ABSTRACT In this review, we propose a term, ‘optochemistry’, a combination of optics and chemistry. In comparison with photochemistry that relates to photon aspect of light, optochemistry is a chemistry that relates to optics in which light is considered as wave or beam. Optochemistry and its applications include optical fibers, optical waveguides, organic resonators, lasers, organic polaritonics, light-matter strong coupling, optical vortices, optical manipulation, ultra-high sensitivity optical sensing, and so forth, that relate to the characteristics of molecules and polymers with chirality, spins (radicals), helices, supramolecules, semiconductors etc. The authors expect that the new-and-old optics and chemistry meet and generate a new field of research, and the term ‘optochemistry’ will gain acceptance to the society in the field of science and technologies.

ABSTRACT Functionally graded materials (FGMs) exhibit continuous property variations that enable unique functionalities and provide efficient platforms for systematic property optimization. Here, we report the fabrication of FGMs with graded structural heterogeneity by annealing an amorphous metal under a one-dimensional temperature gradient. Using lock-in thermography (LIT), we spatially mapped transverse thermoelectric conversion with high spatial and temperature resolution. A pronounced non-monotonic response was observed, with the maximum anomalous Ettingshausen effect, a transverse charge-to-heat conversion in magnetic materials, appearing in the atomic-heterogeneity regime well before crystallization. This enhancement was not captured by conventional structural or longitudinal transport measurements, highlighting the exceptional sensitivity of transverse thermoelectric phenomena to subtle structural variations. Structural analyses using scanning transmission electron microscopy and atom probe tomography revealed Fe-based crystalline alloys and Cu nanoclusters embedded in the amorphous matrix, whose heterogeneity accounts for the enhanced response. These findings establish temperature-gradient-annealed FGMs, combined with LIT, as a powerful methodology for probing structural-heterogeneity-driven transverse electron transport and for designing high-performance flexible materials.

ABSTRACT Although simulation studies focused on polymer network rupture remain relatively limited compared to the broader field, recent advances have enabled increasingly nuanced investigations that bridge molecular structures and macroscopic failure behaviors. This review surveys the evolution of molecular simulation approaches for polymer network rupture, from early studies on related materials to state-of-the-art methods. Key challenges — including mismatched spatial and temporal scales with experiments, the validity of coarse-grained models, the choice of simulation protocols and boundary conditions, and the development of meaningful structural descriptors — are critically discussed. Special attention is paid to the assumptions underlying universality, limitations of current methodologies, and the ongoing need for theoretically sound and experimentally accessible network characterization. Continued progress in computational techniques, model development, and integration with experimental insights will be essential for a deeper, predictive understanding of polymer network rupture.

ABSTRACT The influence of relative density on the dynamic mechanical behavior of porous titanium under combined high-temperature and high-strain-rate conditions is investigated. Using validated finite element models based on three-dimensional Voronoi tessellations, simulations of Split Hopkinson Pressure Bar (SHPB) tests were conducted across a range of relative densities (0.3–0.6), strain rates (3000–8000 s−1), and temperatures (25–550 °C). Results demonstrate that increasing relative density from 0.3 to 0.6 increases the yield stress by 511.8%, attributed to enhanced cell-wall interactions and a concomitant shift in deformation mechanisms. Strain rate strengthening and thermal softening compete, with high relative density amplifying both effects. The stress-strain curves exhibit three characteristic regimes: linear elasticity, plateau, and densification, where higher relative density shortens the plateau stage and advances densification onset. Low-density specimens (ρ r < 0.5) undergo layer-by-layer collapse dominated by cell-wall bending, while high-density specimens (ρ r > 0.5) exhibit matrix-dominated triaxial compression with reduced localized deformation. Quantitative analysis of regionally partitioned displacement confirms that strain rate intensifies the magnitude of localized deformation, whereas temperature primarily induces global softening. These insights provide a predictive framework for designing porous titanium architectures with tailored dynamic performance in extreme environments.

ABSTRACT Co2FeSi is considered a half-metallic ferromagnet and a Weyl semimetal, however, its predicted properties have been shown to be heavily influenced by how the on-site Coulomb interaction is incorporated, which remains controversial. In this study, we measure the anomalous Nernst conductivity (α xy ) and anisotropic magnetoresistance (AMR) effect of a Co2FeSi thin film from low temperature to room temperature, and compare the results with those of first-principles calculations using different values for on-site Coulomb interaction at the Co site (U Co). Our measurements reveal that α xy is less than 0.1 A m−1 K−1 at room temperature and decreases slightly with the temperature. The observed values of α xy are more than one order of magnitude smaller than the predictions unless a small but finite U Co is incorporated. The AMR effect exhibits a notable sign change from negative to positive with increasing temperature, which is inconsistent with the predicted band structure calculated using a large U Co value. By combining these experimental observations with first-principles calculations, we estimate that the appropriate U Co value is approximately 1–2 eV. Our findings provide valuable insight into the correlation effect in Co2FeSi, emphasizing the critical role of the on-site Coulomb interaction in accurately describing the transport properties of Co-based Heusler alloys.

ABSTRACT The humid and highly dynamic milieu of the oral cavity and gastrointestinal tract poses formidable challenges to the precise localization and functionality of drugs and materials. Consequently, materials endowed with intrinsic wet adhesion properties hold great promise for the treatment of oral and gastrointestinal disorders. To a certain extent, the evolution of biomaterials has propelled progress in clinical diagnostics and therapeutic modalities. Wet-adhesive hydrogels, which can adapt to the moist and variable conditions of the digestive tract, display a spectrum of favorable biological attributes, such as antibacterial, anti-inflammatory, antioxidant, and hemostatic effects. These properties render them invaluable in the precision treatment of oral and gastrointestinal diseases. In this review, we scrutinize the adhesion mechanisms of wet-adhesive hydrogels and explore how their biological functions enable them to function efficiently within the gastrointestinal environment.

ABSTRACT We utilized twin network analysis of polycrystalline materials through graph theory to visualize microstructures and examine the behavior of dislocation cluster generation in multicrystalline silicon grown by directional solidification. This approach allows for a rapid and statistical understanding of microstructures and their correlations by representing these features and their changes as network graphs. Our analysis revealed that dislocation clusters are formed at asymmetric Σ27a grain boundaries, which result from a specific twinning process. Gaining this knowledge is expected to assist in identifying grain boundary groups that can minimize the formation of dislocation clusters.

ABSTRACT Ensuring the safety of researchers by protecting them from exposure to toxic gases in laboratories is of paramount importance. This study investigated the effectiveness of using high-surface-area MgO to remove HCl under atmospheric conditions. Two types of MgO were synthesized through the thermal decomposition 1-1-1, Tennodai, Tsukuba, of Mg(OH)2 and MgC2O4·2 H2O. HCl diluted with air passed through both MgO samples, and the amounts of HCl removed and morphological changes in the samples were compared. No significant differences in surface area or crystallinity were observed with the decomposition temperatures. X-ray diffraction analysis showed that the sample prepared from MgC2O4·2 H2O reacted with HCl immediately upon introducing HCl gas. In contrast, the sample obtained from Mg(OH)2 exhibited only MgO peaks, even 30 min after the introduction of HCl gas. Microscopic analysis revealed that the samples derived from Mg(OH)2 showed no significant changes in shape after the reaction, whereas the MgO prepared from MgC2O4·2 H2O exhibited substantial changes in overall shape. No correlation was observed between the surface area and the amount of HCl removed. When MgO is prepared from MgC2O4·2 H2O, the reaction occurs in the bulk material, whereas when MgO is prepared from Mg(OH)2, the reaction hardly progresses after HCl adsorbs onto the MgO surface. The order of magnitude of HCl removal was consistent with the base catalytic activity of the decomposition of diacetone alcohol to acetone. These results suggest that, compared with MgO obtained from Mg(OH)2, MgO derived from MgC2O4·2 H2O generates more active sites, resulting in the reaction with HCl from surface to progress into bulk.

ABSTRACT Hydrogen-assisted (HA) fatigue crack growth (FCG) occurs in ferritic steels, wherein H-dislocation interaction plays a vital role. We aim to model the HAFCG mechanism based on the obstruction of dislocations within the crack tip zone. Our modeling framework is as follows: H is condensed into crack tip and trapped by dislocations; these H significantly decrease dislocation mobility; stress relief via crack blunting is suppressed; localized brittle fracture triggers HAFCG. This model was substantiated experimentally in H2 gas at various load frequencies and temperatures. Theoretical formulations were established considering the thermal equilibrium of H-trapping and dislocation breakaway from the H atmosphere.