Search Results (408)

Small gases pose an unusual problem for studies of molecular transport in proteins. O₂, CO, H₂, and NO can cross short-lived internal spaces opened by protein fluctuations, often faster than experiments can follow continuous migration. Time-resolved crystallography can localize sufficiently populated intermediates, whereas spectroscopy, isotope exchange, and kinetic measurements report molecular exchange over their respective timescales without resolving the complete route. Pressurized noble-gas structures expose internal accommodation sites but rely on surrogate molecules whose size and interactions differ from those of physiological gases. Geometry-based tunnel searches identify available space, while molecular dynamics follows explicit movement through a fluctuating protein. Free-energy and enhanced-sampling approaches can access states or transitions that remain undersampled in direct trajectories. These techniques resolve different quantities rather than progressively more accurate estimates of gas transport. In this Perspective, we argue that gas-migration pathways should be evaluated by the physical consistency of independent observables, with each method interpreted according to the quantity it resolves. This distinction explains why a cavity visible crystallographically may not carry substantial flux, why a rapidly crossed route can remain structurally inconspicuous, and why static narrowing can alter diffusion without predicting its magnitude. Agreement among methods can support a transport assignment when the quantities they resolve are physically consistent with the same mechanism; apparent disagreement may instead reflect differences among occupancy, accessibility, residence, energetic preference, and molecular traffic. Full article

Psychoactive nitrogen-containing compounds represent a structurally diverse group of natural and synthetic molecules whose interactions with metal ions influence their physicochemical properties, biological activity, and analytical behavior. Although numerous studies have reported the synthesis of metal complexes, solution interactions, and metal-assisted analytical methods, the available knowledge remains scattered across compound classes and has not been comprehensively evaluated. This review summarizes advances in the coordination chemistry of psychoactive nitrogen-containing compounds from ScienceDirect, Google Scholar, and the Cambridge Structural Database (CSD), emphasizing donor atoms, coordination modes, structural diversity, crystallographic characterization, spectroscopic and computational investigations, and the biological properties of the resulting metal complexes. The current literature demonstrates that metal complexation can alter molecular geometry, electronic structure, redox behavior, biomolecular recognition, and pharmacological activity, while also offering opportunities to develop compounds with enhanced antimicrobial, anticancer, antioxidant, and DNA-binding properties. By integrating coordination behavior, structural, and biological aspects within a single framework, this review highlights the central role of metal interactions in psychoactive compounds and identifies emerging opportunities to develop advanced analytical methodologies and functional metal-based systems. Full article

The Schmid factor provides a compact link between an applied load and the resolved shear stress on a selected crystallographic system. For uniaxial loading, $m=cos\phi cos\lambda$, and its maximum magnitude is 0.5. This familiar result is conditional on the uniaxial stress model rather than a universal bound. Under a symmetric Cauchy stress tensor σ, the corresponding projection is ${\tau }_{RSS}=b^T\sigma n$. A dimensionless global Schmid factor (GSF) further requires a stated reference stress. When the von Mises equivalent stress ${\sigma }_{eq}=\sqrt{{\displaystyle \frac{3}{2}}s:s}$ is used, with orthogonal unit vectors $b$ and $n$ and ${\sigma }_{eq}>0$, $|GSF|\le {\displaystyle \frac{1}{\sqrt{3}}}$, the uniaxial limit is recovered as a special case. This review separates the tensor projection from effective or modified factors defined for particular loading conditions. SF and GSF describe the favorability of a crystallographic system under a prescribed stress, but they are neither intrinsic material properties nor complete activation criteria. Magnesium alloys are used to examine slip-system competition, twinning polarity, texture, local stress redistribution, and differences in critical resolved shear stress. In addition to calculation procedures, limiting cases, reporting requirements, and research directions, common learning difficulties and a progressive route for interpreting Schmid-based measures are discussed. Full article

Magnetic field-assisted casting technologies have received extensive research attention. Applying a transverse magnetic field during directional solidification offers an effective, non-contact approach to control the microstructure of Cu-Ag alloys by modulating melt convection. However, a comprehensive quantitative understanding of its mesoscopic influence on solute-driven dendritic growth and the columnar-to-equiaxed transition (CET) is still lacking. In this study, a coupled phase-field and lattice Boltzmann (PF-LBM) model is employed to systematically investigate the effect of a transverse magnetic field on columnar dendrite evolution and CET kinetics during the directional solidification of Cu-Ag alloys. Results show that the field-induced Lorentz force disrupts the symmetry of the solute field ahead of the dendrite tip, driving tilted dendritic growth that intensifies with decreasing initial primary spacing. During the CET process, the magnetic field overrides the randomness of grain nucleation by selecting specific crystallographic orientations. More importantly, it effectively mitigates the thermodynamic suppression of equiaxed nucleation typically caused by high temperature gradients. Furthermore, an increased magnetic field intensity not only accelerates the occurrence of CET but also significantly diminishes the inhibitory effect of high nucleation barriers on the transition. Ultimately, this work provides fundamental insights into external field-induced orientation selection mechanisms of as-cast grains and establishes a theoretical framework for quantitatively controlling texture evolution during the subsequent processing of high-flexure Cu-Ag alloys. Full article

Orientation rotation in grain-boundary regions plays a critical role in controlling the crystallographic texture of metallic materials. In this study, the ideal λ texture ({001}<uv0>) in non-oriented silicon steel is chosen as the target orientation. The oriented stability in grain-boundary regions during cold rolling is systematically investigated by combining crystal plasticity simulations and quasi in situ electron backscatter diffraction (EBSD) experiments. Oriented stability is defined as the rate of change in the misorientation angle between an arbitrary orientation and the target orientation, thereby quantifying the rotational tendency relative to the target in grain-boundary regions. The results reveal that the oriented stability in grain-boundary regions is highly sensitive to both the initial and neighboring orientations. For initial orientations near the critical boundary separating convergence and divergence zones, the oriented stability is highly susceptible to neighboring orientations, with some neighboring orientations even reversing the rotation direction. In contrast, when the initial orientation is far from this critical boundary, the influence of neighboring orientations becomes weaker. Furthermore, the concept of contributed oriented stability is introduced to statistically evaluate the effect of different neighboring texture components in polycrystals. This work elucidates the underlying mechanism of orientation rotation in grain-boundary regions, and provides a new theoretical framework and a quantitative strategy for optimizing favorable textures. Full article

This study reports the synthesis and characterization of a dinuclear zinc(II) complex, [Zn₂(L1)₂(L2)]·DMF·Et₃N (C₄₅H₅₄F₂N₁₀O₅S₂Zn₂), constructed from a fluoro-substituted thiosemicarbazone Schiff base ligand (2-(3-fluoro-5-hydroxybenzylidene)-N-methylhydrazine-1-carbothioamide, L1) and a rigid bipyridine auxiliary ligand (1,4-di(pyridin-4-yl)-2,5-dimethoxybenzene, L2) under solvothermal conditions. Single-crystal X-ray diffraction analysis reveals that the complex crystallizes in the monoclinic space group C2/c, featuring discrete dinuclear [Zn₂] units in which each Zn(II) center adopts a distorted square pyramidal geometry. These dinuclear units are extended into one-dimensional zigzag chains along the crystallographic c-axis via bridging L2 ligands, and further assembled into a two-dimensional supramolecular layer through hydrogen-bonding interactions involving lattice triethylamine and DMF molecules, ultimately forming a three-dimensional network. Both DMF and triethylamine molecules are disordered about a twofold rotation axis. This work highlights the structural directing roles of the fluoro-substituted multidentate Schiff base ligand and the rigid auxiliary ligand in the assembly of zinc(II) coordination polymers. Full article

Dissimilar friction stir welding (FSW) of titanium alloys offers a route to spatially optimized aerospace structures, but the asymmetric thermomechanical environment produces heterogeneous microstructures and textures whose interaction with mechanical performance is not well characterized. A near-α/α+β combination of titanium alloys, Ti–6242 SG (advancing side, ADV) and Ti–54M (retreating side, RET), was welded across a matrix of rotation speeds (225–325 rpm) and traverse speeds (100–150 mm·min⁻¹), spanning rotation-to-traverse-speed ratios N/v of 1.80–2.75, which was used throughout as an empirical processing index that orders the conditions of this matrix rather than as a measure of specific heat input. Microstructure, phase identification, relative diffracted-intensity trends, and crystallographic textures were characterized by 2D-XRD at three cross-section locations (ADV, weld nugget center [CEN], RET) and correlated with transverse tensile properties and fracture locations. Partial pole figures were plotted in the simple-shear reference frame with ideal-orientation overlays, intensities in multiples of a random distribution (m.r.d.). The CEN develops the strongest textures, dominated by a basal {002}_α component (20–31 m.r.d.) with poles near the normal direction; this concentration lies away from the ideal shear fiber loci and is more readily explained by orientation inheritance during the β→α transformation on cooling than by direct shear, although unambiguous identification of variant selection would require orientation-resolved measurements. The RET develops {101}_α and {100}_α pole concentrations clustering near the ideal P-fiber loci, consistent with deformation-related texture development, intensifying with both rotation and traverse speed. The ADV shows mixed textures varying non-monotonically with parameters. Two conditions of nearly identical N/v obtained from different parameter combinations (225 rpm/125 mm·min⁻¹ and 275 rpm/150 mm·min⁻¹) nevertheless develop measurably different streak morphologies, microstructures, textures, and tensile responses, showing directly that N/v orders but does not determine the thermomechanical state. Yield strength is uniform (≈900–940 MPa) across the full matrix, consistent with a Schmid-factor estimate in which the basal-near-ND CEN texture gives a very low resolved shear stress on basal systems under transverse loading; joint efficiencies reach ≈90–96%. Ductility, in contrast, tracks consolidation quality rather than texture severity: fracture strain rises almost monotonically with N/v, from ≈0.6–1.4% at N/v ≈ 1.8 (defect-driven, erratic failure) to ≈5.4–6.0% at N/v = 2.60, despite the latter condition carrying the strongest RET pyramidal texture. Full-field strain measurement shows the weld nugget to carry the lowest strain and the highest apparent stiffness of any zone in every condition for which the load record is reliable, with strain accumulating on the advancing side. Consolidated conditions fracture on the advancing side where deformation concentrates, whereas the lowest N/v and longest-exposure conditions fracture in the nugget center; all fracture surfaces are ductile, with the crack path following continuous α layers at prior-β grain boundaries. A favorable processing range within the investigated parameter matrix is N/v ≈ 2.2–2.6, with the best overall combination at 325 rpm and 125 mm·min⁻¹ (N/v = 2.60: UTS ≈ 1010 MPa, ≈5.4–6.0% elongation). Within the parameter range examined here, consolidation quality is the first-order design variable for this dissimilar system, with the zonal texture architecture setting the yield strength level. Full article

Tungsten trioxide (WO₃) and molybdenum trioxide (MoO₃) are redox-active Group VI transition-metal oxides widely used in functional thin-film technologies. Many studies have examined single-phase WO₃ and MoO₃ films. However, WO₃/MoO₃ nanocomposite thin films and heterostructures have not yet been comprehensively reviewed as interface-engineered platforms for smart and sustainable technologies. This review addresses this gap by analyzing WO₃/MoO₃ thin-film nanocomposites through the concept of interfacial synergy. Particular attention is paid to the structural complementarity of WO₃ and α-MoO₃, oxygen nonstoichiometry, mixed W⁶⁺/W⁵⁺/W⁴⁺ and Mo⁶⁺/Mo⁵⁺/Mo⁴⁺ valence states, crystallographic-shear suboxides, W–O–Mo interfaces, and fabrication routes for mixed, graded, and multilayer films. The functional advantages of these systems do not arise from simply combining the two oxides. Instead, they result from charge and oxygen-vacancy redistribution, shortened ion–electron transport pathways, phase stabilization, and the formation of new active sites at interface boundaries. The review also emphasizes the need to distinguish genuine interfacial synergy from apparent improvements caused by surface area, film thickness, porosity, hydration, or measurement conditions. Finally, the review links structural features, defect chemistry, and interface-controlled properties to device-level functionality. This framework highlights promising directions for WO₃/MoO₃ nanocomposite films in a wide range of smart and sustainable technologies. Full article

Background/Objectives: Carbapenem-resistant Acinetobacter baumannii (CRAB) is a WHO critical-priority pathogen, and variations in the outer membrane porin CarO are one mechanism implicated in carbapenem resistance. No prior study has characterized carO mutation patterns among A. baumannii in Tak, Thailand. This study aimed to characterize carO mutation patterns in clinical isolates, evaluate their association with CRAB, reconstruct phylogeny, and predict the structural consequences of CarO representatives relative to a crystallographic reference structure (PDB 4RL9). Seventy-seven A. baumannii isolates were recovered from Mae Sot Hospital, and re-confirmed by PCR based on the presence of bla_OXA-51-like gene. Results: The carO gene was sequenced and mutations compared between CRAB and carbapenem-susceptible (CSAB) isolates. Of the 77 isolates, 70 yielded successfully carO sequence data by next-generation sequencing (NGS), including 64 CRAB (91.43%) and 6 CSAB isolates. Two overlapping mutation clusters were significantly associated among CRAB isolates (73.44% and 75.00%; p = 0.0008 and p = 0.0006) and were absent from all 6 CSAB isolates (8.57%). Phylogenetic analysis resolved 3 clinical lineages, with variant III predominating. AlphaFold2 models predicted structural divergence among CarO variants with the single variant IV isolate showing the most extensive predicted remodeling of the CarO barrel. Conclusions: carO mutation was strongly associated with carbapenem resistance in this Thai cohort. However, these findings do not establish a direct causal role of carO mutation in carbapenem resistance. Predicted structures were consistent with potential alterations of porin function. These findings provide a regional characterization of carO-mediated resistance and support further functional validation of CarO as a resistance marker. Full article

The development of simulated-solar-light photocatalysts for methyl orange (MO) removal is limited by insufficient light utilization, rapid photogenerated charge recombination, and restricted interfacial reaction sites. Here, vertically aligned ZnO nanorods on a conductive nanoporous Cu (NPCu) scaffold were modified with low-abundance RE-containing surface species (RE = Ce, Sm, Er, Tm, and Yb). The notation RE(OH)₃@ZnO/NPCu is retained solely as an operational sample identifier and does not constitute a crystallographic or stoichiometric phase assignment. XRD resolves the ZnO/NPCu framework, EDS confirms the local presence of RE, and XPS identifies RE-dependent oxidation state and surface oxygen environments; collectively, these measurements do not uniquely establish RE(OH)₃ or distinguish hydroxide from oxide, oxyhydroxide, and other hydroxylated/adsorbed surface configurations. The distinguishing feature is a controlled five-RE comparison on one common ZnO/NPCu architecture, together with separate evaluation of NPCu under H₂O₂-free and H₂O₂-assisted conditions. Across three independent H₂O₂-free runs, the Er-modified sample achieved 96.61 ± 0.30% MO degradation within 9 min with k_obs = 0.3930 ± 0.0071 min⁻¹. Dosage screening identified 20 μL of 40 wt% H₂O₂ in 20 mL MO solution (approximately 13.5 mM) as a practical plateau dosage. Photolysis, dark, NPCu/H₂O₂, and catalyst-removal controls support an additional solid-catalyst-dependent Cu-associated peroxide contribution while not excluding trace homogeneous reactions. Three independent cycling experiments and post-cycle SEM/XRD/EDS support operational durability, although quantitative metal leaching was not measured. Tauc, Mott–Schottky, EIS, temperature-dependent kinetic, and scavenger results are interpreted as comparative descriptors or indirect evidence rather than direct proof of intrinsic band gaps, atom-specific carrier densities, or a unique microscopic mechanism. The AI-assisted component is restricted to exploratory contextualization because reference-grouped validation shows poor out-of-reference generalization. The conclusions are confined to the tested MO system. Full article

Magnesium alloys are attractive for temporary orthopaedic applications because of their biodegradability and favourable mechanical properties; however, their relatively rapid degradation under physiological conditions remains a challenge. In this study, the microstructural evolution, residual stress and electrochemical corrosion behaviour of WE43, a rare earth-containing magnesium alloy with yttrium, neodymium and zirconium as alloying elements, coated with titanium, were investigated as functions of deposition time using direct-current magnetron sputtering. Titanium coatings were deposited for 1, 1.5, 2 and 3 h, producing coating thicknesses of approximately 500, 650, 1000 and 1400 nm, respectively. Field-emission scanning electron microscopy, atomic force microscopy and grazing-incidence X-ray diffraction revealed progressive changes from fine-grained to dense and, subsequently, coarse-grained morphologies with increasing deposition time. The 2 h coating exhibited the largest crystallite size (27.17 ± 3.42 nm) and a moderate compressive residual stress of 605.3 ± 15.11 MPa. Potentiodynamic polarisation measurements showed that the 2 h coating produced the lowest corrosion current density (0.133 ± 0.026 mA/cm²) and calculated corrosion rate (2.93 ± 0.57 mm/year), representing a 67% reduction relative to independently measured, uncoated WE43 (8.87 ± 1.11 mm/year). The 3 h coating exhibited a higher compressive residual stress of 992.4 ± 21.7 MPa and a higher corrosion rate of 4.81 ± 0.74 mm/year, accompanied by localised microcracking after corrosion testing. Contact-angle measurements performed on the uncoated alloy and the 2 h coating showed an increase from 75.0 ± 2.1° to 83.0 ± 1.8°. Overall, the results indicated that corrosion performance was governed by the combined effects of coating morphology, crystallographic development and residual stress, with the 2 h deposition condition providing the most favourable balance under the present experimental conditions. Full article

We investigate the dynamic magnetic properties of an epitaxial Co₂₅Fe₇₅ thin film grown on a MgAl₂O₄ (001) substrate using broadband ferromagnetic resonance (VNA-FMR). The film exhibits a pronounced fourfold symmetry of the resonance field, characteristic of cubic magnetocrystalline anisotropy. By combining broadband and angular-dependent FMR measurements, we determined a spectroscopic g-factor of 2.083 ± 0.017, an effective magnetization of 1655 ± 31 kA/m, and a cubic magnetocrystalline anisotropy field of 28.25 ± 0.22 mT. Beyond the expected angular dependence of the resonance field, we experimentally demonstrated a pronounced flattening of the frequency versus magnetic field dependence for magnetic field direction located between the principal crystallographic axes. The effect, predicted by conventional ferromagnetic resonance theory but not previously investigated in detail, originates from the equilibrium rotation of the magnetization and is quantitatively described within the Stoner–Wohlfarth framework. For ${\varphi }_H$ = 34°, the resonance frequency remained nearly constant over the magnetic field interval from 6.8 to 26.2 mT at room temperature. A comparison with other (001)-oriented epitaxial magnetic films revealed that similar frequency plateaus can occur over frequencies ranging from 0.9 to 12.35 GHz and over magnetic field intervals from 0.5 to 63 mT. These findings establish a route toward microwave devices that are insensitive to fluctuations in the applied magnetic field and motivate further studies of spin-wave dynamics in this regime. Full article

The anisotropic mechanical behavior of laser powder bed fused (LPBF) IN718 results from the combined effects of crystallographic texture and grain morphology, although their individual contributions remain difficult to quantify. In this work, six representative volume elements (RVEs) are systematically compared using a unified EBSD–Dream3D–DAMASK crystal plasticity framework to separate the effects of texture and morphology. The microstructures include two EBSD-derived RVEs, two discretized columnar RVEs, and two discretized lamellar RVEs generated from identical orientation distributions. Predicted elastic moduli and yield strengths are validated against experiment, while Taylor factor analysis, directional effective grain size, slip compatibility, KAM, and local crystal plasticity fields are used to identify the governing deformation mechanisms. The results show that crystallographic texture predominantly controls the elastic response, whereas grain morphology governs the onset of plastic deformation. Lamellar RVEs provide the closest agreement with the experimental yield-strength anisotropy by reproducing the directional effective grain size, the connectivity of mechanically hard domains, and the resulting redistribution of stress and plastic strain. Furthermore, texture discretization preserves the dominant anisotropic trends while substantially reducing the computational cost of full EBSD reconstructions, establishing an efficient and physically meaningful framework for crystal plasticity simulations of LPBF materials. Full article

A solid solution treatment (SST) followed by single-stage aging (0–30 h, 140 °C) was performed on 7075 aluminum alloy specimens with longitudinal axes oriented at 0°, 45° and 90° to the rolling direction. The mechanical properties and microstructure were analyzed by tensile testing, optical microscope (OM), electron backscatter diffraction (EBSD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the average tensile strengths of the as-received 7075 aluminum alloy in the three directions were 304 MPa (0°), 295 MPa (45°) and 297 MPa (90°), respectively, with an anisotropy index (AI) of 0.97, indicating that the as-received samples exhibited negligible anisotropic mechanical properties. After SST, elongated grains with coarse size were formed, which is primarily attributed to the inheritance of the deformed fiber texture introduced by hot rolling. EBSD analysis of the 30 h aged specimens revealed that, within the same analyzed area, the total grain-boundary length in the 45° direction (16.4 cm) was much larger than that in the 0° (10.4 cm) and 90° (13.5 cm) directions. As the grain morphology showed no significant change between the SST and aged conditions, this grain-boundary distribution was representative of the microstructural state established during SST and persisted throughout the artificial aging process, contributing to the anisotropic mechanical properties. During artificial aging, prolonged aging time significantly facilitated the precipitation, with the 30 h aged sample exhibiting a significantly higher density of precipitates compared to the 6 h aged sample, leading to enhanced mechanical properties. The tensile strengths of the 30 h aged samples increased to 165 MPa, 236 MPa and 196 MPa in the three directions, respectively. Meanwhile, due to the fixed crystallographic orientation relationship between the precipitates and the Al matrix, the precipitates tended to form on specific planes, which enhanced the anisotropic mechanical properties. Consequently, the AI value increased from 0.97 (as-received) to 1.43 (30 h aged) with prolonged aging time. Full article

Aqueous zinc-ion batteries (AZIBs) are promising for scalable energy storage, yet their practical viability is constrained by zinc dendrite propagation, parasitic hydrogen evolution, and interfacial corrosion. Formulating electrolyte additives represents an economically viable strategy to address these long-standing bottlenecks by modulating the bulk solution and double-layer environments. Diverging from traditional composition-based classifications, this review categorizes recent additive strategies according to their underlying physical chemistry mechanisms. Specifically, we evaluate how these additives regulate the primary and secondary Zn²⁺ solvation sheaths, reconstruct the electric double layer (EDL) for crystallographic facet control, induce sacrificial or mineralized solid electrolyte interphases (SEIs), and establish responsive polymer confinement networks. Furthermore, we critically discuss the operational limitations, trade-offs, and parameter dependencies of these strategies under non-ideal, realistic conditions. Finally, prospective directions are outlined—focusing on descriptor-driven design, operando non-equilibrium characterizations, and performance validation under standard industrial metrics (e.g., low E/C ratios and high depths of discharge)—to provide an objective framework for advancing electrolyte optimization in practical zinc-based energy storage. Full article