Search Results (145)

Flattened bamboo (FB) exhibits pronounced structural and chemical heterogeneity between outer and inner layers and between nodes and internodes. These variations critically influence its interfacial performance with waterborne acrylic coatings. This study aimed to clarify how primer layer configuration and substrate heterogeneity jointly affect the coating adhesion, hardness, and abrasion resistance of FB. Three coating schemes—one primer and one topcoat (1P1T), two primers and one topcoat (2P1T), and three primers and one topcoat (3P1T)—were applied to four types of FB substrates defined by layer and structural position. Adhesion, pencil hardness, and abrasion resistance were measured according to GB/T standards, complemented by surface roughness, contact angle, XPS, and SEM analyses. Results showed that substrate heterogeneity dominated coating behavior. The parenchyma-rich inner-layer internodes, characterized by higher polarity (O/C = 0.296) and rougher texture, exhibited stronger adhesion and superior abrasion stability, whereas the fiber-dense outer layer nodes, with lower polarity (O/C = 0.262), showed weaker bonding. Increasing the number of primer layers improved film continuity only when the substrate microstructure allowed sufficient primer penetration. The combined findings indicate that coating adhesion and wear stability are primarily governed by substrate composition and surface polarity rather than by coating thickness. These results provide scientific and practical guidance for optimizing primer application and surface preparation in the industrial finishing of bamboo-based decorative panels, while also highlighting the environmental and economic advantages of waterborne coating optimization for sustainable bamboo manufacturing. Full article

This study presents a theoretical analysis of the effectiveness of the use of variatropic concretes in multi-layer panel structures of buildings in terms of heat transfer. Theoretical analysis was performed with the aid of the modern numerical modeling software package ELCUT 6.6 and the computer algebra system Maple, which helped improve the reliability of the calculations. The results of this study of the thermophysical parameters of multi-layer panels using variatropic concrete showed that an increase in the degree of variatropy contributes to a rise in the temperature on the inner surface of the panel from 17.94 °C (traditional panel) to 18.87 °C (the most variatropic panel, Scheme 4), which improves indoor comfort conditions and reduces the risk of condensation. Additionally, it is possible to reduce the thickness of the insulation layer without compromising thermal efficiency. The high thermal inertia (D > 7) of variatropic panels ensures the accumulation and retention of heat, which has a positive effect on energy consumption during the heating season. The moisture regime of the studied structures meets regulatory criteria for preventing moisture accumulation, thereby increasing panel durability and eliminating conditions for mold formation or structural degradation. The air permeability performance of the panels also complies with the standards, while the dense outer concrete layers provide additional protection against air infiltration, stabilizing both thermal and moisture balance. The calculated thermal resistance of variatropic panels (Schemes 3 and 4) exceeded the standard requirement (3.20 m²·°C/W) by 1.2 and 1.74 times, respectively. Thus, it was established that the application of the variatropic principle in panel design ensures a more rational distribution of temperature fields, which results in reduced heat losses and improved thermal stability of exterior enclosures. This approach develops new design solutions focused on improving the energy efficiency of buildings and reducing material costs, which is consistent with current trends in Functionally Graded Design (FGD). Full article

Background: Bacterial resistance to antibiotics continues to rise globally, posing a significant public health challenge and incurring substantial social and economic burdens. In response, the World Health Organization (WHO) has published a list of priority pathogens for which effective treatment options are critically limited. Several antibiotics are categorized as Gram-positive-only (GPO) agents due to their lack of activity against Gram-negative species. Although these compounds often target conserved bacterial processes, their limited spectrum is largely attributed to poor penetration of the Gram-negative outer membrane (OM). Results: In this study, we designed and synthesized a series of adarotene-derived compounds to evaluate the impact of introducing positively charged groups on their interaction with the Gram-negative OM. One of the newly synthesized derivatives, SPL 207, displayed minimum inhibitory concentration (MIC) values ranging from 8 to 64 µM against a panel of Gram-positive and Gram-negative bacteria. The ability of SPL207 to disrupt outer and inner membrane permeability was evaluated using fluorescence assays and confocal microscopy, revealing that the compound compromises membrane integrity across all tested Gram-negative bacteria. Strong synergistic activity was observed in combination with colistin against three P. aeruginosa colistin-resistant strains. Atomistic details of membrane interference were elucidated by molecular dynamics (MD) simulations, with SPL207 clearly acting as a membrane destabilizer by enhancing Ca²⁺ ions diffusion and lipids destabilization. Conclusions: Although the observed MIC values remain above clinically acceptable thresholds, these findings provide a promising proof of concept. The further structural optimization of adarotene derivatives may yield novel broad-spectrum agents with improved antimicrobial potency against MDR pathogens. Full article

Anthracyclines have been clinically well established in cancer chemotherapy for decades. The main limitations of this drug class are the development of resistance and severe side effects. In the present investigation, we analyzed 30 anthracyclines in a panel of 59 cell lines of the National Cancer Institute, USA. The log₁₀IC₅₀ values varied from −10.49 M (3′-deamino-3′-(4″-(3″-cyano)morpholinyl)-doxorubicin, 1) to −4.93 M (N,N-dibenzyldaunorubicin hydrochloride, 30). Multidrug-resistant NCI-ADR-Res ovarian cancer cells revealed a high degree of resistance to established anthracyclines (between 18-fold to idarubicin (4) and 166-fold to doxorubicin (13) compared to parental, drug-sensitive OVCAR8 cells). The resistant cells displayed only low degrees of resistance (1- to 5-fold) to four other anthracyclines (7, 18, 28, 30) and were even hypersensitive (collaterally sensitive) to two compounds (1, 26). Live cell time-lapse microscopy proved the cross-resistance of the three chosen anthracyclines (4, 7, 9) on sensitive CCRF/CEM and multidrug-resistant CEM/ADR5000 cells. Structure–activity relationships showed that the presence of tertiary amino functions is helpful in avoiding resistance, while primary amines rather increased resistance development. An α-aminonitrile function as in compound 1 was favorable. Investigating the mRNA expression of 49 ATP-binding cassette (ABC) transporter genes showed that ABCB1/MDR1 encoding P-glycoprotein was the most important one for acquired and inherent resistance to anthracyclines. Molecular docking demonstrated that all anthracyclines bound to the same binding domain at the inner efflux channel side of P-glycoprotein with high binding affinities. Kaplan–Meier statistics of RNA sequencing data of more than 8000 tumor biopsies of TCGA database revealed that out of 23 tumor entities high ABCB1 expression was significantly correlated with worse survival times for acute myeloid leukemia, multiple myeloma, and hepatocellular carcinoma patients. This indicates that ABCB1 may serve as a prognostic marker in anthracycline-based chemotherapy regimens in these tumor types and a target for the development of novel anthracycline derivatives. Full article

The global construction industry faces pressing challenges in enhancing building energy efficiency standards. To address this critical issue, facilitate worldwide green and low-carbon transformation in construction practices and improve the thermal performance of building wall panels to achieve optimal levels, a novel polypropylene fiber-reinforced concrete wall panel has been developed and investigated. A three-dimensional steady-state heat transfer finite element model of the wall panel was established to simulate its thermal performance. Key parameters, including the thickness of the inner and outer concrete layers, insulation layer thickness, connector spacing, and connector arrangement patterns, were analyzed to evaluate the thermal performance of the fiber-reinforced concrete composite sandwich wall panel. The results indicate that the heat transfer coefficients of the G-FCSP and FCSP wall panels were 0.768 W/m² · K and 0.767 W/m² · K, respectively, suggesting that the glass fiber grid had a negligible impact on the thermal performance of the panels. The embedded insulation layer was crucial for enhancing the thermal insulation performance of the wall panel, effectively preventing heat exchange between the two sides. Increasing the thickness of the concrete layers had a very limited effect on reducing the heat transfer coefficient. Reducing the spacing of the connectors improved the load-bearing capacity of the composite wall panel to some extent but had minimal influence on the heat transfer coefficient; to achieve optimal performance by balancing structural load distribution and thermal damage resistance, a connector spacing ranging from 200 mm to 500 mm is recommended. The variation in heat transfer coefficients among the four different connector arrangement patterns demonstrated that reducing the thermal conduction media within the wall panel should be prioritized while ensuring mechanical performance. It is also recommended that the connectors are arranged in a continuous layout. Full article

Carbon lock-in (CLI), defined as the structural persistence of fossil-fuel-based systems, poses a significant barrier to decarbonization. As CLI continues to impede China’s progress toward carbon neutrality, understanding the role of next-generation productive forces (NGPFs) in breaking this path dependence has become increasingly urgent; however, it remains underexplored in empirical research. This study examines the impact of NGPFs on CLI using provincial panel data from 2012 to 2022. Composite indices for NGPFs and CLI are constructed using the entropy weight method. The analysis applies instrumental variable estimation (IV-GMM) to address potential endogeneity, feasible generalized least squares (FGLS) to account for heteroskedasticity, and spatial Durbin models (SDMs) to capture spatial dependence. In addition, quantile regression is used to explore distributional effects, and subsample regressions are conducted to assess regional heterogeneity. The results show that (1) a 1% increase in NGPFs leads to approximately a 0.9643% reduction in CLI, effectively mitigating CLI. (2) NGPF levels are high in Beijing, Shanghai, and Guangdong, while being constrained in Heilongjiang, Gansu, and Qinghai. Provinces like Jiangsu, Zhejiang, and Shandong are rapidly catching up. (3) Shanxi, Inner Mongolia, and Shandong struggle with high comprehensive CLI from carbon-heavy industries; in contrast, Beijing, Shanghai, and Hainan show low CLI. (4) As CLI levels increase (90th percentile), the effectiveness of NGPFs in reducing CLI gradually diminishes (−0.2724). (5) The impact of NGPFs on CLI is not significant in the Eastern region, while in the Central and Western regions, the effects are −1.1365 and −1.0137, respectively. This study offers vital insights for shaping policies that promote sustainable growth and mitigate CLI in China. Full article

Machining deformation is a key bottleneck that restricts the improvement of manufacturing accuracy of aviation thin-walled structural components, such as frames, beams, and wall panels. The initial residual stress of the workblank and the cutting load are the direct factors leading to machining deformation. Based on the initial residual stress measurement and the milling force test, a finite element prediction model for milling deformation of frame-type thin-walled parts with integrated consideration of initial residual stress and the milling force was established and experimentally verified in this study. Then, the influence of milling process factors, such as the frame processing sequence (FPS), the cutting path, and the single frame one-time removal depth (SFORD), on the milling deformation of frame-type parts was studied. The results showed that the established prediction model had high reliability and the prediction accuracy was improved by 6.7% compared with that when only considering the initial residual stress. A smaller machining deformation can be achieved through the use of the FPS to prioritize the width, direction, and symmetrical milling, as well as the inner loop cutting path, and the smaller SFORD. This study can provide a technical reference for the prediction and control of milling deformation of aviation thin-walled structural parts, especially frame-type thin-walled parts. Full article

This paper presents the development of two solutions for sandwich panels composed of a thin-layer alkali-activated composite (AAc) layer and a thicker insulation layer, formed by extruded polystyrene foam or expanded cork agglomerate (panels named AP_XPS or AP_ICB, respectively). The AAc combined ceramic waste from clay bricks and roof tiles (75%) with ladle furnace slag (25%), activated with sodium silicate. The AAc layer was further reinforced with polyacrylonitrile (PAN) fibers (1% content). The mechanical behavior was assessed by measuring the uniaxial compressive strength of cubic AAc specimens, shear bond strength, pull-off strength between the AAc layer and the insulation material, and the flexural behavior of the sandwich panels. The thermal performance was characterized by heat flux, inner surface temperatures, the thermal transmission coefficient, thermal resistance, and thermal conductivity. Mechanical test results indicated clear differences between the two proposed solutions. Although AP_XPS panels exhibited higher tensile bond strength values, the AP_ICB panels demonstrated superior interlayer bond performance. Similar findings were observed for the shear bond strength, where the irregular surface of the ICB positively influenced the adhesion to the AAc layer. In terms of flexural behavior, after the initial peak load, the AP_XPS exhibited a deflection-hardening response, achieving greater load-bearing capacity and energy absorption capacity compared to the AP_ICB. Finally, thermal resistance values of 1.02 m² °C/W and 1.14 m² °C/W for AP_ICB and AP_XPS were estimated, respectively, showing promising results in comparison to currently available building materials. Full article

Forming hybrid structures into complex shapes is key to address lightweighting of automotive parts. Recently, an innovative joining technique between aluminium and Carbon Fibre-Reinforced Polymer (CFRP) based on mechanical interlocking through sheet punching has been developed. However, scaling up the solution requires the assessment of challenges, such as multi-material forming and joint integrity, after forming operations. Therefore, this work proves the feasibility of forming aluminium–CFRP prepreg panels into complex omega-shaped profiles following a conventional cold-stamping process. Forming without defects was possible even in specimens featuring mechanical joints generated through punching. The effect of the CFRP position (in the inner or the outer side of the formed profile), the number of mechanical joints, the addition of a Glass Fibre-Reinforced Polymer (GFRP) intermediate layer to prevent galvanic corrosion and adequate lubrication on necking, cracking, springback behaviour and the final geometry after curing were studied. Compression tests were performed to assess the mechanical response of the hybrid profile, and the results showed that the addition of CFRP in the aluminium omega profile changed the buckling behaviour from global bending to axial folding, increasing the maximum compression load. Additionally, the presence of mechanical interlocking joints further improved the mechanical performance and led to a more controlled failure due to buckling localization in the geometric discontinuity. Full article

Wetlands in the Yellow River Watershed of Inner Mongolia face significant reductions under future climate and land use scenarios, threatening vital ecosystem services and water security. This study employs high-resolution projections from NASA’s Global Daily Downscaled Projections (GDDP) and the Intergovernmental Panel on Climate Change Sixth Assessment Report (IPCC AR6), combined with a machine learning and Cellular Automata–Markov (CA–Markov) framework to forecast the land cover transitions to 2040. Statistically downscaled temperature and precipitation data for two Shared Socioeconomic Pathways (SSP2-4.5 and SSP5-8.5) are integrated with satellite-based land cover (Landsat, Sentinel-1) from 2007 and 2023, achieving a high classification accuracy (over 85% overall, Kappa > 0.8). A Maximum Entropy (MaxEnt) analysis indicates that rising temperatures, increased precipitation variability, and urban–agricultural expansion will exacerbate hydrological stress, driving substantial wetland contraction. Although certain areas may retain or slightly expand their wetlands, the dominant trend underscores the urgency of spatially targeted conservation. By synthesizing downscaled climate data, multi-temporal land cover transitions, and ecological modeling, this study provides high-resolution insights for adaptive water resource planning and wetland management in ecologically sensitive regions. Full article

To improve both the composite performance of precast thermal insulation wall panels and the environmental sustainability of the structure, this study employs recycled concrete, and introduces an innovative four-footstool Glass Fiber Reinforced Plastic (GFRP) connector to join the inner and outer panels of precast thermal insulation wall systems. The experimental program included pull-out, shear, and bending tests to compare the performance of wall panels equipped with traditional Thermomass MS connectors and the novel GFRP connectors, using both conventional and fully recycled concrete. The results indicate that, when paired with recycled concrete, the GFRP connectors exhibited a 14.8% higher pull-out bearing capacity than the traditional connectors. Additionally, shear tests demonstrated that the GFRP connectors offered a 20.6% improvement in shear resistance compared to the Thermomass MS connectors. The bending strength of panels with GFRP connectors also showed an enhancement, with a 16.5% increase in flexural strength relative to those using traditional connectors. Notably, the GFRP connectors contributed to a more uniform crack distribution under loading, thereby improving the overall structural integrity. A reduction factor γ for the GFRP four-footstool connector was proposed based on a fully composite model, and the analysis of the composite degree calculation showed that the recycled concrete sample using the new GFRP connector had the highest composite degree. Full article

Taking Inner Mongolia as a case, this study systematically analyzes the coupling and coordination relationship between carbon emissions from land use (CELU) and high-quality economic development (HQED). The aim is to provide empirical support and policy inspiration for archiving the “dual carbon” goal and HQED strategy in border areas. Panel data from 12 cities in Inner Mongolia from 2000 to 2020 were selected. We established an evaluation index system for CELU and HQED using the entropy-weight TOPSIS method and scientifically evaluated the level of HQED. We applied exploratory spatial data analysis, topic decoupling, coupling coordination degree (CCD), and geographic detector models to comprehensively analyze the coupling coordination status and spatial heterogeneity of CELU and HQED. The driving factors affecting CCD were explored in detail. Although the total CELU in Inner Mongolia has increased, its growth rate has slowed significantly. The CCD of CELU and HQED was low, and an obvious spatial disequilibrium was observed. Seven key factors, including land-use structure, efficiency, and energy intensity, have significant driving effects on the CCD. To support supply-side structural reform, promote HQED, and achieve emission reduction and green development goals, we offer a series of policy recommendations: promote the transformation of resource-based cities, optimize the energy structure, promote industrial structure upgrading, strengthen scientific and technological innovation and green technology applications, and improve regional cooperation and policy coordination. This study reveals the internal relationship between CELU and HQED and provides practical and instructive countermeasures and suggestions for the sustainable development of border areas, such as Inner Mongolia, which have important reference value for promoting the green transformation of regional economies and achieving the “dual carbon” goal. Full article

At present, China is the world’s largest carbon emitter and has also made significant efforts in energy conservation and emission reduction. This study utilized the EDGAR dataset of remote-sensing image inversion to investigate the spatial heterogeneity and clustering patterns of carbon emissions across 2184 counties in China through a data-driven approach. By analyzing the impact of socioeconomic factors on carbon emissions with the Spatial Clustering Autoregressive Panel (SCARP) model, significant regional variations were uncovered. The results reveal significant differences in carbon emission drivers between resource-dependent regions and economically developed areas. For instance, regions with heavy industries, such as Inner Mongolia and Xinjiang, exhibit higher carbon emissions, underscoring the need for policies focused on industrial restructuring and clean energy adoption. In contrast, economically advanced regions such as the Yangtze River Delta and Pearl River Delta show slower emission growth, indicating the potential for further reductions through green technology innovations and energy efficiency improvements. These findings highlight the necessity of regionally tailored carbon reduction strategies, offering policymakers a precise framework to address the specific socioeconomic and industrial characteristics of different regions in China. Full article

Waste rock backfilled into a goaf can function as the main load-bearing carrier to support the overlying strata, so the compressive behavior of backfill materials plays a critical role in the effectiveness of strata control. However, in the laboratory, the specimen size also significantly influences on the accurate prediction of compressive deformation in waste rock backfill materials. To assess the influence of the specimen size on compressive behavior in waste rock backfill materials, a WAW-1000D (Changchun Xinte Testing Machine Co., Ltd., Changchun, Jilin Province, China) electric servo-motor testing machine and self-made compressors of different sizes were used to characterize the compressive deformation of waste rock backfill materials with different specimen sizes. The stress–strain relationships and changes in the void ratio of specimens were analyzed, revealing the influence of the specimen size on the compressive behavior. The research found that when the ratio of the inner diameter of compressors to the maximum particle size of specimens is 15:1 and above, the inner diameter of compressors only has a slight influence. Taking a backfill panel in Xinjulong Coal Mine as the engineering context, waste rock with particle sizes in the range of 0~20 mm was backfilled. The measured roof subsidence was 568 mm, matching the measured experimental value. The results provide data to support roof subsidence predictions following waste rock backfill mining. Full article

To reduce the low-frequency noise inside automobiles, a lightweight plate-type locally resonant acoustic metamaterial (LRAM) is proposed. The design method for the low-frequency bending wave bandgap of the LRAM panel was derived. Prototype LRAM panels were fabricated and tested, and the effectiveness of the bandgap design was verified by measuring the vibration transmission characteristics of the steel panels with the installed LRAM. Based on the bandgap design method, the influence of geometric and material parameters on the bandgap of the LRAM panel was investigated. The LRAM panel was installed on the inner side of the tailgate of a traditional SUV, which effectively reduced the low-frequency noise (around 34 Hz) during acceleration and constant-speed driving, improving the subjective perception of the low-frequency noise from “very unsatisfactory” to “basically satisfactory”. Furthermore, the noise reduction performance of the LRAM panel was compared with that of traditional damping panels. It was found that, with a similar installation area and lighter weight than the traditional damping panels, the LRAM panel still achieved significantly better low-frequency noise reduction, exhibiting the advantages of lightweight, superior low-frequency performance, designable bandgap and shape, and high environmental reliability, which suggests its great potential for low-frequency noise reduction in vehicles. Full article