Search Results (9,294)

This study fabricated choline–acrylic acid deep eutectic solvent (DES) hydrogels via in situ free-radical polymerization and systematically investigated the individual and co-optimization effects of lignin dosage and water content on the chemical structure, micromorphology, compressive mechanical properties, swelling behavior, and thermal stability of the hydrogels. This work quantitatively uncovers the co-optimization mechanism between the two variables in modulating crosslink density and pore architecture, thereby filling a research gap in the dual-factor co-optimization of biomass-based DES hydrogels. The results reveal that a moderate lignin dosage (0.02 g) generates abundant dynamic hydrogen bonds, densifying the crosslinked network and raising the maximum compressive stress from 0.378 MPa to 0.426 MPa, whereas excessive lignin triggers molecular aggregation and deteriorates mechanical performance. Higher water content dilutes crosslinking sites, reduces network compactness, boosts the swelling ratio while lowering compressive strength, and exerts negligible impacts on thermal degradation characteristics. FTIR analysis confirms that lignin participates in network formation solely through non-covalent hydrogen bonds, without forming new covalent bonds. A comprehensive performance evaluation identifies the optimal formulation as 0.02 g lignin and 60 g water. Although this two-factor optimization strategy provides clear experimental and theoretical guidance for designing sustainable soft materials, the present work still has limitations, including the use of only static laboratory characterizations, with no cyclic mechanical measurements or aging assessments. This study advances the customized performance tuning of lignin-derived DES hydrogels and facilitates the high-value valorization of lignin, which is promising for multifunctional green-material applications, including adsorption, flexible electronics, and biological carriers. Full article

Background: Flower color is a primary determinant of ornamental value in flowering plants. Although the biosynthetic pathways of major petal pigments have been extensively documented, the systems-level mechanisms coordinating color diversification across multiple cultivars of Kalanchoe blossfeldiana remain less understood. This study aimed to establish a comparative metabolomic and transcriptomic framework to elucidate these mechanisms. Methods: Petal tissues were collected from five cultivars with white, yellow, orange, red, and purple–red flowers at the full-bloom stage. Metabolomics was performed for flavonoids and carotenoids using UPLC-MS/MS, and transcriptome sequencing was conducted via Illumina NovaSeq 6000. Integrative analysis of metabolome and transcriptome data, together with weighted gene co-expression network analysis, was employed to identify key metabolites, differentially expressed genes, and associated regulatory networks. Quantitative PCR was used to validate the expression patterns of key structural genes. Results: Petal color variation was shaped by coordinated flux partitioning between flavonoid and carotenoid networks rather than by isolated activation of single pathways. A metabolic relay pattern was observed in the phenylpropanoid–flavonoid axis, wherein shared upstream activation fed divergent downstream branches that directed accumulation toward distinct anthocyanin or flavonol profiles. Notably, yellow pigmentation relied more heavily on flavonoid flux than on carotenoid accumulation, and orange coloration arose from the synergistic co-accumulation of multiple pigment classes. Transcriptional module analysis identified gene networks associated with specific color phenotypes. Conclusions: These findings provide a systems-level understanding of pathway crosstalk in flower color formation and offer candidate targets for molecular breeding in K. blossfeldiana and related ornamental plants. Full article

Improving the low-carbon operational performance of wastewater treatment facilities (WWTFs) is important for coordinated pollution reduction and carbon mitigation in China. The interprovincial carbon emission efficiency (CEE) of WWTFs reflects both the low-carbon performance of regional wastewater governance systems and cross-regional linkages shaped by technology diffusion, governance experience, and spatial adjacency. Using operational data from WWTFs in 30 provincial-level regions of China from 2010 to 2023, this study first measures provincial CEE with a super-efficiency slack-based measure (SBM) model incorporating undesirable outputs. It then integrates a modified gravity model, social network analysis, and the quadratic assignment procedure (QAP) to examine the evolution, structure, and formation mechanisms of the association network. The results show that the CEE of provincial WWTFs remained below the efficiency frontier overall, with periodic fluctuations and persistent structural differences. The model-inferred association network first contracted and then expanded, showing dense connections in eastern and central China and sparse connections in the northwest. Its node structure evolved from a dispersed multicore pattern to hub-centered concentration and then back toward a multicore configuration, while inter-block linkages showed a hierarchical transmission structure involving core spillovers, absorptive transmission, and peripheral reception. The QAP results indicate that interprovincial adjacency is the most stable correlate of network formation, whereas differences in technological innovation and capacity utilization show only stage-specific associations. These findings suggest that the CEE of WWTFs is not only a local performance outcome, but also a relational outcome shaped by regional linkages and structural positions. Therefore, low-carbon governance of WWTFs should move beyond single-region efficiency improvement and place greater emphasis on cross-regional collaboration, role-specific policy design, and leadership by core regions. Full article

The mantle of bivalves plays a fundamental role in shell formation and maintenance through biomineralization. Experiments performed on mantle–shell preparations using different experimental techniques revealed the presence of phosphorus (P)-containing compounds in the shell as the first mineral phase formed at the growing edge of the periostracum in the freshwater bivalve Limnoperna fortunei. The low P concentration in the shells suggests that phosphate is restricted to the growth regions and occurs at concentrations too low to be detected by techniques such as X-ray diffraction (XRD). Nevertheless, a crystal morphology closely resembling that of hydroxyapatite (HAp) was identified at the shell growth front, and a Ca/P ratio of 1.67, consistent with HAp, was determined in two of these regions. Fourier transform infrared (FTIR) spectroscopy also revealed the principal and most intense absorption band of the phosphate group (PO₄³⁻) at 1024 cm⁻¹. Enzymes such as carbonic anhydrase (CA), or proteins with equivalent functions, are likely involved in phosphate dissolution and the subsequent precipitation of calcium carbonate. In addition, the occurrence of calcium phosphate was confirmed in the shells of the marine bivalve Perna perna. Phosphate dissolution and carbonate precipitation during biomineralization suggest two important evolutionary advantages: first, the release and availability of phosphate, an essential nutrient for energy production and other metabolic functions; and second, the formation of a calcium carbonate shell, a structure indispensable for the protection, mechanical support, and survival of mollusks. Full article

The combined use of ceramic waste powder (CWP) as a supplementary cementitious material and magnetized water (MW) as mixing water represents a promising strategy for producing sustainable concrete with reduced cement consumption while maintaining mechanical performance and durability. However, the synergistic effects of burnt ceramic waste powder (BCWP) and unburnt ceramic waste powder (UBCWP) combined with MW, particularly under aggressive environmental conditions, remain insufficiently investigated. This study evaluates the influence of BCWP and UBCWP, used as partial replacements for ordinary Portland cement (OPC) at replacement levels of 10%, 20%, and 30% by weight, together with conventional tap water (TW) and MW produced using a dual-field magnetic device (0.9 T and 1.5 T). A total of fourteen concrete mixtures were investigated through compressive strength tests at 7, 28, and 120 days; indirect tensile and flexural strength tests at 28 and 120 days; sulfate resistance after 120 days of MgSO₄ immersion; residual strength after thermal exposure at 200 °C; and microstructural characterization using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The results indicate that increasing the CWP replacement level progressively reduced the mechanical properties of concrete; however, MW consistently mitigated these reductions by promoting cement hydration and producing a denser cementitious matrix. The mixture containing 20% BCWP with MW achieved a 120-day compressive strength comparable to that of the TW control, demonstrating that cement consumption can be reduced without compromising structural performance. Furthermore, MW mixtures exhibited significantly improved durability, with compressive strength losses of only 16–28% after sulfate attack compared with up to 42% for TW mixtures, and 1–13% after thermal exposure compared with up to 53% for TW mixtures. SEM and XRD analyses confirmed the development of denser microstructures with enhanced C–S–H gel formation in MW–CWP concretes. Overall, the findings demonstrate that the synergistic combination of ceramic waste powder and magnetized water provides an effective strategy for producing sustainable concrete with enhanced long-term mechanical performance, improved durability under aggressive environmental conditions, and reduced environmental impact. Full article

During the entire service cycle, the Electro-Hydrostatic Actuators (EHAs) are subjected to multi-physical stresses, including coupling effects, including high temperatures, severe temperature variation, and high-frequency pulses. These stresses not only act on the mechanical structures but also continuously degrade the dielectric properties and mechanical strength of the insulation materials, with long-term accumulation potentially leading to deterioration in insulation performance. Consequently, whether the insulation system can remain stable under such harsh conditions becomes a core factor constraining EHA reliability, and its insulation reliability directly determines the operational safety of aircraft actuation systems. Targeting the aerospace EHA motor insulation system, this paper aims to construct a systematic condition assessment method and a life degradation feature based on the dynamic evolution characteristics of multi-dimensional dielectric parameters. This study conducts accelerated thermal aging and thermal cycling tests on a 270 V Type I aerospace EHA motor insulation system, with multi-parameter tracking of equivalent capacitance (Ceq), partial discharge inception voltage (PDIV), and leakage current (I). The results indicate that Ceq exhibits high sensitivity to early-stage insulation damage. PDIV presents non-monotonic fluctuations during aging, and combined with Paschen’s law, the reduction in air-gap dimensions due to thermal expansion in the mid-stage is the physical origin of its phased recovery—verifying the rationale in using PDIV as the electrical safety boundary. In contrast, leakage current shows significant hysteresis, remaining robust at 0.35–0.55 mA until a sharp jump signals the formation of through-going conductive channels, which serve as the ultimate failure criterion. On this basis, a hierarchical assessment framework is constructed: Ceq captures degradation precursors, PDIV defines the safety boundary, and leakage current acts as the final failure indicator. This study refines the multi-stress evaluation method for aerospace motor insulation and provides experimental support for reliability assessment and life prediction of actuation systems in next-generation more-electric aircraft. Full article

Steep rock slopes are widely distributed in the karst mountainous regions of southwestern China, where structurally controlled rockfalls frequently threaten transportation infrastructure and human safety. Accurate identification of unstable rock blocks (URs) and quantitative assessment of their post-failure hazards remain major challenges because of complex discontinuity networks and fragmentation during rockfall motion. Taking the Zuojiaying steep rock slope in Guizhou Province as a representative case, this study integrates high-resolution UAV photogrammetry, automatic discontinuity identification, unstable rock block detection, and three-dimensional rockfall simulation to investigate the formation mechanisms and hazard characteristics of discontinuity-controlled rockfalls. A high-resolution three-dimensional terrain model was reconstructed from UAV imagery, and six dominant discontinuity sets were automatically identified using the I-MinPts-constrained DBSCAN algorithm. Combined with the Rock Occurrence Kinematic Analysis (ROKA) algorithm and Block Theory, 54 unstable rock blocks were identified, with wedge failure and toppling failure representing the dominant instability modes. The results indicate that discontinuity combinations govern both rock mass segmentation and unstable rock block geometry. Specifically, discontinuity sets J1, J3, and J5 mainly control wedge-shaped blocks, and J2 and J4 dominate columnar toppling blocks, whereas J6 further promotes the formation of isolated unstable rock blocks. Three-dimensional RockGIS simulations considering fragmentation reproduced the complete rockfall process from detachment to final deposition. The maximum travel distance, kinetic energy, and bounce height reached 395 m, 748.5 kJ, and 40.1 m, respectively. Fragmentation increased the number of rock blocks from 54 to 1013, substantially enlarging the potential impact area. A raster-based Rockfall Hazard Index (RHI) further revealed that the middle–lower slope and slope toe constitute the principal high-hazard zones, and under extreme scenarios, high-energy fragments may reach the G246 National Highway and adjacent infrastructure. This study revealed the formation mechanisms and hazard characteristics of unstable rock blocks controlled by discontinuity combinations in the study area, providing a case reference for rockfall hazard identification and mitigation on similar high-steep rock slopes in karst mountainous regions. Full article

Background/Objectives: Time-varying low-frequency electromagnetic fields (LF-EMFs), including pulsed electromagnetic fields (PEMFs) and sinusoidal low-frequency electromagnetic fields, have been investigated as modulators of tissue repair and vascular remodeling. Although numerous studies report pro-angiogenic effects in endothelial systems, the underlying mechanisms remain incompletely understood. This review synthesizes evidence for LF-EMF-induced endothelial angiogenesis and evaluates emerging mechanistic explanations. Methods: Literature was identified through searches of PubMed, Web of Science, and Google Scholar through March 2026. Peer-reviewed studies emphasizing in vitro endothelial angiogenesis models were prioritized, with selected in vivo studies included when relevant to mechanistic interpretation. The review was conducted as a narrative synthesis rather than a systematic review or meta-analysis. Results: Experimental evidence indicates that LF-EMF exposure can enhance endothelial proliferation, migration, sprouting, tube formation, and survival across diverse model systems. Reported mechanisms include modulation of growth factor signaling, calcium-dependent pathways, nitric oxide production, cytoskeletal remodeling, and mechanotransduction. Reexamination of early ultrastructural studies suggests that membrane ruffling, vacuole formation, and vesicular structures observed following LF-EMF exposure may be interpreted within the framework of macropinocytosis and vesicular trafficking, providing a potential mechanistic link between electromagnetic stimulation and endothelial morphogenesis. Conclusions: Current evidence supports the conclusion that LF-EMFs can modulate key endothelial processes involved in angiogenesis and vascular remodeling. Membrane trafficking and macropinocytosis provide a biologically plausible framework linking historical observations with contemporary endothelial cell biology, although direct experimental validation is needed. Future progress will require standardized exposure paradigms and mechanistic studies using physiologically relevant angiogenesis models. Full article

SrAl₂O₄: Eu²⁺, Dy³⁺ polymeric composites are the reference photoluminescent materials in passive signaling due to their high emission intensity and long luminescent persistence. But their real long-term outdoor durability is still poorly understood. This study analyzes a strontium aluminate polymer composite exposed to real weathering for 15 years to evaluate its degradation threshold, exceeding the frameworks of accelerated tests. Using FTIR, Raman, FE-SEM, colorimetry and phosphorescence decay, the weathered material was compared with its reference material. Results show that the luminescent composite retains its structural properties, its optical functionality improving its mechanical properties (increasing the flexural strength between 23 and 64% and microhardness between 136 and 164%), while suffering only a small yellowing, suggesting a longer service life than expected. Finally, it was established that the loss in the optical performance is not due to irreversible degradation of the polymer or pigment but is caused by the accumulation of surface dust and the formation of an opaque outer layer. The application of mechanical surface polishing removes this polluting layer, restoring optical transmittance and effectively recovering almost the original luminosity of the photoluminescent system. Full article

Hyperspectral image (HSI) classification aims to assign a land cover label to each pixel by jointly exploiting spectral signatures and spatial contextual information. Recently, Mamba-based state-space models have shown potential for long-range dependency modeling with improved efficiency compared with Transformer-based architectures. However, directly applying standard Mamba structures to patch-based HSI classification still faces three major limitations: Noisy pixel-level tokens may disturb state-space propagation, conventional scanning paths are not well aligned with central-pixel prediction, and fine-grained spectral signatures may be weakened in deep feature representations. To address these issues, this paper proposes a Region Spectral–Spatial Mamba network with Bidirectional Spiral Scanning and Cross-Attention, termed RSSMamba. Specifically, a Dynamic Spatial–Spectral Saliency Tokenization (DSST) module is first designed to suppress redundant spatial–spectral responses and generate semantically consistent regional tokens. Then, a Bidirectional Spiral Selective Scanning (B3S) mechanism serializes the feature map along clockwise and counter-clockwise spiral paths, enabling contextual information to be aggregated toward the central target pixel. Finally, a Spectral Cross-Attention (SCA) module injects the shallow central spectral feature into the deep center-oriented descriptor through a lightweight, head-partitioned cross-layer fusion, thereby alleviating spectral feature attenuation. Under the adopted random pixel-wise evaluation protocol, experiments on four benchmark HSI datasets, including Indian Pines, WHU-HI-Longkou, Pavia University, and WHU-HI-HanChuan, yield competitive aggregate results relative to the included CNN-, Transformer-, and Mamba-based baselines. In the ten-run reporting format, RSSMamba obtains OA values of $95.37\pm 0.42$%, $98.47\pm 0.21$%, $97.72\pm 0.31$%, and $97.64\pm 0.27$% on the four datasets, respectively. It reports 0.33M parameters and 8.84G FLOPs on Indian Pines. Full article

Bispecific antibodies (bsAbs) are engineered to recognize either two distinct antigens or two different epitopes on the same antigen within a single molecule. This design varies according to the intended indication and mechanism of action; the factors considered during design are critical determinants of antigen binding, pharmacological activity, productivity, and safety. In this review, bsAbs are classified into fragment-based formats and Fc-containing IgG-like formats, with the latter further divided into symmetric and asymmetric architectures. Based on this structural framework, we discuss how key design parameters—including valency, epitope geometry, affinity and binding kinetics, and linker architecture—influence avidity, immune synapse formation, receptor clustering, signaling modulation, and toxicity profiles. We further compare preclinical and clinical examples across representative target combinations, including CD19 × CD3, CD20 × CD3, BCMA × CD3, HER2 × HER2, and EGFR × MET, to illustrate how different molecular formats yield distinct therapeutic outcomes even when the target combinations are similar. By linking structural classification with mechanism-based interpretation and within-target comparisons, this framework relates individual design variables directly to their preclinical and clinical consequences. Finally, we describe how the energy-based molecular modeling platform Rosetta and the deep-learning-based structure-prediction system AlphaFold are applied to support interface optimization, chain-pairing control, epitope geometry prediction, and structure-guided candidate prioritization. Overall, this review can provide a structure–function framework for bsAb design by integrating key structural determinants, their functional consequences, and emerging AI-based predictive strategies to facilitate the selection of optimal molecular architectures for specific therapeutic applications. Full article

The complexity of micrometer-scale pore-throat structures in sandstone reservoirs strongly controls the occurrence state and mobilization degree of residual oil after water-flooding. To clarify the differences in residual oil occurrence between pure oil-zone and transition-zone reservoirs and their microscopic controlling mechanisms, sandstone samples were collected from the SII oil layer group, which belongs to the Upper Cretaceous Yaojia Formation, in the Nanqi area of the Daqing Oilfield, northern Songliao Basin, NE China, and were investigated. Mercury intrusion capillary pressure (MICP), two-dimensional nuclear magnetic resonance (2D NMR), laser scanning confocal microscopy (LSCM), micro-computed tomography (micro-CT), X-ray diffraction (XRD), wettability measurement and fractal analysis were integrated to systematically characterize the pore-throat architecture, mineral composition, seepage capacity, and residual oil occurrence of the two reservoir types. The results show that the pore-throat radius distributions are mainly unimodal. In the pure oil-zone samples, the pore-throat distribution is highly consistent with the corresponding permeability contribution curve, whereas evident deviations occur in some transition-zone samples. Large and medium pore throats exert the most significant control on seepage capacity, and the difference in fractal characteristics is mainly reflected by D1, the fractal dimension of large pore throats. The transition-zone reservoirs generally exhibit moderate to strong water-wet characteristics. Owing to the development of fine pore throats and strong capillary forces, water is prone to retention within pore-throat spaces, resulting in pronounced water-blocking and Jamin effects. After water-flooding, the pure oil-zone reservoirs exhibit lower residual oil saturation, with residual oil occurring mainly in a bound state; in contrast, the transition-zone reservoirs show higher residual oil saturation and relatively high proportions of free and semi-bound residual oil. Mineral composition further modifies pore-throat complexity and residual oil occurrence. D1 is negatively correlated with feldspar content, indicating that increased feldspar content helps improve the pore-throat structure, but positively correlated with clay mineral content, suggesting that clay minerals enhance structural complexity. In the transition-zone reservoirs, kaolinite and illite–smectite mixed-layer minerals are relatively well developed. Their velocity-sensitive and water-sensitive effects readily induce pore-throat blockage and increased flow resistance, which are important causes of residual oil enrichment and difficult oil mobilization in the transition zone. Full article

Long-context modeling is important for long-horizon generation tasks, yet larger context windows do not necessarily ensure stable organizational continuity. We propose Dimension-Constrained Organizational Relay (DCOR), a workflow-level framework that reformulates long-horizon generation as the ordered propagation of finite organizational states rather than repeated replay of complete token histories. DCOR introduces Order and Dimension to represent sequential organizational evolution and task-oriented constraints, and comprises Organizational Set Extraction, Dimension-Constrained Generation, Organizational Relay, and Organizational Convergence. We evaluate DCOR on cumulative multi-instance advertisement generation and long-form article generation. Across ten advertisement runs, DCOR generated 259–315 structured creative blocks per run, averaging 279.3 ± 17.9, while maintaining the required format and producing no exact duplicate blocks. At the matched 30-block scale, its main advantage was cumulative structured production rather than the lowest character-level repetition. In long-form generation, DCOR achieved the lowest mean character-level 4-gram and 6-gram repetition compared with Direct Generation, Rolling-Summary Generation, Hierarchical-Outline Generation, and Neural RAG-Memory, while maintaining high Distinct-2 and Distinct-3 values. Ablation results further showed that removing Dimension, Organizational Relay, or Order increased repetition and reduced sustained multi-section expansion. These findings support organizational-state propagation as a complementary mechanism for structured long-horizon generation under restricted local-context conditions. Full article

Long-chain n-alkane hydroisomerization is a key catalytic route for upgrading wax-rich, bio-derived, and synthetic hydrocarbon feedstocks into diesel fuels, sustainable aviation fuels, and lubricant base oils with improved low-temperature properties. However, selective hydroisomerization remains challenging because mismatches in the spatial proximity and relative strength of metal and acid sites can prolong the residence time of olefin/carbenium-ion intermediates, thereby promoting over-isomerization to multibranched species, deep cracking, and coke formation. This review summarizes recent advances in zeolite-based bifunctional catalysts for long-chain n-alkane hydroisomerization. The catalytic mechanisms are first discussed, including metal-catalyzed dehydrogenation/hydrogenation, acid-catalyzed skeletal rearrangement, and shape-selective pathways governed by pore-mouth and key-lock effects. Catalyst construction strategies are then outlined, with emphasis on the preparation of zeolite supports and the introduction and localization of metal sites. Subsequently, structure–performance relationships are reviewed from the perspectives of support properties, metal site characteristics, and promoter effects, followed by a concise assessment of catalyst performance with real feedstocks under industrially relevant conditions. Finally, this review provides guidance for the precise design of metal–acid bifunctional hydroisomerization catalysts by highlighting descriptor-guided optimization, spatially regulated metal–acid–pore architectures, multiscale characterization and modeling, and scalable catalyst construction under practical reaction conditions. Full article

Due to the fact that municipal sludge incineration generates a large amount of toxic sewage sludge ash (SSA), cement solidification is becoming an efficient harmless treatment method. However, the large amount of phosphorus in sludge ash can delay the setting time of cement pastes and lead to a decrease in its later strength. Moreover, as an important non-renewable resource, the recycling and utilization of phosphorus is also a current research hotspot. To this end, this paper proposes to remove phosphorus from incinerated sewage sludge ash (ISSA) by the acid washing process, and, in response to the problem of reduced volcanic ash activity in acid-washed sewage sludge ash (ASSA), calcium chloride (CaCl₂) is added as an activator to explore the optimal process and hydration mechanism for enhancing ASSA activity. This study removed phosphorus from calcined SSA (800 °C, 2 h) via acid washing (0.3 mol/L H₂SO₄, L/S = 10:1, 2 h) to obtain ASSA, and used CaCl₂ as an activator to improve its pozzolanic activity. Different CaCl₂ dosages (1–3%) were tested for paste setting time, 3/7/28 d compressive strength, and characterized by hydration heat, XRD, SEM, etc. Experimental results indicated that the synergistic addition of 2 wt.% CaCl₂ and 20 wt.% ASSA shortened the initial and final setting times by 38% and 23% to 142 min and 289 min, respectively. Meanwhile, the compressive strength at 28 days was improved by 24%, with a final strength value of 42 MPa. Microanalysis revealed abundant Friedel’s salt formation and a denser structure (fine mesopores 60%, coarse mesopores 26%), confirming CaCl₂ effectively activates ASSA for cement admixture use. Full article