SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3857-1
High-Be Cu-Be alloys exhibit dendritic segregation and brittle β/γ phases, complicating processing and applications. This study investigates the influence of cooling path on eutectoid transformation, microstructure, and mechanical properties in Cu-2.8Be and Cu-3.8Be alloys. A two-step homogenization treatment effectively eliminates segregation and suppresses the formation of harmful acicular phases. Diffusion-kinetic and thermodynamic analyses demonstrate that both the initial temperature and cooling rate determine eutectoid morphology and extent. Crystallographic and Eshelby-based analyses reveal that the β → γ transformation involves an isotropic contraction of ~3.9%, producing much lower strain energy than the anisotropic β → α transformation (~28.5% expansion and ~9.2% contraction), thus explaining the preferential nucleation of γ. Rapid cooling promotes incomplete eutectoid decomposition along grain boundaries, forming fine α/γ lamellae with interlamellar spacing down to ~7 nm. Lattice strain analysis confirms considerable distortions at α/γ interfaces (ε_xx = 0.0167, ε_yy = 0.0095). The mechanical incompatibility and high internal strain at these interfaces cause stress concentration and crack initiation. This work establishes a process-microstructure-property-mechanism framework essential for controlling the performance of high-Be Cu-Be alloys.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3993-y
Conventional liquid-phase in-situ synthesis of Cu-TiB2 composites often suffers from coarse and non-uniformly distributed reinforcements, stemming from insufficient understanding and control over the in-situ nucleation and growth mechanisms of TiB2 particles. This study introduces a novel melt dispersion-turbulent mixing (MDTM) in-situ reaction technology to fabricate high-performance Cu-TiB2 composites. The MDTM strategy synergistically refines reaction micro-regions by reducing the initial melt droplet size via melt dispersion while enhancing solute convection via turbulence, promoting high-density nucleation and refinement of TiB2 particles. Based on turbulence characteristics and in-situ reaction kinetics, we optimized the melt disperser parameters and established a quantitative model linking particle size to disperser rotation speed and reactant solute concentration. It was found that disperser rotation speed governs three distinct nucleation and growth mechanisms for TiB2 particles. Low-density nucleation at low disperser rotation speeds (0–50 r/min) leads to coarse TiB2 particles. At medium rotation speeds (100–150 r/min), the refinement of micro-regions in the dual-melt reaction achieves high-density TiB2 nucleation. Conversely, at high rotation speeds (150–200 r/min), intense turbulence weakens the nucleation driving force and induces TiB2 particle coarsening. This work provides new insights into liquid-phase in-situ reaction mechanisms and offers a novel, controllable route for fabricating high-performance micro/nano particle-reinforced metal matrix composites.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026012605
Synthetic phenolic antioxidants (SPAs) are widely used, leading to environmental contamination and human exposure. However, studies on their effects on adipocyte differentiation and underlying mechanisms, particularly for emerging SPAs, are limited. This study evaluated the impacts of 4-tert-octylphenol (4-t-OP) and three novel antioxidants (AO 3114, AO 1135, AO 702) on adipogenesis using the mouse 3T3-L1 preadipocyte differentiation model. Lipid staining, triglyceride measurement, differentiation-related gene expression analysis, and transcriptomic approaches were employed. All four SPAs significantly promoted differentiation of 3T3-L1 cells into mature adipocytes and upregulated expression of peroxisome proliferator-activated receptor gamma (Pparγ) and mature adipocyte marker genes. Transcriptomic analysis revealed differential effects on gene transcription during early differentiation. GO and KEGG enrichment analyses indicated that these SPAs promoted adipogenesis by enhancing energy metabolism and protein synthesis, as well as regulating PPAR and other signaling pathways. In conclusion, the tested SPAs promote adipogenesis and disrupt lipid metabolism through distinct mechanisms, suggesting long-term exposure may cause metabolic disorder risks and pose a public health threat.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2026031101
Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is widely used for molecular characterization of complex organic matter due to its ultrahigh resolution and mass accuracy. In atmospheric and natural organic matter studies, signal intensity is often used as a proxy for relative abundance or combined with a single internal standard for semi-quantitative comparison. Such practices assume uniform response across species of different mass-to-charge ratios (m/z); however, electrospray ionization (ESI), ion transport, and space-charge effects within the ICR trap can introduce mass-dependent biases. This study systematically evaluated mass discrimination effects on fatty acid analysis using a 9.4 T ESI-FT-ICR-MS, employing C12–C30 straight-chain saturated fatty acids, three deuterated internal standards, and three concentration levels. Results showed: (1) Absolute intensities of fatty acids and internal standards were not linearly proportional to concentration; as fatty acid concentration doubled, intensity increases were non-proportional, while internal standard intensities declined by up to 53% despite constant concentration. At equal concentrations, intensity decreased markedly with molecular weight—triacontanoic acid (C30) was ~40 times lower than lauric acid (C12), indicating severe underestimation of high-molecular-weight species. (2) Response ratios of fatty acids to internal standards versus concentration ratios exhibited good linearity (R² > 0.9). The derived deviation coefficients (F) increased exponentially with m/z (R² > 0.999), reaching >50 for C30. (3) Application to PM2.5 fatty acids showed that after F correction, abundances of long-chain fatty acids (C20–C30) increased 3.6-fold, and the carbon preference index (CPI) shifted from 1.8 (fossil fuel source) to 3.4 (higher plant source), demonstrating that neglecting mass discrimination leads to misidentification of sources. These findings underscore the necessity of systematic evaluation of mass discrimination effects in ultrahigh-resolution mass spectrometry for accurate organic composition and source apportionment.