Search Results (1,082)

Steel/tin bimetallic components fabricated using traditional casting processes have inherent drawbacks, including complicated preparation procedures and a relatively low interfacial bonding strength. To efficiently create metallurgical composite steel/tin bimetallic structures under complex service conditions, we utilized TIG-based additive manufacturing with front wire feeding to prepare the components. The effects of the substrate inclination angle on the macroscopic morphology of the deposited layer, interfacial phase composition, the growth behavior of intermetallic compounds (IMCs) at the bimetallic interfaces, and interfacial mechanical properties were investigated. Our results show that macro-structural defects like cracks, voids and pores were not observed at the steel/tin interfaces. The grains of the interface IMCs were mainly composed of Fe₃Sn, FeSn₂ and FeSb₂ phases; Fe-rich microspheres were dispersed inside the deposited tin layer. Under horizontal substrate conditions, deposited layer morphology and IMC layer thickness presented symmetric distributions. When the inclination angle of the substrate reached 30°, the deposited layers exhibited an asymmetric teardrop morphology, resulting in an increased layer height and width and penetration depth. Meanwhile, tin alloy grains were significantly refined; more high-angle grain boundaries (HAGBs) were formed at the spreading fronts of molten droplets. Tin alloy hardness was improved via synergistic dispersion and grain boundary strengthening. This work reveals the inclination–morphology–microstructure–property correlation, fills the research gap in inclined substrate arc additive manufacturing of steel/tin bimetals, and provides a theoretical foundation for engineering applications. Full article

ZnO is widely used as an electron transport layer in quantum-dot light-emitting diodes (QLEDs) because of its high electron mobility and suitable energy levels. However, rapid electron transport may cause excessive electron injection, leading to charge accumulation and parasitic recombination. SnO₂ provides weaker electron transport, but using it alone limits device performance. Here, a SnO₂/ZnO bilayer electron transport layer was introduced to regulate electron injection. Unlike previously reported structures in which SnO₂ directly contacts the QDs, the present configuration places SnO₂ on ITO and ZnO adjacent to the QD layer. The low-concentration ZnO overlayer reduced the RMS roughness of the SnO₂ film from 1.79 to 1.07 nm and facilitated electron injection, while the underlying SnO₂ layer moderated the electron supply. The bilayer also suppressed leakage current and showed the lowest capacitance peak, consistent with improved charge balance. The bilayer QLED achieved a maximum current efficiency of 13.40 cd/A and a maximum luminance of 33,210 cd/m². Its current efficiency was 100% and 32.7% higher than those of the SnO₂ and ZnO devices, respectively. These results demonstrate that the bilayer improves charge balance through facilitated electron injection and controlled electron supply. Full article

Conventional powdered catalysts for biomass valorization face critical operational limitations regarding recovery and reusability at an industrial scale. To address these challenges, this study developed innovative structured catalysts based on cordierite monoliths coated with carbon derived from oil palm waste, an abundant agricultural byproduct whose improper disposal poses environmental concerns. The carbonaceous layer was functionalized with sulfonic groups and tin (Sn) species to provide synergistic Brønsted and Lewis acid sites. In addition, colloidal silica was incorporated as a binder, significantly improving coating adhesion and homogeneity. Physicochemical characterization confirmed the successful incorporation of sulfonic groups and SnO_x species into the carbonaceous material, leading to dual Brønsted/Lewis acidity, with the B/L ratio increasing from 0.05 in AC to 0.07 in AC20p10Sn. Catalytic evaluation showed that the functionalized monoliths exhibited near 100% of glucose conversion with moderate selectivity towards 5-hydroxymethylfurfural (5-HMF). Notably, despite the surface deposition of solid byproducts, the monolithic architecture successfully eliminated complex downstream separation processes. Furthermore, the structured catalyst exhibited excellent stability, maintaining its catalytic performance over five consecutive cycles. This approach provides a sustainable pathway for structured carbon-coated monoliths derived from biomass waste while overcoming the handling bottlenecks of traditional powder systems by improving catalyst recovery, reusability, and scalability. Full article

This study aims to reveal the formation mechanisms of typical defects in copper alloy castings and propose targeted process optimization strategies for production quality control. Taking the ZCuSn10P1 tin bronze outer layer of copper-clad iron core as the core research object, typical fracture and burr defects in actual mass production were systematically analyzed via multi-scale characterizations including SEM and EDS. Results show that fracture arises from abnormal Sn segregation and coarse hard-brittle δ phase, while burrs stem from insufficient matrix hardness during machining. Shrinkage cavity and porosity defects of aluminum bronze are further comparatively analyzed. A dual strategy of composition regulation and process optimization is put forward, which can effectively suppress defects and improve product qualification rate. This study provides a reliable reference for quality control and technical upgrading of copper alloy castings. Full article

Abiotic stresses—drought, salinity, extreme temperature, flooding, and heavy-metal toxicity—constrain rice (Oryza sativa L.) yield worldwide, and the cellular programmes underlying them are unevenly distributed across cell types that bulk-tissue assays average together. This review examines, from a methodological standpoint, what single-cell and spatial omics technologies can and cannot establish about rice abiotic stress biology. We first define the modality space: single-cell omics measures RNA, chromatin accessibility, DNA methylation, protein, or metabolite features at the resolution of individual cells or nuclei, whereas spatial omics measures such features while retaining tissue coordinates; the two are complementary rather than interchangeable. We then treat each platform class—droplet-based scRNA-seq, combinatorial-indexing approaches including SPLiT-seq, nuclei-based snRNA-seq and multiome, sequencing-based and imaging-based spatial transcriptomics—under a common template covering measurement principle, the questions each can answer, applicability to rice tissues, dominant biases, and the inferences each cannot support. To make evidence strength comparable across a heterogeneous literature, we apply a four-tier scheme throughout: Tier A, direct rice cell-resolved or spatial evidence with functional or field validation; Tier B, robust rice functional and localization evidence without single-cell data; Tier C, cell-resolved evidence without causal validation; and Tier D, cross-species analogy or reasoned proposal. Applying this scheme shows that the genes with genuine breeding traction in rice—SUB1A, OsHKT1;5, OsHMA3, OsNRAMP5, DRO1—rest on Tier B evidence from classical genetics and field testing, whereas the most cell-resolved rice evidence concentrates in root outer layers and barrier formation at Tier C, and heat and cold stress, despite dominating yield loss, lack rice cell-resolved data almost entirely. We extend the discussion beyond transcriptomics to single-cell DNA methylome profiling, spatial proteomics and metabolomics, and three-dimensional analysis of thick plant tissues, in each case distinguishing demonstrated plant capability from mammalian-only capability, and we assess the expanding role of artificial intelligence in annotation, segmentation, batch correction, integration, and perturbation prediction alongside its documented failure modes. Rice, maize, and wheat are compared to identify transferable methodology. Cell-resolved omics has to date improved biological interpretation and candidate prioritization; demonstrating an incremental breeding advantage from it remains an unmet requirement. Full article

The optoelectronic properties of the lead-free perovskite CsSn_0.5Ge_0.5I₃ are investigated by first-principles calculations and numerical simulations using SCAPS-1D. The energy-level alignment between transport layers and the perovskite layer is evaluated, resulting in the establishment of the PCBM/CsSn_0.5Ge_0.5I₃/PEDOT:PSS structure. Key parameters, including bulk defect density, layer thickness, and electrode materials, are optimised, and the effects of resistance, illumination intensity, thermal stability, and carrier generation-recombination rates on device performance are analysed. The optimal device structure FTO/PCBM/CsSn_0.5Ge_0.5I₃/PEDOT:PSS/C achieves a power conversion efficiency (PCE) of 24.50% and a fill factor (FF) of 80.01%. Machine learning (ML) algorithms are applied to predict photovoltaic parameters, with Random Forest (RF) exhibiting the highest accuracy. SHAP analysis identifies absorber layer thickness as the dominant factor influencing efficiency, providing guidance for experimental optimisation. This integrated approach offers a practical pathway for designing high-performance, stable, and environmentally sustainable perovskite solar cells (PSCs). Full article

The surface soil in the Shendong mining area is dominated by aeolian sand and sandy sediment, while precipitation is limited, and evaporation is intense. Under these conditions, shallow reconstructed soil has difficulty retaining plant-available water, which constrains vegetation restoration. This study evaluated how low-range increases in fine-particle clay content affect both water retention and upward water conduction in sandy reconstructed soil. Sandy material from the Shangwan mining area and exogenous river clay were mixed into four treatments, and soil water characteristic curves (SWCCs) were determined by centrifuge over 10–1000 kPa matric suction. The data were fitted with the Van Genuchten model and combined with capillary-rise tests. The results showed that increasing fine-particle content shifted the SWCC upward and raised both saturated and residual volumetric water contents. SN10 reached 17.18% and 5.55% volumetric water content at 10 and 1000 kPa, respectively, and its effective water capacity in the 33–1500 kPa range was 17.9% higher than that of ST. At the same time, fine-particle enrichment in the bottom layer reduced wetting-front rise during capillary testing, indicating a trade-off between water storage and upward replenishment. Within the tested fine-particle range, moderate clay addition improved the hydraulic performance of sandy reconstructed soil, but soil design should balance precipitation retention, infiltration, and capillary supply. Because each treatment and soil-column configuration was represented by only one independently prepared experimental unit, experimental variability and reproducibility could not be evaluated. This study should therefore be regarded as a preliminary and exploratory laboratory assessment conducted under a specific set of material-preparation procedures, specimen geometries, and boundary conditions. The results describe specimen-level hydraulic contrasts rather than reproducible treatment effects and should not be directly generalized to field-scale soil reconstruction. They support a preliminary hypothesis for future replicated testing: fine-particle enrichment may increase water retention while slowing upward capillary replenishment. Full article

In semiconductor photocatalysis, the strong redox ability of a wide band gap and the broad light absorption range of a narrow band gap are a pair of irreconcilable trade-offs. By combining semiconductors with different band gap widths and band edge positions, both of these advantages can be achieved simultaneously. A ternary Cu₂O-SnO₂/g-C₃N₄ (CuSnCN) composite photocatalyst was prepared through the hydrothermal and calcination method. Structural analyses confirm the successful integration of truncated octahedral Cu₂O, spherical SnO₂, and layered g-C₃N₄, which extends the visible-light response to 650 nm. The optimized system achieves a remarkable 96.58% degradation of methyl orange (80 min, 0.2 g/L catalyst, pH = 3) through dual heterojunction synergies: p–n junctions (Cu₂O/g-C₃N₄ and SnO₂/g-C₃N₄) and Z-scheme charge transfer (SnO₂/Cu₂O), with •O₂⁻/h⁺ identified as the dominant reactive species. This work establishes a tunable heterojunction platform for the elimination of multiple pollutants through engineered radical-generation pathways. Full article

This study explores the performance of an ultrathin Cu₂ZnSnSe₄ (CZTSe) absorber-based solar cell using numerical simulations carried out with SCAPS-1D software (version 3.8). Ultrathin absorber layers, generally thinner than 500 nm, are attractive because they require less material, reduce manufacturing costs, and can improve carrier collection due to the shorter distance that charge carriers must travel. However, when the absorber layer becomes very thin, it cannot absorb enough photons, which may limit the overall device performance. To overcome this challenge, the use of back surface field (BSF) layers is examined as a practical approach to improve photovoltaic efficiency. In this work, a solar cell structure composed of Carbon/BSF/CZTSe/CdS/i-ZnO/ITO was designed and simulated, with the thickness of the CZTSe absorber layer kept constant at 85 nm. Three different p⁺-type BSF materials, V₂O₅, Sb₂S₃, and CuSCN, were studied to understand how they influence device behavior. Important parameters such as electron affinity, interface defect density, acceptor defect density in the absorber layer, recombination processes, back contact properties, and operating temperature were systematically investigated. The addition of BSF layers forms a strong electric field at the p⁺–p interface, which helps push minority carriers toward the depletion region and reduces recombination losses at the back contact. The simulation results show that selecting a suitable BSF material can significantly enhance charge carrier collection and improve the efficiency of ultrathin CZTSe solar cells, offering useful guidance for designing more efficient thin-film photovoltaic devices. Full article

Cadmium sulfide has been widely used as a conventional n-type window/buffer layer or heterojunction partner in several p-type thin-film solar cells, including CdTe/CdSeTe-, chalcopyrite-, kesterite-, antimony chalcogenide-, tin sulfide- and iron pyrite-based devices. Its success is related to its ability to form suitable heterojunctions, partially passivate absorber surfaces and provide favorable electronic selectivity. However, the parasitic absorption associated with the relatively narrow band gap of CdS, the toxicity and waste-management issues related to cadmium-containing auxiliary layers and the need for improved band alignment have motivated extensive research on CdS-free window and buffer layers. This review summarizes the main efforts devoted to replacing CdS in thin-film solar cells based on absorbers such as CdTe/CdSeTe, CIS, CIGS, CZTS, CZTSe, CZTSSe, Sb₂S₃, Sb₂Se₃, Sb₂(S,Se)₃, SnS and FeS₂. The most investigated alternative materials, including Zn(O,S), ZnS, In₂S₃, ZnMgO, ZnSnO, TiO₂, SnO₂ and SnS₂, are discussed with emphasis on their optical properties, band alignment, interface quality, deposition methods and impact on device performance. The analysis highlights that CdS replacement cannot be treated as a universal material substitution problem. Instead, each absorber and device architecture requires a specific front-interface design, where chemical compatibility, conduction band offset, defect passivation, optical transparency and process-induced interfacial modifications play a decisive role. CdS-free approaches are relatively mature for CdTe/CdSeTe- and CIGS-based solar cells, whereas kesterite absorbers, antimony chalcogenides and SnS still require further interface engineering. In FeS₂, by contrast, buffer-layer substitution remains secondary to the control of intrinsic surface and bulk electronic defects. This review provides a concise comparison of the most relevant CdS-free front/window materials and identifies key challenges for the future design of sustainable thin-film solar cells. Full article

The marketable viability of perovskite solar cells (PSCs) is currently hindered by challenges related to interfacial charge-carrier extraction and thermal degradation. This study presents a comprehensive finite element method (FEM) analysis using COMSOL Multiphysics to evaluate the efficacy of bi-layer electron transport layer (ETL) engineering in addressing these limitations. We developed a coupled optical–electrical model to investigate three planar architectures: a conventional TiO₂-based reference device, a ${\mathrm{TiO}}_2/{\mathrm{SnO}}_2$ bi-layer configuration, and a ${\mathrm{TiO}}_2/{\mathrm{SnO}}_2:\mathrm{Fe}$ (iron-doped) bi-layer device. Simulation results under AM1.5G illumination reveal that the bi-layer configurations significantly enhance optical absorption across the visible spectrum (350–700 nm) compared to the single-layer counterpart. The incorporation of Fe-doped SnO₂ resulted in optimized energy band alignment, creating a favourable conduction band offset that facilitates electron extraction. Consequently, the ${\mathrm{TiO}}_2/{\mathrm{SnO}}_2:\mathrm{Fe}$ device achieved a peak power conversion efficiency (PCE) of 18.3% at 300 K, outperforming the undoped bi-layer (18.0%) and the reference device (17.5%). Furthermore, thermal stress simulations indicated that the Fe-doped architecture exhibits superior stability, maintaining a PCE of 12.8% at 440 K compared to 12.3% for the reference. This enhanced performance is attributed to the passivation of interfacial defects and the formation of a stronger built-in electric field at the ETL/absorber junction, validating the strategic doping of metal oxides as a robust pathway for high-efficiency, thermally stable perovskite photovoltaics. Full article

The interfacial microstructure evolution and high-speed ball shear reliability of SAC305 (Sn-3.0Ag-0.5Cu)/Cu-20wt%Zn solder joints were systematically investigated after isothermal aging at 180 °C for up to 250 h. SAC305/electroless nickel immersion gold (ENIG) joints were used as a comparative reference. Unlike prior studies that benchmarked Cu-Zn against bare Cu, this work directly compares the two systems, establishing ENIG as the industrially relevant reference. Cu₆(Sn,Zn)₅ was identified as the dominant intermetallic compound (IMC) phase at the SAC305/Cu-Zn interface by SEM/EDS analysis. At the SAC305/ENIG interface, (Cu,Ni)₆Sn₅ formed as the dominant IMC phase, accompanied by a P-rich layer at the (Cu,Ni)₆Sn₅/Ni(P) boundary. The IMC thickness of SAC305/Cu-Zn joints increased from approximately 2.50 μm in the as-reflowed condition to 3.41 μm at 250 h, consistently exceeding that of SAC305/ENIG joints (1.94–2.25 μm) throughout aging. Despite this, the high-speed ball shear strength of SAC305/Cu-Zn joints was equivalent or superior to that of SAC305/ENIG joints at all aging durations. Fractographic analysis confirmed that the P-rich layer in ENIG joints acted as a preferential crack propagation path under impact loading, driving the brittle fracture ratio to approximately 75% at 250 h—compared to approximately 47% in SAC305/Cu-Zn joints. These results demonstrate that Cu-Zn electroplated from a neutral pyrophosphate-based bath constitutes a highly reliable wetting layer, offering impact reliability equivalent or superior to that of the conventional ENIG surface finish. Full article

One of the most promising absorber materials for solar applications is copper zinc tin sulfide/selenide (CZTS), which has good optical properties and basic elements that are readily available, affordable, and environmentally acceptable. This study examines how pulse timing and current density affect the electrodeposition of Cu₂ZnSnS₄/Cu₂ZnSn(S,Se)₄ (CZTS/CZTSSe) thin films from a diluted electrolyte, including deposition quality, film configuration, elemental composition, crystallinity, and photovoltaic performance. It evaluates the impact of these factors on device performance, film properties, layer’s compactness, surface homogeneity, microcrack-free morphology, compositional homogeneity, crystallinity, and suitability for solar device manufacturing. Using a pulsed-current technique, CZTS precursor layers were electrodeposited in a low-concentration solution with periodic changes in current density of roughly 5.3–5.9 mA/cm² and pulse-on/off durations of 50/50, 100/100, and 250/250 ms. The deposited precursors were then added to fully built CZTS-based solar cell topologies after sulphurization or selenization. Structural characteristics were analyzed using X-ray diffraction (XRD), and composition and elemental distribution were assessed using energy-dispersive X-ray spectroscopy (EDS). Measurements of transmittance and reflectance were used to evaluate optical properties relevant to photovoltaic performance. In contrast to films deposited at higher current densities and longer off-times, moderate current densities combined with short off-times yield dense, microcrack-free films with improved crystallinity and near-stoichiometric Cu/(Zn + Sn), Zn/Sn, and chalcogen/metal ratios. Additionally, absorber layers with appropriate optical band gaps and improved device performance are produced by these optimized pulse parameters. Overall, the study shows that controlling pulse parameters in diluted electrolytes is a useful tactic for improving the quality of CZTS films and developing low-cost, solution-based fabrication techniques for high-performance CZTS solar cells. Full article

Background/Objectives: This study investigates the correlation between substantia nigra (SN) hyperechogenicity, detected via transcranial sonography (TCS), and retinal thinning in patients with Parkinson’s disease (PD). Methods: In this cross-sectional study, 86 PD patients (172 eyes) underwent clinical assessment (UPDRS, Hoehn–Yahr), TCS for SN area measurement, and optical coherence tomography (OCT) for retinal nerve fiber layer (RNFL), ganglion cell-inner plexiform layer (GCIPL), and macular thickness analysis. Results: PD patients exhibited significant thinning of the GCIPL, average RNFL, and central macular thickness compared to healthy controls (p < 0.001 in all instances). Pathological SN hyperechogenicity (>0.19 cm²) was detected in 85.9% of patients with a preserved temporal bone window (71 out of 86). A significant negative correlation was found specifically between the SN echogenic area and central macular thickness (r = −0.248, p = 0.003). Patients with pathological SN findings had a significantly thinner central macula (p = 0.006) compared to those with a normal SN, while no significant correlations were observed between the SN area and RNFL or GCIPL. Conclusions: These findings demonstrate a specific correlation between SN hyperechogenicity and central macular thinning. While RNFL and GCIPL effectively differentiate PD from controls, the central macula might serve as a promising biomarker candidate reflecting SN changes. Further longitudinal studies are required to evaluate the role of these combined markers in the PD diagnostic algorithm. Full article

Perovskite solar cells (PSCs) have emerged as a disruptive photovoltaic technology for aerospace and extreme environment applications, driven by their substantial power-to-weight ratio and mechanical flexibility. However, continuous operation under harsh conditions, characterized by the AM0 spectrum, deep vacuum, extreme thermal cycling, and ionizing radiation, exposes the fundamental thermodynamic instability of traditional organic–inorganic hybrid perovskites. This comprehensive review systematically synthesizes 131 recent studies to provide a holistic framework for designing ultrastable, radiation-hardened PSCs. We critically examine the underlying degradation mechanisms, including vacuum-induced volatile desorption, UV-triggered halide segregation, and thermomechanical fracture at buried interfaces. To overcome these critical barriers, we highlight advanced engineering strategies: the transition to all-inorganic CsPbX₃ and lead-free double/chalcogenide perovskites (e.g., Cs₂SnI₆, CaHfS₃), the implementation of dopant-free inorganic transport layers coupled with self-assembled monolayers (SAMs) for cascade band alignment, and the integration of polymeric scaffolds for fracture energy toughening. Furthermore, we emphasize the imperative shift toward solvent-free vacuum deposition techniques (ALD, PLD). A distinctive focus of this review is the integration of Artificial Intelligence; specifically, we evaluate Deep Learning architectures, such as Long Short-Term Memory (LSTM) networks, for predictive State of Health (SOH) monitoring, underscoring the vital transition from simulated to empirical datasets. Finally, coupled with Material Flow Cost Accounting (MFCA), this review outlines a strategic roadmap for the commercialization and deployment of autonomous, self-diagnosing photovoltaic platforms in next-generation satellite and deep-space missions. Full article