Search Results (641)

High-phosphorus iron ore is an abundant yet refractory resource whose industrial exploitation is severely constrained by its elevated phosphorus content. Guided by the ore’s reduction characteristics, two process routes were designed and compared: carbon-composite pellet direct reduction followed by melting separation (CCP-DR–MS) and direct reduction–magnetic separation–melting separation (DR–MS–MS). Systematic experiments under simulated industrial conditions evaluated the metallization degree, dephosphorization efficiency, and smelting performance while clarifying the key factors that govern the differences in phosphorus removal between the two processes. The results show that both routes raised the ore’s metallization degree to above 95% during direct reduction, but the DR–MS–MS route delivered markedly better dephosphorization, achieving a maximum phosphorus removal rate of 89.20%. Although the slags produced by the two processes showed comparable phosphorus capacities, the difference in overall dephosphorization efficiency stemmed from their distinct reduction mechanisms: in DR–MS–MS, metallic iron is generated mainly via CO-mediated reduction, which suppresses phosphorus reduction, whereas in CCP-DR–MS, phosphorus and iron are simultaneously reduced by carbon. Consequently, DR–MS–MS attains superior phosphorus removal. Full article

Isotopic disequilibrium during the formation of high-temperature (HT) metamorphic complexes by anatexis during continental collision is a process that deserves intense discussion since it is fundamental to understand the evolution of continental crust. The axial sector of the Iberian Variscan Belt (IVB) is known by the profusion of synorogenic granites that are sometimes clearly associated with the migmatites composing the HT metamorphic complexes. The Pedregal Migmatitic Complex is located in the autochthonous domain of the IVB and is composed of metatexites and diatexites associated to syntectonic two-mica granites. The anatectic process occurred by dehydration melting of muscovite and biotite with the growth of peritectic minerals such as garnet, K-feldspar, and sillimanite in metatexites; and K-feldspar, sillimanite, and hercynite in diatexites reaching the metamorphic peak at 313.5 ± 0.5 Ma. A process of residuum-melt separation during crustal melting is attested by the Pedregal migmatites, giving origin to metatexites and residual diatexites as indicated by field evidence and their geochemical signature. Zircon oxygen isotopes and inherited zircon ages point to the Douro-Beiras Supergroup metasedimentary sequence (Beiras group) as a possible protolith of the Pedregal diatexites. Conversely, the isotopic composition of the diatexites suggests isotopic disequilibrium caused by residual mineral phases (biotite, monazite and garnet). Full article

Military confined spaces face poor ventilation and severe airborne hazards (toxic gases/particulates), while conventional air purification systems with separate filtration–adsorption units are bulky and hard to miniaturize. Activated carbon fiber paper (ACFP) is a promising integrated filtration–adsorption material, but existing studies lack systematic comparisons of different ACF precursors and rational balancing of adsorption, filtration, and mechanical properties. Herein, ACFPs were fabricated via wet papermaking technology, using two ACFs (rayon-based, RACF, and phenolic-based, PACF) as the adsorptive component, glass wool as a filtration enhancer, and dual-melting-point polyethylene terephthalate (PET) fibers as a mechanical reinforcer. Dynamic adsorption was evaluated via DMMP (a Sarin simulant). Results showed that PACF had a micropore ratio twice that of RACF. Under the optimal formulation (20% glass wool, 30% PET, and 50% ACF), both types of ACFP showed FE_0.3 μm ≥ 90%. PACFP outperformed RACFP in comprehensive performance, showing higher adsorption capacity, tensile strength, and filtration quality factor. Both ACFPs exhibited superior bed utilization efficiency (RACFP: 91.3%; PACFP: 86.0%) to granular activated carbon (AC: 82.7%), confirming better dynamic adsorption kinetics. This work provides a rational optimization strategy for ACFPs, offering a lightweight, integrated material for air purification in military confined spaces. Full article

Superhydrophobic surfaces are typically achieved through the synergistic integration of appropriate nanostructures and low-surface-energy chemical compositions. This study presents a novel and facile method for constructing a superhydrophobic hierarchical structure directly on a pristine selective laser melting (SLM) titanium surface. The intrinsic partially melted Ti particles, which are inherent to the SLM fabrication process, were strategically utilized as a natural microscale template for the in situ growth of TiO₂ nanotubes via electrochemical anodization. Three distinct micro/nano-topographies were successfully fabricated, integrating the spherical microparticles with either conventional TiO₂ nanotube arrays or separated nanotube arrays. The results demonstrate that the resulting superhydrophobic behavior can be effectively regulated by two key factors: the liquid–solid contact mode at the microscale and the strength of capillary action within the nanostructures. Notably, these characteristics can be tailored by controlling the nanotube diameter and intertubular spacing. These findings contribute to a deeper understanding of the role of micro–nano hierarchical structures in engineering superhydrophobic surfaces, thereby opening new avenues for advanced applications. Full article

Variscan two-mica granites are widespread in the Trás-os-Montes region (NE Portugal), yet their emplacement ages, petrogenesis, and relationship with Variscan deformation phases remain poorly constrained. This study integrates U–Pb zircon geochronology, whole-rock geochemistry, and oxygen isotope data to characterise four peraluminous two-mica granites in the Trás-os-Montes area (Fornos, Carviçais, Fonte Santa, and Bruçó) and to refine their tectonomagmatic context within the Central Iberian Zone. All granites are S-type, ilmenite-series, and derived from reduced magmas, as indicated by their strongly peraluminous compositions, mineral assemblages (muscovite ± biotite), absence of magnetite and presence of ilmenite, and high δ¹⁸O values (>11‰), consistent with partial melting of metasedimentary crust. U–Pb ages reveal two distinct magmatic pulses: an older event at ~340 Ma (Fornos and Fonte Santa granites), predating the onset of C3 deformation and likely associated with late C1 crustal thickening to early C2 tectonics, and a younger pulse at ~320–318 Ma (Carviçais and Bruçó granites). These magmatic pulses are linked to contrasting structural controls, with the older granites emplaced within regional-scale antiforms and the younger intrusions localised along structures related to C3 deformation. Together, these results document two discrete crustal melting events separated by ~20 Ma and record a progressive shift from fold-controlled to strike-slip-dominated granite emplacement during Variscan orogenic evolution. Moreover, the study highlights that tungsten mineralisation is preferentially associated with reduced, crust-derived granites emplaced during specific tectonic regimes, providing new constraints for metallogenic models in NW Iberia. Full article

In this study, the effect of temperature on thermal-assisted glass delamination was investigated using two treatment conditions differing in the set temperature of the process (100 °C vs. 140 °C). Thermogravimetric Analysis (TGA) confirmed that ethylene-vinyl acetate (EVA) remains thermally stable up to about 280 °C, with degradation onset near 300 °C, ensuring that both treatments operate below decomposition. Differential Scanning Calorimetry (DSC) analysis identified an endothermic transition attributable to the melting of crystalline regions in EVA within the thermal range of 35–65 °C, indicating enhanced polymer chain mobility at elevated temperatures. This endothermic transition corresponds to the melting of polyethylene crystallites within the EVA copolymer and should not be interpreted as a glass transition, since the Tg of EVA is typically located at approximately −30 to −35 °C. Fourier Transform Infrared (FTIR) analysis verified preservation of ester functional groups, confirming the absence of chemical degradation. The morphological analysis performed via Scanning Electron Microscopy (SEM) revealed a clear temperature-dependent morphology of EVA after thermal-assisted delamination. At 140 °C, enhanced polymer softening and viscous flow led to smoother surfaces and more uniform interfacial separation, whereas at 100 °C, limited mobility resulted in heterogeneous, fragmented residues and predominantly cohesive failure. These results highlight that optimizing temperature is key to balancing effective delamination with residue minimization, supporting more sustainable PV recycling. Full article

Homopolymer addition is a widely used strategy to dilate the microdomain spacing of block copolymers, yet the attainable dilation is often limited by macrophase separation in conventional blends at elevated homopolymer loading. In this work, we investigate an architectural route to suppress macrophase separation while retaining homopolymer-driven dilation: a covalently hybridized bottlebrush copolymer (CH-BBC), a copolymacromer-like bottlebrush architecture in which symmetric AB diblock side chains and A-type homopolymer side chains are covalently grafted to a common backbone. Using dissipative particle dynamics (DPD) simulations, we directly compare the phase behavior of CH-BBC melts with that of composition-matched blends of symmetric AB diblocks and A-type homopolymers. Across the explored window, CH-BBC exhibits microphase morphologies and disorder without an observable two-phase region, whereas the corresponding blends show extensive two-phase coexistence at elevated homopolymer loading. Lamellar analysis and one-dimensional density decompositions further reveal that CH-BBC enables substantially larger microphase dilation and stronger selective swelling of the A-rich domain because tethered A-type homopolymer segments preferentially occupy and dilate the A-rich domain interior while diblock A segments remain localized near interfaces. Full article

Stimulating electronic transitions and promoting exciton dissociation are key to enhancing the photocatalytic performance of polymer carbon nitride (PCN). Herein, a controllable synthesis strategy based on supramolecular self-assembly and mild salt melting crystallization has been developed, successfully preparing carbon nitride-based photocatalytic materials with tunable crystal phase composition. The mixed crystal phases effectively induced significant n→π* electronic transition, expanding the material’s light response range to the near-infrared region (700 nm). Meanwhile, the homojunction promoted the efficient separation of photogenerated carriers through the built-in electric field. Under visible-light excitation, this material exhibits excellent selective catalytic performance, over 99% for the oxidation and removal of H₂S into elemental sulfur. This synergistic mechanism of crystal phase engineering in regulating electronic structure and interface charge dynamics provides a new material design strategy for efficient non-metallic photocatalysts. Full article

Additively manufactured stainless steels are gaining considerable attention in the production of complex components, especially in the aerospace, food production, energy, and biomedical industries. Machining and achieving the desired surface properties of such materials remains a challenge. Abrasive waterjet machining technology appears to be one of the options due to the advantages it brings. Removing support structures and separating individual parts is also one of the possible applications of this technology. This study investigates the effects of process parameters for individual cut qualities (Q1–Q5) of abrasive waterjet on the surface properties of additively manufactured stainless steel (SS 316L) specimens, considering the different mechanical properties of the material due to the direction of layering of the material during its production. Experimental specimens were prepared by selective laser melting technology with parameters ensuring the best possible quality of the resulting part. The results of the study showed changes in the topography of the machined surface, especially in the roughness parameters. Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy analysis proved the presence of fragmented abrasive particles in the cut areas. Full article

Biodegradable nanocomposite materials possessing self-healing behavior are emerging as an attractive option of being used in advanced mechatronic systems. The current study is focused on a thorough examination of the micromechanical properties of graphene–reinforced polylactic acid (PLA)/polycaprolactone (PCL) composite samples, followed by estimation of their self-healing behavior upon heating. Polymer blend–based nanocomposite materials were prepared using the green and reliable in terms of good nanofiller dispersion melt extrusion method. 3D printed nanocomposite specimens with impeccable flatness were subjected to fine microscratch testing by applying a constant force experimental mode. The surface resistance of the three-component polymer materials against the lateral movement of the stylus fulfilling the scratch and the impact of the dual-phase PLA/PCL ratio on the nanocomposite mechanical performance were estimated by calculation of the coefficient of friction (COF = F_x/F_z). COF values in the range of 0.8–1.4 indicated excellent nanocomposite resilience against scratch. Creating a heterogeneous polymer system that combines phase-separated soft and hard domains with close melt and glass transition temperatures, respectively, may facilitate the physical flow of macromolecular chains into voids or free volume areas. This aspect can be critical in the achievement of thermally–induced self-healing properties of the composite material. Scanning electron microscopy (SEM) imaging of the microscratches, made before and after Joule heating of the polymer samples, revealed a significant degree of surface recovery and a sensible reduction in the width of the adjusted scratch grooves. Full article

The influence of Ni and Co additions on microstructure and mechanical properties of (CoCrCuTi)_100−xFe_x high-entropy alloys (HEAs) containing 10 or 15 at. % Fe was investigated. The base HEA consisted of dendritic C14 Laves phases with interdendritic Cu-rich FCC regions. When Ni in the range of 2.5 to 10 at. % was added, a reduction in the Cu-rich phase was observed. Conversely, Co additions in the same range initially increased the Cu-rich phase but eventually led to liquid-phase separation (LPS), forming distinct Cu-lean L1 liquid and Cu-rich L2 globular regions. The average Vickers hardness values of (CoCrCuTi)₉₀Fe₁₀ and (CoCrCuTi)₈₅Fe₁₅ HEAs were measured at 790 ± 33 HV and 760 ± 20 HV, respectively. The additions of Ni and Co decreased overall hardness values. However, while Ni additions caused greater microstructural refinement, Co additions eventually led to heterogeneity due to LPS. For instance, the Vickers hardness of (CoCrCuTi)₉₀Fe₁₀ with 2.5 at. % Ni reached a maximum of 706 ± 95 HV, decreasing in hardness and scatter to 646 ± 19 HV when Ni increased to 10 at. %. In contrast, Co additions led to a marked reduction in hardness, from 574 ± 114 HV at 2.5 at. % Co to 442 ± 246 HV at 10 at. % Co. The fracture toughness (KIC), determined using Vickers indentation testing, indicated that Ni additions reduce fracture toughness, while Co additions increase it. Full article

Platinum group metals (PGMs) are strategic metals, and recycling PGMs in spent automobile exhaust catalysts (SACs) is a key path to alleviate the contradiction between resource supply and demand. This paper proposes a new Cu-Ni capture process and conducts research on the recovery of PGMs from SACs. Through the binary phase diagram analysis of Cu, Ni and PGMs and the thermodynamic calculation of the system reduction reaction, the feasibility of this technology was theoretically confirmed. Experimental results show that under the conditions of a temperature of 1450 °C, a holding time of 90 min, a Cu-Ni ratio of 1:1, and a basicity of 0.58, the recovery rates of Pt, Pd, and Rh reached 99.2%, 99.34%, and 98.48% respectively. Combined with orthogonal experiments, it was verified that temperature is the most influential factor on the recovery rate, and the four-stage capture mechanism of “initial diffusion—droplet aggregation—sedimentation and wetting—slag–metal separation” was clarified. This process reduces the melting temperature and provides new technology for green and efficient recycling of PGMs. Full article

The depletion of natural resources remains an acute global problem, highlighting the importance of developing sustainable technologies that enable the simultaneous extraction of metals and recycling of waste. This paper describes a study of a technology for recycling aluminum slag from foundries to produce secondary aluminum alloy and regenerated flux. Research and processing methods include X-ray phase and spectral analysis of slag composition, multi-stage grinding in a jaw crusher and planetary mill, screening for fraction separation, and selective dissolution of the oxide–salt phase in water or hydrochloric acid followed by filtration and evaporation; obtaining regenerated flux based on phase diagrams of chloride systems; and briquetting and remelting of the extracted aluminum. The technology ensures the extraction of up to 85% of the metallic aluminum from slag and the production of regenerated flux based on the NaCl–KCl–MgCl₂ system with a low melting point. Full article

For addressing difficult detail extraction and low operating efficiency in monitoring sea ice in a large area with wide-field-of-view images from the Chinese Gaofen-1 satellite, a lightweight, high-precision sea ice segmentation network adaptive multistatistic fusion attention (AMFA) module using DeepLabV3+ as the base architecture (AMFA-DeepLab) is proposed. First, the module replaces the backbone network with a lightweight MobileNetV2 to ensure feature extraction capability and greatly reduce model computational complexity using inverted residuals and depthwise separable convolution. Second, to solve the problems of fragmented ice texture blurring and speckle noise interference in optical images, an AMFA is designed and introduced into the decoder side. This module innovatively integrates the global median pooling branch and adapts the recalibrated feature weight through a dynamic channel mixing mechanism, effectively enhancing the model’s capability of capturing fine sea ice edge features and its antinoise robustness in complex backgrounds. Experimental results based on the dataset from Liaodong Bay in the Bohai Sea of China show that the intersection over union of AMFA-DeepLab reaches 92.15% and the F1-score reaches 95.91%, increases of 3.06%, and 1.68%, respectively, compared with those of the baseline model. In addition, only 5.85 million model parameters are needed, the training time is shortened to 4.42 h, and the inference speed is 281.76 frames per second. Visualized analysis and generalization test further demonstrates that this model can accurately eliminate clutter interference from coastal land and seawater and extract the fine filamentous structure of drift ice in the scene of complex melting ice. This research overcomes the precision bottleneck while achieving an ultimate lightweight model, providing efficient technical support for operational dynamic monitoring of sea ice disasters based on Chinese GaoFen-1 satellites. Full article

Polyvinyl alcohol (PVA)-based films are promising biodegradable alternatives to petroleum-derived plastics; however, their high rigidity and moisture sensitivity limit practical applications. In this study, PVA/carnauba wax (CW) films were prepared via solution casting and systematically modified using four plasticizers: glycerol (GLY), sorbitol (SOR), glucose (GLU), and sucrose (SUC), at concentrations of 0.1–0.5% (v/w, relative to PVA). Thermal analysis showed that GLY and SOR effectively reduced the glass transition temperature from 52.35 °C (control) to as low as 49.14 °C (0.2% GLY) and 50.70 °C (0.4% SOR), while SUC and SOR plasticized films exhibited improved thermal stability, with the highest melting temperature observed for 0.3% SUC (80.6 °C). SEM micrographs revealed that GLY at moderate concentrations (0.2–0.3%) produced the most homogeneous film morphology, whereas SUC at higher concentrations led to surface roughness and phase separation. Water contact angle measurements showed increased surface hydrophobicity at low plasticizer contents, with 0.1% GLY and 0.2% GLU exhibiting contact angles above 100° compared to the control film (<90°). Mechanical testing demonstrated that SUC at 0.2% had the highest tensile strength (3.03 MPa) compared to 0.73 MPa (control), while GLY at 0.3% yielded the highest elongation at break (9.26%), compared to 0.62% for the unplasticized film. These results demonstrate that precise control of plasticizer type and concentration enables effective tuning of PVA/CW film properties, offering a viable strategy for designing biodegradable films tailored for packaging and agricultural applications. Full article