Audio-frequency magnetotellurics (AMT) is one of the commonly used methods in geophysical exploration; however, its signal energy is relatively weak and easily submerged by various cultural noises, making denoising a critical step in AMT data processing. Currently, deep learning-based neural networks have achieved superior denoising performance compared to traditional methods in many fields, but in AMT denoising, the neglect of the sparsity characteristic of cultural noise results in degraded denoising performance. To enable the neural network to consider sparsity features during the denoising process and thereby enhance denoising accuracy, we adopt a convolutional neural network (CNN) as the network backbone and design a multilevel wavelet convolutional neural network (MWCNN) from the perspective of sparse representation. This network improves CNN blocks via shortcut connections and enhances feature transmission efficiency by replacing pooling layers and interpolation with wavelet transforms, thereby enabling the network to account for the sparsity of cultural noise, capture underlying noise spectral information and improve denoising performance. Furthermore, we discuss the influence of various network parameters on denoising performance. Finally, we validate the effectiveness of MWCNN in AMT denoising through comparative experiments on both synthetic and field AMT datasets against wavelet transform, bounded influence remote reference processing, data-driven tight frame, CNN and residual networks. Comprehensive evaluations based on signal-to-noise ratio, wavelet time-frequency spectra, denoised results and residuals, apparent resistivity and phase curves, error analysis, one-dimensional inversion results and Nyquist diagrams confirm the superiority of MWCNN for AMT denoising.

Cement production contributes 8 % of global industrial carbon emissions, underscoring the urgent need for innovative strategies to mitigate its environmental impact. Super Sulfated Cement (SSC) is a promising low-carbon alternative, but its carbon sequestration potential remains underexplored. This study integrates biochar and zeolite into SSC to create a near-zero-carbon, high-performance composite with hierarchical transport pathways, enhancing compressive and flexural strength by 63.1 % and 43.8 %. A comprehensive mechanism for the composite's carbon sequestration is proposed, leveraging biochar's tunnel-like channels and zeolite's nano-pores, along with molecular sieve properties, to create a hierarchical pore structure. This structure facilitates CO₂ transmission to greater depths and enables lateral diffusion, increasing carbonation by 37 % and CO₂ uptake to 41.7 kg·CO₂/kg. Its Global Warming Potential is 51.08 kg·CO₂/kg, reducing emissions by 87 % and 51.1 % compared to Ordinary Portland Cement (OPC) and SSC, respectively. This study provides an innovative, scalable pathway to developing ultra-low-carbon cementitious materials, leveraging industrial and agricultural waste to enhance environmental sustainability. The findings offer actionable insights for advancing carbon capture technologies and achieving negative-carbon cement production. Synopsis: Integrating biochar and zeolite into supersulfated cement enhances CO₂ sequestration, reducing lifecycle carbon emissions and addressing solid waste valorization and air quality challenges.

An in-depth exploration of the reaction kinetics and thermo-chemical behaviors of the raceway can offer practical insights for optimizing the operations of blast furnace (BF), thus achieving a more effective iron and steel production process. In this study, the dynamic characteristics and the flow, heat and mass transfer behaviors in the BF raceway were simulated by Discrete Element Method-Computational Fluid Dynamics (DEM-CFD) method at a particulate scale. The effects of coke size distribution and blast velocity on coke combustion characteristics, thermochemical behavior (particle volume fraction, raceway size, carbon loss, and coke temperature) and microscopic properties (coordination number (CN), contact normal force, pore structure and stress) were systematically investigated. The results show that as the blast velocity decreases or the size ratio λ (the largest coke particle size divided by the smallest coke particle size) increases, the raceway size becomes smaller, resulting in a smaller area of high oxygen (O₂) concentration and low carbon monoxide (CO) concentration in the raceway, and higher CO concentration in the packed bed. For the thermal-chemical behaviors, a lower blast velocity or a higher λ value decreases the number of particles experiencing mass loss, as well as increases individual particle mass loss, the average coke temperature and its variance. For microscopic properties, the CN distribution becomes wider as λ increases. The contact normal force in the coke bed with λ > 1 is significantly higher than that of λ = 1. As λ increases or blast velocity decreases, the pore distribution curve shifts to the left and the average pore volume decreases. The stress acting on the particles in the raceway increases with the blast velocity or λ. These new understandings of the complex reactive flow behaviors in the raceway will shed light on energy utilization and process optimization.

Non-oxidative coupling of methane is a promising route to obtain ethylene directly from natural gas. We synthesized siliceous [Fe]zeolites with MFI and CHA topologies and found that they display high selectivity (>90 % for MFI and >99 % for CHA) to ethylene and ethane among gas-phase products. Deactivated [Fe]zeolites can be regenerated by burning coke in air. In situ X-ray absorption spectroscopy demonstrates that the isolated Fe³⁺ centers in zeolite framework of fresh catalysts are reduced during the reaction to the active sites, including Fe²⁺ species and Fe (oxy)carbides dispersed in zeolite pores. Photoelectron photoion coincidence spectroscopy results show that methyl radicals are the reaction intermediates formed upon methane activation. Ethane is formed by methyl radical coupling, followed by its dehydrogenation to ethylene. Based on the observation of intermediates including allene, vinylacetylene, 1,3-butadiene, 2-butyne, and cyclopentadiene over [Fe]MFI, a reaction network is proposed leading to polyaromatic species. Such reaction intermediates are not observed over the small-pore [Fe]CHA, where ethylene and ethane are the only gas-phase products.

Aromatic aldehydes are important aromatic compounds for the flavour and fragrance industry. In this study, a parallel cascade combining aryl alcohol oxidase from Pleurotus eryngii (PeAAOx) and unspecific peroxygenase from the basidiomycete Agrocybe aegerita (AaeUPO) to convert aromatic primary alcohols into high-value aromatic aldehydes is proposed. Key influencing factors in the process of enzyme cascade catalysis, such as enzyme dosage, pH and temperature, were investigated. The universality of PeAAOx coupled with AaeUPO cascade catalysis for the synthesis of aromatic aldehyde flavour compounds from aromatic primary alcohols was evaluated. In a partially optimised system (comprising 30 μM PeAAOx, 2 μM AaeUPO at pH 7 and 40 °C) up to 84% conversion of 50 mM veratryl alcohol into veratryl aldehyde was achieved in a self-sufficient aerobic reaction. Promising turnover numbers of 2800 and 21,000 for PeAAOx and AaeUPO, respectively, point towards practical applicability.

Hydrocarbons are essential base chemicals as energy carriers and starting materials for chemical manufacture. So-called fatty acid photodecarboxylases (FAPs) represent interesting catalysts for the conversion of natural fatty acids into hydrocarbons thereby giving access to alkanes from renewable feedstock. Today, however, only few FAPs are known. In the current study we report a new FAP from the marine organism Micractinium conductrix (McFAP). In contrast to currently known FAPs McFAP exhibits high catalytic activity towards short and medium fatty acids. Recombinant expression and basic biochemical characterisation of this new member of the FAP family is reported.

Nano-copper sintering is one of new die-attachment and interconnection solutions to realize the wide bandgap semiconductor power electronics packaging with benefits on high temperature, low inductance, low thermal resistance and low cost. Aiming to assess the high-temperature reliability of sintered nano-copper die-attachment and interconnection, this study characterized the mechanical properties of sintered nano-copper particles using the high-temperature nanoindentation tests. The results showed that: firstly, the hardness and indentation modulus of the sintered nano-copper particles increased rapidly when the loading rate increased below 0.2 mN·s⁻¹ and then stabilized, and decreased with increased applied load up to 30 mN. Next, by extracting the yield stress and strain hardening index, a plastic stress–strain constitutive model at room temperature for sintered nano-copper particles was obtained. Finally, the high temperature nanoindentation tests were performed at 140 ˚C–200 ˚C on the sintered nano-copper particles prepared under different assisted pressures, which showed that a high assisted pressure resulted in the reduced temperature sensitivity of hardness and indentation modulus. The creep tests indicated that high operation temperature resulted in a high steady-state creep rate, which negatively impacted the creep resistance of sintered nano-copper particles, while the higher assisted pressure could improve the creep resistance.

In this paper, we report on surface-plasmon-resonance enhancement of the time-dependent reflection changes caused by laser-induced acoustic waves.We measure an enhancement of the reflection changes induced by several acoustical modes, such as longitudinal, quasi-normal, and surface acoustic waves, by a factor of 10-20.We show that the reflection changes induced by the longitudinal and quasi-normal modes are enhanced in the wings of the surface plasmon polariton resonance. The surface acoustic wave-induced reflection changes are enhanced on the peak of this resonance.We attribute the enhanced reflection changes to the longitudinal wave and the quasi-normal mode to a shift in the surface plasmon polariton resonance via acoustically induced electron density changes and via grating geometry changes.