Push–pull exhaust systems are widely applied for controlling industry-processing fumes, and their performance is fundamentally governed by the coupling interaction among the air-curtain jet (“push”), the buoyant thermal plume generated by the heat source, and the converging flow induced by the exhaust hood (“pull”). However, the dynamic characteristics and design criteria of this coupled flow field under large temperature differences remain insufficiently explored. Here, a series of scaled experiments combined with numerical simulations is conducted to systematically investigate the coupling behavior of the air-curtain jet and the thermal plume, and two quantitative performance indicators, namely plume deflection height and flow rate along the plume deflection path, are proposed to evaluate flow control effectiveness and energy dissipation. An orthogonal experimental design is further employed to analyze the sensitivity of heat-source and air-curtain parameters with respect to these indicators. The results demonstrate that the air temperature reaches its maximum at approximately 0.8 m downstream of the air-curtain outlet, and that both the supply velocity and outlet width of the air curtain are dominant parameters exerting statistically significant influences on plume deflection height and flow rate along the path (p < 0.01). Furthermore, the Archimedes number effectively characterizes the competition between jet inertia and plume buoyancy in the coupled flow field, with its appropriate value preliminarily recommended to be controlled below 40. This study provides quantitative insights for the engineering design of push–pull exhaust systems operating under high thermal load conditions.

When high-altitude aircraft operate in a low-density environment, the flow instability within their internal ducts poses a severe challenge to aerodynamic design and operational safety. Especially in the intake system of the tandem dual-fan configuration, the asymmetric flow caused by rotating machinery coupled with the low-density effect exacerbates flow distortion, momentum dissipation, and efficiency loss and may even trigger system instability risks such as rotational stall or surge. To address these challenges, this paper establishes a high-fidelity dynamic model of the internal flow field of the aircraft, based on the Reynolds-averaged Navier–Stokes equations and the SST k-ω turbulence model, combined with dynamic mesh technology. It reveals the unstable mechanism caused by angular momentum accumulation under co-rotation conditions and its intrinsic correlation with the degradation of aerodynamic performance. Inspired by the concept of micro-flow regulation, an active flow control strategy integrating discrete auxiliary injection and local geometric shape optimization is proposed. Numerical results show that by reasonably arranging auxiliary injection holes in the intake duct and optimizing local geometric fillets, the uniformity of intake flow can be effectively improved, and the formation of large-scale vortex structures can be suppressed. This method increases the system’s flow capacity by approximately 47.4%, significantly improves the total pressure recovery coefficient and fan aerodynamic efficiency, and reduces the amplitude of low-frequency pressure fluctuations by approximately 23.1%. Research shows that in high-altitude low-Reynolds-number conditions, micro-flow regulation combined with geometric reconstruction can effectively suppress flow instability induced by rotating machinery. This achievement provides a theoretical basis and feasible engineering path for aerodynamic stability design and optimization of key components, such as the aircraft intake and exhaust systems and thermal management systems, and is of significant value for improving the overall performance and reliability of high-altitude long-endurance aircraft.

Municipal solid waste (MSW) management faces increasing pressure due to rapid urbanization and the need for low-emission energy systems. This study investigates the thermogravimetric gasification behavior of Chinese MSW under CO2, mixed air-CO2, and SrMnO3 (SMO) oxygen-carrier atmospheres to identify pathways for producing clean and higher-quality syngas. Using TGA-QMS, the gasification stages were monitored qualitatively and quantitatively over the temperature range of 750–1000 °C, while complementary FTIR, XRD, SEM-EDS, and ICP-OES analyses were employed to characterize the fresh waste and ash samples. Results show that CO2 gasification is strongly dependent on temperature and concentration, producing CO via Boudouard reaction, resulting in a gas composition of 73% CO and 27% CO2. An air-CO2 mixture as a gasification agent shifted conversion toward combustion, producing high CO during oxidation but suppressing gasification, yielding syngas dominated by 90% CO and 10% CO2. Introducing SMO significantly altered the reaction pathway via lattice-oxygen transfer: 7–56.75 mg SMO produced up to 97% CO and 3% CO2, without external oxidants, demonstrating superior per-unit oxidizing capacity compared to CO2. A mild synergistic effect was observed in the mixed CO2-SMO investigation, where CO formation exceeded that obtained with CO2 alone but remained lower than that in SMO-only gasification. In general, SMO-enabled oxygen donation provides a promising low-dilution, high-selectivity route for MSW gasification within thermogravimetric regimes.

This study evaluated the electrochemical and oxidative performance of titanium-supported RuO2–SnO2–Sb2O5 mixed metal oxide electrodes (hereafter denoted as RuO2–SnO2–Sb2O5/Ti) for degrading three aniline-based dyes and their mixture using electro-oxidation (EOx), electro-Fenton (EF), and photoelectron-Fenton (PEF) processes. Electrochemical characterization showed quasi-reversible redox behavior and fast electron-transfer kinetics, while SEM, AFM, and EDS analyses revealed a rough surface with fissures and agglomerates that increased the real electroactive area to 4.85 cm2, supporting the high catalytic activity. Spectroscopic analyses confirmed the functional groups typical of azo dyes, and RNO assays verified sustained hydroxyl-radical production during electrolysis. Current density was the main operational factor: at 50 mA cm−2, decolorization exceeded 90% due to enhanced •OH generation, whereas higher initial dye concentrations decreased reaction rates because of surface saturation and diffusion limitations. Among the oxidation processes, EF was most effective for Brown KK and Brown 5VR, EOx performed best for Brown NT, and PEF showed a slight advantage for the dye mixture owing to UV-assisted regeneration of reactive species. COD removal followed similar trends, with Brown KK mineralizing fastest and Brown 5VR showing the highest recalcitrance. Analysis of H2O2 and active chlorine indicated that EOx favors the accumulation of chlorine-derived oxidants, whereas PEF maximizes H2O2 conversion to •OH and reduces chlorinated by-products, positioning PEF as the most efficient and environmentally favorable option for treating chloride-containing wastewater.

Due to the low hydration activity of steel slag, its mechanical properties are insufficient, which limits its strategic application in steel slag based cementitious composite. In this study, the promoting effect of calcined layered double hydroxide (CLDH) on the hydration process, mechanical properties, and microstructure of high-volume steel slag cementitious materials was systematically investigated. The results showed that the addition of CLDH significantly optimized the material’s performance. When the mass fraction of steel slag was 70 wt% and the CLDH dosage was 2.0 wt%, the 7-day compressive strength reached 42.5 MPa, indicating an increase of 23.9% compared with the control group. Microscopic characterization suggested that CLDH slightly enhanced the hydration reaction of steel slag and increased the generation of hydration products through the nucleation effect. The addition of CLDH demonstrated a change in the composition of C-(A)-S-H to a higher Al/Ca ratio. Meanwhile, the lamellar structure of CLDH effectively filled the pores and promoted the densification of the matrix. This research provides valuable insights for the high-value utilization of steel slag and the design of high-performance cementitious materials.

The objective of this study was to evaluate the influence of sage (Salvia officinalis L.) in various forms on the quality and shelf life of fresh cheese. We hypothesized that incorporating ground sage, its essential oil (EO), and supercritical fluid extract (SFE) would significantly enhance the antioxidant potential and oxidative stability of the product without compromising its fundamental physicochemical profile. Results showed that, although fresh cheese is a complex, heterogeneous matrix, the dry matter remained stable, fluctuating between 32.86% and 39.13% over 30 days. The addition of sage significantly increased the total phenolic content (TPC), reaching 14.28 mg GAE/g in SFE-fortified samples, which directly correlated with a high DPPH radical scavenging activity. The addition of ground sage (XFC-G) reduced lightness (L*) and resulted in less negative greenness values (a* from −2.50 to −1.97) compared to other treatments. Conversely, XFC-C maintained higher lightness but exhibited a progressive increase in total color difference (ΔE). Sensory evaluation confirmed that sage-fortified cheeses, particularly those with ground sage, received high scores for herbal aroma and overall acceptability (4.8/5.0) after the production, but after the 10 days of storage all samples showed the same overall sensory evaluation. These findings suggest that the added forms of sage, especially ground, serve as potent natural preservatives that maintain the functional integrity and sensory appeal of fresh cheese.

Reliable wind power forecasting is essential for maintaining the safe and stable operation of power systems with high renewable energy penetration. This study proposes a short-term wind power forecasting model based on decomposition–optimization–prediction, integrating complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN), the improved football team training algorithm (IFTTA), and the bidirectional long short-term memory network model (BiLSTM). CEEMDAN is employed to decompose the non-stationary wind power sequence into relatively stable intrinsic mode functions (IMFs), thereby separating multi-scale fluctuation features. The IFTTA incorporates a dynamic probability allocation strategy and an adaptive parameter adjustment mechanism, which contributes to a better balance between global exploration and local exploitation. After optimizing the hyperparameters of BiLSTM using IFTTA, the prediction performance significantly improved. Validations were conducted on three datasets from Xinjiang, Ningxia, and Inner Mongolia, China, each containing 1440 samples (1152 for training and 288 for testing). Comparisons with the benchmark forecasting model demonstrate that the pro-posed model reduces the mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE) by at least 25.29%, 29.62%, and 20.66%, respectively. Correspondingly, the coefficient of determination (R2) was improved by at least 0.0069. This model provides an effective solution for short-term wind power prediction in practical engineering.

Dual-fuel combustion is often proposed for diesel engines as a means to partially replace conventional diesel with cleaner and/or more sustainable alternatives, such as those derived from green hydrogen. However, the low reactivity of these fuels (i.e., methane, hydrogen, and ammonia) often leads to prolonged ignition delay (ID) and combustion instability. This challenge could potentially be overcome using nanomaterials, which are additives that could improve reactivity and compensate for autoignition deficiencies. Thus, this study evaluates the effect of carbon nanotubes (CNTs) dispersed in diesel fuel on the autoignition process under dual-fuel operation. CNTs were dispersed at a concentration of 100 mg/L and stabilized with surfactant sodium dodecylbenzene sulfonate (SDBS). The resulting nanofuels were then tested in a constant volume combustion chamber (CVCC) using methane, hydrogen, and ammonia as secondary fuels across various energy substitution ratios and temperatures (535 °C, 590 °C and 650 °C). The results show that the impact of CNTs on ID is negligible, especially at high temperatures. At the lowest tested temperature (535 °C) and 40% methane substitution ratio, only slight reductions in ID were obtained. Nevertheless, this effect is less significant at higher temperatures (590 °C and 650 °C). Regarding pressure gradient, the addition of CNTs and SDBS generally induced a decrease in pressure-peak of up to 15%. This trend is attributed to the trapping of fuel droplets within the CNT structures, which creates a physical barrier that delays vaporization. Results confirm that autoignition, which is expected to be the main phenomenon influenced by CNT addition, is not enhanced.

The mechanical behavior of deep rock masses under high-stress conditions exhibits significant nonlinear characteristics. However, current in situ stress field inversion methods typically rely on linear elastic constitutive models and multiple linear regression analysis. By analyzing the results of triaxial stress–strain tests and confining pressure calibration experiments on rocks, and drawing on the nonlinear concepts from the Duncan-Zhang model, a nonlinear characterization function was developed, represented by mean stress p, bulk modulus K, and shear modulus G. The nonlinear elastic constitutive model was integrated into a numerical simulation framework, and a new in situ stress field inversion fitting method based on nonlinear elastic constitutive modeling was proposed. This method uses initial linear iterations followed by multiple nonlinear iterations until convergence is achieved. Applied to the inversion of the deep in situ stress field at the Xishan Iron Mine, the results demonstrate that compared to traditional linear regression-based methods, the errors in mean stress, deviatoric stress, and the Lode parameter were reduced by 58%, 50%, and 22%, respectively, confirming the effectiveness of this method in in situ stress field inversion in rock mechanics.

This study addresses the challenges posed by weakly cemented strata in mine tunnels, where surrounding rock softens and deforms upon water exposure, which promotes the development of seepage pathways, and exhibits insufficient stability in bolt (cable) support systems. This study conducts laboratory grouting tests using silica sol on typical weakly cemented sandstone from Xinjiang mining areas. The mineral composition and pore structure were characterized using XRD, SEM, and mercury porosimetry. The injectable mixing ratio parameters for silica sol and the catalyst were determined through viscosity-time evolution tests. Grouting was performed using a custom-built constant-pressure grouting apparatus. After curing, unconfined compressive strength (UCS) and porosity-permeability tests were conducted to evaluate the micro-mechanism of grouting effects on the mechanical and permeability properties of weakly cemented sandstone. The results indicate: (1) The sandstone exhibits a high clay mineral content of 39.8%, dominated by illite. Its pores are primarily small-scale (10–100 nm), accounting for 79.31% of the total pore volume. This scale matches that of silica sol nanoparticles (approximately 9–20 nm), facilitating slurry penetration into micro-pores; (2) microscopic analyses reveal that silica sol effectively reconstructs pore structures through permeation filling and surface coating. Compared to KCl-induced gelation (with approximately 8% gel coverage), NaCl-induced gelation forms a more continuous gel film with more complete pore filling, achieving coverage of around 22%. Furthermore, the larger surface area of the gel aggregates indicates a more thorough filling of micro- and nano-pores, effectively enhancing rock mass compactness. (3) Permeability decreased from 6.91 mD to 3.55 mD, a reduction of 48.6%, while porosity decreased from 16.94% to 13.55%, showing a phased reduction during the grouting process; (4) following pressure grouting stabilization, the uniaxial compressive strength of sandstone increased appropriately by approximately 7–14%, while the elastic modulus rose by about 18–28%. The failure mechanism shifted from shear brittleness to a shear-tension composite state, with enhanced post-peak bearing capacity. These findings provide support for optimizing silica sol grouting parameters in weakly cemented strata tunnels and for the synergistic reinforcement of rock mass permeability and strength.