Search Results (387)

Pure Fe soft magnetic composites (SMCs) hold a prominent position in cost-sensitive 10–100 kHz medium-to-low-frequency power devices owing to their low raw-material expenditure and high saturation magnetisation. Nevertheless, the inherently poor interparticle electrical resistivity permits the formation of contiguous conduction paths under alternating magnetic fields, giving rise to marked eddy-current dissipation and localised thermal accumulation. To surmount this limitation, the present work introduces γ-mercaptopropyltriethoxysilane (KH580)-functionalised silicon nitride (Si₃N₄) nanosheets as a multifunctional interfacial regulating layer that simultaneously establishes an electrically insulating barrier and a thermally conductive network on the surface of Fe particles. The structural integrity, surface chemical speciation and deposition behaviour of Si₃N₄-s nanosheets on Fe particles were systematically examined, and correlations among lamellar coverage completeness, interfacial bonding robustness and the coupled electrical–magnetic–thermal response were elucidated. The findings reveal that KH580 silanisation introduces a surface functional layer while preserving the parent α-Si₃N₄ crystal structure, and XPS analysis suggests possible local N–Fe and Fe–S interfacial interactions between Si₃N₄-s and the Fe surface. At a loading of 4 wt.% Si₃N₄-s, a comparatively continuous and uniform lamellar coating develops on the Fe particle surfaces. The corresponding Fe/Si₃N₄ SMCs exhibit the highest volume resistivity and a peak thermal conductivity of approximately 12.1 W·m⁻¹·K⁻¹, while maintaining a core loss of approximately 600.2 kW·m⁻³ at 50 mT and 100 kHz. These results indicate that the 4 wt.% specimen provides the most favourable overall balance among electrical insulation, magnetic response, core-loss suppression and thermal transport within the investigated composition range, furnishing a functionalised lamellar interfacial engineering strategy for performance advancement of low-cost Fe-based SMCs. Full article

In this study, amorphous Cu₈₆P_7.5Sn_4.5Ni₂(wt.%) fillers were prepared using the melt spinning method with different rolling speeds. The wetting performance of these fillers on copper was assessed under different temperatures and holding times. The results indicated that the fillers obtained through the melt spinning technique exhibited lower melting temperatures than the as-cast filler. When processed at a rolling speed of 20 m/s, the amorphization of the filler was not sufficient. The higher rolling speed promoted the formation of the amorphous structure. The amorphous filler produced at 30 m/s exhibited the narrowest melting range and the lowest liquidus temperature (622 °C), which is approximately 100 °C lower than that of the as-cast filler (725 °C). Furthermore, the amorphous fillers also exhibited better wettability toward copper under the same conditions. Notably, the amorphous filler fabricated at 30 m/s demonstrated superior wettability at 750 °C for 90 s. Owing to the optimal wettability of the amorphized filler toward copper and the lower liquid temperature, the brazed copper joint achieved a shear strength of 223.2 MPa. The fracture of the four joints occurred in the base metal. In this study, we explored the brazing performance of amorphized Cu-based fillers, facilitating the solid bonding of copper at lower brazing temperatures. Full article

This study includes an interpretable machine learning (ML) framework for predicting the shear contribution of externally bonded fiber-reinforced polymer (FRP) composites in reinforced concrete beams. A database including total 313 experimental specimens was collected from previous experimental research. The data screening process has been conducted using the Isolation Forest algorithm, resulting in 268 cleaned specimens. The cleaned database was divided into a training subset containing 214 specimens and an independent test set containing 54 specimens. The trained subset was enlarged into 5204 synthetic data using two advanced generative models including Wasserstein generative adversarial network and conditional Variational autoencoder (CVAE). Separate constrained monotonic neural network (CMNN) models were then trained on both datasets and WGAN-based CMNN achieved $R^2=0.9524$ for the synthetic training dataset and $R^2=0.9120$ for the independent test set, whereas the CVAE-based CMNN achieved corresponding values of 0.9632 and 0.9011. To improve practical applicability, response functions were extracted from WGAN-based CMNN and fitted with analytical expressions to derive a closed-form prediction equation. The proposed equation was independently validated using separate unseen test specimens, which were not used in CMNN training and achieved R² $=$ 0.79, RMSE $=$ 24.98 kN, MAE $=$ 19.65 kN, MAPE $=$ 21.72%, VAF $=$ 79.35%, U95 $=$ ±54.94 kN, SI $=$ 3.04, and PI $=$ 0.11. Compared with ACI 440.2R-17, CSA-S806.12, CNR-DT200 R1.2013, TR-55, and JSCE, the proposed equation showed superior accuracy while maintaining a transparent and design-oriented format. Full article

Thermochemical conversion of nitrogen- and sulfur-rich biomass-derived wastes, such as sewage sludge, algae, and agricultural residues, is a promising route for renewable fuel production and waste valorization. However, fuel-bound nitrogen can be released as NH₃, HCN, and HNCO, while sulfur species such as H₂S, SO₂, and COS accelerate catalyst deactivation and generate NO_x/SO_x precursors. Metal-loaded ZSM-5 catalysts are attractive for clean catalytic pyrolysis because they combine the MFI pore confinement and tunable Brønsted/Lewis acidity of ZSM-5 with the hydrogen transfer, dehydrogenation, cracking, redox, and sulfur-tolerance functions of metal species. This review critically summarizes recent advances in metal-loaded ZSM-5 catalysts for catalytic denitrogenation of biomass-derived solid wastes. The formation and migration of NH₃, HCN, HNCO, tar-N, and char-N are first discussed to clarify the chemical basis of fuel-N conversion. The effects of ZSM-5 pore structure, acid-site distribution, Si/Al ratio, hierarchical porosity, and synergy on adsorption, diffusion, C-N bond cleavage, heterocyclic-N ring-opening, aromatization, and nitrogen redistribution are then analyzed. Catalyst deactivation under realistic pyrolysis atmospheres is also highlighted, including coke deposition, metal sintering, framework dealumination, mineral poisoning, and H₂S/SO₂/COS-induced sulfur poisoning. Finally, future directions are proposed for designing multifunctional ZSM-5-based catalysts integrating denitrogenation activity, sulfur resistance, coke resistance, regenerability, and quantitative nitrogen/sulfur mass balance. Full article

Cu-Sn-Ti metallic-bonded CBN (Cubic Boron Nitride) abrasives are widely applied in the precision grinding of superhard materials. However, their high density and high toughness easily lead to poor grain protrusion and inadequate self-sharpening. In this work, ceramic glass powder was incorporated to modify the Cu-Sn-Ti binder, thereby fabricating composite-bonded CBN abrasive blocks with qualified mechanical properties and excellent self-sharpening performance. Flexural strength of abrasive blocks and microhardness of composite binders were measured; microstructure was characterized, phase composition was analyzed by XRD, and tribological tests were carried out between CBN blocks and silicon nitride abrasives. The results indicate that at glass powder contents of 2.94–10.22 wt%, the flexural strength of CBN blocks decreases by 32.5–89.4%, and binder microhardness reduces by 26.5–58.3%. At high brazing temperature, Ti and Cu from Cu-Sn-Ti alloy react with Si and Al in glass powder at the interface to form new phases including Ti₂O₃, Ti₅Si₃ and Ti(Cu,Al)₂, which facilitates favorable interfacial bonding among the alloy matrix, glass phase and CBN grains. With increasing glass powder content, the strength decline gradually slows down. The overall wear resistance of abrasive blocks declines. SEM observations on worn CBN blocks and their composite binders reveal the formation of micropores within glass-containing binders, accompanied by a shift in the fracture mode of CBN abrasives upon glass powder addition. Comprehensive experimental analysis indicates that the No.3 sample with 8.33 wt% glass powder possesses the optimal overall performance. Full article

Pt-Sn/C and Pt-Ru/C electrocatalysts were synthesized by a polyol method at nominal atomic ratios of 1:1, 2:1, and 3:1, and evaluated for the ethanol oxidation reaction (EOR) and ethylene glycol oxidation reaction (EGOR) in alkaline media. EDS confirmed compositions close to the nominal values, XRD evidenced fcc Pt-M alloy formation, and ADF-STEM revealed well-dispersed nanoparticles below 3 nm. Cyclic voltammetry showed that both Sn and Ru enhance activity relative to Pt/C: Pt-Sn_1:1 delivered the highest forward current density in the Sn series (1486 mA mg⁻¹_Pt for EOR; 2583 mA mg⁻¹_Pt for EGOR), whereas Pt-Ru shifted the onset to more negative potentials (down to −539 mV vs. SHE for EOR), with Pt-Ru_3:1 reaching 1858 (EOR) and 2434 mA mg⁻¹_Pt (EGOR). Chronoamperometry revealed higher current retention during EGOR than EOR for all catalysts, indicating fewer poisoning intermediates from ethylene glycol. DFT calculations of CO adsorption on 1:1 and 3:1 model surfaces rationalize the distinct roles of the two metals: Sn excludes CO from Sn sites at both compositions and weakens the Pt-CO bond by 0.602 eV at 1:1, while Ru weakens it moderately yet binds CO strongly at both compositions; the bifunctional supply of OH_ads by Ru, inferred from the more negative onset potentials, accounts for its higher activity. PDOS analysis links these trends to distinct Pt d-band modifications. Full article

A fly ash-based artificial aggregate with a compressive strength of >60 MPa was prepared via cement activation and alkali activation using >75% fly ash as the principal raw material. The mechanical properties of concrete prepared using this aggregate and the characteristics of the interfacial transition zone (ITZ) were compared with those of concrete containing natural aggregate. The results indicated that the compressive strength of concrete prepared using artificial aggregate was lower than that of concrete prepared using natural aggregate by about 19.0–27.6%. Scanning electron microscopy (SEM) revealed that the cement paste bonded tightly to the surface of the natural aggregate; the width of ITZ was 20–30 µm. The ITZ between the cement paste and the fly ash-based artificial aggregate exhibited a relatively loose structure at 28 d, with a width of 30–40 µm; however, the ITZ became narrower and denser at 90 d. EDS indicated that the principal hydration products were calcite crystals and C-S-H gel in the ITZ of natural aggregate concrete and artificial aggregate concrete. According to nanoindentation tests, for both cement pastes with natural and artificial aggregates, the elastic modulus of the ITZ at 28 d was >10 GPa, and it increased slightly at 90 d. The ITZ between the alkali-activated paste and limestone exhibited a relatively dense structure, with a width of 20–30 µm. The ITZ between the alkali-activated paste and the fly ash-based artificial aggregate exhibited a relatively loose structure with numerous pores at 28 d and had a width of 30–40 µm; however, the ITZ became narrower and denser at 90 d. The principal hydration products were N-A-S-H and C-A-S-H in the two kinds of aggregate concrete. Whether the alkali-activated paste contained natural aggregate or artificial aggregate, the elastic modulus of the ITZ at 28 d was 5–6 GPa, and it increased rapidly to >10 GPa by 90 d. The performance of ITZ is primarily influenced by the matrix materials, while also being influenced by aggregates and curing conditions. Qualitative and quantitative analyses revealed the formation mechanisms of artificial and natural aggregates in different matrices. Through continuous hydration and polymerization reactions, artificial aggregates gradually form narrower and denser interfacial transition zones with different matrices, especially in alkali-activated matrices. The continuously improved performance of the ITZ makes it less prone to forming cracks between the ITZ and the artificial aggregate. This study provides an important theoretical basis for the application of fly ash-based artificial aggregates, which can also be used to produce high-strength concrete. Full article

In this work, ZnO, WO₃, and MgO were doped into InSnZnO (ITZO) films via co-sputtering to enhance the mobility and stability of ITO-based thin film transistors (TFTs). ITZO, InSnWO (ITWO) and InSnMgO (ITMO) films were fabricated, and the effect of cation dopants on the oxygen stoichiometry in ITO films was investigated. We further discussed their influence on the electrical parameters of corresponding TFTs, including threshold voltage ($V_{\mathrm{th}}$), subthreshold swing (SS), and field-effect mobility (${\mu }_{\mathrm{FE}}$). Additionally, the positive and negative bias stress stability of these devices was evaluated. The results demonstrate that ITWO TFTs exhibit superior stability despite a reduction in mobility. This is attributed to the high electronegativity of W⁶⁺ and the strong W-O bonding, which effectively mitigate the formation of oxygen vacancies and suppress the adsorption of impurities at the back channel. The findings provide valuable insights for the material design of high-performance TFTs. Full article

Ready-to-eat sea cucumbers (RSC) cannot be preserved at room temperature due to autolysis, which is closely related to the instability of collagen resulting from the disruption of hydrogen bonds. To investigate the protective effect of N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) cross-linking against disruption of hydrogen bonds and its role in stabilizing RSC quality at room temperature, this study designed comparative experiments involving EDC/NHS cross-linking treatments with varying sequences of hydrogen bonds disruption. The results indicated that EDC/NHS positively affects the stabilization of the collagen structure in RSC. The various quality parameters of both groups of RSC that underwent cross-linking treatment before and after hydrogen bonds disruption were significantly better than those of the control group, which only experienced the breaking of hydrogen bonds. Notably, the Eb group, which underwent EDC/NHS cross-linking treatment prior to the disruption of the hydrogen bonds network, yielded even more favorable results. Preliminary analyses of textural properties and moisture content suggested that EDC/NHS helps delay the deterioration of RSC quality. The levels of soluble components and carbonyl groups indicated that prior cross-linking treatment is more effective in mitigating collagen degradation and oxidation. Differential scanning calorimetry revealed that the reduction in ΔH for the Eb group was only 2.4%. Furthermore, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy, examined from the perspectives of secondary and tertiary structures respectively, indicated that the cross-linking mechanism of EDC/NHS involves the formation of a more robust network of amide bonds, thereby preventing the disruption of hydrogen bonds and enhancing collagen stability, enabling it to better resist the cleavage of hydrogen bonds due to urea. The scanning electron microscope and Van Gieson’s staining techniques offer a clearer illustration of this point from a microscopic perspective. Moreover, molecular docking simulations have indicated the cross-linking mechanism of EDC/NHS at the atomic level, thereby establishing a scientific foundation for the potential application and development of EDC/NHS in room-temperature storage technologies for RSC. Full article

Nitrogen-containing molecules are fundamental components of astrobiology and play a key role in planetary environments. These species are particularly important because they may serve as key precursors to prebiotic molecules and contribute to chemical complexity. Reactions involving the highly reactive species methylidyne (CH) play a key role in complex organic formation in astrochemical environments, yet their interactions with nitriles such as acetonitrile (CH₃CN) remain relatively unexplored. In this work, we investigate the reaction network of CH + CH₃CN using high-level quantum-chemical calculations with RRKM and microcanonical transition-state theories to characterize the relative energies of reactants, intermediates, transition states, and products to identify the most favorable reaction pathways. Our results reveal that the most energetically favorable reaction channels proceed via barrierless CH addition to the triple CN bond and three-membered ring opening or CH insertion into a C-H bond, followed by a hydrogen elimination to form acrylonitrile (C₂H₃CN). This route highlights an efficient pathway toward a molecule of astrobiological interest. Acrylonitrile is particularly significant due to its stability and dual functional groups, which enable molecular growth complexity, both in planetary atmospheres and on surfaces, under astrochemical conditions. In addition to acrylonitrile, we identified a few other competing channels leading to an isonitrile species, which emphasizes a previously unexplored aspect of isomerization chemistry in the atmospheric planetary science. These isonitrile products, while less abundant, provide insight to the diversity of nitrogen-containing molecules that may form in environments such as Titan’s atmosphere or the interstellar medium. In these environments, acrylonitrile may serve as a reactive precursor that facilitates cyclization and molecular growth, which enables the formation of nitrogen-containing polycyclic aromatic molecules and N-heterocycles. This, in turn, contributes to the emergence of larger, more complex organic species relevant to prebiotic chemistry and potential origin of life in our solar system. Full article

A critical challenge in coalbed methane (CBM) extraction is the severe formation damage induced by conventional foam fracturing fluids, primarily through polymer retention and hydrogen bond disruption within the microporous matrix. This study presents a molecularly engineered, low-damage foam fracturing fluid that leverages synergistic nanoparticle–surfactant interactions to construct a robust interfacial pseudo-gel network, thereby decoupling effective fracture stimulation from adverse geochemical damage. The primary novelties of this work are threefold: (i) establishing a direct, quantitative cause-and-effect relationship between molecular interfacial architecture and reservoir protection, (ii) proposing a comprehensive “interfacial control” design paradigm that engineers viscoelasticity at the gas–liquid interface rather than through bulk polymer gelation, and (iii) demonstrating the complete decoupling of foam stability from formation damage in a polymer-free system. A systematic optimization methodology was employed: initial foaming agents were screened via the Waring Blender method, evaluating foam volume, half-life, and a derived comprehensive index; subsequently, synergistic binary surfactant mixtures and foam stabilizers were assessed to formulate the final systems. An optimized formulation, designated Foam System I (0.5 wt.% fluorosurfactant FK + 0.5 wt.% nano-silica RX + 2.0 wt.% KCl), demonstrated exceptional foam quality (Γ = 77.1 ± 1.5%) and kinetic stability (T₁/₂ > 350 s). Rheological characterization confirmed shear-thinning behavior conforming to the Herschel–Bulkley model (n = 0.38–0.42, R² > 0.98) and a structural recovery of 92.5 ± 2.1%—comparable to crosslinked polymer gels but achieved without any bulk viscosifier. Core flood analyses revealed that Foam System I induced a permeability damage of only 12.75 ± 1.8%, representing a 55–75% reduction compared to polyethylene glycol (PEG)-stabilized reference fluids (28.36–51.91%). X-ray photoelectron spectroscopy (XPS) correlated this enhanced reservoir compatibility with an 18.0 ± 2.0% suppression of oxygen-containing functional group adsorption, attributed to the steric hindrance conferred by the fluorinated hydrophobic moieties. This work establishes an “interfacial control” paradigm wherein gel-like stabilization for proppant transport is achieved via interfacial viscoelasticity rather than bulk polymer gelation, thereby directly addressing the critical imperative to harmonize fracture conductivity with reservoir protection in unconventional energy development. The findings are validated for shallow CBM reservoir conditions (25–35 °C), with extension to higher-temperature formations identified as a priority for future investigation. Full article

Floridoside (2-(α-D-galactosyl)glycerol) is a compatible solute synthesized in red algae, known for its antioxidant, immunostimulatory, anti-inflammatory, and antimicrobial properties. However, the lack of target validation has limited mechanistic insights into its bioactivity. Mitogen-activated protein kinase 13 (MAPK13), a member of the p38 mitogen-activated protein kinase (p38 MAPK) family with unique structural and functional characteristics, plays an important role in respiratory tissue remodeling, tumor progression, and immune responses, making it an attractive therapeutic target. This study identifies MAPK13 as a high-affinity target of floridoside. In vitro kinase assays validated that floridoside effectively inhibits MAPK13 with a nanomolar inhibitory concentration (IC50 = 13.59 nM), significantly outperforming the classical inhibitor BIRB-796. Unbiased molecular dynamics simulations and steered molecular dynamics simulations reveal that floridoside binds within the MAPK13 hinge region via an ATP-competitive mechanism. Binding free energy analysis combined with computational alanine scanning highlight Asp-113 as a primary interaction hotspot, stabilized by persistent hydrogen bonds with Pro-108 and Met-110. Despite stable complex formation, the flexibility of the glycosidic bond and glycerol tail may limit binding persistence. Comparative simulations with 2-α-glucosylglycerol (2αGG), a stereoisomer of floridoside, demonstrate the sensitivity of MAPK13 binding to subtle structural variations. These findings elucidate the atomistic basis for floridoside’s bioactivity and establish it as a candidate natural scaffold for the design of isoform-selective p38 inhibitors. Full article

Cu is widely employed in power device packaging materials owing to its excellent electrical and thermal conductivity, coupled with economic viability. Sintered Cu currently stands as one of the representative interconnect materials in power device packaging. However, it is prone to oxidation during bonding, requires extended bonding times, and needs considerable pressure. Transient liquid phase bonding (TLPB) technology is regarded as a viable solution for power device packaging, enabling high-melting-point, high-strength, and thermally stable connections at low temperatures. Cu and Sn are widely employed metallic materials in common TLP systems. The Sn-coated Cu particle increases the effective reaction area between Cu and Sn, accelerating the formation of intermetallic compounds (IMCs) and reducing bonding time. Sn-coated Cu particles were produced in this study by chemically plating Sn onto micron-sized Cu powder surfaces. The effects of flux content, bonding time, and applied pressure on joint shear strength were investigated. Results indicate that as flux content increases, the shear strength of the solder joints initially increases and then decreases. The shear strength of the solder joint gradually decreased with increasing bonding time, but no significant change was observed when the time exceeded 20 min. Increasing the applied pressure significantly enhanced the shear strength of the solder joint. The shear strength of the solder joint at 10 MPa is 90.2% higher than at 5 MPa. Full article

Herein, we report the rational design of an A-SnO₂/Si@N-CNT nanocomposite, fabricated via facile ball milling followed by high-temperature annealing. In this design, surface-modified SnO₂ (A-SnO₂) serves as the primary active framework, silicon nanoparticles are introduced to enhance overall capacity, and nitrogen-doped carbon nanotubes (N-CNTs) provide a conductive and mechanically resilient network. The incorporation of silicon nanoparticles and N-CNTs into A-SnO₂ facilitated the formation of strong Si–C and Si–O–Sn bonds, thereby improving electrical conductivity and structural stability and reinforcing interfacial interactions between the active materials and the conductive CNT matrix, resulting in superior electrochemical performance. Morphological analysis confirmed that the composite maintained structural stability without severe cracking after 100 cycles at 100 mAh g⁻¹. The electrode delivered reversible capacities of 1002 and 622 mAh g⁻¹ at 0.1 and 0.5 A g⁻¹, with capacity retentions of 78.7% and 73.17%, respectively. Even at 1.0 A g⁻¹, a stable capacity of 441 mAh g⁻¹ with 80.96% retention was achieved. These findings demonstrate the effectiveness of coupling surface-modified SnO₂ with Si- and N-doped carbon frameworks for advanced lithium-ion battery anodes. Full article

The reaction of the HS^•/S^•− radical (pKa ~3.4), generated selectively from H₂S by γ-irradiated N₂-flushed aqueous solutions at pH 5, with purine nucleosides (dG or dA), a 10-mer double-stranded oligodeoxynucleotide (ds-ODNs), and calf thymus (ct) DNA was investigated, under various experimental conditions. Concurrent quantification of the four purine 5′,8-cyclo-2′-deoxynucleosides (cPu) and two 8-oxo-7,8-dihydro-2′-deoxypurines (8-oxo-Pu) by LC-MS/MS analysis using isotopomeric internal standards was achieved. The formation of 8-oxo-Pu is several tens of times larger than cPu. Mechanistic schemes for the formation of the two product groups are proposed. Hydrogen atom abstraction from C5′–H by S^•− produces the cPu via cyclization of the C5′ radical onto C8, forming a new covalent bond, C5′–C8. The unexpected formation of 8-oxo-Pu should be mechanistically more complex. We propose that an S^•− (coupled with H⁺) adds to the base rings, followed by the elimination of HS⁻ to form the corresponding radical cation; subsequent reactions with H₂O and radical disproportionation with another S^•− lead to 8-oxo-Pu. A comparison of S^•− with the available literature data for HO^• reactivity towards ct-DNA in de-oxygenated aqueous solutions is also presented. Before the present findings, cPu lesions were attributed exclusively to HO^• reactivity toward ct-DNA. The reaction of the thiyl radical (HOCH₂CH₂S^•) with ct-DNA was also investigated, yielding results similar to those of S^•− obtained under comparable experimental conditions. Our results contributed to a better understanding of DNA damage induced by reactive sulfur species (RSS), particularly the formation of purine lesions and the relative abundance of cPu versus 8-oxo-Pu. Full article