Search Results (17,429)

Magnesium metal boasts a high theoretical volumetric specific capacity and abundant reserves. Magnesium batteries offer high safety and environmental friendliness. In recent years, magnesium-ion batteries (MIBs) with Mg or Mg alloys as anodes have garnered extensive interest and emerged as promising candidates for next-generation competitive energy storage technologies. However, MIBs are plagued by issues such as sluggish desolvation kinetics and slow migration kinetics, which lead to limitations including a limited electrochemical window and poor magnesium storage reversibility. Herein, the sodium vanadium phosphate @ carbon (Na₃V₂(PO₄)₃@C, hereafter abbreviated as NVP@C) cathode material was synthesized via a sol–gel method. The electrochemical performance and magnesium storage mechanism of NVP@C in a 0.5 M magnesium bis(trifluoromethanesulfonyl)imide/ethylene glycol dimethyl ether (Mg(TFSI)₂/DME) electrolyte were investigated. The as-prepared NVP@C features a pure-phase orthorhombic structure with a porous microspherical morphology. The discharge voltage of NVP@C is 0.75 V vs. activated carbon (AC), corresponding to 3.5 V vs. Mg/Mg²⁺. The magnesium storage process of NVP@C is tentatively proposed to follow a ‘sodium extraction → magnesium intercalation → magnesium deintercalation’ three-step intercalation–deintercalation mechanism, based on the characterization results of ICP-OES, ex situ XRD, and FTIR. No abnormal phases are generated throughout the process, and the lattice parameter variation is below 0.5%. Additionally, the vibration peaks of PO₄ tetrahedrons and VO₆ octahedrons shift reversibly, and the valence state transitions between V³⁺ and V⁴⁺/V⁵⁺ are reversible. These results confirm the excellent reversibility of the material’s structure and chemical environment. At a current density of 50 mA/g, NVP@C delivers a maximum discharge specific capacity of 62 mAh/g, with a capacity retention rate of 66% after 200 cycles. The observed performance degradation is attributed to the gradual densification of the CEI film during cycling, leading to increased Mg²⁺ diffusion resistance. This work offers valuable insights for the development of high-voltage MIB systems. Full article

Contacted liquid fluids, in most cases, have the tendency to directly merge into a single larger fluid to minimize the surface energy. We present an abnormal drop formation process of contacted Cu liquid films with a radius of 101.7 Å or larger on carbon substrates by using molecular dynamics simulations. The formation process consists of consecutive pinch-off and full coalescence stages connected by detachment. The dominant motions of the bridge, away from the center and downward to the substrate, lead to the pinch-off of the initially connected droplets. The motions of the droplets, which are near each other at all times, leads to the repeated contact and full coalescence of the separated droplets. The abnormality is attributed to the competition between the motions of the droplets and the tiny liquid bridge that connects the droplets. The influence of the surface structures of substrates, especially carbon nanotubes, on the formation behavior is discussed by analyzing the mean square displacement, velocity fields, and density and scaling profiles. This study provides guidance for controlling drop formation behavior by regulating the surface structures of carbon substrates. Full article

This study investigates additive-free cold calendering of ELT-derived rubber powders across three particle size fractions (<0.5 mm, 0.5–0.71 mm, and 0.71–0.90 mm) using a two-roll mill without external heating or virgin polymers, aiming to obtain a cohesive material. Results demonstrate particle size effects on material properties. The finest fraction exhibited the highest crosslink density (5.30 × 10⁻⁴ mol·cm⁻³), approximately 18% greater than coarser fractions, correlating with superior hardness (≈65 ShA) and elastic modulus (≈7.5 MPa). Tensile properties ranged from 1.6–1.8 MPa stress and 60–75% elongation at break, positioning calendered sheets between low-temperature compression-molded GTR and high-pressure sintered materials reported in the literature. The cold calendering process achieves competitive mechanical performance with reduced energy consumption, simplified processing, and complete retention of recycled content. These findings support the development of regulation-compliant ELT recycling technologies, with potential applications in nonstructural construction panels, vibration-damping components, and protective barriers, advancing circular economy objectives while addressing emerging microplastic concerns. Full article

Low-permeability sandstone oil reservoirs, as an important type of oil and gas resource, feature high reservoir density and low permeability. The utilization of pore throats of different scales during their development process is crucial for enhancing oil recovery. Based on nuclear magnetic resonance and CT scanning techniques, this paper systematically studies the utilization limits and energy contribution of pore larynx under different displacement methods. The results show that during the water injection development process, the main pore–throat radius used by water flooding is between 1 and 20 μm. Among them, the contribution of the small pore tends to stabilize after the pressure rises to a certain stage, the contribution of the medium pore increases with the rise in pressure, while the contribution of the large pore gradually decreases with the increase in pressure. After switching to CO₂ gas flooding, the application range of the pore throat was further expanded to a smaller scale. The contribution of the small pore and the middle pore significantly increased in a specific pressure range, while the large pore made a greater contribution at a lower pressure. This paper has certain reference significance for the study of the limit and contribution of pore–throat exploitation in low-permeability sandstone oil reservoirs. Full article

Understanding molecule–nanoparticle interactions is essential for theoretically describing the adsorption process. Here, we employ Kohn–Sham Fragment Energy Decomposition Analysis (KS–FEDA) to dissect the physical components driving pyridine adsorption on silver and gold nanoparticles. KS–FEDA is rooted in Density Functional Theory (DFT) and partitions the total energy into fragment-localized contributions, providing a rigorous decomposition into electrostatics, exchange–repulsion, polarization, dispersion, and exchange–repulsion terms. This framework offers a chemically intuitive interpretation of molecule–metal bonding at the DFT level, and for analyzing and parameterizing interactions at metal–molecule interfaces. The results highlight the relevant role of electrostatics and induction at localized sites and of dispersion over extended facets. Full article

Facing the significant challenges posed by global population growth and urbanization, plant factories, as an efficient closed cultivation system capable of precise environmental control, have become a key direction in the development of modern agriculture. However, high energy consumption, particularly lighting (which accounts for over 50%), remains a major bottleneck limiting their large-scale application. This study systematically explored the effects of dynamic light regulation strategies on lettuce (Lactuca sativa L.) growth, physiological and biochemical indicators (such as chlorophyll, photosynthetic, and fluorescence parameters), nutritional quality, energy utilization efficiency, and post-harvest shelf life. Four different light treatments were designed: a stepwise increasing photosynthetic photon flux density (PPFD) from 160 to 340 μmol·m⁻²·s⁻¹ (T1), a constant light intensity of 250 μmol·m⁻²·s⁻¹ (T2), a three-stage strategy with high light intensity in the middle phase (T3), and a three-stage strategy with sequentially increasing light (T4). The results showed that the T4 treatment exhibited the best overall performance. Compared with the T2 treatment, the T4 treatment increased biomass by 23.4%, significantly improved the net photosynthetic rate by 50.32% at the final measurement, and increased ascorbic acid (AsA) and protein content by 33.36% and 33.19%, respectively. Additionally, this treatment showed the highest energy use efficiency. On the 30th day of treatment, the light energy use efficiency (LUE) and electrical energy use efficiency (EUE) of the T4 treatment were significantly increased, by 23.41% and 23.9%, respectively, compared with the T2 treatment. In summary, dynamic light regulation can synergistically improve crop yield, chlorophyll content, photosynthetic efficiency, nutritional quality, and energy utilization efficiency, providing a theoretical basis and solution for precise light regulation and energy consumption reduction in plant factories. Full article

Aiming at the drawbacks of the classic CoCrFeNi high-entropy alloy (HEA)—low room-temperature strength and softening above 600 °C, which fail to meet strict material requirements in high-end fields like aerospace—this study used the vacuum hot-pressing sintering process to prepare CoCrFeNiTa_x HEAs (x = 0, 0.5, 1.0, 1.5, 2.0 atom, designated as H4, Ta_0.5, Ta_1.0, Ta_1.5, Ta_2.0, respectively). This process effectively inhibits Ta segregation (a key issue in casting) and facilitates the presence uniform microstructures with relative density ≥ 96%, while this study systematically investigates a broader Ta content range (x = 0–2.0 atom) to quantify phase–property evolution, differing from prior works focusing on limited Ta content or casting/spark plasma sintering (SPS). Via X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive spectroscopy (SEM-EDS), microhardness testing, and room-temperature compression experiments, Ta’s regulatory effect on the alloy’s microstructure and mechanical properties was systematically explored. Results show all alloys have a relative density ≥ 96%, verifying the preparation process’s effectiveness. H4 exhibits a single face-centered cubic (FCC) phase. Ta addition transforms it into a “FCC + hexagonal close-packed (HCP) Laves phase” dual-phase system. Mechanically, the alloy’s inner hardness (reflecting the intrinsic property of the material) increases from 280 HV to 1080 HV, the yield strength from 760 MPa to 1750 MPa, and maximum fracture strength reaches 2280 MPa, while plasticity drops to 12%. Its strengthening mainly comes from the combined action of Ta’s solid-solution strengthening (via lattice distortion hindering dislocation motion) and the Laves phase’s second-phase strengthening (further inhibiting dislocation slip). Full article

Background/Objectives: A significantly higher fracture risk characterizes Type 2 diabetes mellitus (T2DM) patients when compared to the non-diabetic population, even though their average bone mineral density (BMD) tends to be normal or high. This elevated risk is primarily driven by defective bone quality. The trabecular bone score (TBS) and radiofrequency echographic multispectrometry (REMS) have recently been proposed to improve the assessment of bone quality in T2DM individuals. This study aimed to evaluate whether TBS and REMS can improve the identification of osteoporosis and fracture risk in these patients. Methods: BMD was measured in 223 consecutive T2DM patients (126 women and 97 man) and 102 controls. BMD values for the lumbar spine (LS), femoral neck (FN), and total hip (TH) were obtained via both dual-energy X-ray absorptiometry (DXA) and radiofrequency echographic multi-spectrometry (REMS). In all patients, TBS and Fragility Score (FS) by REMS were measured and prior major osteoporotic fractures (MOF) were assessed. Results: All BMD T-scores measured by REMS were significantly lower than those obtained by DXA at both lumbar and femoral sites. T2DM patients with previous MOF exhibited lower T-scores for both BMD-LS and BMD-TH, as assessed by DXA and REMS, compared with patients without fractures. However, these differences reached statistical significance for BMD-TH with both techniques and for BMD-LS with REMS, but not for BMD-LS with DXA. Moreover, patients with a history of MOF had significantly lower TBS values (p < 0.05) and significantly higher FS values at both lumbar (p < 0.05) and femoral (p < 0.01) sites compared with those without fractures. Conclusions: The results of this study suggest that the parameters obtained using REMS technology (BMD and FS) may be valuable tools for improving the diagnosis of osteoporosis and assessing fracture risk in patients with T2DM. Full article

Wettability significantly influences fluid distribution and flow behavior in hydrocarbon reservoirs, yet traditional macroscopic measurements fail to capture the micro- and nanoscale interfacial interactions that govern these processes. This study addresses a critical knowledge gap by employing molecular dynamics simulations to systematically investigate how salinity and mineral composition control wettability at the atomic scale—insights that are experimentally inaccessible yet essential for optimizing enhanced oil recovery strategies. We examined five typical reservoir minerals—kaolinite, montmorillonite, chlorite, quartz, and calcite—along with graphene as a model organic surface. Our findings reveal that while all minerals exhibit hydrophilicity (contact angles below 75°), increasing salinity weakens water wettability, with Ca²⁺ ions exerting the strongest effect due to their high charge density, which enhances electrostatic attraction with negatively charged mineral surfaces and promotes specific adsorption at the mineral–water interface, thereby displacing water molecules and reducing surface hydrophilicity. In oil–water–mineral systems, we discovered that graphene displays exceptional oleophilicity, with hydrocarbon interaction energies reaching −7043.61 kcal/mol for C₁₈H₃₈, whereas calcite and quartz maintain strong hydrophilicity. Temperature and pressure conditions modulate interfacial behavior distinctly: elevated pressure enhances molecular aggregation, while higher temperature promotes diffusion. Notably, mixed alkane simulations reveal that heavy hydrocarbons preferentially adsorb on mineral surfaces and form highly ordered structures on graphene, with diffusion rates inversely correlating with molecular size. These atomic-scale insights into wettability mechanisms provide fundamental understanding for designing salinity management and wettability alteration strategies in enhanced oil recovery operations. Full article

In this study, sheets of experimental high-carbon low-density steels (LDSs) with a thickness of 1.7 mm were processed in a combined tool designed for press-hardening. Press hardening, also known as hot stamping or hot press forming, is a manufacturing process used to create car body parts with exceptional mechanical properties and safety standards. These components often require tailored properties, meaning different mechanical characteristics in various parts of the component. LDSs have a lower specific density than conventional steels, so their use would be particularly suitable in automotive applications. Combined tools achieve distinct mechanical properties within a single part through thermomechanical processing. Simultaneous forming and heat treatment create tailored zones of high strength and ductility within the sheet metal. The hardened zone provides crashworthiness, while the more ductile zone absorbs kinetic energy and converts it into deformation energy. Hot stamping enables forming complex geometries from high-strength sheets with limited cold formability, a capability that can also be exploited for the aluminium-alloyed LDS under investigation in this work. Three different high-carbon LDSs with differences in chemical composition were subjected to this experiment, and the hardness, microstructure, and mechanical properties of the two areas of each sheet were evaluated. The aim is to determine their suitability for processing by press hardening and to try to achieve tailored properties (i.e., differences in ductility and strength across one part) as in a typical representative of 22MnB5 boron steel, where a strength limit of 1500 MPa at 5% ductility is achieved in the cooled part and 600 MPa at 15% in the heated part. Tailored properties were also achieved in the investigated LDS, but with only relatively small differences between the two tool areas. The omega profiles were produced by press hardening without visible defects, and it was possible to process the steels without any difficulties. Full article

In this study, we investigated the impact of incorporating energetic substituents such as –NO₂, –NH₂, –Cl, –F, N-methyl-N-nitro (CH₃–N–NO₂), and picryl on the detonation performance and stability of acridone-based compounds. The B3LYP/cc-pVTZ approach was applied to investigate the influence of substitutions on the stability and detonation properties of acridone derivatives. The results obtained exhibit the significant influence of both the type and position of substituents on the energetic performance and stability of the compounds studied. Notably, the acridone derivative bearing a picryl group and four –NH₂ substituents exhibited energetic properties superior to those of 2,4,6-trinitrotoluene (TNT). Its calculated velocity lies in the range [7.45–7.66] km/s, and its detonation pressure is [22.49–24.36] GPa; however, its stability is lower than that of core compounds. This reduction, however, is dependent on both the nature and number of substituents introduced. Full article

The oxygen reduction reaction (ORR) is a pivotal electrochemical process in energy technologies and in the generation of hydrogen peroxide (H₂O₂), which serves as both an effective agent for dye degradation and a fuel in H₂O₂-based fuel cells. In this regard, a titanium (Ti) sheet was anodized to generate a TiO₂ layer, and then the oxide layer was modified with gold (presented as Au/TiO₂/Ti) via electrodeposition. The developed electrocatalyst was confirmed by X-ray photoelectron spectroscopy (XPS), which showed characteristic binding energies for Ti⁴⁺ in TiO₂ and metallic Au. In addition, the Nyquist plot verified the electrode modification process, since the diameter of the semicircular arc, corresponding to charge transfer resistance, significantly decreased due to Au deposition. Voltametric studies revealed that the TiO₂ layer with a Ti surface exhibited a good synergistic effect on Au and the ORR in a bicarbonate medium (0.1 M KHCO₃) by lowering the overpotential, enhancing current density, and boosting durability. The scan rate-dependent study of the ORR produced by the developed electrocatalyst showed a Tafel slope of 180 ± 2 mV dec⁻¹ over a scan rate range of 0.05–0.4 V s⁻¹, thereby indicating a 2e⁻ transfer process in which the initial electron transfer process was the rate-limiting step. The study also revealed that the Au/TiO₂/Ti electrode caused oxygen electro-reduction with a heterogenous rate constant (k⁰) of $4.40\times {10}^{-3}$ cm s⁻¹ at a formal potential (E⁰′) of 0.54 V vs. RHE. Full article

This study examines the swelling behaviour of nitrile-butadiene rubber (NBR) when interacting with tyre pyrolysis oils (TPO), with a focus on the chemical composition of TPO and their interaction with rubber matrices. Initially, a comparative analysis with conventional diesel fuel (DF) was performed using advanced analytical techniques, including two-dimensional gas chromatography coupled to mass spectrometry (2D-GC/MS), infrared (IR) spectroscopy, and nuclear magnetic resonance (¹H-NMR) spectroscopy. The analysis revealed that TPO contains a significantly higher proportion of aromatic hydrocarbons than DF, along with unsaturated and oxygen-containing compounds not present in DF. Based on these compositional differences, blends of TPO and DF were formulated and evaluated for their suitability as liquid energy carriers according to the specifications of DF. In principle, blends with an addition of up to 5 vol% TPO in DF are technically suitable for use as fuel. Subsequently, the sorption behaviour of TPO, DF, and their blends in NBR was investigated. The swelling potential was determined based on mass, density, and volume, and the changes in the hardness and tensile strength of NBR were recorded. The results demonstrate that TPO induces pronounced swelling in NBR, as evidenced by a marked increase in mass uptake and volume expansion. A linear increase was observed between the degree of swelling and the increasing TPO content in the blends. Mechanical property assessments revealed a corresponding decrease in the hardness and tensile strength of NBR upon exposure to TPO, with the most severe effects associated with neat TPO. This work provides a comprehensive assessment of TPO as a potential blend component for DF. It highlights the need for careful consideration of material compatibility in practical applications. Full article

Elemental gamma spectroscopy logging while drilling is crucial for assessing element content in unconventional oil and gas reservoirs. Unlike wireline elemental spectroscopy logging, the high cross section and high-density characteristics of the drill collar can interfere with the detection of formation element content. Using numerical simulation, this paper develops a drill collar background signal removal method based on a dual detector gamma energy and time spectra combination. First, the gamma counts ratio in different time periods from the time spectra of the dual detector and the gamma energy spectra measured by the near detector are used to characterize the drill collar background. Then, the energy spectra measured by the far detector are integrated to reconstruct the pure formation gamma energy spectra. The reconstructed gamma energy spectra demonstrate that the deviation of low-content element yields can be controlled within 0.5%, indicating the accuracy of the drill collar background removal method based on dual spectra information. A numerical simulation case of elemental logging while drilling in unconventional reservoirs is constructed, and the drill collar background is removed using the time spectra and energy spectra information of the dual detector. The calculation of element and mineral contents shows that the maximum calculation errors can be controlled within 2% and 3.5%, respectively, with the calculation error for low cross section elements like Mg reduced to below 0.5%. In conclusion, the proposed drill collar signal removal method based on the time and energy domains effectively improves the accuracy of formation elemental content calculation under drilling conditions, providing theoretical guidance and technical support for elemental content evaluation and mineral analysis in unconventional oil and gas reservoirs. Full article

With the increasing demand for high-energy-density lithium batteries, the role of separators has expanded significantly beyond conventional ion conduction and physical isolation. By integrating sensors and introducing functional coatings, separators have gained the ability to monitor internal states in real time and achieve adaptive regulation. This paper systematically reviews the latest research progress on separators modified with functional materials and coatings to achieve information sensing, intelligent response, and multifunctional integration. Notably, an electrochemical sensor based on MXene/MWCNTs-COOH/MOF-808 has been developed for rapid chemical detection; a fully printed ultra-thin flexible multifunctional sensor array has enabled multi-parameter synchronous monitoring; an ion-selective MOF-808-EDTA separator has induced uniform lithium-ion flux; and a PVDF-HFP/LLZTO/PVDF-HFP trilayer separator has maintained structural integrity at 300 °C. These innovative achievements fully demonstrate the enormous potential of intelligent separators in monitoring internal battery states, inhibiting dendrite growth, preventing thermal runaway, and significantly enhancing battery safety, cycle life, and energy density. This points to a transformative development path for the next generation of batteries with higher safety and intelligence. Full article