Search Results (5,315)

Polymer-bonded Nd–Fe–B and Sm–Fe–N magnets have excellent magnetic properties, but their corrosion resistance is inferior. Polymer-bonded magnets, the binary alloys Nd–Fe and Sm–Fe, and the metals Fe, Nd, and Sm were investigated in electrolytes with a pH range of 1.8 to 12.8. Potentiodynamic polarisation measurements showed that these materials corrode in acidic (H₂SO₄) and near-neutral (Na₂SO₄ and NaCl) electrolytes. Iron passivates at pH > 9, but Nd and Sm passivate only in strongly alkaline electrolytes (pH > 12). The alloys and magnets combine the characteristics of the individual metals. Scanning electron microscopy with energy-dispersive X-ray spectroscopy characterised the surface layers before and after electrochemical measurements. The speciation and the depth distribution of elements in the surface layers were analysed using X-ray photoelectron spectroscopy. In the H₂SO₄, a non-protective layer was formed. In NaCl, the corrosion products were more abundant, consisting of a mixture of oxides, hydroxides, and chlorides, while in NaOH, an oxide/hydroxide layer was formed. The corrosion product layers formed in the H₂SO₄ and NaCl electrolytes were significantly thicker for the Sm–Fe–N magnet than for the Nd–Fe–B magnet. Understanding the differences and similarities in the electrochemical behaviour of magnets in various electrolytes is essential to overcoming corrosion-related problems. Full article

In this study, we report the fabrication and multi-technique characterization of pure and rare-earth (RE)-doped ZnO thin films using nanostructured microclusters synthesized via electrospinning followed by calcination. Lanthanum (La), erbium (Er), and samarium (Sm) were each incorporated at five concentrations (0.1–5 at.%) into ZnO, and the resulting powders were drop-cast as thin films on glass substrates. This approach enables the transfer of pre-engineered nanoscale morphologies into the final thin-film architecture. The morphological analysis by scanning electron microscopy (SEM) revealed a predominance of spherical nanoparticles and nanorods, with distinct variations in size and aspect ratio depending on dopant type and concentration. X-ray diffraction (XRD) and Rietveld analysis confirmed the wurtzite ZnO structure with increasing evidence of secondary phase formation at high dopant levels (e.g., Er₂O₃, Sm₂O₃, and La(OH)₃). Raman spectroscopy showed peak shifts, broadening, and defect-related vibrational modes induced by RE incorporation, in agreement with the lattice strain and crystallinity variations observed in XRD. Elemental mapping (EDX) confirmed uniform dopant distribution. Optical transmittance exceeded 70% for all films, with Tauc analysis revealing slight bandgap narrowing (Eg = 2.93–2.97 eV) compared to pure ZnO. This study demonstrates that rare-earth doping via electrospun nanocluster precursors is a viable route to engineer ZnO thin films with tunable structural and optical properties. Despite current limitations in film-substrate adhesion, the method offers a promising pathway for future transparent optoelectronic, sensing, or UV detection applications, where further interface engineering could unlock their full potential. Full article

The Sanqi–pine agroforestry (SPA) system is considered a sustainable agroforestry model. However, empirical studies that clearly elucidate the impact of Sanqi cultivation on soil fertility and the heavy metal content within the SPA system are still lacking. This study established monoculture Pinus armandii (MPA) and SPA systems to conduct a comparative analysis of dynamic changes in soil physicochemical properties and the heavy metal content of Sanqi and pine over one year (with semi-monthly sampling), followed by a comprehensive evaluation of soil fertility and heavy metal pollution. Following the land use conversion from MPA to SPA, there was a notable increase in soil moisture (SM), total nitrogen (TN), and nitrate nitrogen (NO₃⁻-N) levels within Sanqi soil. Conversely, total potassium (TK), ammonium nitrogen (NH₄⁺-N), plumbum (Pb), and chromium (Cr) levels experienced a significant reduction. In the case of pine soil, soil moisture (SM), pH levels, and ammonium nitrogen (NH₄⁺-N) content exhibited an increase. However, soil organic carbon (SOC), total phosphorus (TP), total potassium (TK), zinc (Zn), manganese (Mn), plumbum (Pb), and chromium (Cr) contents all significantly decreased. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) demonstrated that Sanqi cultivation not only significantly enhanced soil fertility for Sanqi rather than pine but also reduced the heavy metal content in the soil of both Sanqi and pine within the SPA system. Furthermore, the Nemerow pollution index for both Sanqi and pine soils has decreased, transitioning the pollution status from relatively safe to safe. This suggests that the introduction of Sanqi promotes the sustainable development of the SPA system. Full article

This paper presents the design of a permanent-magnet-assisted synchronous reluctance motor (PMa-SynRM) for compressor applications using Sm-series injection-molded magnets that eliminate heavy rare-earth elements. The high shape flexibility of the injection-molded magnets enables the formation of a curved multi-layer flux-barrier rotor geometry based on the Joukowski airfoil potential, optimizing magnetic flux flow under typical compressor operating conditions. Furthermore, electromagnetic performance, irreversible demagnetization behavior, and rotor stress sensitivity were analyzed with respect to key design variables to derive a model that satisfies the target performance requirements. The validity of the proposed design was confirmed through finite element method (FEM) comparisons with a conventional IPMSM using sintered NdFeB magnets, demonstrating the feasibility of HRE-free PMa-SynRM for high-performance compressor drives. Full article

With the growing global demand for rice and the urgent need to enhance sustainable production, ratoon rice systems and selenium (Se) biofortification technologies have become important strategies. This study investigated the effects of the foliar application of ethylenediaminetetraacetic acid Se (EDTA-Se) during key growth stages of the main rice season on the yield, grain quality, and Se accumulation in ratoon rice. Two rice varieties—Fengliangyouxiang-1 (FLYX1) and Jinliangyouhuazhan (JLYHZ)—were selected for a two-year field experiment. A systematic analysis was performed on yield components, processing quality, appearance quality, nutritional quality, and Se speciation. The results showed that under an equivalent total amount of spraying EDTA-Se, the best effect on improving the yield, grain quality, and grain Se content of ratoon rice was observed at the heading stage and seven days after full heading. This treatment increased ratoon season yield by 6.45%, primarily due to enhanced grain filling rate (GF) and spikelets per panicle (SP). Processing quality was significantly improved; milled rice rate (MR) increased by 5.59–6.24% in FLYX1 and 3.38–3.52% in JLYHZ, while appearance quality also improved, with chalky grain rate (CGR) decreasing by 21.51–22.93% in FLYX1 and 14.50–14.53% in JLYHZ. These improvements were closely associated with elevated protein content and increased accumulation of selenomethionine (SM). Notably, FLYX1 exhibited higher efficiency in converting selenium to organic forms, whereas JLYHZ showed a greater accumulation of inorganic selenium, highlighting genotype-specific responses. This study confirmed that the foliar application of EDTA-Se during key growth phases of rice during the main season can synergistically optimize yield and quality in ratoon rice while achieving Se biofortification and providing a theoretical basis and technical support for improving the quality and efficiency of ratoon rice, as well as producing Se-enriched ratoon rice. Full article

Bitumen ages during production and in asphalt pavements, leading to structural issues and reduced durability of asphalt pavements. The alteration of bitumen’s viscoelastic properties, predominantly attributable to oxidation phenomena, is a hallmark of these processes. This study analyzed the use of a new generation of synthetic wax (SW_LC), which was selected for its low carbon footprint, ability to reduce binder viscosity, and ability to enable the production of WMA. Tall oil amidopolyamines (TOAs), a renewable raw material-based adhesive and aging inhibitor, was also used in this study. It compensates for the unfavorable effect of stiffening the binder with synthetic wax. SW_LC at concentrations of 1.0%, 1.5%, 2.0%, and 2.5% by mass in bitumen, in conjunction with TOAs at concentrations of 0.0%, 0.2%, 0.4%, and 0.6% by bitumen weight were tested at various concentrations. Short-term and long-term aging effects on penetration, softening point, and viscosity multiple creep and stress recovery tests (MSCR), oscillatory tests for the combined complex modulus |G*| and phase shift angle sin(δ) (DSR), and low-temperature characteristics S_m and m_value (BBR) were analyzed. The chemical composition of the binders was then subjected to Fourier Infrared Spectroscopy (FTIR) analysis, which enabled the determination of carbonyl, sulfoxide, and aromaticity indexes. These results indicated that the additives used inhibit the oxidation and aromatization reactions of the bitumen components. The optimal SW_LC and TOA content determined was 1.5% and 0.4% w/w, respectively. These additives reduce aging and positively affect rheological parameters. Full article

Fusarium crown rot, a widespread and destructive disease affecting cereal crops (particularly wheat and barley), is primarily caused by the soil-borne fungal pathogen Fusarium pseudograminearum. Secondary metabolites (SMs) play a crucial role in colonization and host tissue invasion by pathogenic fungi. In this study, we investigated the functional role of FpTox2, a secondary metabolite-related gene in F. pseudograminearum. An FpTox2 deletion mutant exhibited significantly reduced radial growth compared to wild-type F. pseudograminearum. Notably, the mutant strain completely lost conidiation capacity under induced conditions. Furthermore, although it showed decreased sensitivity to the cell membrane inhibitor sodium dodecyl sulfate (SDS), the mutant demonstrated enhanced susceptibility to NaCl, a metal ion stressor. Most importantly, the pathogen’s virulence was markedly attenuated in wheat stem base infections following FpTox2 deletion, and we demonstrated that FpTox2 regulates pathogen virulence by influencing deoxynivalenol production. In conclusion, FpTox2 is crucial for vegetative growth, asexual development, abiotic stress responses, and full virulence in F. pseudograminearum. Full article

Optimal camera placement (OCP) is a crucial task for ensuring adequate surveillance of both indoor and outdoor environments. While several solutions to this problem have been documented in the literature, there are still research gaps related to the maximization of surveillance coverage, particularly in terms of optimal placement of omnidirectional camera (OC) sensors in indoor and partially occluded environments via metaheuristic optimization algorithms (MOAs). In this paper, we present a study centered on several popular MOAs and their application to OCP for OC sensors in indoor environments. For our experiments we considered two experimental layouts consisting of both a deployment area, and visual obstructions, as well as two different omnidirectional camera models. The tested MOAs include popular algorithms such as PSO, GWO, SSO, GSA, SMS, SA, DE, GA, and CMA-ES. Experimental results suggest that the success in MOA-based OCP is strongly tied with the specific search strategy applied by the metaheuristic method, thus making certain approaches preferred over others for this kind of problem. Full article

Conductive hydrogels are attractive for flexible electronics; however, achieving high mechanical strength and conductivity simultaneously remains challenging. Herein, we present a facile strategy to fabricate a tough and conductive hydrogel by immersing a physically crosslinked gelatin/glucose hydrogel in an aqueous sodium citrate. The introduction of sodium citrate induced multiple physical interactions via the Hofmeister effect, which synergistically reinforced the hydrogel network. The resulting hydrogel exhibited excellent mechanical properties, with a fracture strength of 2.7 MPa, a fracture strain of 932%, and a toughness of 9.5 MJ/m³. Moreover, the incorporation of free ions imparted excellent ionic conductivity of 0.97 S/m. A resistive strain sensor based on this hydrogel showed a linear and sensitive response over a wide strain range and stable performance under repeated loading–unloading cycles. These features enabled accurate and reliable monitoring of various human movements. This work offers an effective strategy for designing hydrogels with both high strength and conductivity for flexible and wearable electronics. Full article

This study explored the use of Borassus fruit fiber as reinforcement for earthen matrices (BFRC). The experimental results of the testing carried out on the structural properties were used to generate a primary dataset for training and testing machine learning (ML) models. Linear regression (LR), Decision tree regressor (DTR), and gradient boosting regression (GBR) were used to build an ensemble learning (EL) model during the prediction of the hygroscopic properties, Young’s modulus, and compressive strength of the BFRC. Fiber content, activation concentration, curing days, dry weight, saturated weight, mass, flexural vibration, longitudinal vibration, correction factor, maximum load, and cross-sectional area were the various inputs considered in the structural properties prediction. The performance of both EL and single models (SMs) was appraised via three performance metrics—mean square error (MSE), root mean square (RMSE), and the coefficient of determination (R²)—to comparatively ascertain the model’s efficiency. Results showed that all models exhibited high accuracy in predicting Young’s modulus and compressive strength. Ensemble learning outperformed single models in predicting these properties, with MSE, RMSE, and R² of 0.01 MPa, 0.1 MPa, and 99% and 3,923,262.5 MPa, 1980.7 Pa, and 99% for compressive strength and Young’s modulus, respectively. However, for hygroscopic behavior, linear regression (LR) demonstrated superior performance compared to other models, with MSE, RMSE, and R² values of 0.13%, 0.36%, and 99%. Full article

Phytophthora fruit rot caused by Phytophthora capsici is a devastating disease in many solanaceous vegetables, resulting in tremendous yield and economic losses. However, the underlying resistance or susceptibility to P. capsici in eggplant remains obscure. In this study, the transcriptomic analysis was performed between the resistant (G42) and susceptible (EP28) eggplant genotypes at 0, 1, 3 and 5 days post-inoculation (dpi). Taking 0 dpi as the control, a total of 4111, 7496 and 7325 DEGs were expressed at 1, 3 and 5 dpi, respectively, in G42 and 5316, 12675 and 12048 DEGs were identified at 1, 3 and 5 dpi, respectively, in EP28. P. capsici infection induced substantial transcriptional changes in the inoculated fruits. The analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) identified defense-related pathways including ‘plant-pathogen interactions’, ‘mitogen-activated protein kinase (MAPK)’ and ‘hormone biosynthesis and signal transduction’. The hormone-related genes encompassing ethylene, abscisic acid, auxins and gibberellins showed differential expression between G42 and EP28 eggplant genotypes, signifying their important roles in plant disease resistance. P. capsici infection induced the expression of major transcription factors such as MYB, NAC/NAM, bHLH, WRK, HSF, HD-ZIPAP2/ERF and Mad-box. qRT-PCR validation of the selected genes corroborates with RNA-seq, depicting the precision and consistency of the transcriptomic data. According to qRT-PCR and RNA-seq analyses, the expression of the pathogenesis-related gene transcriptional activator, SmPTI6 (Smechr0603020), is upregulated in G42 and downregulated in EP28. This differential expression suggests a potential role in the resistance to P. capsici. Functional analysis via a virus-induced gene silencing (VIGS) system found that silencing SmPTI6 in G42 enhanced infection by P. capsici, indicating that SmPTI6 performs a critical role in response to pathogen attack. The comprehensive results obtained in this study provide a valuable resource for understanding the molecular mechanisms underlying eggplant resistance to P. capsici and for establishing breeding resistant eggplant genotypes to P. capsici. Full article

Hollow dendritic Na₄La₂(CO₃)₅ crystals doped with Sm³⁺ ions were synthesized with sodium carbonate using a hydrothermal method. The unique lifetime of Sm³⁺ enables the optical measurement of luminescent ion content. The X-ray diffraction spectrum indicates that the nanocrystals maintain structural stability with a hexagonal arrangement, even when the concentration of Sm³⁺ reaches 50 at.%. As the concentration of Sm³⁺ increases, the emission intensity of Na₄(La_1−xSm_x)₂(CO₃)₅ first rises and then falls. The maximum emission intensity of the fluorescent powder occurs at a Sm³⁺ concentration of 0.04. Beyond this concentration, concentration quenching takes place, primarily due to electric dipole–dipole interactions. Using an excitation wavelength of 404 nm and monitoring at 596 nm, the fluorescence lifetime of Na₄(La_1−xSm_x)₂(CO₃)₅ shows a strong dependence on Sm³⁺ concentration, which can be described by a precise equation. Over the range of Sm³⁺ concentrations from 0.005 to 1, the lifetime decreases from 3.126 ms to 0.023 ms. Therefore, optical monitoring of fluorescent powders is crucial for confirming the composition of coatings used in applications such as solid-state lighting and anti-counterfeiting, by utilizing the relationship between lifetime and doping concentration. Full article

The synergistic effect of using D2EHPA and TOPO together to enhance the extraction of samarium(III) from aqueous media via emulsion liquid membrane (ELM) technology was explored. D2EHPA in binary mixtures with TBP and in ternary mixtures with TOPO and TBP was also tested. Among the tested extractants, a binary mixture of 0.1% (w/w) D2EHPA and 0.025% (w/w) TOPO achieved 100% samarium(III) extraction at a low loading. This mixture outperformed D2EHPA-TBP and other systems because D2EHPA strongly binds to Sm(III) ions, while TOPO increases the solubility and transport efficiency of metal complexes. Additionally, process factors that optimize performance and minimize emulsion breakage were examined. Key insights for successfully implementing the process include the following: 5 min emulsification with 0.75% Span 80 in kerosene at pH 6.7 (natural), 250 rpm stirring, a 1:1 internal/membrane phase volume ratio, a 20:200 treatment ratio, and a 0.2 N HNO₃ stripping agent. These insights produced stable, fine droplets, enabling complete recovery and rapid carrier regeneration without emulsion breakdown. Extraction kinetics accelerate with temperature up to 35 °C but declined above this limit due to emulsion rupture. The activation energy was calculated to be 33.13 kJ/mol using pseudo-first-order rate constants. This suggests that the process is diffusion-controlled rather than chemically controlled. Performance decreases with Sm(III) feed concentrations greater than 200 mg/L and in high-salt matrices (Na₂SO₄ > NaCl > KNO₃). Integrating these parameters yields a scalable, low-loading ELM framework capable of achieving complete Sm(III) separation with minimal breakage. Full article

Single crystals of the layered EuRECuTe₃ series with RE = Nd, Sm, Tb and Dy are obtained for the first time, completing the series of studies on quaternary tellurides synthesized using the halide flux method. These compounds crystallize in the orthorhombic space group Pnma (no. 62) with unit cell parameters ranging from a = 11.5634(7) Å, b = 4.3792(3) Å and c = 14.3781(9) Å for EuNdCuTe₃ to a = 11.2695(7) Å, b = 4.3178(3) Å and c = 14.3304(9) Å for EuDyCuTe₃. The influence of prismatic polyhedra [EuTe₆₊₁]⁷⁻ structural units on the stabilization of 3d framework composed by 2d layered fragments [RECuTe₃]²⁻, which have a key role in the interlayer interaction, is established. A comparative analysis of structural and magnetic properties dependence on the rare-earth element radius r_i(RE³⁺) in the EuRECuTe₃ series (RE = Sc, Y, Nd–Lu) is carried out. The structural contraction, including decrease in degree of tetrahedral polyhedra distortion, bond lengths shortening and unit cell volume shrinking with increasing r_i(RE³⁺), is established. It is shown that the structural alternation leads to transition from ferromagnetic to ferrimagnetic ordering. It was established that changes in the cationic sublattice have a more significant impact on structural transitions in the series of quaternary tellurides than changes in the anionic sublattice. The electronic structure and elastic and dynamic properties were estimated using ab initio calculations. The exfoliation energy for each compound is obtained by estimation of monolayer ground state energy as a result of structure relaxation. The symmetry and structural properties of monolayer EuRECuTe₃ (RE = Nd, Sm, Tb, Dy) compound are established and the orthorhombic symmetry is obtained with layer group pm2_1b. Full article

Purpose: This study aimed to investigate the migration and distribution characteristics of trace elements in the soil–tea system in the Cuiya tea area of Meitan County, Guizhou Province. Methods: The contents of trace elements (Cd, Fe, La, Mg, Mn, Ni, Se, Pr, Sm, Zn) in tea and soil samples were determined by inductively coupled plasma emission spectrometry (ICP-OES). Results: The average contents of heavy metals in soil and tea from Meitan County were below the Chinese national standards, while also meeting the criteria for selenium enrichment. Within the soil–tea system, Mn in tea leaves exhibited a significant negative correlation with soil Mn, while Cd showed a significant positive correlation with soil Cd. This pattern was consistent across both the topsoil and subsoil. The tea plants exhibited a high enrichment capacity for Mn, Mg, and Zn, but a low capacity for Sm, Fe, and Cd. Among the studied areas, the enrichment effect was most pronounced in SL, XH, and MJ towns. Conclusions: Significant spatial variations were observed in the concentrations of trace elements in both tea and soil across the Meitan tea area. This study provides a scientific basis for understanding the enrichment and migration of trace elements within the soil–tea system of Meitan County, Guizhou, and for tracing the geographical origin of its tea. Full article