Search Results (739)

A series of Cu-MnO_x/GF catalytic electrodes, with graphite felt (GF) pretreated via microwave modification as the catalyst carrier, were prepared under various hydrothermal conditions and characterized using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), X-ray photoelectron spectroscopy (XPS), N₂ adsorption–desorption, and Raman spectroscopy. The catalytic oxidation activity of catalytic Cu-MnO_x/GF electrodes toward toluene was evaluated in an all-solid-state electrocatalytic device under mild operating conditions. The evaluation results demonstrated that the microwave-modified catalytic electrode exhibited high electrocatalytic activity toward toluene oxidation, with Cu-MnO_x/700W-GF exhibiting significantly higher catalytic activity, indicating that an increase in catalyst loading capacity can promote the removal of toluene. Only CO₂ and CO were detected, with no other intermediates observed in the reaction process. Moreover, the catalytic effect was significantly affected by the relative humidity. The catalytic oxidation of toluene can be fully realized under a certain humidity, indicating that the conversion of H₂O to strongly oxidizing ·OH on the catalytic electrode is a key step in this reaction. Full article

The topic of environmental pollution by petroleum products is highly relevant due to rapid urbanisation, including industrial development, road infrastructure and fuel distribution. Potential threat areas include refineries, fuel stations, pipelines, warehouses and transshipment bases, as well as sites affected by accidents or fuel spills. This study aimed to determine whether organic and mineral materials could mitigate the effects of diesel oil pollution on the soil’s trace element content. The used materials were compost, bentonite and calcium oxide. Diesel oil pollution had the most pronounced effect on the levels of Cd, Ni, Fe and Co. The levels of the first three elements increased, while the level of Co decreased by 53%. Lower doses of diesel oil (2.5 and 5 cm³ per kg of soil) induced an increase in the levels of the other trace elements, while higher doses caused a reduction, especially in Cr. All materials applied to the soil (compost, bentonite and calcium oxide) reduced the content of Ni, Cr and Fe. Compost and calcium oxide also increased Co accumulation in the soil. Bentonite had the strongest reducing effect on the Ni and Cr contents of the soil, reducing them by 42% and 53%, respectively. Meanwhile, calcium oxide had the strongest reducing effect on Fe and Co accumulation, reducing it by 12% and 31%, respectively. Inverse relationships were recorded for Cd (mainly bentonite), Pb (especially compost), Cu (mainly compost), Mn (mainly bentonite) and Zn (only compost) content in the soil. At the most contaminated site, the application of bentonite reduced the accumulation of Pb, Zn and Mn in the soil, while the application of compost reduced the accumulation of Cd. Applying various materials, particularly bentonite and compost, limits the content of certain trace elements in the soil. This has a positive impact on reducing the effect of minor diesel oil pollution on soil properties and can promote the proper growth of plant biomass. Full article

It is of great importance to explore how plants respond to excess accumulation of Cu and Ni in soil, yet the mechanisms by which Euphorbia marginata, a common ornamental plant in China, responds to heavy metal stress remain unclear. In this study, E. marginata seedlings were subjected to CK, Ni 500 mg/kg, and Cu 900 mg/kg, with Ni-Cu combined stress, and their growth, physiological indexes, heavy metal accumulation, and their corresponding gene expression were evaluated after 45 d. The results showed that the two heavy metals mainly accumulated in plant roots and severely inhibited root growth, while the combined stress promoted the accumulation of heavy metals to a small extent. Either Cu or Ni stresses inhibit photosynthetic pigment synthesis as well as activate antioxidant and osmoregulatory systems, but there are differences in their effects. Combined stress has a synergistic stress effect, severely damaging the cell membrane structure and leading to dysregulation of antioxidant and osmoregulatory systems. The expression of CDPK, CaMCML, MEKK3/6 signaling factors, UFGT, and COMT was severely suppressed under the combined stresses of Cu and Ni compared to the single stress of both. These results provide evidence of a specific defense response to heavy metal stress in E. marginata, which could help guide new research efforts and support the development of strategies for phytoremediation using E. marginata. Full article

The efficient simultaneous removal of NO_x and CO from sintering flue gas under low-temperature conditions (110–180 °C) in iron and steel enterprises remains a significant challenge in the field of environmental catalysis. In this study, we present an innovative strategy to enhance the performance of CuSmTi catalysts through silver modification, yielding a bifunctional system capable of oxygen structure regulation and demonstrating superior activity for the combined NH₃-SCR and CO oxidation reactions under low-temperature, oxygen-rich conditions. The modified AgCuSmTi catalyst achieves complete NO conversion at 150 °C, representing a 50 °C reduction compared to the unmodified CuSmTi catalyst (T_100% = 200 °C). Moreover, the catalyst exhibits over 90% N₂ selectivity across a broad temperature range of 150–300 °C, while achieving full CO oxidation at 175 °C. A series of characterization techniques, including XRD, Raman spectroscopy, N₂ adsorption, XPS, and O₂-TPD, were employed to elucidate the Ag-Cu interaction. These modifications effectively optimize the surface physical structure, modulate the distribution of acid sites, increase the proportion of Lewis acid sites, and enhance the activity of lattice oxygen species. As a result, they effectively promote the adsorption and activation of reactants, as well as electron transfer between active species, thereby significantly enhancing the low-temperature performance of the catalyst. Furthermore, in situ DRIFTS investigations reveal the reaction mechanisms involved in NH₃-SCR and CO oxidation over the Ag-modified CuSmTi catalyst. The NH₃-SCR process predominantly follows the L-H mechanism, with partial contribution from the E-R mechanism, whereas CO oxidation proceeds via the MvK mechanism. This work demonstrates that Ag modification is an effective approach for enhancing the low-temperature performance of CuSmTi-based catalysts, offering a promising technical solution for the simultaneous control of NO_x and CO emissions in industrial flue gases. Full article

The utilization of the widely distributed saline–alkali lands by planting forage grasses is a hot topic. However, the promotion of plant growth remains a great challenge during the exploration of this stressful soil. While halotolerant bacteria are beneficial for plants against saline–alkali stress, their stable colonization on plant roots should be further strengthened. In this study, we investigated the effect of moss biochar on the root colonization of the exogenous halotolerant Halomonas salifodinae isolated from saline lake sediments. During the incubation with the bacteria, the biochar strongly bound the bacterium and induced biofilm formation on the biochar surface. When the biochar and the bacterium were added into the culturing soil of the forage grass Medicago sativa, the biochar remarkably assisted the root binding and biofilm formation of this bacterium on the plant roots. Under the biochar–bacterium combined treatment, the numbers of total bacteria, halotolerant bacteria, and nitrogen-fixing bacteria increased from 10^5.5 CFU/g soil to 10^7.2 CFU/g soil, from 10^4.5 CFU/g soil to 10^6.1 CFU/g soil, and from 10^4.7 CFU/g soil to 10^6.3 CFU/g soil, respectively. After 30 days of culturing, the biochar and the bacterium in combination increased the plant height from 10.3 cm to 36 cm, and enhanced the accumulation of chlorophyll a, reducing sugars, soluble proteins, and superoxide dismutase in the leaves. Moreover, the combined treatment increased the activity of soil enzymes, including peroxidase, alkaline phosphatase, and urease. Meanwhile, the levels of various cations in the rhizosphere soil were reduced by the combined treatment, e.g., Na⁺, Cu²⁺, Fe²⁺, Mg²⁺, Mn²⁺, etc., indicating an improvement in the soil quality. This study developed the biochar–halotolerant bacterium joint strategy to improve the yield of forage grasses in saline–alkali soil. Full article

Cu-Ni-Si is a prominent example of a high-end lead frame copper alloy. The enhancement of strength without compromising electrical conductivity has emerged as a prominent research focus. The evolution of the precipitates exerts a significant influence on the strength and electrical conductivity of Cu-Ni-Si-Co-Mg alloys. In this paper, the effects of aging treatment and Mg addition on the properties and precipitates of cold-rolled Cu-Ni-Si-Co alloys were studied. The precipitate was (Ni, Co)₂Si and was in a strip shape. During aging, precipitation and coarsening of the (Ni, Co)₂Si precipitates were observed. In the early stage of aging, a significant number of fine (Ni, Co)₂Si precipitates were formed. These fine precipitates could not only have a better effect of precipitation strengthening, but also impeded the dislocation movement, thus increasing the dislocation density and improving the dislocation strengthening effect. However, the coarsening of the precipitates became dominant with increasing aging times. Therefore, the strengthening effect was weakened. The addition of 0.12% Mg promoted finer and more diffuse precipitates, which not only improving the tensile strength by 100–200 MPa, but also exhibiting a smaller effect on the electrical conductivity. However, further increases in Mg contents resulted in a significant decrease in electrical conductivity, with little change in the tensile strength. The optimum amount of added Mg was 0.12%, and the aging parameters were 300 °C and 20 min. Full article

Background: Exploring new strategies to improve type 2 diabetes mellitus (T2DM) is one of the frontier hotspots in the field of healthy food. Flavonoid–metal complexes have become one of the research hotspots in the field of health foods due to their unique structural and functional properties. Methods: In this study, the effect of hesperetin–copper(II) complex [Hsp–Cu(II)] on the gut microbiota of mice with T2DM was investigated by the 16S rRNA high-throughput sequencing. Results: The analyses of α and β diversity indicated that the richness and diversity of gut microbiota in the T2DM mice decreased and the community structure was significantly different from the normal mice. Hsp–Cu(II) increased the abundances of the beneficial bacteria (Lactobacillus, Ligilactobacillus, Romboutsia, Faecalibaculum, and Dubosiella), and decreased the amounts of the harmful bacteria (Desulfobacterota, Corynebacterium, and Desulfovibrio) and the ratio of Firmicutes/Bacteroidetes (from 44.5 to 5.8) in the T2DM mice, which was beneficial for regulating the composition of intestinal microbiota. The linear discriminant analysis effect size analysis showed that the intervention of Hsp–Cu(II) made the short-chain fatty acid (SCFA) producers (o_Lachnospirales, f_Lachnospiraceae, g_Faecalibaculum, g_Romboutsia, and g_Turicibacter) and the lactic acid bacteria producers (f_Lactobacillaceae and o_Lactobacillales) highly enriched, and the production of its metabolite SCFAs (acetic acid, propionic acid, butyric acid, and valeric acid) were increased in a dose-dependent manner, promoting the SCFA metabolism. Conclusions: Hsp–Cu(II) may improve glucose metabolic disorders and alleviate T2DM by modulating gut microbiota composition, promoting probiotics proliferation and SCFAs production, restoring intestinal barrier integrity, and suppressing local inflammation. These research findings may provide a theoretical basis for developing Hsp–Cu(II) as a new hypoglycemic nutritional supplement, and offer new ideas for the dietary food nutritional regulation to alleviate T2DM. Full article

This research aimed to evaluate the effects of different concentrations of neodymium (Nd: 0, 2.885, 5.770, and 8.655 mg L⁻¹, referred to as Nd0, Nd1, Nd2, and Nd3, respectively) and zinc (Zn: 0.1, 0.2, and 0.3 mg L⁻¹, designated as Zn1, Zn2, and Zn3, respectively), as well as their combined interaction, on the nutritional content of lettuce (Lactuca sativa) cv. Ruby Sky. The seedlings were grown in a floating hydroponic system under greenhouse conditions. After 48 days of treatment, leaf samples were collected to determine their nutrient content. Leaf contents of N, P, Ca, Mg, S, Fe, Mn, B, and Nd were higher with the Nd1 (2.885 mg Nd L⁻¹ + Zn1 (0.1 mg Zn L⁻¹) treatment. The Nd3 (8.655 mg Nd L⁻¹) + Zn3 (0.3 mg Zn L⁻¹) treatment significantly increased the leaf contents of Cu and Zn. The K content was higher in leaves treated with Nd2 (5.770 mg Nd L⁻¹) + Zn3 (0.3 mg Zn L⁻¹). The joint application of Nd and Zn had positive effects on the nutrition of hydroponic lettuce, and Nd promoted the biofortification of lettuce by increasing leaf Zn content. Full article

This study investigates the effects of molybdenum (Mo) additions on the crystallization behavior and soft magnetic properties and of Fe_82-xSi₄B₁₂Nb₁Mo_xCu₁ (x = 0–2) nanocrystalline alloys. Molybdenum enhances glass-forming ability (GFA) and magnetic properties by increasing negative mixing enthalpy ($∆{\mathrm{H}}_{\mathrm{m}\mathrm{i}\mathrm{x}}$), mixing entropy ($∆{\mathrm{S}}_{\mathrm{m}\mathrm{i}\mathrm{x}}$), and atomic size mismatch ($\delta$), which stabilize the amorphous phase. X-ray diffraction (XRD) analysis shows that Mo addition improves amorphous phase stability, further enhancing GFA. The simultaneous addition of Mo and Nb increases mixing entropy, promotes nucleation rates, and creates favorable conditions for optimizing nanocrystallization. Upon annealing, this optimized microstructure demonstrated low coercivity and high permeability. Notably, the Fe₈₀Si₄B₁₂Nb₁Mo₂Cu₁ ribbon, annealed at 470 °C for 10 min, exhibited exceptional soft magnetic properties, with a coercivity of 4.54 A/m, a maximum relative permeability of 48,410, and a saturation magnetization of 175.24 emu/g. High-resolution transmission electron microscopy (TEM) revealed an average crystal size of 18.16 nm. These findings suggest that Fe_82-xSi₄B₁₂Nb₁Mo_xCu₁ (x = 0–2) nanocrystalline alloys are suitable for advanced electromagnetic applications pursuing miniaturization and high efficiency. Full article

The addition of beryllium (Be) to Al–Cu alloys enhances their mechanical properties and corrosion resistance. This study aims to investigate the effects of solidification cooling rates and the addition of Be on the microstructural refinement and corrosion behavior of an Al–5wt.%Cu–1wt.%Si–0.5wt.%Be alloy. Radial solidification under unsteady-state conditions was performed using a stepped brass mold, producing four distinct cooling rates. An experimental growth law, λ₂ = 26${\dot{\mathrm{T}}}^{-1/3}$, was established, confirming the influence of Be and the cooling rate on dendritic size reduction. The final microstructure was characterized by an α-Al dendritic matrix with eutectic compounds (α-Al + θ-Al₂Cu + Si + Fe-rich phase) confined to the interdendritic regions. No Be-containing intermetallic phases were detected, and beryllium remained homogeneously distributed within the eutectic. Notably, Be addition promoted a morphological transformation of the Fe-rich phases from angular or acicular forms into a Chinese-script-like structure, which is associated with reduced local stress concentrations. Tensile tests revealed an ultimate tensile strength of 248.8 ± 11.2 MPa and elongation of approximately 6.4 ± 0.5%, indicating a favorable balance between strength and ductility. Corrosion resistance assessment by EIS and polarization tests in a 0.06 M NaCl solution showed a corrosion rate of 28.9 µm·year⁻¹ and an Epit of −645 mV for the Be-containing alloy, which are lower than those measured for the reference Al–Cu and Al–Cu–Si alloys. Full article

Saffron spice is obtained from the flower’s stigmas through a labor-intensive process. However, other organs (particularly the leaves and tepals) are often regarded as waste. To investigate the health benefits of saffron leaf by-products, an optimized methodology was developed to obtain a phenol-enriched fraction. The main components of this fraction were identified by HPLC-DAD/ESI-MS and the antiproliferative and metal-chelating effects on colon cancer cells (Caco-2) and Fe²⁺ and Cu²⁺ ions, respectively, were evaluated. The process involved the extraction of saffron leaves with a 70% hydroalcoholic solution, followed by purification using liquid chromatography. Chemical characterization revealed the presence of several phenolic compounds, including flavonoids (kaempferol, luteolin and quercetin glycosides) as major constituents; whereas, in vitro assays revealed a strong dose-dependent inhibition of cell proliferation. Likewise, the sample exhibited significant iron- and copper-chelating activity, suggesting its potential as a natural chelator to help mitigate the carcinogenic effects of metal accumulation in humans. In summary, this study underscores the potential of the saffron leaf fraction as a promising natural and complementary chemoprotective agent in colorectal cancer. Additionally, these results underscore the value of agricultural by-products, supporting a circular bioeconomy by reducing environmental impact and promoting the sustainable use of natural resources. Full article

Based on the innovative mode driven by “data + artificial intelligence”, in this study, three methods, namely Gaussian noise (GAUSS Noise), the Generative Adversarial Network (GAN), and the optimized Generative Adversarial Network (GANPro), are adopted to expand and enhance the collected dataset of element contents and the hardness of the AlCoCrCuFeNi high-entropy alloy. Bayesian optimization with grid search is used to determine the optimal combination of hyperparameters, and two interpretability methods, SHAP and permutation importance, are employed to further explore the relationship between the element features of high-entropy alloys and hardness. The results show that the optimal data augmentation method is Gaussian noise enhancement; its accuracy reaches 97.4% under the addition of medium noise (σ = 0.003), and an optimal performance prediction model based on the existing dataset is finally constructed. Through the interpretability method, it is found that the contributions of Al and Ni are the most prominent. When the Al content exceeds 0.18 mol, it has a positive promoting effect on hardness, while Ni and Cu exhibit a critical effect of promotion–inhibition near 0.175 mol and 0.14 mol, respectively, revealing the nonlinear regulation law of element contents. This study solves the problem of revealing the mutual relationship between the element contents and hardness of high-entropy alloys in the case of a lack of alloy data and provides theoretical guidance for further improving the performance of high-entropy alloys. Full article

Highly efficient photocatalysts for solar energy conversion require effective charge carrier separation and rapid interfacial transport kinetics to maximize electron availability. Two-dimensional Ti₃CNT_x, a novel conductive material in the MXene family with exceptional electrical conductivity, has emerged as an ideal electron transfer mediator due to its large specific surface area and abundant active terminal groups. In this work, we strategically integrated the 2D multi-metal sulfide Cu-Zn-In-S (CZIS) with 2D Ti₃CNT_x nanosheets through physical mixture, constructing a heterostructured 2D/2D CZIS/Ti₃CNT_x composite photocatalyst for the hydrogen evolution reaction. The unique architecture significantly accelerates electron migration from CZIS to Ti₃CNT_x, while synergistically promoting the spatial separation and directional transfer of photogenerated electron–hole pairs (e⁻/h⁺). When the hydrogen evolution reaction is carried out under identical conditions, the hydrogen yield rate is 4.3 mmol g⁻¹ h⁻¹ with pristine CZIS but is improved dramatically to 14.3 mmol g⁻¹ h⁻¹ when the composite containing an adequate amount of 2D Ti₃CNT_x is used. This study offers new insight into the rational design and controllable synthesis of Ti₃CNT_x-based composite photocatalytic systems for efficient photocatalytic hydrogen production. Full article

Electrocatalytic urea synthesis offers great potential for sustainable strategies through CO₂ and NO₃⁻ reduction reactions. However, the development of high-performance catalysts is often hampered by the complexity of synthetic methodologies and the unresolved nature of C-N coupling pathways. In this study, we present a copper–indium co-doped titanium dioxide (CuIn-TiO₂) catalyst that exhibits remarkable efficacy in enhancing the synergistic reduction of CO₂ and NO₃⁻ to produce urea. The bimetallic CuIn site functions as the primary active site for the C-N coupling reaction, achieving a urea yield rate of 411.8 μg h⁻¹ mg_cat⁻¹ with a Faradaic efficiency of 6.7% at −0.8 V versus reversible hydrogen electrode (vs. RHE). A body of experimental and theoretical research has demonstrated that the nanoscale particles enhance the density of active sites and improve the feasibility of reactions on the surface of TiO₂. The co-doping of Cu and In has been shown to significantly enhance electronic conductivity, increase the adsorption affinity for *CO₂ and *NO₃⁻, and promote the C-N coupling process. The CuIn-TiO₂ catalyst has been demonstrated to effectively promote the reduction of NO₃⁻ and CO₂, as well as accelerate the C-N coupling reaction. This effect is a result of a synergistic interaction among the catalyst’s components. Full article

In this study, lanthanum (La), a rare earth element, was added at concentrations of 0.25 wt.%, 0.5 wt.%, and 0.75 wt.% to an Al–10%Si–2%Cu-based alloy prepared by die casting. The effects of solution and aging heat treatment conditions on the mechanical properties and corrosion resistance were investigated. Microstructural changes, hardness, and corrosion behavior were analyzed as functions of La content and heat treatment parameters. The optimal hardness was achieved at a solution treatment temperature of 500 °C or higher and an aging time of 2 h. In particular, the addition of 0.5 wt.% La led to significant refinement of the α-Al grains, enhancing hardness through the Hall–Petch strengthening mechanism. Furthermore, the combined effects of aging treatment and La addition promoted the formation of a fine, uniform microstructure and stable dispersion of precipitates, resulting in improved mechanical performance. Electrochemical polarization tests revealed that the alloy containing 0.5 wt.% La exhibited the best corrosion resistance. This enhancement was attributed to the formation of the LaCu₂Al₄Si intermetallic compound, which has a lower electrochemical potential than the Al₂Cu phase, thereby reducing corrosion susceptibility within the microstructure. Full article