Search Results (6,210)

China hosts a large number of closed coal mines containing abundant residual resources. Driven by resource recycling, mine safety, environmental protection, and the dual-carbon goals, research on gas resources in closed coal mines has expanded rapidly. In some closed mines, substantial unmined coal resources remain with high gas content, making in situ gas resources a key focus of investigation. Given the Xinzhuangzi closed coal mine as a case study, this study analyzed the distribution of coal resources based on the monitoring results of coal extraction and remaining reserves, and the distribution of gas content based on regression equation. Furthermore, it applied a volumetric calculation method to estimate the gas resources of any a certain unit, all units, and summarize the gas resources across different coal seams, structural divisions, mining levels and the entire coal mine, thereby characterizing the in situ gas resources. The results indicated that the area below –412 m in the closed Xinzhuangzi coal mine was favorable for in situ gas resource development, containing 20,061.1 × 10⁴ t of coal resource and 2250.32 × 10⁶ m³ of gas resources, with a gas resource abundance of 1.96 × 10⁸ m³/km². C13, B11b, B4, B7a, B6, and B8 were favorable targets for in situ gas resources, each containing over 100 × 10⁶ m³ of gas resources, and these seams were thick and stable. Levels 6 and 7 were favorable zones for in situ gas resources, each containing abundant coal resources with high gas content, holding 644.94 × 10⁶ and 1407.77 × 10⁶ m³ of gas resources, respectively. These findings provided not only a scientific basis for the future evaluation and development of gas resources in this coal mine, but also important references for the study of in situ gas resources in other abandoned mines. And, several suggestions were given about the development prospects of gas resources. Full article

Phytohormones, or plant hormones, are intrinsic organic compounds within plants. These compounds have a significant impact as essential plant growth and development regulators, influencing processes from seed germination to fruit ripening. The exogenous application of these phytohormones, such as gibberellic acid (GA₃), indole-3-acetic acid (IAA), and brassinosteroids, has been shown to significantly enhance horticultural productivity, with reported increases in germination, growth, and yield ranging from 10–40%. These signaling molecules are also vital for micro and macroalgae development and functioning. Recognizing their presence within algae presents a fresh perspective for horticultural researchers and cultivators, offering opportunities to enhance the quality and application of horticultural crops. Nevertheless, the challenge arises from the presence of phytohormones in trace amounts, complicating their extraction and identification. This paper will offer a comprehensive overview of phytohormone classification and detection methods and highlight their presence in algae, which may serve as an alternative for promoting plant growth in agriculture. Full article

Selective harvesting of Hotan roses requires distinguishing between buds and blooms for different industrial uses. However, balancing detection accuracy and computational efficiency for edge deployment remains a challenge. This study proposes an integrated framework combining a lightweight detection model, Rose_YOLO, with an adaptive path-planning algorithm, the ROSE algorithm, to address these issues. The Rose_YOLO model optimizes the YOLOv8n architecture by incorporating the C2f-Faster-CGLU module and a Rose_Head detection head to enhance feature extraction while reducing redundancy. The ROSE algorithm integrates an improved genetic algorithm (GA) with a reciprocating search mechanism to dynamically optimize picking sequences based on scene complexity. Experimental results demonstrate that Rose_YOLO achieves a precision of 90.4% and a mAP@0.5 of 96.6% for blooms and a precision of 88.4% with a mAP@0.5 of 91.7% for buds. Compared to the baseline YOLOv8n, the model reduces parameters by 47.46% to 1.579 million, compresses the size to 3.19 MB, and lowers computational complexity to 4.6 GFLOPs. For path planning, the ROSE algorithm generates optimal paths with an average length of 2796.94 pixels, which is 73.1% shorter than the reciprocating algorithm and 51.6% shorter than the standard GA. Furthermore, it achieves an average runtime of only 7.33 ms, significantly outperforming traditional methods with respect to computational speed. In conclusion, the proposed framework achieves a superior balance between lightweight design and detection performance. The successful deployment on edge devices validates its effectiveness in providing real-time visual guidance and efficient path planning, offering a robust technical solution for the automated selective harvesting of roses in complex field environments. Full article

Large-scale and long-term hydrogen storage is one of the main obstacles to the wider use of hydrogen as a possible substitute for natural gas. A solution could be depleted natural gas fields, which have proven capacity and are already geologically prospected. However, part of this field remains occupied by residual natural gas, meaning that hydrogen is mixed with natural gas during storage and purification after extraction is therefore necessary. The aim of this study was to design and evaluate a hydrogen purification process for separating hydrogen from natural gas after extraction from a depleted natural gas field while maintaining the required hydrogen purity and recovery. Input data provided by Nafta a.s. were used for the mathematical simulation of hydrogen separation throughout a 150-day extraction period. A mathematical model of membrane separation and pressure swing adsorption (PSA) was developed. A single membrane stage was only able to operate effectively during the first 50 days of withdrawal while maintaining at least 80% hydrogen recovery. A two-stage membrane configuration achieved hydrogen purity above 98% with final recoveries above 80–85%, while the hybrid membrane–PSA system enabled hydrogen purity of 99.8% and total recovery of 82.5% on the last day of extraction. Full article

Maintaining asphalt pavements requires substantial quantities of materials and energy, which significantly contribute to greenhouse gas emissions in the road infrastructure sector. This study quantified the carbon dioxide equivalent (CO₂e) emissions associated with a maintenance and rehabilitation plan for an asphalt pavement using a simplified life-cycle perspective integrated with the Highway Development and Management Model (HDM-4). The methodology combined HDM-4 to define a 35-year intervention plan (2022–2057) with CO₂e emission factors for three quantified components: material production, transportation, and construction machinery operation. The approach was applied to a 7.8 km section of the Mexicali–San Felipe highway in Baja California, Mexico. The results indicate that the intervention plan generated approximately 2483.9 t CO₂e over the 35-year analysis period. Reconstruction was the most carbon-intensive activity, accounting for 1890 t CO₂e, while milling and overlay generated 292.15 t CO₂e per direction. Material extraction and production were the dominant sources of emissions, contributing about 70% of the total emissions in milling and overlay and 60% in reconstruction; in the latter case, transportation also represented a substantial share (35%) due to long haul distances. These findings show that the proposed approach can identify the most emission-intensive activities and processes within pavement maintenance plans and provide quantitative environmental criteria to support more sustainable road management decisions. Full article

Ciprofloxacin residues in chicken blood pose a potential food safety risk; however, rapid detection methods for complex chicken blood matrices are lacking. This study aimed to establish a surface-enhanced Raman spectroscopy (SERS) method for the rapid detection of ciprofloxacin in chicken blood using gold colloid as the SERS substrate. Gold colloid was synthesized via the Frens method with slight modification, and key SERS detection conditions were systematically optimized to maximize SERS intensities at 1265 cm⁻¹, including the amount of trisodium citrate solution, the electrolyte type, the amount of gold colloid, the amount of NaCl solution, and the adsorption time. Raw SERS spectra were pretreated with adaptive iteratively reweighted penalized least squares (air-PLS) combined with Savitzky–Golay (SG) smoothing. A genetic algorithm (GA) was used to extract characteristic Raman shifts, and a GA-SVR prediction model with radial basis function (RBF) as the kernel was constructed, with its performance compared with multivariate linear regression (MLR) and partial least squares regression (PLSR) models. The GA-SVR model exhibited the best performance, with a coefficient of determination for the calibration set ($R_{\mathrm{c}}^2$) value of 0.9893 and for the prediction set ($R_{\mathrm{p}}^2$) value of 0.9874. The root mean square error of calibration (RMSEC) and prediction (RMSEP) were 1.2953 and 1.8617, respectively, outperforming the MLR and PLSR models. These results demonstrate that the SERS method combined with GA-SVR enables rapid quantitative detection of ciprofloxacin residues in chicken blood, providing a technical reference for monitoring veterinary drug residues in livestock and poultry products. Full article

In this study, a homogeneous polysaccharide, designated as PFP-80, was isolated from the dried root of Polygonatum filipes using enzymatic extraction combined with graded ethanol precipitation. Structural characterization suggested that PFP-80 was a fructan polysaccharide with a molecular weight of 4.06 kDa. The analysis with gas chromatograph–mass spectrometer (GC–MS) and nuclear magnetic resonance (NMR) further confirmed that PFP-80 consisted of →1)-β-D-Fruf-(2→ and →1,6)-β-D-Fruf-(2→ linkages, with branching occurring at the O-6 position. After 48 h of fermentation, the pH was decreased while SCFAs were increased significantly due to the utilization of PFP-80. Furthermore, PFP-80 was found to modulate the gut microbiota by enhancing microbial abundance and diversity, and by impeding the growth of deleterious pathogens such as Ruminococcus gnavus. In summary, the present results provide a scientific basis for the subsequent development of PFP-derived functional food products. Full article

Bias temperature instability (BTI) degradation is commonly described using empirical power-law kinetics; however, extraction of the time exponent and projection of lifetime remain highly sensitive to baseline definition and data representation. In conventional approaches, the threshold voltage shift is referenced to an initial value that cannot be measured simultaneously with stress, introducing uncertainty that can produce apparent curvature and variability in the extracted exponent. In this work, a baseline-independent linearization method is applied to representative published datasets spanning advanced silicon, SiC MOSFETs, and GaN power devices. By analyzing the measured degradation trajectories directly in a transformed time coordinate, the method removes curvature associated with baseline ambiguity and enables consistent extraction of the effective power-law exponent. Across all material systems examined, the extracted exponent exhibits systematic dependence on applied stress once baseline effects are reduced. This behavior challenges the commonly assumed constant-exponent formulation used in conventional lifetime projections and shows that even modest variations in the exponent can produce large differences in projected time-to-failure. A transformed lifetime representation based on is introduced, in which the influence of exponent variation is separated from the intrinsic voltage and temperature acceleration of the degradation rate. In this representation, the extracted acceleration parameters become more stable and physically interpretable. This formulation is consistent with standard reliability frameworks, including JEDEC JEP122G, in which the time exponent enters directly into the lifetime expression. These results demonstrate that baseline-independent analysis provides a unified framework for interpreting BTI degradation across disparate semiconductor technologies and suggest that explicit treatment of stress-dependent exponents is required for physically consistent lifetime modeling. Full article

In this study, five solvent fractions from Litsea cubeba (Lour.) Pers. fruit were extracted and investigated for their antioxidant profiles. Results showed that the petroleum ether fraction (PEF) and n-butanol fraction (NBF) exhibited prominent free radical scavenging capacities in DPPH, ABTS, and hydroxyl radical assays. Gas chromatography–mass spectrometry (GC-MS) identified citral as the dominant bioactive component in both active fractions. Further mechanism analysis demonstrated that citral exerted potent antioxidant effects via dual pathways: direct free radical scavenging and transition metal ion chelation. These findings not only elucidate the material basis and molecular mechanism underlying the antioxidant activity of L. cubeba but also provide a scientific rationale for the high-value utilization of citral-rich fractions in functional foods, cosmetics, and healthcare products. Full article

Draining peatlands for peat extraction converts them into significant sources of greenhouse gas (GHG) emissions. Quantifying GHG emissions at the regional scale remains challenging because direct field measurements are spatially limited, while GHG accounting for land-use planning requires spatially explicit information. Building on the advances in remote sensing (RS) as a scalable low-cost emission accounting tool for large areas, this study presents a proof-of-concept workflow that integrates satellite-based land-cover classification with an emission-factor (EF) approach to support spatial upscaling of peatland GHG estimates. Using Sentinel-2 imagery and a supervised Random Forest classifier, peatland-related land-cover classes were mapped for selected sites in Latvia. The classification results show higher accuracy for spectrally distinct classes such as raised bogs and active peat-extraction areas, while more heterogeneous classes exhibited lower performance. The study provides an overview of how to utilize the RS approach to generate accurate land-cover maps, which can be used to upscale GHG estimation in Latvia when field data is limited. The study does not include calibration against site-level flux measurements, uncertainty propagation, or temporal variability analysis; therefore, the emission results are illustrative and consistent with current EF-based inventory practice rather than validated site-specific fluxes. Full article

Background: Zebrafish (Danio rerio) embryos are transparent in early stages of embryonic development; however, pigment formation at later stages hinders internal organ visualization during imaging. Chemicals such as 1-phenyl-2-thiourea (PTU) and kojic acid, used to block pigmentation, pose significant toxicity risks to human health. Therefore, effective and risk-free depigmentation agents are needed. This study investigates the efficacy of Alchemilla vulgaris (Lady’s mantle) as a safe, natural alternative for zebrafish embryo depigmentation. Methods: A. vulgaris was extracted using four solvents of varying polarities and evaluated for depigmentation efficacy and toxicity. Gas chromatography–mass spectrometry (GC–MS) was used to identify major constituents of the extract. Results: Ethyl acetate extract was more effective at removing pigments than all other extracts, and exhibited the lowest toxicity compared to PTU and kojic acid. Ethyl acetate extract of A. vulgaris remained effective even when administered 48 h post fertilization (post-pigmentation), making it suitable for long-term experiments requiring optical clarity. GC-MS revealed that this extract was rich in linoleic acid, various fatty acid esters, and phenolics, which likely contributed to its depigmentation activity. Conclusions: Based on these findings, we propose that ethyl acetate extract of A. vulgaris is a safer, natural alternative to PTU and kojic acid for depigmenting zebrafish embryos, particularly in long-term imaging experiments. The extract exhibits high efficacy at low concentrations, accompanied by a favorable toxicity profile, demonstrating potential as a depigmentation agent during early zebrafish development. However, further studies are needed to elucidate its mechanism of action. Full article

Reverse chemical looping pyrolysis (RCLPy) utilizes a reduced oxygen carrier to extract oxygen from the biomass feedstock during the pyrolysis stage and transfer it for the subsequent gasification stage. This decoupled mechanism enables efficient in situ utilization of oxygen and hydrogen inherent in the biomass to produce a hydrogen-rich syngas. In this work, Ca–Fe–Ni composite oxygen carriers for RCLPy were synthesized and their impact on the hydrogen production was investigated and optimized. The results demonstrate that the reduced Ca–Fe–Ni oxygen carrier exhibited both excellent deoxygenation and catalytic cracking capability, significantly promoting the generation of hydrogen and CO. Specifically, the reduced CaFeNi15 oxygen carrier decreases the CO₂ content in the pyrolysis gas from 40.4 vol.% without an oxygen carrier to 6.89 vol.% and with a hydrogen yield of 280.2 mL⸱g⁻¹ biomass and has a total hydrogen production of 318 mL⸱g⁻¹ biomass during the whole pyrolysis–gasification process. These findings underscore the advantages of the RCLPy process in utilizing inherent biomass hydrogen for high-purity syngas production. Future efforts should focus on developing oxygen carriers with enhanced long-term cyclic stability. Full article

Hydraulic fracture geometry is of great importance for evaluating stimulation effectiveness and supporting the efficient development of unconventional oil and gas reservoirs, and it can be estimated from field shut-in water hammer signals. However, field signals are commonly characterized by strong noise, pronounced non-stationarity, strong dependence on manual extraction of effective response segments, and limited automation in inversion analysis. To address these issues, this study develops an integrated automated interpretation framework for shut-in water hammer analysis, which combines an adaptive shape-preserving Kalman filter for non-stationary signal denoising, an automatic response segment identification method, and a particle swarm optimization-based inversion strategy for fracture geometry estimation. The framework is validated using field high-frequency pressure data from hydraulically fractured wells. The results show that the proposed denoising method improves the signal-to-noise ratio from 11.99 dB to 25.05 dB while preserving key transient features. The response segments can be extracted efficiently, with runtimes of 0.84–1.22 s and onset errors within 0–5 s. For a representative fracturing stage, the relative errors of the inverted fracture half-length and fracture height are 6.21% and 3.04%, respectively. The proposed framework provides a low-cost and field-applicable tool for fracture evaluation and engineering decision-making. Full article

Globally, greenhouse gas (GHG) emissions have risen dramatically due to accelerated industrialization, excessive fossil fuel extraction, and agricultural activities, leading to global warming and ecosystem collapse. Achieving net-zero carbon emissions has therefore become a crucial global priority. Despite substantial international efforts, only a small number of countries have achieved carbon neutrality so far, with the majority aiming to do so by 2050 or 2060. Progress remains hindered by fragmented international coordination and inadequate integration of mitigation and adaptation co-benefits. However, agriculture is a major carbon emitter with significant mitigation potential. Attaining local carbon neutrality in agricultural landscapes is highly costly and strongly impacted by the spatial heterogeneity of GHG emissions and the diversity of available mitigation possibilities. This sector remains a major contributor to methane (CH₄) and nitrous oxide (N₂O) emissions, mainly through enteric fermentation and fertilizer use, and thus must be prioritized in global carbon neutrality strategies. Tactics such as improved livestock management, reduced use of synthetic fertilizers, conservation agriculture, afforestation, and renewable energy adoption can reduce emissions. These technical approaches should be supported by effective policy instruments, like carbon taxes, cap-and-trade schemes, low-carbon practice subsidies, and regulatory frameworks. Together, these measures can enable a transition toward long-term sustainability in agriculture by balancing emissions with removals through enhanced carbon sinks and credible offset mechanisms. Full article

As a finite strategic resource, helium is extracted from natural gas (NG). The concentration of helium in NG is very low, which makes helium hard to separate. The hydrate-based gas separation (HBGS) was proposed as a promising method for the separation of the NG with low helium content in this work. This work systematically investigated the HBGS of helium from simulated NG. The thermodynamic analysis reveals that the existence of 5.00 mol% tetrahydrofuran (THF) in the liquid phase decreased the gas–liquid–hydrate equilibrium pressure by 92.11%, compared to the deionized water system. The single-stage HBGS experimental results show that high THF concentration, low temperature, and high pressure benefited the gas processing capacity and helium purification, but they led to a low helium recovery rate. The best HBGS performance was limited by the “hydrate shell effect”. The decrease in gas–liquid ratio led to an increase in helium concentration without losing the gas processing capacity, but it caused a decrease in the helium recovery rate. Through three-stage HBGS optimization, the helium concentration was increased from 0.54 mol% to 13.54 mol% (a 25.07-fold enrichment), and a total helium recovery of 87.34% was achieved. The mathematical model proposed in this work accurately predicts the performance of HGBS with 2.09% average relative error compared to the experimental data. Full article