Search Results (1,156)

Eclogites exhumed from subduction channels are pivotal for deciphering the thermal structure of continental subduction zones. However, heterogeneities in bulk-rock composition and evolutionary history within the subduction channel can lead to variations in petrographic textures and elemental characteristics among eclogites. Therefore, investigating the pressure–temperature (P-T) evolution of eclogites from different outcrops is crucial for refining dynamic models of convergent plate boundaries. The Western Dabie Mountain represents an ideal locality for studying the petro-thermodynamics of continental subduction channels. This study focuses on samples collected from the Dongyuemiao area, situated at the boundary between the high-pressure and ultrahigh-pressure metamorphic belts in the Western Dabie. We integrate petrographic observations, mineral chemistry, phase equilibrium modeling, Zr-in-rutile thermometry and hornblende-plagioclase thermobarometry to constrain the P-T evolution of the eclogite. The samples exhibit a consistent mineral assemblage: garnet + omphacite + amphibole + quartz + phengite, with accessory minerals including rutile and titanite. Garnet grains display characteristic “cloudy-core” and “atoll” textures. Major and trace element analyses of large garnet porphyroblasts reveal pronounced growth zoning in divalent cations, with cores showing enrichment in light rare earth elements (LREEs). Based on phase equilibrium modeling and calculated isopleths for garnet (Ca, Mg) and phengite (Si content), we interpret that the garnet core mineral assemblage (glaucophane + rutile + sphene) records a blueschist-facies metamorphic stage, situated near the rutile-titanite transition. A prograde P-T path is reconstructed, comprising an initial stage of isobaric heating (from ~480 °C at 20 kbar to ~550 °C at 21 kbar), followed by an isothermal compression to the Pmax stage (from ~550 °C at 21 kbar to ~575 °C at 26 kbar). Subsequent retrograde evolution is characterized by decompression and cooling, with symplectite formation recording conditions of ~570 °C and 13 kbar. This study demonstrates that the reconstructed P-T path for the Dongyuemiao eclogites shows stepped geothermal gradient for the prograde stage, and that fluid activity during exhumation resulted from a combination of internal and external factors. Full article

As a new generation of structural materials, Fe-Mn-Al-C lightweight steels with low density, high strength, and excellent strength-toughness properties have shown significant application potential in fields such as transportation, aerospace, and energy equipment. In the present work, the effects of Mo alloying and annealing processes on the microstructural evolution and mechanical properties of Fe-18Mn-8Al-1C-3Cu lightweight steel are investigated. Due to the addition of Mo, the recrystallization temperature is significantly increased, and the recrystallization process is delayed. The fine and dispersed Mo₆C precipitated phases can effectively impede dislocation movements and pin the grain boundaries, hindering recrystallization and grain growth. After annealing at 900 °C, the yield and tensile strengths of the Mo-alloyed steel were enhanced, achieving 1181 MPa and 1345 MPa, respectively, while maintaining an elongation of 24%, thus exhibiting excellent comprehensive performance. Quantitative analysis of strengthening mechanisms confirmed that the strength enhancement primarily resulted from the synergistic contributions of grain refinement strengthening (~152 MPa), solid solution strengthening (44 MPa), dislocation strengthening (131.6 MPa), and Mo₆C precipitation strengthening (52.23 MPa). Through Mo alloying and annealing process optimization, a high-strength, ductile lightweight steel was successfully developed, providing theoretical foundations and technical pathways for its application in high-performance structural materials. Full article

This study presents the effect of gamma rays of up to 2000 kGy on the chemical structure and the physical properties of a poly(butylene adipate-co-terephthalate) (PBAT) with 48% mol of terephthalic units. PBAT is a polymer with properties similar to polyethylene (PE) but it is biodegradable and not toxic to the environment, and it can be prepared with a renewable content of up to 68.6% weight, with uses in biomedicine and packaging. Previous studies found in the literature have been conducted using low doses and the results were contradictory. The results for gel content and crosslinking efficiency were in agreement with the results found in the literature. Molecular weight decreased and widened with the increase in dose. Proton NMR analysis was used for the first time in PBAT to determine the changes in chemical species, the formation of new chemical species, and the bonds more susceptible to be broken by gamma rays. Both thermal and mechanical properties were explained by the scission of the chains in the amorphous phase and at the boundaries of the crystallites. The thermal parameters most affected by irradiation were the crystallization temperature and temperature of melting after cooling from the melt. Stress and strain at break suffered a continuous decrease with dose until PBAT became fragile at high dose. Full article

TaC/amorphous-carbon (TaC/a-C) composite coatings with varied a-C contents were deposited on graphite by dual-target magnetron sputtering to mitigate the thermal-expansion mismatch that commonly triggers cracking and spallation in TaC coatings on carbon substrates during rapid thermal cycling. However, existing TaC–C (often termed “free carbon”) approaches rarely identify the carbon’s structural state and spatial distribution explicitly, and a clear correlation between carbon fraction, thermal-shock-driven microstructural evolution, and cyclic damage remains insufficiently established. Increasing the a-C fraction progressively refines the TaC grain structure and introduces an a-C phase along grain boundaries, thereby lowering the effective coefficient of thermal expansion (CTE) and improving compatibility with the graphite substrate. Under laser thermal cycling, coatings with higher a-C contents exhibit markedly enhanced resistance to cracking and spallation. After 15 cycles, the high-a-C (~28.99 at.%) coating remains free of through-thickness cracks, maintains its thickness, and retains a single-phase TaC structure without detectable Ta₂C, whereas the low-a-C coating shows severe thinning, through-cracks, and partial TaC → Ta₂C transformation. Microstructural observations indicate that the a-C phase forms a compliant, stress-relaxing boundary network and promotes a porous, mechanically interlocked TaC architecture, synergistically redistributing thermal stresses and deflecting crack propagation. Full article

The tensile and compressive behavior of hot-forged Al5Co35Cr30Fe20Ni5 high-entropy alloy (HEA) has been studied at room temperature. The forged HEA has a dual-phase microstructure consisting of a predominant face-centered cubic (FCC) matrix and a body-centered cubic (BCC) phase. The BCC phase embeds a low volume fraction of ordered BCC nanoparticles (B2 structure). During forging, the BCC phase recrystallizes more easily than the FCC phase. Yielding is controlled by the deformation of the FCC phase, although BCC grains assume an additional part of the load transferred by FCC grains, even during the elastic regime. During the onset of plastic deformation, slip is activated preferentially in the FCC phase in those grains that are favorably oriented for slip in planes (111). Dislocation pile-ups at FCC/BCC interfaces induce dislocation slip in the BCC phase. In the BCC phase, B2 particles act as effective obstacles to dislocation motion through the Orowan mechanism. As the deformation proceeds, dislocation activity causes an increase in the misorientation in both phases, resulting in the formation of subgrains whose boundaries are effective for blocking dislocation motion. The combination of high strength and ductility arises from the dual-phase FCC–BCC microstructure of the alloy. The load borne by the BCC phase partially relieves the stress applied to the FCC matrix, enabling the latter to continue deforming. Full article

Continuous-variable quantum communication (CVQC) relies on finite-window estimation of phase space moments, making receiver decisions sensitive to finite measurement resolution, calibration uncertainty, and confidence-calibrated tolerances. This paper develops a receiver-centric threat modeling framework for structured (including adversarial) physical-layer disturbances under finite-sample inference. We introduce an operational taxonomy, reconnaissance, exploratory, and denial-of-service, defined by statistical visibility relative to acceptance regions rather than by assumed physical mechanisms. Using an effective estimator space Gaussian model ${\widehat{\mathbf{r}}}^{\prime }=G\widehat{\mathbf{r}}+\mathbf{\xi }$ with additive covariance N, we show how distinct mechanisms can be observationally equivalent within finite tolerances and we propose a protocol-agnostic scalar severity coordinate $\Delta E$ based on the covariance trace. We derive ${\chi }^2$-based missed-detection expressions and a soft detectability boundary scaling as $1/\sqrt{n}$, and we corroborate the predicted $P_{\mathrm{miss}}\left(\nu \right)$ behavior via Monte Carlo simulations across representative block sizes. The resulting framework clarifies the delimitation from conventional CV-QKD excess noise parameterization and provides a structured basis for monitoring-layer design and comparative threat-taxonomy mapping. Full article

This study was conducted to investigate and identify correlations among sensory and comprehensive consumer test results with rheological, textural, and tribological properties of milk chocolate in response to varying levels of particle size and emulsifier. To simulate realistic oral conditions, artificial saliva was incorporated into instrumental analyses. Rheological analysis revealed that increasing particle size and emulsifier concentration significantly reduced plastic viscosity, while emulsifier concentration alone increased yield stress due to structural reorganization within the fat phase. Tribological measurements demonstrated that larger particles increased friction in boundary and mixed lubrication regimes, whereas emulsifiers reduced friction in these regimes by enhancing fluid film formation. Under elastohydrodynamic conditions and with artificial saliva, friction was more influenced by the interaction between particle size and emulsifier level. Textural analysis showed that both parameters significantly influenced hardness, with saliva further softening the samples, especially those with higher emulsifier levels. Sensory evaluations indicated that emulsifiers enhanced flavor release and mouthfeel attributes, while smaller particles contributed to smoother texture and more balanced flavor perception. Consumer acceptance tests confirmed that samples with smaller particles and higher emulsifier levels received the highest scores in overall liking, taste, and texture. Instrumental parameters strongly correlated with key sensory attributes, with yield stress showing the highest positive associations with creaminess, smoothness, fat/milk flavor, and liking, while higher viscosity and friction were negatively linked to flavor release and mouthfeel. Instrumental hardness negatively correlated with cacao intensity and astringency, while saliva-induced softening was positively associated with sweetness and liking, highlighting the role of dynamic oral softening. Full article

Forest canopy cover is a crucial indicator for measuring ecological functions. However, traditional plot-based measurement methods suffer from low efficiency and insufficient spatial continuity. Addressing issues in UAV RGB imagery—such as tree crown boundary adhesion, shadow interference, and texture confusion—this paper proposes a lightweight and edge-sensitive tree crown segmentation network. The model employs MobileNetV3-Large to replace the traditional U-Net encoder, significantly reducing parameter count and computational load while satisfying the potential for edge device deployment. In the decoding phase, a Semantic-guided Channel Compression and Focus (SCCF) module is designed to enhance semantic-guided channel compression and feature focusing. Furthermore, a Gradient-guided Morphological Tree Crown Attention Module (G-MTCAM) is proposed. By utilizing Gradient-Induced Center Difference Convolution (GI-CDC) and a variance-based statistical gating mechanism, this module constructs a dual-stream architecture for morphology and texture interaction, achieving precise cutting of tree crown boundaries and effective filtering of background noise. Additionally, a boundary-enhanced composite loss function is introduced to improve the accuracy of crown edge identification. Experimental results indicate that the proposed model achieves an IoU, Acc, and F1 score of 88.59%, 88.62%, and 93.77%, respectively. Compared to the classic U-Net, these represent improvements of 2.77%, 1.71%, and 1.44%, while the parameter count and computational cost are only 5.98 M and 6.71 GFLOPs. The forest Canopy Cover (CC) estimated based on the segmentation results shows high consistency with ground-based near-zenith canopy hemispherical percentage ($CH{P}_{0–30}$, denoted as $C{C}_{obs}$), with a correlation coefficient ($R^2$) exceeding 0.90. This verifies the effectiveness of the method in forest canopy structure monitoring and provides technical support for the application of consumer-grade UAVs in forestry surveys. Full article

The Tinjar–West Baram Fault in the southern South China Sea is a major NW-trending strike-slip fault that has remained tectonically active since the Oligocene. It forms a key structural boundary between the Zengmu, Beikang, and Nansha Trough basins. Multi-phase strike-slip movements have strongly controlled sediment provenance dispersal pathways, and reservoir development in the Zengmu Basin, yet the sedimentary response to these tectonic processes remains poorly understood. This study integrates 2D seismic profiles to analyze the fault geometry, kinematics, and impact on deep-water sedimentary systems. Results indicate that Oligocene right-lateral motion directed sediment supply from the southwest, mainly sourced from Kalimantan, forming fluvial–deltaic systems with depocenters in the southern basin. Since the Late Miocene, a transition to left-lateral motion reoriented sediment provenance toward the southeast, leading to delta-front complexes and northward migration of depocenters. Strike-slip activity deformation enhanced rock fragmentation and sediment supply, producing fan delta, fluvial, and shallow lacustrine facies near the fault. Associated uplift and subsidence induced relative sea-level fluctuations, resulting in alternating transgressive–regressive sequences. From the Late Eocene to Miocene, the basin evolved from a land–sea transitional system to a deltaic–carbonate complex controlled by the paleo-Sunda River. During the Pliocene–Quaternary, sedimentation was dominated by shallow-marine shelf and semi-deep-marine deposits. Fault-related fracturing significantly enhanced porosity and permeability, creating favorable conditions for hydrocarbon migration and entrapment in both sandstone and carbonate reservoirs. These findings demonstrate a strong coupling between strike-slip fault activity and sedimentary system evolution, providing important insights into sedimentary processes and hydrocarbon potential in strike-slip fault-bounded basins globally. Full article

The influence of YB₄ particle addition on the microstructure and the associated thermal and mechanical properties of AISI 420 stainless steel composites fabricated using the vacuum induction melting technique was investigated. Microstructural analysis using scanning electron microscopy (SEM) confirmed the presence of YB₄ particles within the BCC-structured martensitic matrix and also along the grain boundaries across all weight fractions. In addition, YB₄ addition resulted in a pronounced refinement of the martensitic matrix, as evidenced by a progressive reduction in the size of the packets, i.e., a group of martensitic laths/plates sharing the same habit plane variants with the parent austenite grain. The presence of YB₄ particles induced internal stresses and microstrains, leading to peak shifting and broadening of the X-ray diffraction (XRD) peaks corresponding to that of the martensitic matrix phase. The coefficient of thermal expansion (CTE) decreased significantly from 13.4 × 10⁻⁶ K⁻¹ for monolithic AISI 420 to 8.06 × 10⁻⁶ K⁻¹ for the AISI 420/4 wt.% YB₄ composite and was attributed to the excellent dimensional stability of YB₄ particles. The maximum hardness (913.12 HV) and tensile strength (930 MPa) were achieved for the AISI 420/4 wt.% YB₄ composite. Fractographic analysis using SEM indicated a transition from ductile to brittle fracture with increasing YB₄ content, suggesting a reduction in strain-hardening capacity. The contributions of various strengthening mechanisms were quantified using the summation of strengthening and modified Clyne models, revealing that strengthening due to load bearing is dominant across all composites. Insights gained from these results are important to strategize the design of boride-based metal-matrix composites with enhanced strength–ductility synergy for structural applications. Full article

Water scarcity and climate stress are increasingly framed as matters of individual consumption, even though structural drivers remain decisive. To examine how corporate communication participates in sustainability governance, this study asks how Finish Türkiye’s “Water of Tomorrow” initiative (2019–2025) defines the water problem, allocates responsibility, and builds legitimacy across time (RQ1–RQ2) using a longitudinal critical discourse analysis of multimodal materials (campaign videos, social media, web content, and reporting genres). We identify three phases: (i) household norm-setting through responsibilization scripts, (ii) scale-shifting legitimation via NGO/media alliances and ecosystem narratives, and (iii) metricization through quasi-institutional “water status” reporting and proprietary indices. While such strategies can raise salience and offer actionable guidance, they may also depoliticize allocation and equity questions by foregrounding consumer routines over infrastructural, agricultural, and industrial determinants. Practically, the paper proposes governance-relevant boundary conditions for corporate sustainability communication in water-stressed contexts: transparent sourcing of quantified claims, explicit role division with public and civil-society actors, alignment with basin-level and equity-sensitive governance, and avoidance of exaggerated individualization. Full article

A transient numerical framework incorporating dynamic mesh techniques was developed to simulate the launch process. On this basis, a thermal–fluid–structural multi-physics coupling paradigm was proposed to interpret the evolution of the flow field and the associated load response throughout the entire firing sequence. The results show that flow development follows a multi-stage dynamic pattern, comprising gas-impact filling, gap-jet formation, and subsequent free-jet expansion. A pronounced spatially heterogeneous phase lag was observed in the pressure–Mach number response. This phenomenon arises from a mismatch among the characteristic time scales of pressure-wave propagation, flow inertia, and shock–boundary-layer interaction. Quantitative analysis further indicates that the spatial superposition of high-temperature zones, high-Mach regions, and elevated-pressure areas activates a thermal–fluid–structural positive-feedback loop that drives the local peak temperature to approximately 2.5 × 10³ K. The temperature response lags behind the pressure maximum by approximately 30–50 ms, reflecting the governing time scale of thermal inertia. In addition, vortical structures near the tube base account for nearly 15% of the total thrust. These findings provide a theoretical foundation for predicting transient peak loads in concentric cylindrical systems and for optimizing instantaneous thermal protection strategies. Full article

Intergranular corrosion (IGC) and exfoliation corrosion (EXCO) limit the durability of 2219 Al–Cu in chloride-rich, cyclic-humidity aerospace environments, and conventional thermal stress relief can worsen grain boundary precipitates and grain boundary non-precipitation zones (PFZs), motivating evaluation of low-temperature resonant vibration stress relief. Using polarization tests and microstructural analysis, we show that RRV lowers corrosion current, strengthens passivation, and reduces IGC and EXCO susceptibility. Alternating tensile–compressive stresses build dislocation networks that convert continuous or semi-continuous grain boundary precipitates into discrete distributions, increasing corrosion path tortuosity and slowing intergranular attack. A more discrete cathodic phase, a narrowed solute-enriched anodic band, and reduced PFZs disrupt corrosion channel continuity, weaken microgalvanic driving forces via a more uniform θ′ distribution, and limit corrosion product wedging, while homogenized precipitates suppress local galvanic coupling in EXCO-like media. Overall, RRV synergistically optimizes dislocation configuration and precipitate redistribution to intrinsically enhance corrosion resistance and offers a practical, low-temperature, scalable route to improve the durability of high-strength aluminum alloy structures in aerospace service. Full article

Linear integrators are traditionally used in motion control systems to compensate for static effects and suppress low-frequency disturbances. However, their use is inevitably accompanied by phase delays that limit the performance and robustness of control systems, especially in conditions of parametric uncertainty. In this regard, nonlinear integrators have been considered for several decades as a promising alternative that can weaken phase constraints and improve the quality of transients. In this paper, the concept of nonlinear integrators is reinterpreted in the context of self-organizing motion control of precision stages. In contrast to traditional approaches focused primarily on frequency analysis and the method of describing the function, a method is proposed for the synthesis of a self-organizing control system for nonlinear SISO objects based on catastrophe theory, namely in the class of elliptical dynamics with the property of structural stability. The control action is formed in such a way that transitions between stable modes occur due to bifurcation-conditioned self-organization, without using external switching logic. To ensure strict analytical guarantees of stability, the Lyapunov gradient-velocity vector function method is used, which guarantees aperiodic robust stability, suppression of oscillatory and chaotic modes, as well as monotonic convergence of trajectories under conditions of parameter uncertainty. The parameters of the nonlinear integrator are adapted using Self-Organizing Maps (SOM), while any parameter changes are allowed only within the regions that meet the conditions of Lyapunov stability. This approach ensures the alignment of analytical and data-oriented methods without violating the structural stability of the system. The results of numerical experiments demonstrate the superiority of the proposed method in comparison with classical linear and adaptive regulators in problems of controlling the movement of stages, especially near bifurcation boundaries and with significant parametric uncertainty. The results obtained confirm that the integration of nonlinear integrators with catastrophe theory and self-organization mechanisms forms a promising basis for the creation of robust and high-precision motion control systems of a new generation. Full article

Digital calendars are interactive representations of time that shape both scheduling outcomes and the micro-process of searching, verifying, and revising candidate placements. We examine calendar horizon—whether weekend time is visible in the default week view—as a boundary affordance in scheduling interfaces. Using eye tracking and interaction logs, we model each scheduling episode as a sequence of placement attempts and align gaze to each attempt, partitioning it into Early/Mid/Late phases and summarizing attention across structural AOIs (task panel, calendar grid, and the weekend column when present). Two experiments used drag-and-drop and dropdown slot-picking; weekend visibility was manipulated within the dropdown interface, while evening slots remained available. Across 105 participants (1018 task episodes), AttemptsCount ranged from 1 to 7. AttemptsCount predicted gaze-based process cost: each additional attempt corresponded to ~56% more total fixation duration. Personal tasks required more attempts than work tasks and elicited stronger Late-phase weekend verification when the weekend was visible. Horizon cues also shifted boundary outcomes: hiding the weekend reduced weekend placements and increased reliance on evening scheduling, indicating displacement into adjacent time regions. These findings position calendar horizon as a design lever that shapes both process (verification) and outcomes (boundary placements), with implications for calendar UIs and mixed-initiative scheduling tools. Full article