Search Results (2,104)

For continuous crystallization of pharmaceutical and organic chemical compounds in a plug flow crystallizer, seed slurry, prepared in advance, is continuously fed into the crystallizer for controlled secondary nucleation and subsequently desired crystal properties. It is well known that the preparation of macro seed crystals using either the dry or wet method is a highly time-, energy- and material-intensive process, often taking many hours to prepare a 1 L seed slurry. The focus of this work is to examine whether how the seed slurry is made up could have any effect on the final crystal properties. We divide the seed slurry into two parts: the “saturation part” corresponds to the amount of solute required to establish solid–liquid equilibrium and is fully dissolved, and the “supersaturation part” involves a small amount of solid seed crystals in excess of the equilibrium saturation condition. The hypothesis states that if dissolved seed crystals have lost their surface properties (such as size, morphology, interfacial effects), the final crystal size distributions would then inherit that of the solid seed crystals. If this is true, this would provide a great and efficient shortcut for the lengthy and energy-intensive process of making up seed slurries, as product crystals from a previous batch of any size distribution could be used for the make-up of the saturation part of the seed slurry. Using adipic acid and L-glutamic acid with high and low solubilities, the hypothesis has been validated experimentally under batch conditions. Full article

In this work, three biochars were synthesized from a mixture of an abundant agricultural waste (date palm fronds) and an animal biomass (chicken manure) at pyrolysis temperatures of 700 °C (B-700), 800 °C (B-800), and 900 °C (B-900), respectively. These biochars were characterized and used as electrode materials in a capacitive deionization (CDI) process to remove salts from saline water. The CDI results show that the B-700 electrode displayed the highest desalination efficiency of 10.2% with 100 ppm NaCl. Further mixing the B-700 with 10% and 20% of multi-walled carbon nanotubes (CNT) revealed an enhanced desalination performance. For instance, a biochar-20%CNT electrode achieved a salt adsorption capacity (SAC) of 11.32 mg/g at 200 ppm NaCl, which is 7.6 times higher than that of B-700 alone. The performance enhancement is attributed to carbon nanotubes acting as conductive channels between biochar particles, thereby improving electrical conductivity and electrochemical properties of the CDI electrode. Additionally, the presence of well-known hydrophilic functional groups on CNT surfaces enhances hydrophilicity, providing a highly porous surface area. The results suggest that the CDI method with biochar–CNT electrodes offers opportunities for energy-efficient, low-cost freshwater production, with significant scaling up potential for the treatment of brackish and wastewater. Full article

Coral reefs are typical ecosystems of high diversity and productivity, but they are facing significant degradation in their structure and function due to the dual stresses of climate change and human activities. To uncover the trophic structure, energy flow, and environmental driving mechanisms of nearshore coral reefs in Hainan, this study constructed mass balance models for five regions, Sanya, Changjiang, Lingao, Wenchang, and Wanning, using Ecopath with Ecosim, and conducted quantitative analysis in conjunction with satellite environmental monitoring data. The results showed that the trophic levels of functional groups in different ecosystems ranged from 1.00 to 5.00, with Sanya and Changjiang having the highest trophic levels (4.505, 4.656), higher than Lingao, Wenchang, and Wanning (3.776–3.924). The system average trophic transfer efficiency ranged from 15.98% to 30.25%, generally higher than the classic Lindeman 10% rule, with Changjiang being the highest (30.25%) and Lingao the lowest (15.98%). In terms of material cycling, the energy utilization efficiency of primary trophic levels was low, with a large amount of energy retained as detritus at lower trophic levels; Sanya and Changjiang showed more complete detritus chain energy cycling, with Finn cycling indices reaching 7.69 and 2.53, respectively, indicating higher maturity. Keystone analysis identified zooplankton, corals, and medium carnivorous fish as key functional groups with a decisive impact on system stability. Environmental correlation analysis revealed that particulate inorganic carbon (Pic), light diffuse attenuation coefficient (Kd), chlorophyll-a concentration (Chl_a), and sea surface temperature (Sst) were the main regulating factors, among which Pic showed a significant peaked relationship with the total system throughput, total biomass, and total production, with an optimal range of 0.0050–0.0075 mol/m². Overall, the material cycling and energy flow states of the Sanya and Changjiang coral reef ecosystems were stronger than those of Lingao, Wenchang, and Wanning, with lower fishing pressure in the former contributing to a more complex food web and enhanced community structural stability. This study provides the first systematic quantitative assessment of food-web structures across five distinct nearshore coral reef regions in Hainan, introducing an early-warning threshold for particulate inorganic carbon that offers direct, actionable reference for regional ecosystem-based management. Full article

Carbon fiber (CF)-reinforced polyethylene (PE) composites have low density, outstanding corrosion resistance and good processability. These materials are widely promising for household appliances, automobiles and construction industries. Nevertheless, PE is a non-polar inert matrix with extremely low surface energy, leading to poor interfacial wettability and bonding force with CF. Interfacial debonding frequently occurs along with low load transfer efficiency, failing to meet the service requirements of high-performance structural components. In this study, CF was carboxylated with hydrogen peroxide, and Cu-BTC porous materials were in situ grown on the fiber surface to obtain modified CF (CF-Cu-BTC). The CF-Cu-BTC was then incorporated into a low-density polyethylene (LDPE) matrix. The MOF layer improves the interfacial compatibility and bonding force between the fibers and the matrix and enhances the overall mechanical properties and structural stability of the composites. The mechanical performance of CF composites is remarkably superior to that of pure LDPE. Compared with the pristine sample with a tensile strength of 11.04 MPa, the composite exhibits an enhanced tensile strength of 26.63 MPa, an increase of 141.20%. Scanning electron microscopy results confirm that no gaps exist between the CF and LDPE, verifying favorable interfacial compatibility. MOF-modified CF effectively improves the mechanical properties of resin-based composites. This study provides practical guidance for advanced composite applications. Full article

Polymer-based sandwich structures have garnered significant interest as energy-absorbing protective materials. However, common damage modes in composite sandwich panels include matrix cracking, delamination, core crushing or core fracture, and debonding between the face sheets and the core. Among these, face–core debonding is one of the most prevalent failure mechanisms. This paper investigates a sandwich configuration designed to enhance blast resistance by incorporating a self-adhesive, stiffened polyimide foam (ASPI) into a steel–foam–steel architecture. The thermogravimetric analysis exhibits that ASPI foam obtained excellent thermal stability, and the residual mass retention at 800 °C was more than 36.2%. Experimental results show that at scaled distances of 1.077 m/kg^1/3 and 1.292 m/kg^1/3, the ASPI foam-based sandwich panels exhibited mid-span displacements as low as 8.5 mm and 6.7 mm, respectively. Under a scaled distance of 1.077 m/kg^1/3, the mid-span displacement of the ASPI foam-based sandwich structure decreased from 15.0 mm to 8.5 mm, representing a 43.3% reduction compared with that of the neat polyimide foam-based sandwich structure. Moreover, compared with neat PI foam, the ASPI foam exhibited superior adhesion to steel face sheets, and no interfacial debonding was observed after blast loading. To further elucidate the underlying damage mechanisms under blast loading, a well-validated finite element model was developed and employed. Complementary scanning electron microscopy (SEM) analyses were conducted to examine the microstructural morphology of the ASPI foam core’s cross-section and surface after blast exposure. This study presents an investigation of a lightweight, self-adhesive, high-thermal stability, blast-resistant polymer-based composite foam. Full article

Driven by the dual-carbon target strategy, the new energy vehicle industry has achieved large-scale and rapid development. As the core protective component of power batteries, the surface quality of battery shells directly determines the operational safety and reliability of batteries. However, defects such as scratches, pits, and cracks easily occur on battery shells during forming processes, including stamping and deep drawing. Traditional manual detection suffers from bottlenecks, such as high labor intensity, low detection efficiency, and high false detection rates, making it difficult to adapt to the large-scale and high-cycle production requirements of modern industry. Firstly, this study systematically elaborates the material system, preparation process, and defect formation mechanism of battery shells, and clarifies the coupling mechanisms of material properties, process parameters, and equipment and environmental conditions for defect evolution. Subsequently, it compares and analyzes the principles, advantages and disadvantages, and applicable scenarios of traditional machine-vision- and deep-learning-based detection technologies, and focuses on analyzing the application performance and optimization paths of single-stage and two-stage object detection algorithms in shell defect recognition. Furthermore, it addresses the core challenges of deep-learning-based battery shell defect detection technologies in data, algorithm deployment, detection dimensions, and other aspects, and proposes targeted optimization strategies. Finally, the development directions, such as system integration and online learning, are forecasted. This study can provide theoretical support and technical references for the intelligent manufacturing of battery shell stamping and forming, as well as for surface defect detection. Full article

Biochar has attracted increasing attention for aquatic pollution control, particularly due to its capacity to accelerate the rate-limiting steps of denitrification in wastewater treatment. While early research primarily focused on the adsorption capacity of biochar, recent studies have increasingly investigated its role as a redox-active mediator that facilitates electron transfer. This review critically synthesizes the multifaceted mechanisms of biochar-enhanced denitrification, establishing a link between synthesis parameters (feedstock, pyrolysis kinetics) and physicochemical functionalities (pore architecture, redox-active functional groups). Specifically, we elucidate how precise regulation of pyrolysis temperature dictates the dominant electron transfer pathway: low-temperature biochar (<500 °C) facilitates electron shuttling via oxygen-containing functional groups (e.g., quinone moieties), whereas high-temperature biochar (>700 °C) promotes direct interspecies electron transfer (DIET) through graphitic conduction. We systematically decouple biochar-mediated electron transfer into three pathways: functional group-driven shuttling, solid-state conductive matrix transfer via conjugated π-electrons, and material-assisted DIET. Crucially, we emphasize that validating true DIET requires direct biological evidence of electroactive machinery. Furthermore, the review details how biochar modulates the biological microenvironment, upregulating key denitrification genes (narG, nirS/K, nosZ) and enriching functional microbial consortia. By integrating advances in surface modification—such as heteroatom doping and metal loading—we propose strategies to engineer biochar for optimized nitrate-to-nitrogen conversion. Future perspectives underscore the need for balancing electron-donating capacity with structural stability, developing low-energy functionalization techniques, and conducting life-cycle assessments to facilitate the scale-up of sustainable, high-efficiency nitrogen removal systems. Full article

Landscape structures generate significant life-cycle embodied carbon due to material redundancy and low structural efficiency. While topology optimization provides a scientific basis for material reduction, its resulting free-form surfaces and complex joints often hinder manufacturing and on-site assembly. This study introduces the Design for Manufacture and Assembly (DfMA) method to address these challenges, using landscape benches, pavilions, and bridges in the Beijing Olympic Forest Park as case studies. After data collection, we performed topology optimization via Autodesk Fusion and applied DfMA principles to simplify complex topological forms into standardized, modular structural systems. Life-cycle embodied carbon emissions were then compared across initial, topology-optimized, and DfMA-simplified designs. The results indicate that while topology optimization reduces material usage by 19–85%, it may increase total carbon emissions, especially in complex metal structures, due to higher construction energy demands and recycling difficulties. In contrast, DfMA simplification significantly improves manufacturing feasibility, cutting total carbon emissions by 33–64% compared to initial designs. The material production phase exhibited the most prominent carbon reduction, contributing an average of 60% to total emission savings. Ultimately, this study highlights that topology optimization alone is not universally carbon-reducing, and it requires DfMA-oriented simplification to achieve reliable low-carbon outcomes. 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

Ultracold neutrons (UCNs) are free neutrons with kinetic energies so low that their equivalent thermal temperature lies below 3.5 mK (below 3 × 10⁻⁷ eV). At these extreme energies, neutrons exhibit de Broglie wavelengths on the order of hundreds of angstroms and move slowly enough to be confined in material, magnetic, and gravitational traps through total internal reflection. For context, this is about three orders of magnitude colder than the 1 K regime used in superfluid helium UCN sources, which underscores why these neutrons are called “ultracold”: their equivalent thermal energy is comparable to millikelvin physics, even though UCN sources themselves typically operate at 0.8–5 K and produce UCN through superthermal downscattering rather than thermal equilibrium. Over the past several decades, substantial progress in ultracold-neutron source technology has been achieved through the transition from mechanical neutron turbines to superthermal converters based on solid deuterium and superfluid helium. This review provides a comprehensive analysis of modern reactor-based (ILL, PNPI, TRIGA) and spallation-driven (PSI, TRIUMF, SNS, ESS) UCN sources, together with next-generation facilities targeting UCN densities of 10³–10⁴ cm⁻³. Particular attention is devoted to anomalous neutron losses during storage. It is shown that hydrogen-containing surface contaminants, inelastic scattering processes, and wall-induced depolarization contribute significantly to losses beyond those predicted for ideal materials. Current approaches for loss reduction are discussed, including diamond-like carbon coatings, magnetron sputtering techniques, optimization of the ortho–para ratio in neutron converters, and purification of superfluid ⁴He from trace concentrations of ³He impurities. The review further examines key precision experiments that drive advances in UCN technology, including investigations of the neutron lifetime discrepancy and searches for the neutron electric dipole moment at sensitivities approaching 10⁻²⁷–10⁻²⁸ e·cm as probes of CP violation and baryon asymmetry of the Universe. Finally, future directions for increasing UCN density, extending storage times, and enhancing the sensitivity of fundamental physics experiments are discussed. Full article

Sodium-ion batteries (SIBs) have become a crucial supplementary technology for large-scale energy storage due to abundant sodium resources and their low cost. Biomass-derived hard carbon materials have been considered as one of the most promising anode materials for commercial SIBs. However, the inherent structures of different biomass materials vary significantly, which directly affects the electrochemical performance of the resulting hard carbon anode materials. In this review, raw materials are classified into four types based on the natural structure characteristics of biomass: fibrous, granular, dense, and special. This review highlights the structural characteristics of each biomass type and their influence on sodium storage performance. The carbonization process, including the treatment of raw materials before carbonization, the parameter control during the carbonization process, and the surface optimization after carbonization, is proposed as an effective strategy for regulating the structure of biomass-derived hard carbon. The existing structural deficiencies in current carbon materials are also analyzed. Finally, the selection of biomass precursors and the structural regulation strategies for commercial SIBs are discussed. Full article

Thermal energy storage using suitable materials is a strategic solution for integrating renewable energy and decarbonising industrial processes. Current Power-to-Heat systems using solar salt rely on electric heaters; however, the low thermal conductivity of molten solar salt promotes localised hot spots, leading to material degradation and reduced performance. Microwave heating is a promising alternative due to its volumetric heating capability and compatibility with renewable electricity. Nevertheless, dielectric characterisation shows that molten solar salt behaves as a highly conductive ionic medium with significant dielectric losses, limiting microwave penetration and resulting in predominantly surface-localised heating. To investigate this limitation, two cavity configurations were analysed using multiphysics simulations and parametric design studies: a single-mode elliptical cavity operating at 915 MHz with an iris, and a quasi-cylindrical multimode cavity operating at 2.45 GHz for scalable applications. The coupled electromagnetic, fluid-flow, and thermal behaviour was evaluated through the resulting field distributions and heating patterns. Complementary experiments assessed microwave-transparent container materials and determined the emissivity of molten solar salt from thermographic measurements, highlighting key engineering considerations for integrating microwave heating into next-generation Power-to-Heat technologies. The results demonstrate that microwave heating of highly conductive molten solar salt is fundamentally constrained by the limited electromagnetic penetration depth, defining practical design limits for its integration into next-generation Power-to-Heat systems. Full article

Multicomponent ferrite oxides with mixed valence states and tunable oxygen-defect chemistry are promising active materials for low-power memristive synapses. In this work, Ag/Ni_0.3Cu_0.2Zn_0.5Co_0.005Mn_0.005Fe_1.99O/Ag memristors were fabricated by pulsed laser deposition, and the effects of post-deposition annealing at 700–900 °C on film structure, chemical states, magnetic behavior, resistive switching, and synaptic performance were investigated. The film annealed at 800 °C exhibited a dense surface morphology, improved crystallinity, and uniform elemental distribution. X-ray photoelectron spectroscopy confirmed the coexistence of Fe²⁺/Fe³⁺ states and oxygen-related defect components, indicating the presence of oxygen vacancies. Room-temperature magnetic hysteresis measurements revealed ferrite-type magnetic behavior in the annealed films, with the 800-annealed sample showing a relatively well-defined normalized hysteresis response. The optimized device exhibited representative bipolar resistive switching within ±0.5 V, distinguishable high- and low-resistance states, Ohmic conduction in the low-resistance state, and Schottky-emission-dominated transport in the high-resistance state. These results suggest that reversible oxygen-vacancy migration and interfacial barrier modulation govern the switching process. The device showed preliminary synaptic-like transient current responses. Further systematic reliability and conductance-modulation measurements are still required to fully evaluate endurance, reproducibility, and synaptic weight-update behavior. This study demonstrates that annealing-controlled multicomponent ferrite oxides offer a feasible route for energy-efficient memristive synaptic devices. Full article

Waterproofing is crucial for maintaining the structural integrity and extending the longevity of buildings. However, traditional waterproofing materials possess limitations, including restricted durability, complex installation procedures, and environmental pollution, making them insufficient to meet the advanced waterproofing demands of modern buildings under complex conditions. Superhydrophobic materials, characterized by a water contact angle greater than 150° and a water sliding angle less than 10°, exhibit low surface energy, self-cleaning properties, and corrosion resistance due to their distinctive micro–nano structure and chemical composition, thereby serving as an innovative high-performance solution for building waterproofing and helping address some limitations of traditional waterproofing technologies. This review systematically elucidates the fundamental wetting theory and formation mechanisms of superhydrophobic materials, categorizes superhydrophobic materials used in building waterproofing mainly according to substrate type, discusses their modification strategies and key functional components, and conducts a detailed analysis of their application scenarios, performance advantages, and engineering test data in the waterproofing of concrete structures, steel structures, and building envelope materials (wood, stone, building coatings). Furthermore, this review analyzes the technical bottlenecks, performance limitations, and industrialization challenges associated with the current practical application of superhydrophobic building waterproofing materials, and outlines future development trends and engineering application strategies from the perspectives of material performance optimization, cost control, construction technology enhancement, and standardization. Full article

Coal gasification slag (CGS), a massive industrial solid waste, possesses inherent adsorptive potential that remains underutilized due to pore blockage by amorphous siliceous phases. Conventional modification strategies typically rely on energy-intensive high-temperature processes. Herein, we report a facile, low-temperature alkaline activation approach to transform CGS into a high-efficiency adsorbent (denoted NCGS) for Cd²⁺ removal. Sodium hydroxide (NaOH) solution was employed under mild conditions (90 °C) to selectively etch siliceous species, thereby generating a porous architecture and enriching surface oxygen-containing functionalities. Orthogonal experimental design identified optimal synthesis parameters (1 mol/L NaOH, solid–liquid ratio of 1:30 g/mL, 12 h), yielding NCGS with significantly enhanced textural properties. The adsorption isotherm was well described by the Langmuir model, with a maximum capacity of 87.06 mg/g at pH 6.0, while kinetic studies indicated the adsorption process could be described by pseudo-second-order kinetic model. Comprehensive characterization via SEM-EDS, FTIR, and XPS elucidated a multi-mechanistic adsorption pathway mainly involving ion exchange (Na⁺/Cd²⁺) and coordination complexation. Life cycle assessment analysis revealed that NCGS production generates 11.23 kg CO₂ eq emissions, with transportation accounting for 88%. This study presents an energy-saving and environmentally friendly strategy to unlock the adsorptive potential of CGS, providing a highly promising waste-based adsorption material for the remediation of Cd²⁺-contaminated water. Full article