Search Results (899)

Low-emission zones, known in Poland as clean transport zones, grant or deny access according to a vehicle’s Euro standard, age and fuel. These administrative labels, however, are only loosely connected to what an internal combustion engine (ICE) actually emits on the road. The founding assumption of a Euro-based zone is that the Euro stage is a usable proxy for the mass a vehicle emits, so admitting newer classes lowers the fleet emission inventory, the activity-weighted sum of class emission factors defined as the product of fleet frequency, in-zone activity and emission factor. This paper tests that assumption directly. A paradox follows: a newer, compliant, large and heavy vehicle can release more carbon dioxide (CO₂), nitrogen oxides (NOx) and particulate matter (PM) than an older, smaller vehicle that the same rule turns away. We develop a reproducible emission-accounting framework that pairs real-world emission factors, resolved by Euro standard, fuel, engine displacement and mass, with a mass-dependent treatment of non-exhaust particles. Given the number of petrol, diesel, liquefied-petroleum-gas (LPG) and electric vehicles in a fleet and the areas of the city and the zone, the model returns daily emissions and their density per square kilometre before and after a rule is applied. For a fleet parameterised on Polish statistics, the Warsaw and Kraków criterion removes about 80% of zone NOx, because the oldest vehicles are also the high-NOx diesels; the same rule, however, removes only about 40% of CO₂ and 48% of PM, and it shifts the admitted fleet toward heavier vehicles that produce more non-exhaust PM. Emission-based, fuel-based and hybrid criteria deliver larger and fairer reductions at the same level of stringency. Aligning zone access with real combustion emissions is therefore both more effective and more equitable, and it supports the wider goals of sustainable, low-carbon urban mobility. Full article

Electrochemical reactions in proton exchange membrane fuel cells (PEMFCs) predominantly occur within the membrane electrode assembly (MEA), dictating power output and lifetime. As a key functional component of the catalyst layer (CL), ionomer plays a decisive role in establishing effective three-phase boundaries, maintaining proton-conducting networks. While the impact of ionomer-to-carbon (I/C) ratio on MEA performance has been recognized, its coupled effect on durability remains underexplored. Herein, MEAs with I/C ratios ranging from 0.4 to 1.2 were fabricated, and the influence of ionomer content on performance and durability was systematically investigated through microstructural characterization, electrochemical measurement, and accelerated stress testing. Results reveal distinct trade-offs: insufficient ionomer impairs proton transport and durability, while excess ionomer hinders mass transport and electrochemical performance but helps maintain CL stability. Specifically, an I/C ratio of 1.2 exhibits the highest durability but the lowest performance. An I/C ratio of 0.8 achieves the optimal peak power density (1156 mW cm^–2) while maintaining good durability, superior to lower I/C ratios. Balancing performance and durability, an I/C ratio of 0.8 emerges as the optimal choice. This work provides both experimental evidence and mechanistic insights into the influence of ionomer content in CL, offering guidance for the design of high-performance and durable PEMFCs. Full article

Road infrastructures are fundamental for ensuring connectivity, safety, and the efficient functioning of transportation networks. However, extreme weather conditions, particularly low temperatures and ice formation, pose significant risks to user safety and road conditions. This research focuses on the development of a geospatial model designed to identify road sections exposed to these harsh weather conditions. The model integrates different sources of information, including meteorological and satellite data, topographic information, and road maintenance plans, through a consistent methodology for data processing and analysis. A combination of geospatial analysis and advanced processing techniques was employed to identify and map regions most vulnerable to the formation of ice. The results show good spatial agreement between the areas identified by the model and the available local information, supporting its ability to characterize areas with greater susceptibility to winter-related hazards. This work highlights the potential of the developed geospatial model to support the planning of preventive and maintenance measures on roads. By providing spatial information on susceptibility to low temperatures and ice formation, the model can serve as a decision-support tool for road management, contributing to the planning of targeted interventions and improved road safety. Overall, this study underscores the importance of integrating advanced geospatial techniques into infrastructure management to improve response strategies in the face of extreme weather events. Full article

The increasing interest in carbon-free fuels has positioned ammonia as a promising energy carrier for Internal Combustion Engines (ICEs), particularly in hard-to-abate sectors such as Heavy-Duty (HD) transport and maritime applications. However, its low reactivity, narrow flammability limits, and intrinsic nitrogen content pose significant challenges for stable combustion and emissions control. This work presents a predictive Quasi-Dimensional (QD) combustion model applied to simulate ammonia-fueled engines operating under both Spark Ignition (SI) and Reactivity Controlled Compression Ignition (RCCI) modes. The proposed framework couples a turbulent premixed combustion sub-model with a diffusive combustion sub-model, including a dedicated fuel-NO_x mechanism to capture nitrogen oxide formation pathways associated with fuel-bound nitrogen. The model accounts for key physical and chemical processes governing combustion, such as ignition delay, mixture stratification, and heat release dynamics, while maintaining computational efficiency suitable for parametric studies. The model is validated against experimental data from a Single-Cylinder Engine (SCE) over a wide range of operating conditions, including variations in equivalence ratio, spark timing, Ammonia Energy Fraction (AEF), and injection strategy. Results demonstrate good agreement in terms of in-cylinder pressure evolution, Apparent Heat Release Rate (AHRR), and NO_x emissions, with peak-pressure errors below 4 bar and peak-pressure locations predicted within 2 crank angle degrees. Notably, the dedicated fuel-NO_x sub-model substantially improves emission predictions, revealing that fuel-bound nitrogen is the dominant source of NO_x in ammonia combustion. Overall, the proposed QD model represents a robust and efficient tool for the analysis and optimization of ammonia-fueled engines, supporting the development of low-carbon combustion strategies for future energy systems. Full article

The rapid melting of Arctic sea ice has significantly lengthened the window for Northeast Passage navigation, but the frequent occurrence of accompanying extreme weather events poses severe challenges to shipping safety. Based on 1991–2020 climate data and 2021–2024 NCEP reanalysis data, this study uses wave activity flux diagnosis, composite analysis and statistical test methods to reveal the causes of abnormal circulation and the energy propagation mechanism of heavy precipitation events during the navigation period (July–October) in the starting section of the Arctic Northeast Passage (from the Barents to the Kara Sea). The results show that from 2021 to 2024, there was a high proportion of heavy precipitation events during the navigation period (July–October), with significant temporal and spatial variability; abnormal circulation is triggered by the synergistic effect of the eastward shift in the Ural blocking high and the southward extension of the Arctic polar vortex. The enhanced upper-level westerly jet and the mid-level “tripole-type” teleconnection wave drive jointly drive the northward transport of warm, moist air, and the low-level cyclonic circulation and upper-level divergence trigger a baroclinic lifting mechanism. Rossby wave energy originates from the Mediterranean–Black Sea region, propagating eastward to the study area along the jet axis and enhancing the ascending motion through wave activity flux divergence. The heavy precipitation event in August 2023 is a typical example of the cross-seasonal synergistic sea temperature–sea ice–atmosphere effect. This study reveals the following complete teleconnection chain: “sea temperature anomaly → wave train excitation → sea ice feedback → circulation maintenance”, which will support predicting disastrous weather and developing climate adaptation strategies in the Arctic Passage. Full article

Saline–alkali stress severely restricts cucumber (Cucumis sativus L.) growth by disrupting ion balance, water status, photosynthesis, and redox homeostasis. Here, we examined the effects of exogenous selenium (Se) on cucumber seedlings exposed to NaHCO₃ stress. Se supplementation improved plant growth and root activity and partly restored photosynthetic performance by maintaining chlorophyll content, gas exchange, and chlorophyll fluorescence. Se reduced oxidative injury through lower ROS and MDA levels and by enhancing antioxidant enzyme activities together with the AsA–GSH cycle. In parallel, Se moderated ion toxicity by limiting Na⁺ accumulation, increasing K⁺, Ca²⁺, and Mg²⁺ uptake, and stimulating H⁺-ATPase and H⁺-PPase activities. Enhanced TCA cycle activity and organic acid accumulation suggested improved energy metabolism and ionic regulation. Se also promoted osmotic adjustment via soluble sugars and proline, and upregulated aquaporin genes (PIP1;2 and PIP2;4) to sustain water transport. Moreover, Se increased salicylic acid levels by upregulating CsPAL and CsICS, pointing to a role of SA signaling in Se-induced tolerance. Full article

The leakage and dispersion behavior of CO₂ in the ground injection stage of oilfield CCUS systems is highly complex under high-pressure, low-temperature, and continuous-operation conditions, while quantitative criteria for emergency control distances remain insufficient. To address this issue, a liquid CO₂ storage tank in an oilfield CO₂ cyclic injection station was selected as the research object. A 1:1 two-dimensional and three-dimensional computational model was established. A two-stage simulation framework was developed in this study, where PHAST was first employed for rapid multi-scenario consequence screening, followed by three-dimensional CFD validation using KFX under representative high-risk scenarios. The proposed framework was used to systematically investigate CO₂ leakage and dispersion characteristics under various leakage aperture sizes, ambient temperatures, and wind speed conditions. Risk zoning and risk quantification were further conducted based on high-concentration CO₂ toxicity thresholds of 10%, 15%, 20%, and 30%. The results show that the leak aperture is the dominant factor controlling dispersion consequences. As the aperture increased from 5 mm to 50 mm, the maximum dispersion distance increased from 8.8–9.4 m to 132–146 m, and the maximum cloud footprint increased from 4.8–5.4 m² to 2204.1–2599.6 m². Higher temperature enhanced CO₂ dispersion capacity, whereas wind speed exerted a dual effect involving near-field dilution and downwind transport. The KFX three-dimensional simulation indicated that buildings and equipment arrangements induced near-ground flow separation and local accumulation. Under a 25 mm leak and an average wind speed of 4.6 m·s⁻¹, the cloud approached full coverage of the injection station within approximately 300 s and tended to spread beyond the site boundary. Liquid CO₂ leakage was accompanied by flashing, dry-ice formation, and sublimation, leading to a leakage-rate pattern characterized by an initial decrease followed by an increase and gradual stabilization. This indicates that emergency response should account for the ice-plugging and de-plugging process. The risk zoning results show that the downwind region can be divided into fatal, severe-injury, minor-injury, adverse-reaction, and relatively safe zones. A risk level on the order of 10⁻⁶ still existed at 100 m from the leakage source. It is recommended that CO₂ concentration monitoring and alarm systems be deployed within 100 m of the station, warning signs be placed near the maximum impact boundary of 146 m, and 300 s be used as a critical time window for coordinated evacuation between the plant area and surrounding residential areas. The findings provide a technical basis for safety-distance verification, monitoring layout design, and emergency-plan development for ground injection systems in oilfield CCUS projects. Full article

Arctic shipping should not be understood as a sustainable transport outcome that will emerge automatically as sea ice declines. Rather, its long-term viability depends on whether stable operations can be achieved under persistent environmental and political uncertainties. Existing studies have examined Arctic shipping risks, governance arrangements, and route feasibility, but have paid limited attention to how cargo owners, shipping companies, and governments interact strategically under composite risk constraints. To address this gap, this paper develops a three-party evolutionary game model involving cargo owners, shipping companies, and the government under weather risk and political risk, and uses numerical simulation to examine system evolution, policy thresholds, and external shock responses. The results show that the system tends to converge toward a high-coordination equilibrium under low-risk conditions, whereas medium-risk conditions may lead to bistability and a low-coordination trap when government support remains below a critical threshold. Composite political shocks further amplify system vulnerability and weaken sustainable route operation. These findings suggest that the key challenge of Arctic shipping lies not in physical route accessibility alone, but in whether risk governance, market participation, and institutional support can jointly stabilize expectations and promote sustainable Arctic shipping operations. Full article

Conventional valorization of blast furnace slag commonly involves granulation, fine grinding, mechanical activation, or chemical activation, which increase energy demand and processing complexity. This study investigated a minimally processed blast furnace slag (MP-BFS), defined here as the fraction passing 64 µm obtained by sieving a 0–8 mm industrial material without grinding, additional granulation, thermal treatment, or chemical activation. MP-BFS replaced 10–50% of the cement by mass to reduce clinker in industrial mortars formulated at a constant flow spread of 23–24 cm and tested from 8 h to 90 d. Bulk density, water-accessible porosity, total and capillary water absorption, and compressive and flexural strengths were evaluated. Replacing 10% of the cement with slag improved compressive strength from the earliest test age and increased the 28-day compressive and flexural strengths by 5.1% and 9.5%, respectively, relative to the control mortar; this response coincided with a reduction in measured porosity from 8.95% to 8.01%. This improvement is consistent with a physical filling effect and improved particle packing, although these mechanisms were not directly verified by microstructural analyses. At higher replacement levels, water-accessible porosity increased, reaching 24.45% at 50% slag replacement, alongside greater water ingress and delayed strength development. Exploratory empirical regression analyses described associations among slag content, porosity, water transfer, and compressive strength within the investigated formulations. A simplified screening-level constituent-production-and-transport comparison per cubic meter, based on generic ICE factors and an assumed 50 km transport distance, estimated a maximum embodied carbon reduction of 44% at 50% replacement. Curing energy, use, carbonation, maintenance, and end-of-life stages were excluded. Overall, 10% MP-BFS replacement provided the most favorable performance–carbon content balance, whereas 30–50% achieved larger carbon reductions but showed early-age strength losses that limit their suitability for rapid-demolding applications under the investigated conditions. Full article

Ice–snow tourism in Northeast China is developing rapidly. Against this backdrop, revealing the spatial network structure of ice–snow tourism cities and assessing their disturbance resistance capacity is of great significance for achieving high-quality development of regional ice–snow tourism. This study takes 25 cities across the three northeastern provinces as network nodes, using data covering the period from January 2024 to March 2025. Integrating a complex network analysis framework, this paper comprehensively employs an accessibility model, tourism symbiotic linkage intensity model, and core–periphery model to distinguish core and peripheral cities within the network, analyze its structural characteristics and spatial patterns, and evaluate network vulnerability by simulating two scenarios: random attacks and deliberate attacks. The results indicate that: (1) Accessibility presents a concentric zonal pattern that attenuates gradually from the center to the periphery, accompanied by pronounced north–south disparities. Urban symbiosis intensity is strongly influenced by transportation distance, exhibiting a distinct proximity symbiosis pattern. (2) An ice–snow tourism symbiotic network has initially taken shape among northeastern cities. The network displays small-world properties; however, urban development is unbalanced, with marked hierarchical differentiation. Based on geographic location and resource endowments, the network can be divided into four cohesive subgroups. (3) The symbiotic network proves robust under random attacks, whereas connectivity declines sharply under deliberate attacks, embodying typical “robust-yet-vulnerable” structural characteristics. Both expanding the scale of core nodes and optimizing inter-node connection weights can significantly enhance network robustness. The static identification and dynamic dependency evaluation framework constructed in this study can effectively identify key nodes and vulnerable links within ice–snow city networks, and can serve as a reference for the coordinated development and structural optimization of ice-snow tourism in Northeast China. Full article

Pixelless infrared imaging devices based on optoelectronic up-conversion offer a compact and scalable alternative to conventional focal plane arrays; however, their performance is fundamentally limited by lateral carrier diffusion, image smearing, and the trade-off between spatial resolution and conversion efficiency. Existing systems employing quantum well infrared phototransistors (QWIPTs) integrated with light-emitting diodes (LEDs) suffer from degraded modulation transfer function (MTF) at high spatial frequencies and restricted design flexibility. In this article, a quantum cascade detector (QCD)–LED pixelless imaging architecture is proposed and comprehensively modeled as a next-generation alternative. A unified analytical framework is developed to describe carrier concentration, modulation transfer function, image resolution, and image conversion efficiency (ICE) in QCD-LED systems under spatially modulated far-infrared illumination. The models explicitly account for cascade transport, diffusion–drift dynamics, photon recycling, and radiative recombination, enabling direct comparison with conventional QWIPT-LED imagers. Numerical investigations reveal that multi-stage cascade transport significantly suppresses lateral carrier spreading, resulting in a pronounced enhancement in spatial-frequency response. The proposed QCD-LED architecture demonstrates a >32.5% improvement in maximum MTF, a 32.5% increase in conversion efficiency, and a 25% enhancement in response speed, while maintaining comparable or improved image resolution. An optimal performance is achieved for a 10-stage quantum cascade detector with a 2.5 μm period length and a radiative-to-nonradiative lifetime ratio of 0.999, yielding a figure of merit (R × ICE) of 30.99, outperforming previously reported QWIPT-LED systems. Experimental validation confirms excellent agreement with theoretical predictions (R² = 0.989), particularly at high spatial frequencies where QCD-LED devices exhibit more than 140% improvement in contrast transfer. These results establish quantum cascade detector-based pixelless imagers as a robust platform for high-resolution, high-speed infrared imaging, offering superior spatial fidelity and design flexibility for next-generation optoelectronic imaging systems. Full article

6-PPD quinone (6-PPDQ) has been recognized as a typical emergent contaminant with the potential to cause multiple aspects of damage to organisms. Creatine is an important metabolite that mediates energy homeostasis. In Caenorhabditis elegans, creatine content was reduced by 0.1–10 μg/L of 6-PPDQ, which was accompanied by a decrease in the expression of argk-1 encoding a creatine kinase and snf-5 encoding a potential creatine transporter. Creatine content could be reduced by RNAi of argk-1 and snf-5. Moreover, RNAi of argk-1 and snf-5 aggravated 6-PPDQ-induced immunosuppression, reflected by decreased expression of antimicrobial genes (lys-7 and spp-1), and double RNAi of argk-1 and snf-5 resulted in more severe immunosuppression induction in 6-PPDQ-exposed nematodes. After 6-PPDQ exposure, RNAi of argk-1 and snf-5 decreased the expression of aak-2 encoding AMPK, and aak-2 RNAi also strengthened 6-PPDQ-induced immunosuppression. During control of 6-PPDQ caused immunosuppression, ARGK-1, SNF-5, and AAK-2 modulated expressions of PMK-1/p38 MAPK and DAF-16 signals. The immunosuppression and inhibition in PMK-1 and DAF-16 expressions induced by 6-PPDQ could be further suppressed by creatine treatment. Therefore, the environmental exposure risk of 6-PPDQ in disrupting creatine synthesis and transporter was suggested, which potentially contributes to the induction of immunosuppression in nematodes. Full article

Climate warming is accelerating permafrost degradation in alpine regions, promoting the development of thaw-related slope deformation through active-layer thickening, ground-ice thaw, and hydro-mechanical weakening. Permafrost degradation margins are particularly sensitive to climatic warming, where enhanced heat transfer and active-layer water migration can accelerate shallow slope instability; however, the underlying mechanisms require further investigation. This study investigates two representative freeze–thaw-related landslides in the western Qilian Mountains: an active-layer detachment developed in degraded discontinuous permafrost and a freeze–thaw-induced shallow creep landslide located near the lower limit of permafrost occurrence. UAV photogrammetry, electrical resistivity tomography, and SBAS InSAR were integrated to characterize geomorphic features, internal frozen ground conditions, and deformation patterns. The active-layer detachment shows strong subsurface heterogeneity, with residual high-resistivity frozen bodies separated by localized thawed zones. Its deformation is mainly concentrated in the upslope detachment zone and central depletion–transport zone, where meadow-mat cracking, turf stripping, and exposed mineral soil coincide with thawed corridors between discontinuous permafrost bodies. In contrast, the freeze–thaw-induced shallow creep landslide exhibits the largest deformation in the upper permafrost-margin sector, where weakly discontinuous permafrost persists, whereas deformation decreases downslope in the seasonally frozen ground sector. This study highlights the critical role of discontinuous permafrost, localized thawing, and active-layer water migration in promoting shallow slope deformation and suggests that permafrost degradation margins may become increasingly susceptible to freeze–thaw-induced landslide activity under continued climate warming. Full article

Hydrophobic and superhydrophobic surfaces have emerged as key solutions for fluid transport, biofouling prevention, and energy efficiency, with market forecasts projecting a compound annual growth rate (CAGR) of over 15% through 2030 due to their broad range of applications. This review critically examines the principles of natural hydrophobicity, as exemplified by lotus leaves and shark skin, and their translation into engineered surfaces via micro/nanofabrication techniques, such as laser patterning, etching, and self-assembly. Recent advances in hybrid nanomaterials have demonstrated WCAs in the range of 140–160°, along with enhanced mechanical strength and chemical stability, enabling applications in self-cleaning, anti-corrosion, and oil–water separation technologies. Superhydrophobic coatings are particularly important for reducing ice adhesion by more than 80%, while drag reduction in pipelines can reach up to 30%, contributing to energy savings. Despite these advances, challenges remain in achieving long-term stability under harsh environmental conditions, minimizing environmental impact, and developing cost-effective, scalable fabrication techniques. Future directions focus on environmentally friendly, multifunctional nanocomposites with switchable wettability, including pH- and light-responsive coatings capable of reversibly transitioning between superhydrophilic (<5°) and superhydrophobic (>150°) states, paving the way for sustainable and adaptable surface technologies. Full article

Silicon anodes hold great promise in high-energy lithium-ion batteries (LIBs) owing to their ultrahigh theoretical specific capacity, appropriate operating voltage, and low costs. However, the drastic volume expansion, inferior electronic conductivity, and unstable solid electrolyte interphase of Si anodes severely restrict their practical application. Herein, a nest-shaped microporous silicon (NMPSi) is rationally designed via acid–base co-etching and then synergistically regulated by surface thin-film carbon coating and ZIF-67-derived hard carbon nanotemplate (NMPSi@THC) by an in situ liquid-phase coating strategy. The constructed unique architecture is capable of buffering the huge volume expansion of inner NMPSi during cycling and constructing an optimized electron/ion transport network, thereby stabilizing the SEI film and preserving the electrode’s structural integrity. When it is evaluated as a LIB anode, the NMPSi@THC exhibits typically improved initial coulombic efficiency (ICE) and outstanding long-life cyclic stability (622.7 mAh g⁻¹ after 300 cycles at 1 A g⁻¹ and 2 mg cm⁻²). Furthermore, the NMPSi@THC//LiFePO₄ full cell delivers an ultrahigh ICE of 94% and a capacity retention rate of 86%, demonstrating its practical application potential. Compared with most recently reported Si anodes, this report delivers better cycling stability and maintains more intact electrode structure under relatively high current density and areal mass loading in half/full cells after long-term cycling. This research offers a convenient and scalable route to fabricate highly stable microporous Si anodes toward high-energy and long-lifespan LIBs. Full article