Search Results (6,958)

Pavement markings are critical traffic safety facilities that provide continuous and clear visual guidance to road users, thereby supporting traffic order and driving safety. During long-term service, however, white pavement markings are prone to yellowing under ultraviolet (UV) irradiance and elevated temperatures, which may reduce visibility. This study conducted accelerated aging tests on white thermoplastic and two-component pavement markings under four levels of ultraviolet irradiance (0–1.5 W/m² at 340 nm) and temperature (20–80 °C) to quantitatively characterize the macroscopic evolution of yellowing (YI) under controlled environmental conditions. Generalized linear mixed-effects models (GLMMs) were then used to quantify the effects of UV exposure, temperature, and time on the yellowing behavior of white pavement markings. The results indicate that temperature is a key environmental driver of YI increases. UV irradiance also has a pronounced promoting effect, and the yellowing responses differ markedly between material types. The results clarify how UV irradiance, thermal conditions, and material systems jointly influence the yellowing behavior of white pavement markings, providing a scientific basis for evaluating anti-yellowing performance, improving durability design, and guiding engineering applications under complex environmental conditions. Full article

Pseudomonas syringae pv. syringae (Pss) is an economically significant bacterial pathogen that causes canker in sweet cherry trees. In Chile, sweet cherry (Prunus avium L.) is a key crop whose exponential production growth has increased phytosanitary pressure. However, the genetic diversity and adaptive mechanisms of local Pss populations have remained poorly understood. This study characterized 41 Pss isolates from major Chilean production regions. Their genomes were sequenced and compared with 152 public genomes from the PG2 phylogenetic group. The analysis revealed a predominance of the PG2d subgroup among the Chilean isolates, with a population structure defined by at least 18 genomic clusters, some of which are exclusive to Chile. A characteristic feature of this entire PG2d subgroup is the presence of indole-3-acetic acid (IAA) synthesis genes (iaaM and iaaH). Furthermore, this subgroup displayed a marked increase in ancestral gene gain and loss events, indicating extensive remodeling of the shell genome and supporting a model of lineage-specific adaptive evolution. We also identified lineage-specific orthogroups, structural variants of the T-PAI pathogenicity island, and a differential distribution of Hop-type effector proteins. Furthermore, an extended copper resistance operon (cop and cus systems) was detected in a subset of strains, and a dominant lineage was found to have a dual i1-type of T6SS system. These findings highlight the local diversification of Pss in Chile, likely driven by agro-environmental pressures. This study provides crucial insights into the evolution, adaptation, and pathogenic potential of this important pathogen in a crop of high strategic value. Full article

Rock pore–fracture systems exhibit inherent fractal characteristics, which exert a significant influence on fluid transport. In this study, coal rock is selected as the representative medium. Based on fractional calculus in physical fractal space, and by integrating operator algebra with the force–electric analogy method, a fractional order control equation is derived. To validate the proposed model, porosity measurements of coal and limestone were performed using the two-compartment Boyle’s law method and compared with conventional porosity calculation approaches. The results demonstrate that the fractional order model achieves a coefficient of determination (R²) of up to 0.99 for porosity and 0.98 for pressure, representing an improvement of approximately 0.07 over the exponential model. Moreover, the root mean square error (RMSE) of porosity is as low as 0.0008, while the RMSE of pressure is 0.0715, both significantly lower than those obtained using the exponential model. These results indicate that the fractional order model more effectively captures the non-Darcy flow behavior and the temporal evolution of porosity, providing substantially improved fitting accuracy. Further analysis reveals that the porosity–time relationship is jointly governed by fluid compressibility and pore compressibility under effective stress conditions. Comparative results across different lithologies reveal that the pore compressibility coefficient increases with porosity; for the same rock type, a higher coefficient implies a more complex pore structure and a longer equilibration time. Overall, the proposed fractional order framework provides a more accurate description of the fractal pore structures in rocks, establishing a clear link between microscale fractal geometry and macroscale fractional order response. Full article

This study investigates the hot deformation behavior of electroslag remelted (ESR) 25Cr2Ni2MoV steel, focusing on the effects of deformation temperature and strain rate on flow stress, microstructure evolution, and dynamic recrystallization (DRX) mechanisms. Hot compression tests were performed at temperatures ranging from 1120 °C to 1210 °C and strain rates from 0.01 s⁻¹ to 10 s⁻¹ to generate true stress–strain curves. The friction and adiabatic temperature effects were corrected to ensure accurate results. The data reveal that the material exhibits a single-peak true stress–strain curve, characteristic of dynamic recrystallization softening. The flow stress is negatively sensitive to temperature and positively sensitive to strain rate. An Arrhenius-type constitutive model was developed, and the activation energy for hot deformation was determined to be 371.3 kJ/mol. EBSD analysis show that the recrystallized grain size is highly dependent on strain rate, with finer grains formed at lower strain rates (0.01–0.1 s⁻¹). A processing map constructed at a true strain of 0.5 identified an optimal hot-working window at deformation temperatures of 1160–1200 °C with strain rates below 0.37 s⁻¹, providing guidance for the forging process of large 25Cr2Ni2MoV steel. Full article

Global climate change has amplified extreme weather events, threatening ecological security and sustainable development. The impact of extreme weather events on sustainable land use (SLU) has attracted increasing attention. While previous studies have focused on the average effect, the question of whether its impacts vary across SLU levels remains unexplored. This knowledge gap is particularly pronounced in mountainous Chongqing, where complex terrain and urban heat islands interact to compound heterogeneous climate risks. To bridge this gap, we construct an indicator system based on the United Nations Sustainable Development Goals (SDGs) with which to assess the spatio-temporal evolution of SLU across all 38 districts of Chongqing from 2013 to 2023. The results show that Chongqing’s SLU level fluctuated upwards between 2013 and 2023, with high-value areas concentrated in the central urban core areas and regional gaps narrowing. Extreme climate indices exhibited significant spatial heterogeneity, with heat islands in urban areas, cold events in mountainous regions, floods in the southeast and droughts in the central western area. By overcoming average-effect limitations through quantile regression, this study further examines the heterogeneous effects of extreme weather on SLU across different development levels. It finds that simple daily intensity index (SDII) exerted stable negative effects—and the number of heavy precipitation days (R10), very wet days (R95p), monthly maximum value of daily maximum temperature (TXx) and diurnal temperature range (DTR) showed positive effects. While most climate variables exhibited stable effects, a critical finding was the divergent effect of variables such as tropical nights (TR20), which negatively impacted low SLU areas but positively influenced high SLU areas. This mechanistically confirms that regions at different levels of development experience fundamentally distinct impacts from the same climatic stressors. By focusing on uneven regional impacts and identifying region-specific extreme weather types, this study provides empirical support for targeted climate adaptation and balanced land management in mountainous cities. Full article

This study investigates a duckbill-type hole seeder to elucidate the kinematic and force characteristics of hole formation under the dry sowing–wet emergence regime and to provide theoretical support for the optimization of key structural parameters. A bidirectional coupling simulation model based on the discrete element method (DEM) and multibody dynamics (MBD) was established to analyze the motion trajectories of the fixed and movable duckbills, the evolution of three-directional forces, and the associated soil–plastic film disturbance under different combinations of front and rear angles. The results indicate that soil disturbance during hole formation is dominated by vertical penetration and uplift, accompanied by forward cutting and lateral redistribution. The three-directional forces acting on the fixed duckbill exhibit a non-monotonic response with respect to the front angle, decreasing first and then increasing, while the force level during the expansion stage of the movable duckbill generally increases with the rear angle. Within the investigated parameter range, a front angle of 18° combined with a rear angle of 38° resulted in a relatively lower overall force level during penetration and expansion, which is favorable for stable hole formation. Field experiments conducted with this configuration showed an average seed placement deviation of 0.50 cm, satisfying the requirements for precision cotton planting under plastic mulch. The findings provide theoretical insight and methodological support for the structural optimization and engineering design of cotton hole seeders operating under the dry sowing–wet emergence regime. Full article

Coal mine fires represent one of the major threats constraining sustainable and safe production in the coal industry. To investigate the mechanisms of accident causation and coupling evolution, this study proposed a fire risk analysis method integrating the N-K model (a model for quantifying interactions among system components) with complex network theory. Seventy-five coal mine fire accident cases were selected as samples to identify the coupling types and coupling mechanisms among human, management, technology, environment, and equipment risk factors. The N-K model was employed to determine accident coupling types and calculate risk coupling values. Based on association rule mining among risk factors, a coal mine fire risk network model was constructed. By integrating accessibility characteristics derived from complex network analysis with the N-K model, the normalized out-degree of network nodes was adjusted using N-K coupling values to better reflect node influence, thereby identifying key risk factors. The results showed that management factors were the dominant dimension driving risk coupling, and an increase in the number of coupled factors significantly affected the level of coal mine fire risk. The top four key risk factors were inadequate safety supervision by regulatory authorities, insufficient safety training and education, illegal production organization, and incomplete safety technical measures. Finally, targeted prevention and control strategies were proposed. The findings provide critical support for advancing sustainable and safe coal mine production by informing targeted safety interventions and optimizing resource allocation in safety management. Full article

The microstructural and textural evolution in hot-rolled Fe–3.0 wt.% Si steel sheets was investigated by quasi in situ electron backscatter diffraction (EBSD) analysis. During recrystallization, the Goss texture intensity in the surface region remains essentially unchanged, whereas the α and α* textures are strengthened. In the center region, the α texture weakens, and the α* texture shows little variation, while the Goss texture becomes intensified. In the surface region, {112}<110> recrystallized grains nucleate by consuming deformed matrices with orientations near {114}<221> and {110}<112>. Recrystallized {114}<481> and {001}<210> grains consume deformed matrices near {114}<221> and Goss orientations, while Goss grains nucleate by consuming Goss-oriented deformed matrices. In the center region, {112}<110>, {114}<481>, and {001}<210> recrystallized grains nucleate and grow by consuming α and λ type deformed matrices, whereas Goss recrystallized grains preferentially consume deformed matrices with orientations of {111}<112>. Full article

Background/Objectives: Short Interspersed Nuclear Elements (SINEs) constitute major components of mammalian genomes, but the structural diversity and evolutionary dynamics of their characteristic 3′ poly(A) tails have not been fully characterized. Methods: Based on the custom-developed SINEtail-scan pipeline, 1,018,332 SINEs with tail in the pig reference genome (Sus scrofa 11.1) were identified and systematically classified, revealing the diversity of tail sequence structures. According to nucleotide composition and microsatellite repeat patterns, the tail sequences were divided into 16 different structural types. Results: A-rich sequences predominated (66.3%), while non-A-rich tails exhibited characteristic architectures including AT-format, AC-format, and AG-format repeats. Temporal analysis spanning 85 million years demonstrated progressive tail modification, with A-rich proportions declining from 84.2% in recent insertions to 31.9% in ancient elements, accompanied by accumulation of complex non-A-rich structures. Comparative genomic analysis across 10 pig genome assemblies identified 308 SINE tail insertions within protein-coding sequences, of which 45 (14.6%) exhibited inter-individual structural polymorphism. Detailed investigation of a polymorphic insertion in the VWA8 gene revealed a 16-bp tail variant causing a frameshift mutation and C-terminal protein structure divergence. Conclusions: These findings establish SINE tail sequences as dynamic evolutionary substrates undergoing continuous modification through slippage-mediated mechanisms, with implications for genome evolution, population genetics, and gene function modulation in mammals. Full article

Cavitation erosion is a critical problem for many engineering components, such as ship propellers, diesel engine exhaust valves, cylinder liners, pump impeller blades, hydraulic turbines, and bearings, which are exposed to high-velocity flowing fluids or to vibratory fluid motion. It represents a mechanical degradation of the surface caused by the continuous collapse of bubbles in the surrounding liquid, which seriously affects flow efficiency and component service life, increasing maintenance frequency and refurbishment costs. The intensity and evolution of the cavitation erosion phenomenon depend on the hydrodynamic conditions to which the component surface is exposed, the properties of the liquid, and the judicious selection of the most suitable material. This paper aims to modify the microstructure of a Ni-based superalloy by applying recrystallization annealing heat treatment in order to obtain surfaces resistant to cavitation erosion for components that handle fluids under local pressure fluctuations. Experimental tests are carried out using a vibratory apparatus with piezoceramic crystals operating at a frequency of 20 kHz and an amplitude of 50 µm. The cavitation erosion performance of the Ni-based superalloy INCONEL 625, heat treated by recrystallization annealing, are compared with that of austenitic stainless steel AISI 316L subjected to solution treatment. For both metallic alloys, based on mass loss measurements, the characteristic time-dependent curves of the mean cumulative erosion penetration depth, MDE(t), and the mean erosion rate, MDER(t), are determined. The comparison of these curves and of the parameters defined and recommended by the ASTM G32 standard demonstrates that, for the Inconel 625 superalloy, resistance to cavitation erosion increases by 77–81% compared to that of AISI 316L austenitic stainless steel. X-ray diffraction analyses (XRD) show that, in the microstructure of the Inconel 625 superalloy, in addition to austenite, MC-type carbides, M₂₃C₆ carbides, and intermetallic phases γ″ = Ni₃(Nb, Al, Ti) and δ = Ni₃(Nb, Mo) are also present. Full article

The Southwest China vortex (SWV) is a high-impact mesoscale cyclonic vortex that typically originates over Sichuan Province, China, and frequently produces hazardous rainfall. Yet systematic knowledge of the structural and microphysical properties of SWV precipitation remains insufficiently quantified. Using Global Precipitation Measurement Dual-frequency Precipitation Radar (GPM/DPR) observations from 2014 to 2022, this study investigates the vertical structure and macro- and microphysical characteristics of SWV precipitation, and quantifies their differences across life-cycle stages and precipitation types. The mature stage is characterized by higher echo tops, stronger radar reflectivity, higher strong-echo altitudes, and larger near-surface rainfall, together with a clearer melting-layer bright band and a stronger post-melting shift toward larger drops and lower number concentrations. The developing stage is weakest and shows the largest fraction of coalescence–breakup balance signatures, whereas the dissipating stage features enhanced evaporation- and breakup-related signals. Among precipitation types, deep strong convection exhibits the greatest vertical extent with enhanced ice/mixed-phase growth; stratiform precipitation produces stronger radar echoes and higher rainfall rates than deep weak convection despite similar echo-top heights; and shallow precipitation is characterized by smaller drops, higher concentrations, and active warm-rain spectral evolution. These findings provide satellite-based constraints for microphysics parameterization evaluation and improved numerical prediction of SWV-related rainfall over complex terrain. Full article

This study presents integrated zircon U-Pb geochronology, whole-rock geochemistry, and Sr-Nd-Hf isotopic investigations of quartz diorite and gneissic quartz diorite from the Datian Complex along the western Yangtze Block, elucidating their petrogenesis and tectonic implications. Key findings reveal: (1) The crystallization ages of the Datian Complex (~770–755 Ma) record episodic magmatic activity over a ~16 Ma period, indicating a multi-stage tectonic evolution; (2) Both rock types exhibit intermediate SiO₂ (57–64.58 wt.%), high Al₂O₃ (15.44–17.80 wt.%), and MgO (2.18–3.67 wt.%; Mg# = 47.41–52.65) with calc-alkaline signatures (Na₂O/K₂O = 1.14–2.65), coupled with adakitic traits including pronounced LREE/HREE fractionation (La_N/Yb_N = 3.83–26.4), negative Eu anomalies (δEu = 0.61–1.05), elevated Sr (372–701 ppm), and Sr/Y ratios (24.6–56.2), collectively classifying the complex as high-Si adakite; (3) The isotopic homogeneity (whole-rock Sr-Nd: ⁸⁷Sr/⁸⁶Sr(i) = 0.7038–0.7048, εNd(t) = −1.5 to–3.8; zircon Hf: εHf(t) = 1.24–6.88) supports a two-stage petrogenetic model involving partial melting of subducted oceanic slab, followed by mantle wedge metasomatism during magma ascent. These results position the Datian Complex as a Neoproterozoic arc-related adakitic magmatic system within the active continental margin of the Yangtze Block. Full article

The North China Craton (NCC), one of the oldest cratons worldwide, may provide information on the evolution and geodynamic processes of the early Earth, especially during the pre-Mesoarchean period. Many ancient zircons have been discovered in the Jiapigou terrane of the northeastern NCC on the basis of our recent studies, providing an excellent opportunity to trace the early crustal evolution trend of the NCC. Here, we present a detailed study of the petrography, mineralogy, zircon U–Pb dating and Lu–Hf isotopes of supracrustal rocks (biotite schist) obtained from the Jiapigou terrane. Geochronology combined with the internal structures and Th/U ratios of the zircons reveal that the zircons acquired from the supracrustal rock can be divided into the following two types: magmatic zircons and metamorphic zircons. Among the magmatic zircons, the youngest zircon age (2.49 Ga) is considered to represent the time at which the protolith of the supracrustal rock (i.e., Neoarchean) crystallized, whereas the others were likely captured or inherited from their magma sources. The zircon Hf isotopes reveal that unexposed Hadean–Paleoarchean crust (4.18–3.57 Ga) is present beneath the Jiapigou terrane, and its growth history can be traced back to the Hadean period. Moreover, the evidence derived from this and previous studies indicates that the Jiapigou terrane underwent two crustal recycling events (3.37–3.20 Ga and ~2.96 Ga) during the Paleoarchean, two crustal reworking episodes (2.53 Ga and 2.49 Ga) during the Neoarchean, and later metamorphism at 2.41 Ga. Thus, the Jiapigou terrane has undoubtedly recorded multiple episodes of early crustal growth and/or reworking that are similar to, but not limited to, those of the northern and southern margins of the NCC. Full article

Late Cretaceous plutonic rocks are commonly observed along the Southeastern Anatolian Orogenic Belt (SAOB), which constitutes a significant part of the Alpine–Himalayan Orogenic Belt. Here, we present new whole-rock geochemical analyses, zircon U–Pb ages, and zircon trace element data of plutonic rocks located in the SAOB (eastern Türkiye). This study aims to determine the petrogenesis of the studied plutonic rocks in light of new data and to contribute to the tectonic evolution of the SAOB. Geochemical data demonstrate that the studied granodiorites, diorites, and gabbros are tholeiitic–calc–alkaline in composition, metaluminous, and I-type granite. Zircon U-Pb ages yielded crystallisation ages of 73.52 ± 0.24 Ma for the studied granodiorites and 78.86 ± 0.39 Ma for the diorites. These age data indicate that the studied plutonic rocks represent the youngest granodiorite and diorite formations observed around the study area. High Th/U ratios (granodiorite: 0.15–0.29; diorite: 0.31–0.96) and positive Ce/Ce* (granodiorite: 8.11 to 609.86; diorite: 58.07 to 564.31) and negative Eu/Eu* (granodiorite: 0.49 to 0.62; diorite: 0.59–0.97) values obtained in zircon grains suggest that they are of magmatic origin. Geochemical data indicate that the studied diorites and gabbros originate from a spinel-bearing source representing shallow depths. In light of all the data, the studied plutonic rocks are products of arc magmatism resulting from the subduction of the NeoTethys Oceanic lithosphere along the SAOB. Full article

As a fundamental component of GNSS signals, messages act as a critical medium for transmitting information required for PNT, serving the needs of both service providers and users. Over the years, message structures for GNSS signals have evolved from fixed formats to pseudo-packetized and mixed formats. This evolution has facilitated the integration of supplementary data and has driven further research to incorporate new types of information. These developments have highlighted the necessity of flexible and transmission-efficient message structures. In this paper, we propose a set of performance metrics designed for the comprehensive evaluation of GNSS message structures. Using these metrics, we analyze the performance of existing message formats. From the results, it is observed that optimizing message formats based on the purpose and characteristics of the transmitted information could achieve flexibility and transmission efficiency. Based on these findings, we propose a novel approach to designing message structures that address future requirements. Full article