To advance China’s carbon neutrality goals, this study introduces a novel integrated framework to analyze agricultural carbon emission efficiency with unprecedented granularity. Moving beyond traditional provincial-level analyses, we utilize panel data from 266 prefecture-level cities between 2003 and 2023. Our primary innovation lies in the comprehensive methodology, which combines an improved global dynamic super-efficiency SBM model for robust efficiency measurement, the Dagum Gini coefficient for precise decomposition of regional disparities, and spatial convergence models to investigate dynamic trends. The empirical results reveal several key insights: (1) A counter-intuitive spatial pattern of “high efficiency in the west, low in the east” is identified, with inter-regional gaps being the primary source of overall disparity. (2) Kernel density estimates uncover a clear trend of multipolar polarization, indicating widening inequalities. (3) A crucial finding is the paradox of convergence: while no σ-convergence exists, significant absolute and conditional β-convergence is confirmed. By providing a multi-dimensional and city-level perspective, this research offers a more scientifically robust basis for designing targeted, region-specific policies to foster coordinated and low-carbon agricultural development.

Laser-based directed energy deposition (DED-LB) represents a promising additive manufacturing technique to produce large-scale parts and an urgent requirement of geometric accuracy with high-value products. However, achieving high forming accuracy remains a challenge, primarily due to extensive back-and-forth toolpaths and layer-by-layer thermal accumulation. During the actual manufacturing process, planned toolpaths dominate the dynamic spatiotemporal input of the laser beam and powder stream, which involves intricate heat transfer within deposition layers and results in potential geometric deviations. This study developed a virtual simulation framework that couples the manufacturing system states with a heat transfer model to predict the part-scale geometric morphology of deposited parts. An identification method was proposed to obtain kinematic timing sequence data from the dynamic manufacturing system with a prediction error of less than 1%, which considers the acceleration-deceleration phenomenon and laser switch time delays. The constructed model clearly elucidates heat dissipation mechanisms and visually illustrates the diverse deposition features caused by differences in melt pool area under different path patterns. Furthermore, the findings strongly confirm that the manufacturing system states significantly influence the geometric morphology, heat-affected depth, and heat-affected steadystate temperature. Simplified simulations that ignore the actual system states may overestimate the volume of deposited parts by a maximum of 53 % due to excessive thermal accumulation. The proposed virtual simulation method offers essential insights for practical guidance in path planning and machine tool configuration during the DED-LB process.

This study examines the coupling relationship between digital transformation and green development in Chinese listed companies, with a particular focus on the agriculture and food industry from 2009 to 2022. Using principal component analysis (PCA) combined with TOPSIS and FEMA, the paper constructs a multidimensional measurement model to assess the coupling coordination degree between digital and green systems. The results reveal that overall coupling has significantly improved over time, especially in the service industry, while the agriculture sector shows a slower but upward trend due to digital infrastructure constraints. Digital transformation notably enhances green innovation and environmental performance, but challenges remain, such as strategic green innovation behaviors and financial policy gaps. The study highlights the need for targeted policies to bridge digital divides and promote substantive green innovation in agriculture and food sectors. These findings provide valuable insights for policymakers and corporate leaders aiming to accelerate the dual digital-green transformation in China's industrial sectors.

While urban shrinkage has extensively befallen cities around the world, the current responses to urban shrinkage have been regarded as deficient and required optimization to help shrinking cities achieve sustainable economic growth and higher quality of life. This paper deploys difference-in-difference (DID) and successfully finds, based on China's national smart city pilot projects, significant effects of smart city development on shrinking cities in catalyzing sustainable economic growth by upgrading and diversifying local industries, promoting economic growth, and providing a better quality of life for citizens through improved wages, enhanced urban environment and public service.

Acetylation of N4-cytidine (ac4C) has recently been discovered as a novel modification of mRNA. RNA ac4C modification has been shown to be a key regulator of RNA stability, RNA translation, and the thermal stress response. However, its existence in eukaryotic mRNAs is still controversial. In plants, the existence, distri-bution pattern, and potential function of RNA ac4C modification are largely unknown. Here we report the presence of ac4C in the mRNAs of both Arabidopsis thaliana and rice (Oryza sativa). By comparing two ac4C sequencing methods, we found that RNA immunoprecipitation and sequencing (acRIP-seq), but not ac4C sequencing, was suitable for plant RNA ac4C sequencing. We present transcriptome-wide atlases of RNA ac4C modification in A. thaliana and rice mRNAs obtained by acRIP-seq. Analysis of the distribution of RNA ac4C modifications showed that ac4C is enriched near translation start sites in rice mRNAs and near translation start sites and translation end sites in Arabidopsis mRNAs. The RNA ac4C modification level is positively correlated with RNA half-life and the number of splicing variants. Similar to that in mammals, the translation efficiency of ac4C target genes is significantly higher than that of other genes. Our in vitro trans-lation results confirmed that RNA ac4C modification enhances translation efficiency. We also found that RNA ac4C modification is negatively correlated with RNA structure. These results suggest that ac4C is a conserved mRNA modification in plants that contributes to RNA stability, splicing, translation, and second-ary structure formation.

Laser Additive Manufacturing (LAM) faces various technical challenges, encompassing issues with dimensional accuracy, mechanical properties, and processing-related defects, such as surface roughness, cracking, and residual porosity. Currently, the quality of safety-critical parts produced by LAM processes, which is still improved through trial-and-error adjustments of multiple process variables, have limited real-time monitoring capabilities. This study introduces an innovative method for real-time quality assessment of laser-directed energy deposition (LDED) procedures across multiple scales (macroscale, mesoscale, and microscale) utilizing a single sensor. This approach is founded on two fundamental components: the single-sensor system for data acquisition and the algorithm for simultaneous multi-scale quality monitoring. For the data acquisition system aspect, a singlesensor, high dynamic range (HDR), multi-scale information acquisition system has been developed to mitigate intense radiation, eliminate plume disturbances, and rectifies backlight shadows, facilitating clearer images of deposition contours and the molten pool region. In the realm of data monitoring algorithms, a physics modeldriven supervisory algorithm is employed to enable monitoring of contour height instability, while a convolutional neural network (CNN), driven by image data, is utilized for porosity prediction. Then, this algorithm adeptly tackles the challenge of simultaneously monitoring macroscopic contour and mesoscale porosity. Regarding the validation of the method, the outcomes of single-sensor multi-scale quality monitoring in additive manufacturing of ceramic thin-wall parts indicate a 100% recognition rate for deposition contour and molten pools, contour feature recognition with a relative error of under 0.05%, porosity prediction accuracy surpassing 99%, and a monitoring time of 80.4 ms per frame. Single-sensor multi-scale real-time quality monitoring can serve as a methodological support for future real-time quality control in LDED.

Today's world is characterized by competition to fulfill high and sustainable development via increased economic activities associated with production and consumption, which then lead to higher demand and pressure on the natural resources and environment. The Belt and Road initiative (BRI) countries are not an exception. Accordingly, this study assessed in depth the spatial direct and spillover influence of financial development (FD), renewable energy consumption (RECO), and institutional quality (IQ) on the ecological footprint consumption (EFC), carbon footprint consumption (CFC), and non-carbon footprint consumption (NCFC) of 57 BRI countries based on panel data from 1992 to 2018. We also linked the findings to the implementation level of the relevant Sustainable Development Goals (SDGs). To do so, this study employed the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model and econometric spatial analysis methodology and conducted a test through a heatmap with labels. The empirical outcomes noted spatial autocorrelation (SAR) for the EFC, CFC, and NCFC between the BRI countries. In addition, FD has a positive direct and spillover influence on EFC, CFC, and NCFC, but the exact opposite for RECO and IQ. In terms of direct influence, gross domestic product (GDP), urbanization (URBP), and foreign direct investment (FDI) raise the EFC, CFC, and NCFC levels, whereas globalization (GLI) and total natural-resources rent (TNR) reduce them. Regarding the spillover effect, GDP enhances EFC, CFC, and NCFC; FDI escalates EFC and CFC, whereas GLI and TNR lower ECF and NCFC, respectively. Furthermore, the test using a heatmap with labels on the implementation level of SDGs supported the empirical findings on BRI countries. Overall, the empirical results are robust, thus providing policymakers new insights to ameliorate the environmental performance of BRI countries.

Morphology and temperature are two important features of molten pools in laser deep penetration welding. An experimental platform equipped with a high-speed camera and a two-color pyrometer was built to observe the variations in the morphology and temperature, and a floating layer on the surface of a molten pool was discovered. The floating layer's morphology, temperature, and thickness were described, and there was a correlation between the morphology of the floating layer and the temperature distribution of the molten pool. The results revealed that the variation range of floating layer thickness is primarily related to three factors: the floating layer area, the molten pool's temperature, and the inclination angle of the floating layer immersed in the molten pool. Surface tension is an important factor in allowing the solidified thin layer to float on the surface of the molten pool. During laser deep penetration welding, the floating layer area goes through three stages during laser welding: growth, reduction, and dynamic stabilization. Finally, the floating layer abbreviated as "STL", is defined as the solidified thin layer. As the laser power increases, the STL area decreases and the weld reinforcement is lower. Weld reinforcement is linearly related to the STL area. In summary, this study's results provide a theoretical foundation for predicting the welding quality in laser deep penetration welding in the future.

Pores are some of the most common defects that form during direct laser deposition of ceramic materials. A mathematical model of pore formation for Al 2 O 3 -ZrO 2 ceramic was developed. The pore formation model, which was developed from the bubble escape factor, reveals the relationship between the movement of the solid-liquid interface of the molten pool and that of the bubbles. In the frontier region of the molten pool, with increasing laser power, the proportion of bubbles that escaped and the area from which bubbles escaped increased. With increasing laser power, the actual and theoretical porosity decreased from 80 % to 40 %. At the central region of the molten pool, the bubble escape factor increased with increasing bubble diameter under the same laser power. The theoretical porosity and the actual porosity decreased with increasing laser power. The pore formation model provides a basis for fabricating high-quality Al 2 O 3 -ZrO 2 ceramics by direct laser deposition.

Indeed, the Belt and Road Initiative (BRI) plays an increasingly important role in global economic and climate change mitigation. However, scientists have insufficient attention to the issues related to the elements that contribute to justifying these impacts and bolstering its response in BRI nations. Accordingly, the existent study executed an in-depth examination of the spatial direct and spillover effects of foreign direct investment inflows (FDI) and biomass energy consumption (BEC) on greenhouse gas emissions (GHG) for 57 BRI countries (1992-2012). We applied the spatial lag model (SLM), the spatial error model (SEM), and the spatial Durbin model (SDM) with five different weights matrices to verify the existence of the pollution haven hypothesis (PHH), the pollution halo hypothesis (P-HH), and the N-shaped environmental Kuznets curve (EKC). We linked the study results with the implementation level of the sustainable Development Goals (SDGs). The findings of local Moran's I (LMI) and Lagrange Multiplier (LM) tests confirm the existence of spatial autocorrelation (SAR). The empirical results revealed that FDI has a positive direct and spillover influence on GHG emissions, which supports the presence of PHH. Also, the nexus between economic growth and GHG emission is an N-shaped curve. The results revered that BEC has a negative sign for direct and spillover effects. In contrast to BEC, Fossil Fuel Energy Consumption (FFEC) and population positively sign for direct and indirect impact. Some policy proposals and future research directions are discussed for BRI countries.

What are the causes of the change in the north-south gap of industrial pollution discharge in 2008 and 2016? In order to solve this problem, this paper makes theoretical and empirical research. The results show that (1) the difference in economic growth pattern transformation is the root cause of the change in the north-south gap of industrial pollution discharge.(2) The international financial crisis is the direct cause of the change in the north-south gap of industrial pollution discharge in 2008. The international financial crisis forced the industrial transformation and upgrading of the southern region, which made the TFP of the southern region relatively improve, and then led to the relative reduction of industrial pollution discharge in the southern region. (3) The supply-side structural reform is the direct cause of the change in the north-south gap of industrial pollution discharge in 2016. However, the supply-side structural reform proposed by the central government in 2016 is essentially a further continuation of the policy of "resolving overcapacity" implemented in 2013. In fact, the north-south gap in the growth rate of industrial discharge has changed since 2013.

The plasma characteristics generated in laser welding are closely related to the weld penetration state and the resultant weld properties. In this paper, a real-time monitoring platform was built to monitor the plasma plume and spectral in laser deep penetration welding of the H340LA high-strength steel tailor rolled blanks. The image processing method and the spectral processing method were used to investigate the correlation of the penetration on the plasma plume and spectral. The weld penetration state was divided into three categories: excessive penetration, moderate penetration and partial penetration. It was found that the penetration was mainly affected by centroid height, plasma area and intensity. The weld gradually transitioned from partial penetration, mod-erate penetration to excessive penetration with the centroid height, plasma area and spectral intensity decreased. When the centroid height was 2.42-4.19 mm, the area was 6.96-17.58 mm(2), and the spectral intensity was 447.98-1453.95 a.u., moderate penetration weld can be obtained. A plasma plume-spectrum based multi-features Back Propagation (BP) neural network model was purposed to predict the weld penetration state with an accuracy of 97%, which is greatly higher than that of the single-feature neural network model. This work provides technical guidance for realizing real-time control of weld penetration.

Using low-retraction double-tensioned steel strands vertical prestress system (DTSSVPS) to replace finish rolled rebars (FRR) a vertical prestress system could effectively enhance the vertical prestress efficiency and reduce the occurrence of diagonal cracks on the webs of long-span prestressed concrete (PC) box-girder bridges. This study will conduct a T girder test, short rectangular slab test, double-tensioned anchor (DTA) performance test as well as field tests on two bridges with DTSSVPS to investigate the immediate prestress loss, shear cracking performance of the web, and minimum biting length (d) between the anchor nut and cup. The results showed that the immediate prestress loss using DTSSVPS reduced from 20% to 40% after one tension to approximately 10% after two tensions and the prestress efficiency was much higher than FRR. Therefore, it is recommended that the design retraction value of the DTA was 2 mm. The experimental shear cracking load of the web with DTSSVPS was 1.39-1.45 times the theoretically calculated load. Following unloading, the diagonal cracks on the web were closed and the web worked in the elastic stage. Finally, based on the single-hole DTA performance test, the minimum d between the anchor cup and nut was 10 mm. The design tension force (f) carried by the unit arch length of the thread between the anchor cup and anchor nut was 130 N/mm. A formula is proposed for the design of the minimum d of a multiple hole DTA. In addition, the stress distribution on the surface of the anchor nut was investigated. This study could provide a basis for a wide application of DTSSVPS technology in the future.

This study introduces ideas from political science to investigate urban politics under asymmetric power structures, which, as a crucial political context, have not been emphasised sufficiently in the literature. Such a study reveals a new understanding of urban politics in Chinese urban regeneration, a resilient relationship between social demand and governmental response that comes from asymmetric power structures and can strengthen such structures. This investigation is based on the changing policies and practices of the Enning Road Regeneration Project in Guangzhou, China, since 2006. Three main research findings have been displayed: 1) a mode of resilient governance with adaptive purposes, flexible patterns and responsive mechanisms—the reactive pre-emption mechanism—in urban regeneration in China; 2) the dialectic relationship between resilient governance and asymmetric power structures; and 3) the preconditions for producing resilient governance under asymmetric power structures. On the basis of our empirical evidence and theoretical analyses, the research perspective we call 'resilient governance under asymmetric power structures' has been constructed as a bridge between formerly separate fields in political science and urban governance. The resilient asymmetric power model has been established to reveal the political nature of governance with more resilience and asymmetric power compared with other power models.

In recent years, the number of large cities and the incidence of urban haze have been increasing. However, whether population growth inevitably leads to air pollution is controversial. The expansion of city scale is accompanied by changes in traffic mode and traffic congestion. However, whether such expansion influences traffic and wields a significant impact on air pollution remains unknown. Thus, this research attempts to clarify the influence mechanism of city-scale expansion on air pollution and analyze the expansion of city scale, traffic, and air pollution in the same framework. First, we find that city-scale expansion can directly influence air pollution. The scale effect of energy consumption caused by such expansion significantly aggravates air pollution, whereas the structural and technological effects can effectively improve air quality. Second, green mode of transportation can reduce air pollution, whereas traffic congestion worsens air pollution by increasing the commuting time. Third, we find that the city-scale expansion can both alleviate and worsen air pollution by promoting public transport and exacerbating traffic congestion, respectively. Therefore, the effect of city-scale expansion on air quality by influencing traffic is clearly a "double-edged sword."

The existing literature on environmental efficiency focuses on economic and social factors, and rarely on the role of local leadership. Thus, this study aims to measure the environmental efficiency and analyze the impact of mayors' characteristics on environmental efficiency. By using the metafrontier-stochastic frontier analysis two-step estimate method, the average value of the overall environmental efficiency in China is only 0.523, which is high in the eastern region and low in the central and western regions. Empirical results show that mayors' tenure plays an inverted U-shaped effect on environmental efficiency. Mayors who are highly educated, young, and aware of environmental protection can improve environmental efficiency. Moreover, mayors' experience in official exchange can improve environmental efficiency; mayors with work experience in the central government are effective in terms of environmental governance. The policy implication is that improving the educational level of leaders, appointing young cadres, and strengthening official exchanges can effectively improve environmental efficiency.

This study investigates the spatial influence and spillover effects of foreign direct investment (FDI) on environmental pollution (EP) by using panel spatial data in 1970–2016 for 12 selected Arab countries. It employs the STochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model. The spatial econometric approach is applied to examine the validity of the pollution haven hypothesis (PHH) and the pollution halo hypothesis (P-HH) (from now on, we will use the acronyms PHH and P-HH to denote the pollution haven hypothesis and pollution halo hypothesis, respectively). The Sustainable Development Goals (SDGs) are linked to the study results with a focus on cleaner production practices. The global Moran’s I, local Moran’s I, and Lagrange multiplier (LM) tests are used to ascertain the existence of spatial autocorrelation (SAR) and determine its trend. We also apply the spatial lag model (SLM), the spatial error model (SEM), and the spatial Durbin model (SDM) to achieve the study objectives. Data are analyzed by using the SDM on the basis of the results of the Wald and likelihood ratio tests. The results of the LM and global and local Moran’s I tests confirm the existence of SAR. The SDM results reveal that a slight increase in CO2 is an influence of the FDI on EP. Findings support the existence of PHH in the Arab countries. The direct effect of the FDI is increased CO2 and environmental degradation, and the spatial spillover effects are statistically insignificant. This study suggests a set of policies for managing and directing FDI toward clean technology-based industries and reduced CO2 emissions. Such policies may contribute to the achievement of some SDGs and balancing economic development and environmental sustainability according to the cleaner production practice perspective in the Arab countries and other states with similar conditions.