Search Results (958)

The field of electrochemical devices, encompassing energy storage, fuel cells, electrolysis, and sensing, is fundamentally reliant on the electrode materials that govern their performance, efficiency, and sustainability. Traditional materials, while foundational, often face limitations such as restricted reaction kinetics, structural deterioration, and dependence on costly or scarce elements, driving the need for continuous innovation. Emerging electrode materials are designed to overcome these challenges by delivering enhanced reaction activity, superior mechanical robustness, accelerated ion diffusion kinetics, and improved economic feasibility. In energy storage, for example, the shift from conventional graphite in lithium-ion batteries has led to the exploration of silicon-based anodes, offering a theoretical capacity more than tenfold higher despite the challenge of massive volume expansion, which is being mitigated through nanostructuring and carbon composites. Simultaneously, the rise of sodium-ion batteries, appealing due to sodium’s abundance, necessitates materials like hard carbon for the anode, as sodium’s larger ionic radius prevents efficient intercalation into graphite. In electrocatalysis, the high cost of platinum in fuel cells is being addressed by developing Platinum-Group-Metal-free (PGM-free) catalysts like metal–nitrogen–carbon (M-N-C) materials for the oxygen reduction reaction (ORR). Similarly, for the oxygen evolution reaction (OER) in water electrolysis, cost-effective alternatives such as nickel–iron hydroxides are replacing iridium and ruthenium oxides in alkaline environments. Furthermore, advancements in materials architecture, such as MXenes—two-dimensional transition metal carbides with metallic conductivity and high volumetric capacitance—and Single-Atom Catalysts (SACs)—which maximize metal utilization—are paving the way for significantly improved supercapacitor and catalytic performance. While significant progress has been made, challenges related to fundamental understanding, long-term stability, and the scalability of lab-based synthesis methods remain paramount for widespread commercial deployment. The future trajectory involves rational design leveraging advanced characterization, computational modeling, and machine learning to achieve holistic, system-level optimization for sustainable, next-generation electrochemical devices. Full article

This paper presents a numerical study on the deployment of Overfire Air (OFA) technology in coal-fired thermal power plants in Kazakhstan to reduce harmful emissions. The simulation utilized a digital model of the combustion chamber of the BKZ-75 boiler at Shakhtinsk thermal power plant, which utilizes high-ash Karaganda coal containing 35.10% ash. During the development of two-stage combustion technology, different methods of supplying extra air via OFA injectors were examined. Various positions within the combustion chamber were evaluated for their placement: at heights of h = 0.165 m; 0.75 m; 1.375 m; 2.25 m; 2.5 m; 8 m; 9.4 m; 10 m; 11 m; and 12 m. The baseline combustion mode (OFA = 0%) and several additional air injector settings were analyzed, including OFA levels of 5%, 10%, 15%, 18%, 20%, 25%, and 30% of the total air volume. Numerical simulations generated temperature distributions along with carbon monoxide (CO) and nitrogen (NO) concentration fields, both inside and outside the combustion chamber outlet. Research indicates that the most effective reduction in pollutant emissions happens when OFA injectors are positioned at 9.4 m and supply supplementary air at an OFA rate of 18%. Under these settings, the carbon monoxide concentration at the combustion chamber outlet decreases by approximately 36%, while nitrogen oxide levels drop by 25%, compared to the baseline condition (OFA = 0%). These insights can be utilized to upgrade boiler units, promoting cleaner fuel combustion in coal-fired thermal power plants. Full article

This study presents the development of a smart packaging material utilizing garlic-derived nitrogen-doped carbon dots (CDs) integrated into a whey protein–starch (WP-S) emulsion. The research aimed to create a real-time, non-invasive biosensor capable of detecting microbial spoilage. The synthesized CDs demonstrated strong pH-sensitive photoluminescence, exhibiting distinct changes in CIE coordinates and fluorescence intensity in response to varying pH values. The WP-S-CDs emulsion was tested against E. coli, S. aureus, and C. albicans. The results showed that the composite film provided a clear colorimetric shift and fluorescence quenching, both of which are directly correlated with microbial metabolic activity. The physical and electronic properties of the composite were investigated to understand the sensing mechanism. Scanning electron microscopy (SEM) of the dried film revealed that the WP-S-CDs system formed a more porous structure with larger pore sizes (3.63–8.18 µm) compared to the control WP-S film (1.62–6.52 µm), which facilitated the rapid diffusion of microbial metabolites. Additionally, density functional theory (DFT) calculations demonstrated that the incorporation of CDs significantly enhanced the composite’s electronic properties by reducing its band gap and increasing its dipole moment, thereby heightening its reactivity and sensitivity to spoilage byproducts. In a practical application on apples, the WP-S-CDs coating produced a visible red spot, confirming its function as a dynamic sensor. The material also showed a dual-action antimicrobial effect, synergistically inhibiting C. albicans while exhibiting an antagonistic effect against bacteria. These findings validate the potential of the WP-S-CDs emulsion as a powerful, multi-faceted intelligent packaging system for food quality monitoring. Full article

Investigating light–nitrogen interactions during bamboo shoot bud germination of Dendrocalamus latiflorus provides a theoretical basis for regulating shoot emergence through optimized light intensity and nitrogen supply. This study further elucidates how such coupling effects can guide stand density adjustments in bamboo plantations. Additionally, it provides actionable insights for improving nutrient management strategies in practical bamboo cultivation systems. This study evaluated the effects of different nitrogen levels (1.5, 4.5, and 7.5 g·clump⁻¹) combined with varying light intensities (10%, 40%, and 100%) on shoot germination and physiological characteristics of bamboo. Two-way ANOVA revealed a significant interaction between light intensity and nitrogen concentration on bamboo shoot bud germination (p < 0.05). Under low nitrogen conditions, bamboo shoot bud germination was highest (3 buds·clump⁻¹) at 10% light intensity. However, under high nitrogen conditions, the highest germination (4.75 buds·clump⁻¹) occurred at 40% light intensity. Moreover, leaf carbon, nitrogen, and starch contents were positively correlated with shoot bud germination. Pearson correlation and path analyses indicated that total chlorophyll, chlorophyll a/b, photochemical quenching coefficient, sucrose, and leaf nitrate were the main photosynthetic traits associated with bamboo shoot bud germination. Among these, the photochemical quenching coefficient was the most critical factor. Based on this, the nitrogen management, nitrogen utilization, and low-light adaptability of D. latiflorus could be optimized. Full article

The interaction between organic and inorganic nutrients, bacterial communities, and soil fertility has been well documented over time. Conventional agricultural systems heavily utilize both inorganic and organic fertilizers, each exerting distinct effects on soil microbial dynamics and plant growth. The objective of our experiments was to identify the most effective fertilization strategy for improving the biological quality of a microbiologically impoverished and low-productivity soil. To this end, four fertilization strategies were evaluated: (i) organic fertilizers characterized by a high content of organic carbon (Fertil 4-5-7—variant 1); (ii) organic fertilizers with 12% organic nitrogen from proteins (Bio Ostara N—variant 2) (iii) combined inorganic–organic fertilizers (P35 Bio—variant 3) and (iv) mineral (inorganic) fertilizers (BioAktiv—variant V4). This study aimed to assess the short-term effects of fertilizers with varying chemical compositions on the density of cultivable heterotrophic bacteria and their associated dehydrogenase (DH) activity in a petrocalcic chernozem soil containing pedogenic carbonates. Soil sampling was conducted according to a randomized block design, comprising four replicates per treatment (control plus four fertilizer types). The enumeration of cultivable bacteria was performed using Nutrient Agar and A2R Agar media, whereas dehydrogenase activity (DHA) was quantified based on the reduction of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) to 1,3,5-triphenyl-tetrazolium formazan (TPF) by bacterial dehydrogenase enzymes. Marked differences were observed in both parameters between the plots amended with inorganic fertilizers and those treated with organic fertilizers, as well as among the organic fertilizer treatments of varying composition. The most pronounced increases in both bacterial density and dehydrogenase activity (DHA) were recorded in the plots receiving the fertilizer with a high organic nitrogen content. In this treatment, the maximum bacterial population density reached 6.25 log₁₀ CFU g⁻¹ dry soil after approximately two months (May), followed by a significant decline starting in July. In contrast, DHA exhibited a more rapid response, reaching its peak in April (42.75 µg TPF g⁻¹ soil), indicating an earlier DHA activation of microbial metabolism. This temporal lag between the two parameters suggests that enzymatic activity responded more swiftly to the nutrient inputs than did microbial biomass proliferation. For the other two organic fertilizer variants, bacterial population dynamics were broadly similar, with peak densities recorded in June, ranging from 5.98 log₁₀ CFU g⁻¹ soil (V3) to 6.03 log₁₀ CFU g⁻¹ soil (V1). A comparable trend was observed in DHA: in V3, maximum DHA was attained in June (30 µg TPF g⁻¹ soil), after which it remained relatively stable, whereas in V1, it peaked in June (24.05 µg TPF g⁻¹ soil) and subsequently declined slightly toward the end of the experimental period. Overall, the temporal dynamics of bacterial density and DHA demonstrated a strong dependence on the quality and biodegradability of the organic matter supplied by each fertilizer. Both parameters were consistently lower under inorganic fertilization compared with organic treatments, suggesting that the observed increases in microbial density and activity were primarily mediated by the enhanced availability of organic substrates. The relationship between the density of culturable heterotrophic bacteria and dehydrogenase (DH) activity was strongly positive (r = 0.79), indicating a close functional linkage between bacterial density and oxidative enzyme activity. This connection suggests that the culturable fraction of the heterotrophic microbial community plays a key role in the early stages of organic matter mineralization derived from the applied fertilizers, particularly in the decomposition of easily degradable substrates. Full article

Lacustrine shale oil in the Chang 7 Member of the Ordos Basin is controlled by a multi-scale pore–throat system in which oil occurrence, spontaneous imbibition, and pore-structure evolution are tightly coupled. In this study, nitrogen adsorption and micro-computed tomography (μCT) were employed to characterize pore-size distribution and connectivity, whereas nuclear magnetic resonance (NMR) T₂ relaxation was utilized to classify oil occurrence states, and X-ray diffraction (XRD) and total organic carbon (TOC) analyses were performed to determine mineralogical and organic compositions. Spontaneous imbibition experiments were conducted at 60 °C and subsequently extended to temperature–pressure sequence tests. The Chang 7 shale exhibits a stratified pore system in which micropores, mesopores, and macropores jointly define a three-tier “micropore adsorption–mesopore confinement–macropore mobility” pattern. As pore size and connectivity increase, the equilibrium imbibed mass and initial imbibition rate both rise, while enhanced wettability (contact angle decreasing from 81.2° to 58.7°) further strengthens capillary uptake. Temperature elevation promotes imbibition, whereas increasing confining pressure suppresses it, revealing a “thermal enhancement–pressure suppression” behavior. μCT-based network analysis shows that imbibition activates previously ineffective pore–throat elements, increasing coordination number and connectivity and reducing tortuosity, which collectively represents a capillary-driven structural reconfiguration of the pore network. When connectivity exceeds a threshold of about 0.70, the flow regime shifts from interface-dominated to channel-dominated. Building on these observations, a multi-scalecoupling framework and a three-stage synergistic mechanism of “pore-throat activation–energy conversion–structural reconstruction” are established. These results provide a quantitative basis for predicting imbibition efficiency and optimizing capillary-driven development strategies in deep shale oil reservoirs. Full article

Novel hybrid semiconducting thin films comprising CdSe with the addition of nitrogen-doped carbon dots (NCDs) were developed onto titanium substrates using a one-step electrocodeposition technique. The deposition took place using an acidic aqueous electrolytic bath containing hydrothermally produced ΝCDs under direct and pulse current regime. The specimens were studied using XRD, SEM-EDS, and UV-Vis spectroscopy techniques to determine their microstructural characteristics, surface morphology and composition and the energy gap, respectively. Their photochemical behavior was studied utilizing a photoelectrochemical cell (PEC). Variations in physical properties, along with significantly improved photoelectrochemical responses, were observed for the NCD-infused semiconductive thin films compared to their plain CdSe counterparts. These variations were highly affected by the incorporation rate of the NCDs in each thin film, as well as the imposed electrolysis conditions. Full article

Natural humus, characterized by its high organic carbon content and high degree of humification, is widely used in soil improvement. However, the impact of natural humus on the multifunctionality of saline–alkali soils and its relationship with soil microbial diversity remain poorly understood. This study conducted experiments with varying concentrations of natural humus to explore changes in soil multifunctionality and its driving factors. The results indicate that the addition of natural humus increases soil organic matter (by 23.5–45.73%) and alkali-hydrolyzable nitrogen (by 40–81.57%), while reducing electrical conductivity (by 1.8–35.9%). These changes enhance soil microbial diversity and improve soil multifunctionality. As natural humus is a high C/N material, nitrogen limitation in soil microorganisms may occur with increasing humus addition. However, the increase in K-strategy fungi (which are more efficient in resource utilization) helps maintain a relatively high level of soil multifunctionality. At the maximum application rate (30 t/ha), soil multifunctionality reached its peak value of 0.41. These findings highlight the significant role of natural humus in improving saline–alkali soils and enhancing soil functions, particularly through its effects on microbial communities, especially K-strategy fungi. Full article

The overuse of chemical fertilizers can result in elevated concentrations of nitrogen (N) and phosphorus (P) in soil, potentially impacting rock weathering processes and carbon flux in karst regions. This study analyzed the impacts of chicken dung fertilizer and compound fertilizer on the weathering of carbonate rocks within the water-soil-rock system, yielding the following results: (1) The peak concentrations of various ions in the compound fertilizer system (Ca²⁺: 36.8 mg/L, Mg²⁺: 4.3 mg/L, N: 284.2 mg/L, P: 920.6 mg/L, HCO₃⁻: 16,170.3 mg/L) were generally superior to those in the chicken manure fertilizer system (15.4 mg/L, 1.9 mg/L, 306.9 mg/L, 27.9 mg/L, and 4576.5 mg/L, respectively), with a difference of approximately fourfold between the two systems; (2) Nitric acid generated by nitrification in fertilizers and phosphoric acid in compound fertilizers modify the chemical equilibrium of rock weathering, enhance dissolution, and influence the dynamics of HCO₃⁻; (3) Nitrogen and phosphorus in compound fertilizers are predominantly eliminated through ion exchange and adsorption. Calcium-phosphate precipitates are generated on the limestone surface within the 20 cm soil column, exhibiting a greater degree of weathering compared to the chicken manure fertilizer treatment; (4) analyses utilizing XRD, FT-IR, XPS, SEM, and additional approaches verified that substantial weathering and surface precipitation transpired on limestone throughout the 20 cm compound fertilizer column. Full article

A combination of stomach contents analysis (SCA) and nitrogen (δ¹⁵N) and carbon (δ¹³C) stable isotope analysis (SIA) was used to assess the trophic structure of nine fish species (two belonging to the family Mullidae, Mullus barbatus and Mullus surmuletus, and seven belonging to the family Sparidae, Diplodus sargus, Diplodus vulgaris, Pagellus acarne, Pagellus erythrinus, Pagrus auriga, Pagrus pagrus, and Sparus aurata) with high commercial value in the Bay of Cádiz, Southern Spain. A total of 91 different food items were identified in the stomachs, mainly belonging to four animal phyla (Arthropoda, Mollusca, Annelida, and Echinodermata). Crustaceans (primarily decapods and amphipods) were the most common prey consumed by the species of Mullus, Pagrus, and Pagellus, whereas macroalgae, polychaetes, and molluscs were dominant in D. sargus, D. vulgaris, and S. aurata stomachs, respectively. Diet composition and isotopic signature differed among fish species, indicating food partitioning among coexisting species. Some discrepancies appeared when comparing fish trophic level using SCA versus SIA, since SCA provides information on recently consumed items, while SIA generates data about source utilization over a period of several months. Integration of both approaches offers a more comprehensive understanding of feeding strategies. Dietary studies shed light on the trophic ecology of commercial fish species, being the baseline for future ecological modelling and long-term management of marine resources. Full article

Desert plants develop unique functional traits and resource utilization strategies under environmental stress, among which, water and nitrogen utilization strategies are the key resource utilization strategies for desert plants. Research on plant water and nitrogen utilization and leaf functional traits has rarely involved high-altitude desert shrubs. The synergistic or trade-off relationship between water and nitrogen utilization in desert shrubs remains unclear, and the variation patterns of leaf functional trait combinations related to water and nitrogen utilization along environmental gradients urgently need to be studied. This study takes the typical desert shrubs in the eastern part of the Qaidam Basin on the Qinghai–Tibet Plateau in China as the research object, selects the stable carbon and nitrogen isotopes (δ¹³C, δ¹⁵N) of plant leaves to characterize the water use efficiency (WUE) and nitrogen use strategy (NUE) of plants, explores the main leaf functional traits related to water and nitrogen utilization, and analyzes the relationship between leaf functional traits and environmental factors. The results show that the resource utilization traits of desert shrubs can be divided into two groups: water and carbon utilization centered on δ¹³C and nutrient utilization centered on δ¹⁵N. There are synergistic or trade-off relationships among plant functional traits. There is a trade-off relationship between water and nitrogen utilization in plants. The leaf functional traits related to water and nitrogen utilization in plants form a “water and nitrogen utilization leaf economic spectrum” along the gradients of temperature, drought, salinity, and nutrients. In conclusion, desert plants adapt to the environment of high cold, drought, high salt content, and limited nutrients by adjusting the relevant leaf functional traits. This study combines the stable carbon and nitrogen isotopes of plant leaves with the combined characteristics of leaf functional traits under different environmental gradients, providing a new perspective for understanding the water and nitrogen utilization strategies of high-altitude desert shrubs and their adaptation mechanisms to arid environments. Full article

Lead and zinc pollution is a prevalent issue in agricultural soils surrounding lead and zinc mines, posing a serious risk to crop growth and soil health. Heavy metal-resistant, plant growth-promoting bacteria (PGPB) capable of supporting plant development under high metal exposure have significant potential for mitigating these deleterious effects. Here we isolated and identified the Pb- and Zn-resistant and plant growth-promoting bacterial strain Serratia ureilytica T6 based on 16S rRNA and average nucleotide identity (ANI) analysis. Furthermore, 14 strains (T1–T14) from a rice paddy soil irrigated by Pb-Zn mine effluent were isolated and identified, and their phytopromoting characteristics were determined. Genome analysis of S. ureilytica T6 showed a genome size of 5,102,941 bp, with G + C content of 59.74%. A total of 4822 genes were annotated by RAST, among which 15 genes were putatively associated with Pb-Zn resistance. The genome of S. ureilytica T6 was found to possess multiple genes associated with probiotic properties by a comparative analysis of KEGG, GO, and COG databases. Several taxonomic identifications of S. ureilytica T6 revealed that strain T6 is Gram-negative, facultative anaerobic and motile. The pH growth range of S. ureilytica T6 was between 4.00 and 9.50; temperature growth range was 4–37 °C; NaCl tolerance was 0–9%. S. ureilytica T6 displayed a high tolerance to a variety of heavy metals, with minimum inhibitory concentrations of 1.5 and 9 mmol·L⁻¹ for Pb and Zn. S. ureilytica T6 can utilize a variety of carbon sources and nitrogen sources. T6 has the ability to produce indole-3-acetic acid (IAA), siderophore, and phosphorus and potassium solubilization, and it was initially judged that strain T6 has the potential for plant growth-promoting ability. Different plant growth-promoting effects of T6 inoculations were observed in improving rice biomass, plant height, etc. We observed that with increasing Pb and Zn stress, SOD activity first increased and then decreased, while POD and CAT activities gradually decreased. The addition of S. ureilytica T6 significantly enhanced the activities of SOD, POD, and CAT in rice seedlings under low to moderate Pb and Zn stress but had no significant effect under high concentrations (150 mg·L⁻¹) of Pb or Zn. In addition, S. ureilytica T6 has the potential to be used as a phytoremediation tool. Full article

In this study, the effect of heat stress on the synthesis and the structural and physicochemical properties of exopolysaccharides (EPSs) from Rhodotorula glutinis YM25079 as well as its underlying mechanisms were explored. The results showed that the monosaccharide compositions of the purified YM25079 EPSs produced under normal culture conditions and heat stress (named EPS Y-1 and EPS Y-2, respectively) were consistent. Analyses of ion-exchanged chromatography, Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy suggested that these two EPSs should be dextran, consisting mainly of α-(1→6)-linked glucopyranose units with α-(1→3) branches. Scanning Electron Microscope observed obvious differences in their surface morphologies, with EPS Y-1 showing a smooth, glossy lamellar structure and EPS Y-2 showing an irregular porous structure. According to Atomic Force Microscopy analysis, they formed aggregations with different cohesive structures. EPS Y-2 also had higher molecular weight and thermal stability than EPS Y-1, while EPS Y-1 had better α-amylase inhibitory activity. In addition, transcriptomic analysis unveiled changes in the metabolic pathways related to the uptake and utilization of carbon, nitrogen and phosphor sources, the biosynthesis of steroid and the oxidoreductase activity, as well as the regulatory genes implicated in the EPS biosynthesis under heat stress. Full article

Escherichia coli O157:H7 is a major food safety concern through contamination of beef and produce. Non-antibiotic interventions to minimize O157:H7 in food animals and products are highly desired and one strategy to improve food safety is to reduce O157:H7 in cattle, a main asymptomatic reservoir, through probiotic administration. Non-pathogenic E. coli populating the intestine represent a compelling probiotic source, as these strains are already host-adapted. The challenge is to identify non-pathogenic strains capable of competing with O157:H7 for nutrients or those producing compounds to inhibit O157:H7 growth. Here, E. coli isolated from cattle fecal and recto-anal junction swab samples were sequenced and screened for the ability to compete with O157:H7. Fourteen genetically distinct, non-Shiga toxin-encoding, non-O157:H7 E. coli strains were recovered, and individual isolates representative of each strain were assessed. Nearly all strains possessed complete genetic pathways for the utilization of carbon and nitrogen sources required for O157:H7 colonization of the cattle intestine. Growth curve assays were conducted, and growth metrics were compared between bovine non-O157:H7 E. coli isolates and two O157:H7 isolates. While no strain outperformed both O157:H7 strains for all nutrients tested, at least one strain outperformed O157:H7 for each of the carbon sources tested. No strain grew significantly better than O157:H7 in media supplemented with ethanolamine. A “highly competitive” consortium of 4 non-O157:H7 isolates that grew significantly better than O157:H7 reduced O157:H7 counts CFU/mL by 1.53 log₁₀ and >0.72 log₁₀ under anaerobic and aerobic conditions, respectively, in competition assays. A consortium of “low-competitive” strains reduced O157:H7 counts by >0.47 log₁₀ and >0.51 log₁₀ under anaerobic and aerobic conditions. These results suggest that cattle harbor non-O157:H7 E. coli strains capable of limiting O157:H7 growth in vitro. Surveys of commensal non-O157:H7 isolates from cattle using growth-based phenotypic assays may be useful in identifying E. coli strains capable of outcompeting O157:H7 in the bovine intestine for further in vivo testing as probiotics. Full article

Continuous cropping affects soil health, microbial diversity, and organic matter dynamics, but its long-term impacts on soils under Aralia continentalis Kitag. (a medicinally important Northeast China-native plant) remain unclear. This study evaluated effects of 2-, 6-, and 12-year continuous cropping on soil microbial communities, physicochemical properties, and dissolved organic matter (DOM) of bulk soils, and elucidated links between cropping duration and soil health indicators. Results showed that key physicochemical properties (total organic carbon, TOC) and available nutrients (available nitrogen, AN; available phosphorus, AP; available potassium, AK) declined with cropping duration: AN, AP, and AK decreased from 75.24 ± 1.2, 16.39 ± 0.05, and 104.8 ± 0.27 mg·kg⁻¹ (2 years) to 63.47 ± 1.53, 13.38 ± 0.16, and 88.71 ± 0.94 mg·kg⁻¹ (12 years), respectively. Microbial diversity increased initially but stabilized after 6 years, with communities shifting from copiotrophic taxa (e.g., Proteobacteria) to oligotrophic taxa (e.g., Acidobacteria). Partial Least Squares Path Modeling (PLS-PM) revealed strong positive correlations between dissolved/organic carbon (DOC/TOC) and microbial diversity, highlighting organic matter’s role in sustaining microbial richness. UV-visible and 3D fluorescence spectroscopy indices correlated significantly with microbial diversity, confirming their utility for monitoring DOM quality and microbial dynamics. This study clarifies dynamic interactions between soil properties, microbial diversity, and organic matter under continuous cropping, providing insights for sustainable cultivation of A. continentalis. Full article