The traditional Discrete Element Method (DEM) can track the motion details of individual particles, but its computational cost becomes excessively high when simulating large-scale systems involving millions or even billions of particles. In this study, a coarse-grained DEM approach was employed to analyze the flow behavior of mixed particles in a coal powder silo. This method maintains reasonable simulation accuracy while effectively reducing the total number of computational particles and significantly improving computational efficiency. After conducting investigations on the mesh-to-particle size ratio and model validation, this paper focuses on examining the effects of coal particle size distribution and mixing ratio on the characteristics of particle motion. The results indicate that during the discharge process of mixed particles, the downward velocity of particles in the central axis region near the outlet is significantly higher than that in the wall region, exhibiting typical funnel flow characteristics. The particle size distribution has a notable impact on the particle descent velocity. The uniform distribution case shows the highest descent velocity, the linear distribution case the lowest, while the normal distribution case falls between the two. Notably, in the normal distribution case, the descent velocity in the central axis region is similar to that of the uniform distribution, while the descent velocity in the wall region approaches that of the linear distribution. This presents a combined characteristic of the two extreme distributions rather than a simple transitional state. In contrast, the particle mixing ratio has a relatively minor influence on the overall motion characteristics. The mass flow rate of particles and the cross-sectional velocity distribution remain largely consistent, with only slight differences observed in the velocity within the central axis region.

We investigated the effects of atmospheric-pressure plasma treatment on the growth of Saccharomyces cerevisiae by directly comparing plasma exposure and plasma-activated medium (PAM) under strictly identical discharge conditions. An atmospheric-pressure plasma jet operated with argon (Ar) or nitrogen (N2) was used. Yeast growth was analyzed using a phase-resolved kinetic framework that separately evaluated early growth behavior and exponential growth rate based on optical density measurements. Growth curves were normalized to same-day untreated controls to minimize day-to-day variability. Under N2 plasma conditions, both direct exposure and PAM treatment resulted in limited changes in growth kinetics (μrel = 0.67–0.97; trel ≈ 1.02–1.09). In contrast, Ar plasma treatment produced clear mode-dependent effects. Direct exposure delayed growth initiation (trel = 1.00–1.40) with a moderate reduction in μrel (0.63–0.84). PAM treatment strongly suppressed μrel (0.19–0.50), whereas trel varied across conditions without systematic prolongation (0.59–1.09). These findings demonstrate that treatment mode strongly influences which growth phase is predominantly affected, highlighting the importance of phase-resolved kinetic analysis for distinguishing plasma-induced biological effects beyond conventional endpoint measurements.

Methane, a highly hazardous gas mixture when exposed to open flames, is commonly encountered in coal mines. Its primary component is CH4, making the detection of its concentration, especially under diverse environmental conditions, highly significant. In this study, La0.7Gd0.3Fe0.9Co0.1O3 nanomaterials were prepared using an ultrasound-assisted hydrothermal method. Through dual-site synergistic regulation involving Gd doping at the A-site and Co doping at the B-site, rapid detection of CH4 at low temperatures was achieved. At 150 ∘C, the sensor demonstrated a significantly enhanced response to 100 ppm CH4, with a sensitivity of 10.22. This value represents an approximately tenfold improvement over that achieved with pure LaFeO3. In addition, the sensor responded rapidly to the gas exposure within 6.3 s and recovered within 5.4 s, respectively, at the same gas concentration. Such swift recovery capabilities enable reliable detection across multiple environmental conditions. Moreover, the sensor not only shows excellent repeatability but also maintains a high response value of 9 even under highly humid conditions (95% RH). The performance enhancement is attributed mainly to lattice distortion induced by A-site doping and the increased active sites provided by B-site doping. The development of this sensor lays a foundation for future CH4 detection and industrial safety applications.

The surface chemistry of graphene oxide (GO) and its nanocomposite with 12-tungstophosphoric acid (WPA) (up to 50 wt.% WPA) was studied both in aqueous suspension and in the solid state. The titrations revealed the formation of the composite already in the suspension and that WPA influences GO’s functionalities and their conversion (-COOR to -COOH). There is a loading of WPA (>20 wt.%) beyond which the WPA dominates the chemical character of the GO/WPA suspension. Part of the nanocomposite titrated with NaOH was processed into a powdered form and compared with an annealed sample (450 °C, Ar atmosphere). An FTIR analysis revealed the removal of functional groups in both titrated and thermally annealed samples. Annealing did not induce structural changes in WPA within the composite, whereas titration led to noticeable modifications of WPA-related bands. The TPD measurements revealed that the extent of functional group removal by titration was lower compared to annealing. The zeta-potential measurements demonstrated improved stability of the nanocomposite as the WPA content increased. Methylene blue adsorption experiments showed that the presence of oxygen functional groups and WPA on the GO enhances adsorption performance compared to pristine GO. Titration improved the adsorption capacity of the composites, whereas annealing completely suppressed their adsorption properties.

Clean energy systems are at the forefront of current discussions on the protection of our environment against global warming [...]

The journal retracts the article titled “Rheological Characterization and Shale Inhibition Potential of Single- and Dual-Nanomaterial-Based Drilling Fluids for High-Pressure High-Temperature Wells” [...]

This study was aimed at producing galactooligosaccharides (GOS) from Porungo cheese whey in immobilized enzyme bioreactors. The β-galactosidase was produced, concentrated, and immobilized on chitosan–genipin supports. Initially, GOS production was conducted in conical flasks, investigating three different variables: enzyme concentration (50–150 U/mL), Porungo cheese whey concentration (200–400 g/L), and temperature (37–43 °C). The highest GOS yields (15.24%) occurred under intermediate process conditions (100 U/mL, 300 g/L, 40 °C), reaching a GOS concentration of 27.04 g/L. These conditions were then used in a packed-bed column bioreactor operated in batch mode, achieving yields of 19.72%. Repeated batches were carried out, and the system was stable until the fifth cycle, with enzyme activity remaining at 83.56% of the initial level. Continuous bioreactors were conducted, varying feed flow rates (1–3 mL/h), with the highest yields and lactose conversion occurring for the longest residence time (24.63% and 68.38%), respectively, with high GOS concentration (44.14 g/L). Microorganisms isolated from Porungo cheese showed the ability to metabolize the GOS produced, demonstrating its prebiotic potential. This work can contribute to optimizing the production of GOS, an important product for pharmaceuticals and food industries.

Following the publication of this article, concerns were raised regarding a potential undisclosed conflict of interest for the original publication [...]

Hydrocarbon resource potential evaluation represents the primary and core component of whole petroleum system studies. However, compared with the substantial progress achieved in understanding hydrocarbon generation mechanisms, quantitative assessments of hydrocarbon generation amounts from source rocks in the Songliao Basin remain relatively limited. Given that the genetic method is capable of comprehensively reflecting both the intrinsic hydrocarbon generation potential and conversion efficiency of source rocks and is supported by robust geological principles, this study was conducted within a genetic framework. Stratigraphic data and lithological descriptions from more than 2000 wells in the northern Songliao Basin, logging data from 387 wells, and measured basic geochemical data from 201 wells were integrated. Combined with the ΔlogR method, original hydrocarbon generation potential restoration techniques, and results from thermal simulation experiments, the planar distributions of key geochemical parameters of the first member of the Qingshankou Formation were systematically characterized. On this basis, the hydrocarbon generation potential and total hydrocarbon generation amounts of different structural units within the Songliao Basin were quantitatively evaluated. The results indicate that the cumulative hydrocarbon generation of the first member of the Qingshankou Formation reached approximately 506.55 × 108 t. Among the structural units, the Qijia–Gulong Sag contributed 266.13 × 108 t, the Sanzhao Sag 132.71 × 108 t, the Longhupao Terrace 66.81 × 108 t, and the Daqing Placanticline 40.90 × 108 t. These results demonstrate significant heterogeneity in hydrocarbon generation capacity among different structural units, with the Qijia–Gulong Sag identified as the most important hydrocarbon generation center in the study area. This study provides a critical quantitative foundation for whole petroleum system research in the northern Songliao Basin. It not only supplies essential data support for subsequent resource apportionment of conventional and shale hydrocarbons but also offers important constraints for analyses of reservoir-type distribution and hydrocarbon accumulation mechanisms.

Disk-type electromagnetic direct-drive centrifugal pumps have broad application prospects in fluid transport due to their compact structure and seal-free design. However, the significant axial force caused by pressure imbalances on both sides of the impeller severely affects the operational stability and the service life of the pump. This study selected the IS50-32-160 pump as the research object, seeking to optimize various balance hole structures for reducing axial force and enhancing pump efficiency. Using ANSYS-ICEM 2022 for hydrodynamic performance mesh generation and Fluent for numerical simulations, we systematically analysed 24 balance hole models with varying diameters, lengths and aperture gradient profiles to evaluate their effects on pump hydrodynamic performance, motor air-gap pressure, leakage rate and axial force. The results demonstrate that the balance hole diameter predominantly affects axial thrust, whereas the length exhibits negligible influence. Specifically, when the diameter was increased from 0 to 8 mm, the axial force dropped sharply, from 703.45 N to 125.57 N. The most pronounced reduction, of 54.7%, occurred within the 3 to 5 mm diameter range, after which the decline rate significantly slowed. In contrast, increasing the length from 84 to 100 mm only caused a marginal 4.08% rise in axial force, from 307.22 N to 320.30 N. The diverging balance holes, characterized by a linear diameter expansion from the shaft end toward the impeller side, achieved continuous and stable pressure distribution. This design not only effectively mitigated axial force but also prevented abrupt pressure fluctuations at the shaft end. The study confirms the feasibility of improving pump performance through balance hole optimization and provides a theoretical foundation for designing disk-type electromagnetic direct-drive centrifugal pumps.