Search Results (118)

This study presents a thermodynamic analysis of the dissociation and association behavior of the Fe–Si system using the Bjerrum–Guggenheim osmotic coefficient. An equilibrium thermodynamic approach was applied to evaluate the Gibbs free energy, equilibrium constant, and degree of association of the congruently melting compound FeSi over a wide temperature range. The Fe–Si system was analyzed across three characteristic crystallization regions: Fe-rich, FeSi, and Si-rich. It was established that the Fe-rich region exhibits behavior approaching ideality with a nearly linear dependence of the osmotic coefficient, whereas the Si-rich region is characterized by strong deviations from ideality due to intensive association processes. The FeSi crystallization region represents a transitional regime in which association and dissociation processes occur simultaneously. The formation and partial dissociation of [Fe_xSi_y] clusters significantly affect the thermodynamic behavior of the melt. It was shown that accounting for FeSi dissociation leads to a linearization of the osmotic coefficient dependence and improves the accuracy of thermodynamic description. The proposed analytical approximations demonstrate high correlation coefficients (R² ≈ 0.99), confirming the reliability of the developed approach. The results provide a consistent thermodynamic framework for describing phase transformations and structural evolution in Fe–Si melts and can be applied to the optimization of metallurgical processes involving silicon-containing alloys. Full article

To address the issue of motion artifact interference faced by wearable ECG monitoring devices in dynamic environments, this paper proposes an adaptive motion artifact removal framework based on improved Variational Mode Decomposition (VMD). By designing a parameter self-adjustment mechanism and a multi-feature fusion mode selection strategy, the algorithm’s adaptability to non-stationary ECG signals and noise separation accuracy are enhanced. Experiments on the MIT-BIH Arrhythmia Database demonstrate that the improved VMD algorithm outperforms traditional wavelet transform, Recursive Least Squares (RLS), and conventional VMD methods in multiple performance metrics. Specifically, the signal-to-noise ratio (SNR) is improved by 5.17 dB, the Percentage Root Mean Squared Difference (PRD) is reduced to 49.13%, the correlation coefficient is increased to 0.88, and high real-time processing capability (Real-Time Processing Ratio, RTR = 22.5) is maintained, meeting the low-latency requirements of wearable devices. Moreover, case studies on pathological recordings (e.g., Wolff–Parkinson–White syndrome and third-degree atrioventricular block) reveal that the improved VMD better preserves clinically significant features such as delta waves and dissociated P waves. Furthermore, a downstream arrhythmia classification task using a CWT-CNN classifier achieves 91.67% accuracy on denoised heartbeats, which is 2.67 percentage points higher than that on raw noisy signals (89.00%), confirming the practical benefit of the proposed preprocessing for AI-based diagnosis. This study provides an effective processing solution for improving the signal quality of wearable ECG monitoring. Full article

The lithium resource reserves in Xinjiang’s Dahongliutan reach 1.1 million tons, making it one of the most representative spodumene deposits in China. Through process mineralogy analysis, the ore was identified as having inherent characteristics that control density-based separation: Coarse crystallization, a high monomer dissociation degree, and a density contrast. Based on these mineralogical characteristics, dense-medium separation experiments were conducted to investigate the mineralogically controlled separation behavior as a function of particle size and medium density. Three process flows (two-product, pressureless three-product, and two-stage, two-product) were further designed and comparatively evaluated. It indicated that the dense-medium separation efficiency is positively correlated with the monomer dissociation degree of spodumene, and the 0.5~6 mm size fraction is the optimal particle size range because it achieves a balance between ore crushing dissociation and coarse-grain dense-medium separation adaptation. Furthermore, all three dense media processes can save grinding energy, and each of them has its own advantages and disadvantages. Comprehensively considering the grade of the concentrate, recovery, the grade of the tailings, and grinding energy consumption, it is recommended to adopt a combined process of two-stage, two-product dense-medium separation and flotation. Full article

The subject concerns the determination of activation energy under dynamic conditions using two theoretical isothermal models, and subsequently experimental data, with reference to the α–T relationship matrix. In recent years, the Vyazovkin method, classified as one of the isoconversional variants, has gained the greatest recognition. Comparison was made between two isothermal models of the thermal dissociation of calcite, which in chronological terms are associated with a kinetic–nucleation reaction/process (the H-CL, as a kinetic model) and a kinetic–desorption reaction/process (the V, as a thermodynamic model). A comparison of numerical values, understood as the logarithm of the reaction/process rate with respect to temperature, shows correspondence in the temperature range up to the equilibrium temperature. The H-CL model is characterized by a strong dominance of the nucleation process relative to the chemical reaction, whereas the V model exhibits a certain type of balance resulting from the course of the chemical decomposition reaction combined with the transformation of a metastable oxide into a crystalline form. It was confirmed that both models describe the same phenomenon within the transformation process, which implies that for a constant conversion degree, the proportions of the chemical reaction and the physical process vary. Pointwise with increasing temperature, the H-CL model leads to a minimum activation energy E → 0, whereas the V model reaches a negative activation energy E < 0. In both cases, the apparent activation energy summed over the process is constant, and the assigned conversion degree, treated as isoconversional, remains fixed and corresponds to the assumed activation energy of the completed reaction/process. Several simple methods for its determination under dynamic/isoconversion conditions are used. Full article

China’s coking coal resources are scarce, and maximizing the recycling of these resources is the primary objective of coal processing and utilization. The embedding features of inorganic minerals within coking middling coal resources are an inherent factor influencing their liberation and separation efficiency. However, current research lacks a systematic investigation into how the embedding features of inorganic minerals in coking middling coal affect their liberation characteristics and flotation separation performance. This study examines three Chinese coking middling coal samples with distinct embedding features. Based on quantitative characterization of inorganic mineral embedding, grinding tests with varying durations and flotation separation tests on post-grinding products were conducted. Liberation and separation efficiencies were evaluated to explore the influence of inorganic mineral embedding on liberation degree and the subsequent impact of the liberation degree on flotation performance. The results indicate that the three coking middling coal samples with different embedding features exhibit significant differences in the dissociation behavior between inorganic minerals and organic matter. The particle size (D) of inorganic mineral phases is the primary factor influencing the liberation degree of inorganic minerals, while the complexity of intergrowth between inorganic minerals and organic matter (CIG) is a secondary factor. The CIG is the primary factor affecting the liberation of organic matter. As the liberation of inorganic minerals and organic matter increases, the separation efficiency improves for the Liuwan middling coal samples, whereas it deteriorates for the Shaqu and Changzhi samples. Full article

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the leading cause of chronic liver disease worldwide, distinguished by pronounced clinical heterogeneity and a frequent dissociation between metabolic risk factors and the degree of hepatic injury. These observations, together with the limited contribution of genetic heritability, have prompted a re-evaluation of the traditional conceptual framework of the disease. In this context, the question has emerged as to whether MASLD could be, at least in part, a transmissible condition. While there is no evidence to suggest that MASLD is contagious in humans, as no data support person-to-person transmission, gnotobiotic animal studies demonstrate that human gut microbiota can transfer susceptibility to steatosis, inflammation, and systemic metabolic disturbances through immunometabolic mechanisms, independent of host genetics. In parallel, human studies involving microbiota-targeted interventions support the concept that the gut ecosystem is a modifiable determinant of metabolic and hepatic phenotypes. Crucially, these findings do not imply natural transmission of disease, but rather underscore the functional plasticity of microbiota-host interactions. This narrative review integrates epidemiological, experimental, and clinical data to explore the hypothesis that MASLD may be functionally transmissible. MASLD is increasingly recognized as an eco-biological disease, where liver disease risk is not only shaped by host genetics and environment, but also by the ecological configuration and functional outputs of the gut microbiome. This perspective redefines disease susceptibility as, in part, context-dependent and microbiota-mediated, without implying infectiousness in the traditional sense. Full article

The hydrogen gasochromic phenomenon offers a new strategy for real-time sensing technologies for hydrogen leakage to ensure hydrogen safety. However, the limited recovery kinetics impede the cycling and further practical applications. Herein, we designed a series of PtAg-decorated WO₃ nanowires via the chemical reduction deposition method, which could exhibit obvious and reversible color changes for H₂ detection. With the assistance of Ag, the oxygen adsorption and dissociation were accelerated; then, the sample could exhibit a constant rapid recovery rate. The crystalline Pt-Ag/WO₃ nanowires could attain a 50% recovery degree within 52 s, and the recovery time of the Pt-Ag/WO₃ sample was reduced to one fifth that of Pt/WO₃. This study provides a fundamental solution to the challenge of slow recovery kinetics in H₂ gasochromic crystalline materials. Full article

Designing ionic liquids (ILs) where a single functional group orchestrates a suite of enhanced properties remains a key challenge in materials science. Here, we introduce 1-butyl-3-methylimidazolium mandelate, [Bmim][Man], a novel IL where the hydroxyl group on the mandelate anion simultaneously enhances hydrogen bonding, thermal stability, antimicrobial activity, and extraction selectivity. The structure-property relationships of [Bmim][Man] were investigated through measurements of density, viscosity, and conductivity and were compared with analogous ILs. The presence of the hydroxyl group on the mandelate anion resulted in the highest density and viscosity among the series, attributed to strong hydrogen bonding and efficient ion packing. Notably, [Bmim][Man] exhibited a high molar conductivity that decouples from its high viscosity, suggesting an unusual degree of ion dissociation facilitated by the hydroxyl group. Thermogravimetric analysis revealed superior thermal stability. Furthermore, the investigated ionic liquid demonstrated a low critical aggregation concentration (CAC = 0.01982 mol·dm⁻³) in water, indicating a strong propensity for self-aggregation. [Bmim][Man] showed synergistic, enhanced antibacterial activity against E. coli and P. aeruginosa. Finally, the functional utility of this designed liquid was demonstrated in separation science, where [Bmim][Man]-based aqueous biphasic systems showed selective extraction capabilities for transition metals, a process driven by the same hydrogen-bonding and coordination interactions that define its bulk properties. These findings establish [Bmim][Man] as a promising multifunctional material where the mandelate anion concurrently dictates liquid microstructure, thermal resilience, antimicrobial performance, and application in extraction. Full article

The composite material MgH₂-EEWNi-Cr (20 wt. %) with a hydrogen content of 5.2 ± 0.1 wt.% is characterized by improved hydrogen interaction properties compared to the original MgH₂. The dissociation of the material occurs in three temperature ranges (86–117, 152–162, and 281–351 °C), associated with a complex of effects consisting of changes in the specific surface area of the material, alterations in the crystal lattice during ball milling, and changes in the electronic structure in the presence of a Ni–Cr catalyst, based on first-principles calculations. The decrease in desorption activation energy (E_d = 65–96 ± 1 kJ/mol, ΔE_d = 59–90 kJ/mol) is due to the catalytic effect of N–Cr, leading to a faster decomposition of the hydride phase. Based on the results of ab initio calculations, Ni–Cr on the MgH₂ surface leads to a significant decrease in hydrogen binding energy (ΔE_b = 60%) compared to pure magnesium hydride due to the formation of Ni–H and Cr–H covalent bonds, which reduces the degree of H–Mg ionic bonding. The results obtained allow us to expand our understanding of the mechanisms of hydrogen interaction with storage materials and the possibility of using these as mobile hydrogen storage and transportation materials. Full article

This study aimed to investigate the interactions between soluble soybean polysaccharides (SSPS) and milk proteins, namely, casein and whey protein, and to evaluate their effects on the stability of acidified milk beverages under different degrees of thermal denaturation. Casein, whey protein, and SSPS were used as raw materials to prepare mixed solutions under varying pH conditions. A combination of analytical techniques, including centrifugal sedimentation rate, particle size distribution, ζ-potential measurement, differential scanning calorimetry (DSC), size-exclusion chromatography (SEC), and LUMisizer stability analysis, was employed to systematically examine the interactions between SSPS and the two proteins, as well as the influence of thermal treatment at 120–140 °C (casein) and 65–78 °C (whey protein). The results demonstrated that under acidic conditions (pH 3.5–4.5), SSPS formed compact complexes with casein, effectively stabilizing casein dispersions through steric hindrance and electrostatic repulsion. In contrast, SSPS exhibited a limited stabilizing ability toward whey protein due to its strong tendency to aggregate, which hindered the formation of uniform complexes. Regarding thermal denaturation, casein heated at 140 °C for more than 40 min showed pronounced κ-casein dissociation and aggregation, resulting in reduced stability of the SSPS–casein system. For whey protein, increasing thermal denaturation (complete denaturation at 78 °C for 30 min) led to the formation of larger aggregates, with particle size increasing from 198.23 nm to 213.33 nm and ζ-potential decreasing from −3.77 mV to −2.01 mV, thereby diminishing the stability of the SSPS–whey protein system. Overall, this study elucidates the interaction mechanisms of SSPS with casein and whey protein, and highlights the role of thermal denaturation, thereby providing theoretical guidance for the effective application of SSPS in acidified milk beverages. Full article

This study investigated the concentration-dependent effects of zinc oxide nanoparticles (ZnO NPs, 30–70 nm) on the freshwater microalga Lobosphaera sp. under different salinity conditions (0–4 g L⁻¹ NaCl). ZnO NPs demonstrated dual effects: low concentration (0.75 mg L⁻¹) enhanced growth and alleviated salt stress, while higher concentrations (7.5–75 mg L⁻¹) caused significant growth inhibition (up to 52%) and induced oxidative stress. Salinity did not significantly affect NPs aggregation patterns, and neither salinity nor aggregation degree influenced toxicity outcomes. NPs concentration plays a dominant role of toxicological effects. Dose-dependent increases in catalase activity and ROS-positive cells confirmed NPs-induced oxidative stress. Crucially, zinc bioaccumulation correlated with NPs concentration but dissociated from dissolved Zn²⁺ release, demonstrating particle-driven toxicity. Our findings challenge the ion-release paradigm and highlight the potential of low-dose ZnO nanoparticles as effective stress-protectors in algal biotechnology, offering new strategies for enhancing microalgal resilience under environmental stress. Full article

Spring low temperatures are a serious natural threat to wheat production in the Huang-Huai wheat region, and they are often accompanied by weak light environments during the day. To elucidate the response patterns and adaptation mechanisms of winter wheat leaves to low-temperature and weak-light environments, we simultaneously measured prompt chlorophyll a fluorescence, delayed chlorophyll a fluorescence, and modulated 820 nm light reflection; moreover, we analyzed the effects of low temperature and weak light treatment for different duration (2 h and 4 h) on the donor-side activity of photosystem II (PSII), the degree of PSII unit dissociation, the efficiency of light energy absorption and capture by PSII, electron transfer to Q_A⁻ and PSI terminal, PSI activity and cyclic electron transport activity in isolated wheat leaves under controlled conditions. The results, which were corroborated using the three methods, revealed that in low-temperature and weak-light environments, the degree of PSII unit dissociation, and the efficiency of light energy absorption, capture, and electron transfer to Q_A⁻ decreased, while the donor-side activity remained unaffected. In contrast, the efficiency of electron transfer to the PSI terminal and the overall performance of photosynthetic electron transport increased. Comprehensive analysis suggests that the increase in the electron receptor pool at the PSI terminal under low-temperature stress is a crucial factor contributing to the enhanced electron transfer efficiency to the PSI terminal and the improved overall performance of the photosynthetic electron transport chain, which is also a crucial factor in the high cold tolerance of winter wheat. Full article

We investigate the impact of normal linear strips—both perpendicular and parallel to the direction of vortex motion—on the dynamics of fractional vortices in a two-band superconducting slab. In the absence of pinning, composite vortices dominate throughout the sample, while non-composite (dissociated) vortices appear only near the vortex entry edge, with energy dissipation primarily governed by the motion of composite structures. To modulate vortex behavior, we introduce linear regions of locally suppressed superconductivity, oriented either perpendicular or parallel to the vortex trajectory. A single perpendicular strip confines fractional vortices to the injection region, whereas two perpendicular strips stabilize composite vortices in the central domain and induce fractional vortex states near the boundaries. In contrast, parallel strips promote the dissociation of vortices across the entire sample, significantly altering the spatial configuration and dynamics of the vortex matter. Furthermore, the interband correlation coefficient serves as a direct indicator of the degree of spatial overlap between vortices in the two condensates. These findings highlight the critical role of pinning geometry in shaping vortex dynamics and energy dissipation, offering new strategies for controlling flux behavior in multiband superconductors for technological applications. Full article

The selection of grinding media significantly impacts the resulting mineral’s liberation degree and grinding quality; this is particularly impactful for granite pegmatite-type quartz. Accordingly, in this study, we investigate the effects of different grinding media on the breakage characteristics of muscovite granite pegmatite-type quartz, focusing also on quartz mineral flotation. An analysis of scanning electron microscope images reveals distinct fracture characteristics among different minerals. Notably, the fractal dimension of mineral fracture roughness in ball-milled products is larger compared to that of rod-milled products, which exhibit a smaller fractal dimension. This fractal dimension serves as a quantitative measure of the microscopic morphology of mineral fractures in the grinding products, establishing a relationship between the roughness of the fractures and the type of grinding medium used. Further analysis of particle size distribution and mineral dissociation indicates that the rod mill produces a higher yield of coarse fractions compared to both ceramic and steel balls, while the fine fraction yield is significantly lower than that of the rod mill and steel balls. Importantly, the rod mill enhances the dissociation degree of quartz, suggesting that it can improve the liberation of mineral monomers and increase the yield of qualified fractions during the grinding process while effectively reducing the phenomenon of overgrinding. Our flotation experiments demonstrate that the recovery rate of quartz using the rod mill is 2.59% and 5.07% higher than that achieved with the ball mill and ceramic mill, respectively. These findings provide theoretical support for the optimization of grinding media and enhancement of mineral flotation recovery. Full article

We discuss an innovative thin film deposition method, Plasma Assisted Supersonic Jet Deposition, which combines the chemistry richness of a reactive cold plasma environment and the assembly control of the film growth allowed by a supersonic jet directed at the substrate. Optical Emission Spectroscopy was used to characterize the plasma state and the supersonic jet, together with its interaction with the substrate. We obtained several results in the deposition of silicon oxide thin films from Hexamethyldisiloxane, with different degrees of organic groups retention. In particular we exploited the features of emission spectra to measure the plasma dissociation and oxidation degree of the organic groups, as a function of the jet parameters. If controlled growth is achieved, such films are nanostructured materials suitable for applications like catalysis, photo catalysis, energy conversion and storage, besides their traditional uses as a barrier or protective coatings. Full article