties, the addition of hematite has a minor effect on the reducibility index (RI) but substantially improves the reduction swelling index (RSI). A notable decrease in the RSI is observed at addition levels of 30% and above. Critically, the LTD is significantly enhanced. The optimal improvement is attained with a 20 wt.% hematite blend, resulting in a- LTD_{+6.3 mm} fraction of 97.48 wt.%, a- LTD_{−3.2 mm} fraction of only 2.18 wt.%, and a whole pellet ratio of 88.01% after reduction. Considering the comprehensive performance, a blend of hematite concentrate between 20 wt.% and 30 wt.% yields fired pellets with superior characteristics, meeting the production requirements for gas-based shaft furnace direct reduction processes. This study provides an effective technological pathway for producing high-performance DRI-grade pellets from high-grade magnetite concentrates, contributing to the green and low-carbon transformation of the iron and steel industry. Full article

The growing demand for direct reduced iron (DRI) in green steel production requires high-quality fired pellets as the burden for the gas-based shaft furnace direct reduction process. However, the properties of magnetite concentrate as pellet feed present a significant impact on the quality of fired pellets, especially the metallurgical performance. A systematic study of the effect of pretreating the magnetite concentrate on the properties of fired pellets was conducted using two pretreatment technologies, i.e., damp-milling and high-pressure roll grinding (HPRG). Green balls were made from pretreated magnetite concentrates and fired under optimal conditions. Their performance was then evaluated in a laboratory-scale setup simulating the HYL shaft furnace environment. Key metrics included cold compressive strength (CCS), reducibility index (RI), reduction swelling index (RSI), and dynamic low-temperature reduction degradation (LTD). The pretreatment of magnetite concentrates with HPRG twice showed significant benefits. The fired pellets not only have a CCS of 2500 N/p at a roasting temperature 150 °C lower, but also achieve an RI of 3.37 and an RSI of 3.15%, respectively. Furthermore, the reduction degradation tendency was markedly reduced; the +6.3 mm fraction reached 94.72% with a whole pellet ratio of 75.49%. Conversely, while damp-milling improved the LTD, it required a 100 °C increase in preheating temperature and yielded a whole pellet ratio of only 49.15%, failing to meet industrial requirements. The improvement in metallurgical performance is attributed to the intense micro-cracking induced by the two-pass HPRG process, which optimizes the particle size distribution, specific surface areas and improves the microstructure and pore properties of the fired pellets. Full article

Beta-2-microglobulin (B2M) is a key component protein in the processing and presentation of major histocompatibility complex (MHC)-I antigens and plays an important role in the immune system regulation. Previous studies have shown that B2M is significantly overexpressed in the intestinal tissues of sheep that are resistant to E. coli F17b infection (defined by milder clinical symptoms post-challenge) compared to those that are susceptible (exhibiting severe diarrhea). Based on this finding, this study aimed to investigate whether B2M influences the adhesion of E. coli F17b to sheep intestinal epithelial cells (IECs) and to assess its role in regulating IEC proliferation and migration. We tested this by overexpressing and knocking down B2M in IECs, and then measured bacterial adhesion through colony counts and fimbrial gene expression (RT-qPCR). Moreover, cell health was assessed using proliferation (CCK-8 and EdU) and migration (scratch) assays. The results showed that upregulation of B2M expression inhibited E. coli F17b adhesion and promoted IEC proliferation and migration. Silencing B2M increased bacterial adhesion and impaired cell function. In summary, B2M helps protect sheep IECs from E. coli F17b by strengthening the epithelial barrier through improved cell growth, proliferation, and migration. These findings elucidate part of the host defense mechanism against E. coli F17b, providing a basis for further research. Full article