Search Results (799)

To address the issues of resistance and food safety stemming from the overuse of chemical fumigants in stored-grain pest control, this study aimed to systematically optimize the insecticidal process of pulsed electric field (PEF) treatment on Tribolium castaneum (T. castaneum) and to investigate its electro-neurotoxicity mechanism. Single-factor experiments were used to determine parameter ranges, and response surface methodology (RSM) was employed to analyze the effects of electric field strength, pulse frequency, and treatment time. The finite element method (FEM) was used to simulate the physical field distribution, and acetylcholinesterase (AChE) activity was measured to explore neurotoxicity. The results indicated that electric field strength, pulse frequency, and treatment time all had highly significant effects (p < 0.0001), with electric field strength being the primary factor. The optimal process parameters were determined to be: electric field strength of 26 kV/cm, pulse frequency of 20 kHz, and treatment time of 140 s. Under these conditions, the predicted and actual mortality rates were both 100%, and this efficacy was validated in rice samples. Simulation confirmed that PEF achieves physical targeting through a “tip effect” on the insect’s nerve endings; mechanism tests demonstrated that PEF treatment significantly inhibited AChE activity (p < 0.01). This study confirms the “electro-neurotoxicity” mechanism of PEF, providing theoretical support for this green physical control technology. Full article

Conducting laboratory tests in geotechnical engineering is a costly, time-consuming, and labor-intensive process. As an alternative solution, this study employs various machine learning methods to predict the unconfined compressive strength (UCS) of fine-grained soils stabilized by combining chemical additives (such as Portland cement, lime, and industrial and agricultural waste) and nanosilica. After preparing a comprehensive database of a collection of studies from the literature, ten machine learning models were developed for modeling, and their performances were compared using various metrics. After comparing the performance of the models in predicting the UCS with experimental results, the CatBoost model was determined as the optimal model. The variables of curing time, liquid limit of soil, and additive contents were identified as the most effective parameters on the stabilized soil’s UCS. The best-performing model on the applied dataset was determined and compared with experimental models. After determining the effective parameters for predicting the strength of stabilized soil, the nonlinear relationships between the most important variables and the stabilized soil’s UCS were analyzed and investigated. Full article

Titanium alloys are widely employed for biomedical implants due to their high strength, biocompatibility, and corrosion resistance, yet their lack of intrinsic antibacterial activity remains a major limitation. Incorporating copper, an antibacterial and β-stabilising element, offers a promising strategy to enhance implant performance. This study investigates Ti-6Al-7Nb modified with 1–9 wt.% Cu via in situ alloying during metal-based laser powder bed fusion (PBF-LB/M), with the aim of assessing processability, microstructural evolution, and mechanical properties. Highly dense samples (>99.9%) were produced across all Cu levels, though chemical homogeneity strongly depended on processing parameters. Increasing Cu content promoted β-phase stabilisation, Ti₂Cu precipitation, and pronounced grain refinement. Hardness and yield strength increased nearly linearly with Cu addition, while ductility decreased sharply at ≥5 wt.% Cu due to intermetallic formation, hot cracking, and brittle fracture. These results illustrate both the opportunities and constraints of rapid alloy screening via PBF-LB/M. Overall, moderate Cu additions of 1–3 wt.% provide the most favourable balance between mechanical performance, manufacturability, and potential antibacterial functionality. These findings provide a clear guideline for the design of Cu-functionalised titanium implants and demonstrate the efficiency of in situ alloy screening for accelerated materials development. Full article

Zirconium and its alloys are widely used in nuclear power engineering due to their favorable physical and mechanical properties and their low thermal-neutron absorption cross-section. Their high corrosion resistance in aqueous and steam environments at elevated temperatures is essential for the reliable operation of fuel assemblies and is associated with the formation of a stable, compact ZrO₂ oxide layer. However, under reactor conditions, the presence of hydrogen, iodine and other fission products can reduce corrosion resistance, making detailed corrosion assessment necessary. Manufacturing technology, alongside alloy composition, also plays a decisive role in determining corrosion behavior. This study presents corrosion test results for a Zr-1%Nb alloy processed under thermomechanical conditions corresponding to rolling in a special type of three-roll skew rolling–Radial-Shear Rolling (RSR). The applied rolling technology ensured the formation of a pronounced ultrafine-grained (UFG) structure in the near-surface layers, with an average grain size below 0.6 µm. EBSD and TEM observations revealed a largely equiaxed microstructure with refined grains and increased grain boundary density. The corrosion testing was performed in high-temperature steam vessels at 400 °C and 10.3 MPa for 72, 336, 720 and 1440 h. The results demonstrate that RSR processing is an efficient alternative to conventional multi-pass normal bar rolling with vacuum heat treatments, allowing a significant reduction in processing steps and eliminating the need for expensive tooling and intermediate thermal or chemical treatments. Bars manufactured using this method meet the ASTM B351 requirements. The specific weight gain did not exceed 22 mg/dm² after 72 h and 34.5 mg/dm² after 336 h. After 1440 h, the samples exhibited a continuous, uniform dark-grey oxide layer with an average thickness below 5.3 µm. Full article

This study examined the sediment microbial communities at 12 stations within the Meretrix meretrix farming area in Rudong, Jiangsu Province, utilising high-throughput sequencing. It elucidates the ecological relationships between the sediment microbial communities and the primary physical and chemical factors influencing the farming water and sediment. The results indicated that the microbial communities comprised 55 phyla. The Shannon index ranged from a minimum of 8.97 to a maximum of 9.96, while the Simpson index varied from 0.996 to 0.997, indicating a uniform species distribution. β diversity analysis revealed significant spatial diversity among the communities. Dominant bacterial groups included Proteobacteria (25.2–38%) and Desulfobacterota (10.4–14.4%), with Desulfobacterota reaching a peak of 14.4% at tidal creek station S2, reflecting the sulphate reduction process associated with organic pollution input. At the genus level, Woesia (9.15–17.16%), Desulfobacterota, and Subgroup_22 were identified as core functional bacteria. Redundancy analysis indicated that phosphate and nitrate were the primary drivers of community variation, accounting for a cumulative interpretation rate of 43.2%. Spearman correlation analysis confirmed that fine-grained sediments were more likely to store organic matter, significantly promoting the colonisation of AQS1 (p < 0.05) and Cohaesibacter (p < 0.05), while inhibiting Puniceispirillales (p < 0.01). An alkaline environment positively selects for sulphur-cycling bacteria, such as Desulfatiglans (p < 0.05). This study provides technical support for the regulation of sediment environments and the promotion of healthy clam culture practices. Full article

Improving the interfacial stability of graphite anodes remains a major challenge for extending the lifetime of lithium-ion batteries. In this study, ultrananocrystalline diamond (UNCD) and nitrogen-incorporated UNCD (N-UNCD) coatings were employed as protective layers to enhance the electrochemical and mechanical robustness of graphite electrodes. Half-cells were cycled for 60 charge–discharge cycles, and their behavior was examined through electrochemical impedance spectroscopy (EIS), Distribution of Relaxation Times (DRT), and Equivalent Circuit Modeling (ECM) to disentangle the characteristic relaxation processes. The potential–capacity profiles exhibited the typical LiC₁₂–LiC₆ transition plateaus without any additional features for the coated electrodes, confirming that the UNCD and N-UNCD films do not participate in lithium storage but serve as chemically inert and electrically stable interlayers. In contrast, the uncoated reference graphite anodes showed greater capacity fluctuations and increasing interfacial impedance. DRT and ECM analyses revealed four consistent relaxation processes—electronic transport (τ₁), ionic transport through the electrolyte (τ₂), Solid Electrolyte Interface (SEI) response (τ₃), and lithium intercalation (τ₄). The τ₂ process remained invariant, whereas τ₃ and τ₄ were markedly stabilized by the UNCD and N-UNCD coatings. UNCD exhibited the lowest SEI-related resistance and the most stable charge-transfer kinetics, while N-UNCD displayed an initially higher τ₃ resistance followed by progressive self-stabilization after 20 charge/discharge cycles, linked to reorganization of nitrogen-rich grain boundaries. Overall, polycrystalline diamond coatings—particularly UNCD—proved to be highly effective in suppressing SEI layer growth, minimizing impedance rise, and preserving lithium intercalation efficiency, leading to enhanced long-term electrochemical performance. These findings highlight the potential of diamond-based protective layers as a durable and scalable strategy for next-generation graphite anodes. Full article

With the increase in strength of pipeline steels manufactured by thermomechanical control process (TMCP), the softening of the welding heat-affected zone (HAZ) becomes another important factor affecting the properties of welded steel pipes and the safety of pipeline operation. In this work, based on the actual welding process of steel pipes, the strength, phase transformation, and microstructure of the HAZ of six pipeline steels with different chemical compositions were studied by using a thermomechanical simulator, and the effect of chemical composition on the softening of HAZ was discussed. Results show that the strength of HAZs is significantly influenced by the peak temperature, and the softening zone mainly occurs in fine-grained HAZ (FGHAZ) when peak temperature is 900~1000 °C. Meanwhile, the degree of softening is also affected by the chemical composition of the steels. The effects of peak temperature and chemical composition of the steels on the strength of the HAZs when the peak temperature is over Ac₃ are attributed to their effect on the austenite transformation during the heating process, and then the effect on phase transformation during the cooling process and final microstructure. The strength of the HAZs is linearly related to the beginning phase temperature during the cooling process, and the strength of sub-HAZs at the same peak temperature is linearly related to the value of carbon equivalent (Ceq) of steels. Therefore, controlling the appropriate value of Ceq is necessary to improve the softening of HAZs for high-strength pipeline steels. Full article

Lacustrine fine-grained sediments commonly exhibit well-developed laminations, with significant variations in structural characteristics such as thickness and continuity, which are closely related to depositional environments and genetic processes. This paper focuses on the characteristics and formation mechanisms of the upper Es4 to lower Es3 members of the Shahejie Formation in the Dongying Sag. Through polarized light microscopy, field-emission environmental scanning electron microscopy (FE-SEM), electron probe microanalysis (EPMA), and X-ray diffraction (XRD), we systematically analyzed the types, characteristics, and genetic mechanisms of laminations in fine-grained sedimentary rocks. Results indicate that the mineral composition of these rocks is dominated by carbonates and clay minerals, allowing classification into calcareous and argillaceous mudstones. The types of laminae include calcareous laminae, argillaceous laminae, and silty laminae, which are formed by chemical precipitation, suspension settling, and low-density turbidity currents, respectively. The primary lamination associations are argillaceous–calcareous interbeds and argillaceous–silty interbeds, exhibiting rhythmic cyclicity. In the upper Es4 member, variations in climate, sediment supply, and seasonal factors caused fine-grained sediments to transition from flocculent suspension settling to chemical precipitation, forming periodic intercalations of argillaceous and calcareous laminae. In the lower Es3 member, seasonal turbidity currents triggered the deposition of normally graded silty layers and fine-silty laminae, followed by a return to suspension deposition, resulting in argillaceous–silty interbeds. This study reveals diverse transport and depositional mechanisms of fine-grained sediments under varying hydrodynamic conditions. It provides a new case for understanding the genesis of fine-grained sedimentary rocks and offers geological insights for shale oil exploration and development in the Dongying Sag. Full article

The 2000 series aluminium alloys are an attractive option for lightweight structures, but solidification cracking in fusion welding remains an issue in additive manufacturing technologies. Al-Cu-Li alloys, in particular, have gained considerable attention due to their excellent strength-to-weight ratio and corrosion and fatigue resistance, making them highly suitable for aerospace components. Nevertheless, their narrow solidification range makes them highly susceptible to cracking, porosity formation, and elemental evaporation during fusion-based AM processes. These challenges underscore the necessity for advanced processing technologies and the development of suitable feedstock materials to ensure weld integrity and optimal performance. Although Al–Cu–Li alloys are highly valued in the aerospace sector, the application of wire arc additive manufacturing (WAAM) is currently limited by the lack of commercially available wire compositions. This study focuses on the use of powder metallurgy Al-Cu-Li wires in wire arc additive manufacturing, specifically using plasma metal deposition technology, to explore welding characteristics. This research demonstrates the development of an alternative wire using powder metallurgy for WAAM. Powder metallurgy wires were deposited on 5053 and 7075 aluminium substrates, and their microstructure, chemical composition, and mechanical properties were analysed. Key findings include significant elemental losses of Li and Cu during deposition—approximately 55% and 25%, respectively—as well as noticeable variations in microstructure, porosity, and grain morphology, depending on the substrate. Deposits on the 5083 aluminium exhibited more equiaxed grains and a higher chemical homogeneity compared to those on the 7075 substrate. This work establishes a link between material design and additive manufacturing by demonstrating that powder metallurgy Al–Cu–Li wires can be effectively processed by WAAM, achieving controlled elemental losses and a uniform microstructure that enhances weld integrity in aerospace components. Full article

We introduce a fully solution-processed interlayer strategy for n–p CdS/PbS thin film solar cells that combines a sol–gel ZnO compact coating with an electrospun ZnO nanofiber network. The synthesis and characterization of ZnO, CdS, and PbS thin films, complemented by electrospun ZnO nanofibers, are aimed at low-cost photovoltaic applications. Sol–gel ZnO films exhibited a hexagonal wurtzite structure with a bandgap (Eg) of approximately 3.28 eV, functioning effectively as electron transport and hole-blocking layers. CdS films prepared by chemical bath deposition (CBD) showed mixed cubic and hexagonal phases with an Eg of about 2.44 eV. PbS films deposited at low temperature displayed a cubic galena structure with a bandgap of approximately 0.40 eV. Scanning Electron Microscopy revealed uniform ZnO and CdS surface coatings and a conformal 1D ZnO network with nanofibers measuring about 50 nm in diameter (ranging from 49.9 to 53.4 nm), which enhances interfacial contact coverage. PbS films exhibited dense grains ranging from 50 to 150 nm, and EDS confirmed the expected stoichiometries. Electrical characterization indicated low carrier densities and high resistivities consistent with low-temperature processing, while mobilities remained within reported ranges. The incorporation of ZnO layers and nanofibers significantly improved device performance, particularly at the CdS/PbS heterojunction. The device achieved a V_oc of 0.26 V, an J_sc of 3.242 mA/cm², and an efficiency of 0.187%. These improvements are attributed to enhanced electron transport selectivity and reduced interfacial recombination provided by the percolated 1D ZnO network, along with effective hole blocking by the compact film and increased surface area. Fill-factor limitations are linked to series resistance losses, suggesting potential improvements through fiber densification, sintering, and control of the compact layer thickness. This work is a proof-of-concept of a fully solution-processed and low-temperature CdS/PbS architecture. Efficiencies remain modest due to low carrier concentrations typical of low-temperature CBD films and the deliberate omission of high-temperature annealing/ligand exchange. Overall, this non-vacuum, low-temperature coating method establishes electrospun ZnO as a tunable functional interlayer for CdS/PbS devices and offers a practical pathway to elevate power output in scalable productions. These findings highlight the potential of nanostructured intermediate layers to optimize charge separation and transport in low-cost PbS/CdS/ZnO solar cell architectures. Full article

Agricultural chemicals are indispensable in the process of traditional grain production and are also a major contributor to agricultural carbon emissions. Exploring the relationship between agricultural chemical carbon emissions and grain production is of significant importance for reducing agricultural emissions and promoting environmentally friendly grain production. To this end, this study employs the Tapio model and the LMDI factor decomposition model to analyze the decoupling relationship between agricultural chemical carbon emissions and grain production in Shandong Province—a typical grain-producing region in northern China—from a production perspective, focusing on the period from 2011 to 2023. The results indicate that during this period, Shandong Province achieved improvements in grain production technology, leading to a gradual improvement in the decoupling relationship between grain production and agricultural chemical carbon emissions. The factors influencing agrochemical carbon emissions during grain production initially shifted from being suppressed by output scale effects and promoted by technological effects to being suppressed by technological effects and promoted by output scale effects. Ultimately, synergistic development was achieved in Shandong Province by reducing agrochemical emissions and increasing grain production. This study provides a theoretical basis for synergistic development in agrochemical emission reduction and grain yield enhancement, while also offering a new perspective for research on reducing emissions during grain production. Full article

Maw-sit-sit jade resembles kosmochlor-jadeitite in appearance and is spatially associated with it in the Myanmar Jade Belt. However, the mineral composition, microstructure, and petrogenesis of this type of jade remain unclear. To address this gap, this study investigated high-quality Maw-sit-sit jade using a range of analytical techniques, including conventional gemological tests, infrared spectroscopy, petrographic observations, electron probe microanalysis (EPMA), and backscattered electron (BSE) imaging. Results show that Maw-sit-sit jade primarily consists of albite and chromium-omphacite, with minor amphibole (eckermannite and richterite). Jadeite and relict chromite are absent in the studied samples. Its high albite content gives it lower refractive index (RI: 1.55–1.56) and specific gravity (SG: 2.69–2.73) compared to kosmochlor-jadeitite and jadeite jade. Additionally, Maw-sit-sit jade exhibits punctate or banded fluorescence under ultraviolet (UV) light, distinguishing it from kosmochlor-jadeitite and jadeite jade (both inert). Petrographically, euhedral albite fills interstices between early-formed Cr-omphacite and eckermannite, which is textural evidence of its late-stage origin. Eckermannite and Cr-omphacite occur as enclosed grains with embayed boundaries and dissolution pores, indicating they experienced mechanical disruption and chemical dissolution during subsequent geological processes. Petrogenetically, Maw-sit-sit jade (defined as “Cr-omphacite-albitite”) forms via a two-stage process: (1) Under high-pressure/low-temperature (HP/LT) conditions in the subduction zone, Na-Al-Si-rich fluids metasomatize chromite-bearing serpentinite protoliths, generating an early assemblage of jadeite, Cr-omphacite and amphiboles; (2) During subsequent plate exhumation and decompression, jadeite underwent retrograde metamorphism under low-pressure/low-temperature (LP/LT) conditions involving residual Na-Al-Si fluids, resulting in the formation of albite. This process led to the replacement of early-formed minerals by euhedral albite, ultimately generating the Ab+Cr-Omp+Eck symplectic texture. This study elucidates the mineralogical, gemological identity and petrogenesis of high-quality Maw-sit-sit jade, advancing our understanding of fluid evolution within a subduction zone. Full article

A comprehensive understanding of the denitration kinetics of nitrocellulose-based propellants is crucial for optimizing combustion performance and achieving controllable fabrication. However, most existing studies rely on a single kinetic model, which is restricted by formulation composition and grain geometry, limiting their general applicability. In this work, the denitration rate was quantified using the change in explosion heat, introducing an energy-based characterization approach instead of traditional mass-loss measurements. Three kinetic models (the shrinking-core, pseudo-homogeneous, and Avrami models) were employed to identify the rate-controlling step. The shrinking-core model provided the most accurate description of the process. At moderate reagent concentrations (8 wt.% and 12 wt.%) and temperatures (65–75 °C), denitration was primarily reaction-controlled, while at higher temperatures (80 °C), internal diffusion resistance became significant. The apparent activation energy ranged from 69.8 to 73.7 kJ·mol⁻¹, confirming that chemical reaction is the dominant mechanism. This study refines the kinetic understanding of nitrocellulose denitration and provides theoretical guidance for the controlled fabrication of gradient nitrocellulose propellants with tunable progressive-burning behavior. Full article

Graphite anodes are widely used as consumable electrodes in the high-temperature electrolytic production of rare earth metals within fluoride molten salts. However, their rapid and complex corrosion presents significant economic and operational challenges, including high consumption costs, process instability, greenhouse gas emissions, and product contamination. While the corrosion morphology of specific graphite types has been studied, a systematic investigation linking the intrinsic properties of diverse graphite materials to their microstructural and chemical evolution during corrosion is lacking. This study elucidates the corrosion mechanisms of three distinct graphite anodes—fine-grained, isostatically pressed graphite anodes (#1), medium-coarse-grained, extruded graphite anodes (#2), and recycled, extruded graphite anodes (#3) in industrial PrNdF₃–LiF molten salt electrolytes at 1050 °C. Through a multifaceted analytical approach encompassing SEM, EDS, XRD, Raman, and FT-IR, we investigated the macro- and microscale corrosion behaviors across multiple scales. The results revealed markedly different degradation patterns: the #1 anode exhibited intergranular corrosion with granular exfoliation; the #2 anode developed a protective but cracked resolidified salt layer; and the #3 anode suffered the most severe uniform and pitting corrosion. Postcorrosion analysis confirmed surface enrichment with fluorine, praseodymium, and neodymium, the formation of PrF₃ and NdF₃ phases, and substantial degradation of the graphitic structure. Raman spectroscopy specifically revealed a reduction in the crystallite size, introduction of in-plane point defects, and disruption of the interlayer stacking order. On the base of infrared spectroscopy analysis, all key characteristic absorption peaks of the graphite anodes undergo consistent attenuation after corrosion. This work provides critical insights for the informed selection and optimization of graphite anodes to increase the efficiency and sustainability of rare earth electrolysis. Full article

Lignocellulosic biomass—the non-edible fraction of plants composed of cellulose, hemicellulose, and lignin—is the most abundant renewable carbon resource and a key lever for shifting from fossil to bio-based production. Agro-industrial residues (straws, cobs, shells, bagasse, brewery spent grains, etc.) offer low-cost, widely available feedstocks but are difficult to process because their polymers form a tightly integrated, three-dimensional matrix. Within this matrix, lignin provides rigidity, hydrophobicity, and defense, yet its heterogeneity and recalcitrance impede saccharification and upgrading. Today, most technical lignin from pulping and emerging biorefineries is burned for energy, despite growing opportunities to valorize it directly as a macromolecule (e.g., adhesives, foams, carbon precursors, UV/antioxidant additives) or via depolymerization to low-molecular-weight aromatics for fuels and chemicals. Extraction route and severity strongly condition lignin structure linkages (coumaryl-, coniferyl-, and sinapyl-alcohol ratios), determining reactivity, solubility, and product selectivity. Advances in selective fractionation, reductive/oxidative catalysis, and hybrid chemo-biological routes are improving yields while limiting condensation. Remaining barriers include feedstock variability, solvent and catalyst recovery, hydrogen and energy intensity, and market adoption (e.g., low-emission adhesives). Elevating lignin from fuel to product within integrated biorefineries can unlock significant environmental and economic benefits. Full article