Search Results (6,223)

Seed dimensions (length and width), surface color, frictional properties (static and kinetic coefficients of friction), thousand-seed weight, and angle of repose are five important categories of seed physical properties. Conventional methods generally measure these properties separately and rely heavily on manual operation, resulting in limited applicability and difficulty in balancing measurement efficiency and accuracy. To address these limitations, this study developed an automated method and an integrated platform incorporating automatic feeding, individual-seed positioning, state recognition, parameter acquisition, and cyclic control. After a single sample loading, the platform sequentially processed individual seeds, measured their dimensions, surface color, and static and kinetic coefficients of friction, and accumulated the measured seeds for subsequent thousand-seed weight and angle-of-repose determination, thereby enabling continuous automated measurement of the five categories of physical properties. Experiments were conducted using maize kernels, red kidney beans, and sunflower seeds to evaluate the measurement performance, repeatability, and cross-material adaptability of the platform. The standard deviations of repeated seed-dimension measurements were below 0.042 mm for all three seed types. The first moments of H and S in the HSV color space and a* and b* in the CIELAB color space were selected for color analysis and exhibited relatively low sensitivity to illumination variation under the tested imaging conditions. Within the stable-sliding intervals, the coefficients of determination for the relationship between actual seed displacement and squared time were all greater than 0.99, supporting the approximation of uniformly accelerated translational motion and the calculation of sliding acceleration for kinetic-friction determination. When the sample size used for thousand-seed weight estimation exceeded 50 seeds, further reductions in the coefficient of variation and average relative error were no greater than 0.2 percentage points. The angle-of-repose measurements distinguished differences in the pile formation characteristics of the three seed types. All three seed types completed the entire measurement procedure, corresponding to a platform adaptation success rate of 100%. In the cross-material validation, the coefficients of variation of all evaluated repeated-measurement indicators were no greater than 2.5%. These results indicate that, under the tested material and experimental conditions, the platform exhibited good operational stability, measurement repeatability, and cross-material adaptability, providing an effective approach for the automated and integrated measurement of multiple seed physical properties. Full article

The Mao open-pit coal mine waste dump in Hequ, Shanxi, is a loose, anthropogenic mass accumulated over the original topography. Following a recent sliding and significant settlement event, this dump became the subject of intense stability concerns. Due to the high moisture sensitivity of its interlayered soil and coal gangue structure, rainfall infiltration can reduce internal effective stress, triggering slope instability. Although conventional geological surveys have mapped surface fractures, implementing precise, targeted drainage control requires characterizing the internal geometric structure and preferred seepage directions. To address this, this study integrates electrical resistivity tomography (ERT), surface nuclear magnetic resonance (SNMR), and spontaneous potential (SP) methods. Multiple ERT profiles (270–600 m long) were deployed across several benches at varying elevations, supplemented by fixed-point SNMR sounding over typical low-resistivity anomalies and dense SP grid scanning. The integrated results successfully delineate the internal architecture and seepage characteristics of the dump. Specifically, ERT imaging resolves the primary geoelectrical interface (tentatively inferred as the potential sliding surface) separating the overlying loose mass from the stable underlying strata while mapping the spatial extent of the inferred water accumulation zone (IWAZ). SNMR sounding quantitatively reveals a two-layer water-bearing structure at the specific sounding site, with a deep primary water-bearing zone at 45–80 m depth. Furthermore, SP inversions illuminate the seepage process, demonstrating that meteoric water deflects along the geoelectrical interface to converge laterally toward the central axis at approximately 42°, before transitioning into a high-angle vertical deep infiltration zone (61.7°) within the axial region. These findings suggest a potential engineering direction for remediating surficial fractures and designing subsurface drainage along this 1040 m bench axis, which would mitigate future landslide risks by reducing internal pore water pressure. Full article

Persulfate-based Fenton-like oxidation is one of the most promising technologies for in situ chemical oxidation (ISCO) remediation of groundwater contamination, yet the mechanisms affecting persulfate activation efficiency remain underexplored. Herein, we investigated the efficiency and mechanisms of peroxydisulfate (PDS) and peroxymonosulfate (PMS) activation by cobalt-doped pyrite (Co-FeS₂) nanoparticles for degradation of 4-chlorophenol (4-CP), a model groundwater contaminant. Notably, the degradation kinetics in the Co-FeS₂/PDS system exhibited a unique “three-stage” characteristic, wherein the 4-CP degradation rate underwent a jump during the 3–5 min phase. This kinetic anomaly stems from the specific generation dynamics of ferryl species (Fe^IV=O), which experienced a 3 min lag phase followed by a rapid burst. Theoretical calculations revealed that surface-accumulated SO₄²⁻ reduces the thermodynamic energy barrier for Fe^IV=O formation, which accounts for this rapid generation subsequent to the initial lag phase. Furthermore, while hydroxyl (•OH) and sulfate (SO₄^•−) radicals were critical in both systems, •OH concentration was higher than SO₄^•− concentration in the Co-FeS₂/PDS system, whereas the Co-FeS₂/PMS system exhibited the reverse trend. Moreover, homogeneous persulfate activation mediated by dissolved Fe(II) contributed to 4-CP degradation, but to different degrees in the two systems. This study provides mechanistic insights into persulfate-based ISCO processes for groundwater remediation. Full article

Expansion joint anchorage zones are prone to premature cracking and fatigue deterioration under repeated wheel impact and interfacial stress concentration. Engineered cementitious composites (ECCs) are promising anchorage materials because of their tensile strain-hardening behavior, multiple fine cracking, and high deformation capacity. However, how ECC strength–ductility characteristics affect vehicle-induced stress redistribution and fatigue damage accumulation remains unclear. This study develops a material–structure–fatigue framework for ECC anchorage zones. Three PVA-ECC mixtures were tested, and their measured constitutive relationships were incorporated into a three-dimensional vehicle–expansion joint coupled finite element model validated using reported field strain data from a C50 concrete anchorage zone. Critical tensile stress histories were extracted for rainflow counting and Miner-based fatigue assessment. Results show that ECC reduced tensile stress concentration and increased tensile safety margins compared with C50 concrete. Under the defined loading scenario, the estimated fatigue life increased from 9.93 years for C50 concrete to 83.15 years for the best-performing ECC scheme. Ten-year comparative field observations supported the predicted durability trend. By linking ECC strength–ductility characteristics with vehicle-induced stress redistribution and cumulative fatigue damage, the proposed framework provides a quantitative basis for fatigue-resistant material selection and durability-oriented design of expansion joint anchorage zones. Full article

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract. Current treatments, including anti-inflammatory drugs and biologics, often have limited efficacy and significant side effects, highlighting the need for novel therapeutic approaches. Phellodendrine (PHE) is a characteristic ingredient of Phellodendri chinensis, yet its effects and mechanisms on IBD remain elusive. The present study evaluated the potential of PHE for preventing dextran sulfate sodium-induced IBD in zebrafish. PHE effectively reduced inflammatory cell infiltration and modulated polarized macrophages. The qPCR results further confirmed the down-regulation of pro-inflammatory genes and up-regulation of anti-inflammatory factors. Consequently, PHE promoted the resolution of IBD inflammation. PHE also restored intestinal barrier integrity by enhancing MUC2 expression, increasing goblet cell counts, and reducing intestinal permeability of both chemical and physical barriers. In addition, PHE was associated with alterations in the gut microbiome, including a reduction in potentially pathogenic microbes and an increase in beneficial microbial populations. PHE also alleviated oxidative stress. Network pharmacology suggested the potential involvement of the IL-17 signaling pathway, the lipid and atherosclerosis pathway, and the TNF signaling pathway in the preventive effects of PHE against intestinal inflammation in the zebrafish model. In vivo gene expression analysis suggested that JUN, PTGS2, IL1B, DRD2, CALM1, and HSP90AA1 may serve as putative targets of PHE. Collectively, our results indicate that PHE demonstrates potential anti-inflammatory and barrier-protective activities in a zebrafish model of intestinal inflammation. The pharmacological mechanisms by which PHE restores intestinal barriers (microbial, chemical, physical, and immune barriers) include resolving inflammation, decreasing ROS production, and enhancing lipid accumulation in the lumen overlying the intestinal mucus barrier. This study provides novel insights into the preventive effects of PHE against intestinal inflammation in a zebrafish model, suggesting its potential as a candidate for further investigation. Full article

Coal mining in areas with high groundwater levels often induces land subsidence and water accumulation, leading to the formation of artificial secondary wetlands. Reclaimed wetlands may provide important opportunities for regional biodiversity recovery. Taking Shuoxi Lake Wetland in Huaibei City as a case study, this research aims to reveal the characteristics of waterbird diversity in artificial wetlands after ecological reclamation in a coal mining subsidence area and to identify their key environmental drivers, thereby providing a scientific basis for optimizing the habitat service functions of such wetlands. Based on habitat identification and classification of the reclaimed wetland, waterbird diversity was surveyed, and redundancy analysis (RDA), Mantel tests, and ridge regression models were used to identify the major environmental factors influencing the distribution of different waterbird groups and to quantify their relative contributions. The results showed that after ecological reclamation, a total of 28 waterbird species belonging to 7 families and 6 orders were recorded in the artificial wetland of the coal mining subsidence area. Redundancy analysis (RDA) indicated that wader assemblages were more sensitive to vegetation cover (VC), distance to water bodies (DTW), and distance to buildings (DTB), whereas waterfowl assemblages were mainly affected by distance to buildings (DTB), area (A), and distance to water bodies (DTW), and showed no significant response to vegetation heterogeneity. Mantel tests further confirmed significant spatial correlations between waterbird assemblages and area (A), distance to major roads (DTR), distance to buildings (DTB), water depth (WD), and distance to water bodies (DTW). Ridge regression analysis showed that, under conditions in which anthropogenic disturbance was minimized, vegetation cover (VC) and water depth (WD) were the main positive drivers of wader diversity, whereas perimeter to area ratio (PAR) was the main negative driver. Waterfowl diversity was mainly negatively affected by perimeter to area ratio (PAR) and distance to water bodies (DTW). These findings suggest that appropriately regulating water depth, increasing vegetation cover, and reducing patch fragmentation and anthropogenic disturbance are key measures for enhancing the habitat service functions of artificial secondary wetlands in mining areas. These management strategies provide an important reference for wetland rehabilitation in other coal mining subsidence areas. Full article

To clarify the pollution characteristics and source composition of heavy metals in the paddy soils of the Yellow River irrigation district of Ningxia, a total of 515 surface soil samples were collected, and the concentrations of As, Hg, Pb, Cd, and Cr were measured. Regional-scale pollution assessment and source apportionment were conducted using the geo-accumulation index, spatial interpolation analysis, and the Positive matrix factorization (PMF) model. Based on the regional pollution assessment and spatial distribution patterns, a representative area with relatively elevated Cd accumulation and more pronounced anthropogenic influence was selected for local-scale isotope investigation. Eight paddy soil samples and potential end-member samples were collected, and, combined with literature-based end-member data, Pb and Cd isotopes were analyzed using the MixSIAR Bayesian (version 3.1.12) mixing model to further constrain the sources of Pb and Cd in village soils. The results showed that some sampling points in the study area exceeded the soil background values, but none of the points surpassed the screening values for agricultural soil pollution risk, indicating that the overall risk of paddy soils in the study area remained low. Geo-accumulation index results indicated that As, Pb, and Cr were predominantly classified as unpolluted, whereas Hg and Cd showed more pronounced accumulation, with most sampling points reaching unpolluted to moderately polluted or higher. PMF results revealed that heavy metals in the study area primarily originated from natural sources, agricultural activities, coal combustion-related sources, and industrial–traffic mixed sources. Cd was mainly influenced by agricultural sources, Hg was primarily affected by coal combustion and related industrial activities, and Pb exhibited a mixture of multiple sources. Local isotope analysis in the representative area further indicated that industrial and agricultural sources were the main contributors to soil Cd, accounting for 34.3% and 33.1%, respectively. Pb was primarily derived from agricultural activities (38.1%), while coal emissions, industrial sources, natural sources, and traffic contributed 19.2%, 18.3%, 16.9%, and 7.5%, respectively, indicating a complex mixture of agricultural, industrial, coal-combustion, natural, and traffic-related inputs. The combined application of PMF and Pb/Cd isotopes allowed for constraints on heavy metal sources at both regional and local scales, providing a scientific basis for pollution control and agricultural safety management in paddy soils of the Yellow River irrigation district. Full article

Ion-adsorption rare earth deposits (IADs) constitute the primary global source of medium-to-heavy rare earth elements. The sustainable exploitation of these resources hinges on the precise characterization of the weathered crust architecture and its hydrogeological properties. Conventional drilling often fails to resolve the complex vertical heterogeneity of regolith profiles, thereby limiting orebody delineation and the optimization of in situ leaching (ISL). To address this, this study integrates Electrical Resistivity Tomography (ERT) with Archie’s Law and the Kozeny–Carman equation. Focusing on the YZK1 and YZK2 survey lines in the Dabu mining area, southern Jiangxi, we derived 2D distributions of porosity and permeability from resistivity inversions. Our results delineate the weathered crust into four distinct vertical strata: a surface accumulation layer, a completely-to-highly weathered granite layer, a moderately-to-slightly weathered layer, and fresh bedrock. Quantitatively, the completely-to-highly weathered layer exhibits a “low resistivity (10–700 Ω·m)–high porosity (8.7%–17%)–high permeability (0.04–1.2 mD)” mode, serving as the primary leachable reservoir. In contrast, the surface and moderately weathered layers display “high resistivity (>800 Ω·m)–low porosity (3.4%–6.4%)–low permeability (0.01–0.04 mD)” characteristics. Crucially, although the fractured bedrock zones on both YZK1 and YZK2 profiles exhibit similar absolute permeability values (~0.016 mD), they represent two distinct hydraulic architectures. On the YZK1 profile, the fractured zone acts as a relatively homogeneous potential leakage pathway. Conversely, the YZK2 profile displays significant vertical segmentation: the upper and lower margins function as permeable pathways, while the central core, likely infilled with fault gouge, acts as a sealing zone that impedes fluid flow. Consequently, resistivity data alone are insufficient to accurately assess hydraulic conductivity; joint interpretation incorporating both permeability and porosity is essential to definitively determine whether a fault zone acts as a “conduit” or a “barrier.” By transitioning from qualitative imaging to quantitative parameter evaluation, this study provides a robust technical paradigm for fine-scale exploration and ISL optimization in IADs. Full article

Yaks are a distinctive livestock species native to the Qinghai–Tibet Plateau. However, the low in vitro maturation rate of their oocytes significantly limits the efficiency of assisted reproductive technologies. Curcumin (CUR), known for its bioactive functions, including antioxidant and anti-inflammatory properties, suffers from low water solubility and bioavailability, which restricts its practical applications. This study aimed to develop a curcumin-loaded bovine milk-derived exosome nanodelivery system (CUR-mEXOs) and investigate its effects on the in vitro maturation of yak oocytes and the embryonic development of parthenogenetic embryos, leveraging its natural biocompatibility and targeted delivery properties. The results indicated that the isolated mEXOs exhibited typical exosome morphology and nanoscale particle size characteristics and were effectively internalized by the oocytes. During in vitro maturation, treatment with 10 μM CUR produced optimal outcomes. Compared to free CUR, CUR-mEXOs significantly enhanced the cumulus expansion index and the rate of first polar body expulsion, reduced intracellular ROS accumulation and mitochondrial superoxide levels, and improved mitochondrial function and spindle morphology, while simultaneously upregulating the expression of factors related to mitochondrial autophagy and oocyte maturation. Following intervention with the mitochondrial autophagy inhibitor CsA, the promotive effect of CUR-mEXOs was significantly diminished, leading to increased blastocyst apoptosis and a decrease in the total cell count. In summary, CUR-mEXOs can enhance the quality of in vitro maturation of yak oocytes and their embryonic developmental capacity following parthenogenesis by regulating mitochondrial autophagy. This study established an experimental foundation for optimizing the in vitro maturation system of yak oocytes and developing strategies for the delivery of natural bioactive substances. Additionally, this study provides a theoretical basis for enhancing the efficiency of assisted reproductive technologies in yaks. Full article

A hyper compressor is one of the most critical pieces of equipment for synthesizing low-density polyethylene (LDPE) with a discharge pressure up to 350 MPa. Such a high discharge pressure creates significant challenges for safety and reliability. In this study, a 3D transient computational fluid dynamics (CFD) model of a hyper-compressor’s interstage pipeline was adopted to examine the characteristics of pressure pulsation inside the interstage pipeline. First, flow channels of multiple poppets in the combined valve were simplified into a single channel while keeping the flow area identical. A single-degree-of-freedom equation was employed to calculate the dynamic motion of the simplified valve. Then, the acceleration, velocity, and lift of the valve were acquired by accumulating pressure-induced forces. Finally, the entire model was solved, and the p–θ diagram inside the working chambers and the pressure pulsation inside the interstage pipeline were acquired. It was found that the isotropic indexes of compression and expansion processes were 29.1 and 3.17 for the first stage of the hyper-compressor, and 36.85 and 3.65 for the second stage, respectively. The indices were significantly higher than those of the common compressor due to the higher compressibility of ethylene at hyper-pressures. The maximal pressure pulsations around the first stage and the second stage were 17.5% and 16.22%, respectively. Strain gauges were adopted to measure the on-site pressure pulsation. The results showed that the proposed CFD model was able to predict the coupling of thermodynamic processes in the working chamber and pressure pulsation in the pipeline. The comparison between the predicted and measured frequency vs. amplitude diagrams showed that the discrepancies at lower harmonics were smaller than those at higher harmonics. The maximum discrepancy of the dominant harmonic amplitudes between the CFD prediction and the strain gauge measurement was within approximately ±13%. Full article

A bidirectional tribo-dynamic coupled model for a double-helical gear transmission is established by integrating tooth surface wear, thermal elastohydrodynamic lubrication (TEHL), eccentricity error, tooth profile error, and temperature-induced deformation. The time-varying mesh stiffness and meshing impact excitation is also calculated. The proposed model distinguishes itself from previous works through the bidirectional coupling between the dynamic model and the TEHL/wear sub-models, which allows tribological evolution (wear accumulation and thermal expansion) to feed back into the vibration response—a feature absent in previous studies. Using this model, the influence of multi-source excitations on vibration characteristics is investigated, and the distributions of film thickness, pressure, temperature rise, and friction coefficient in the contact zone are obtained. The results show that eccentricity error affects vibration displacement more strongly than velocity (ratio ≈ 2:1), whereas wear influences velocity more than displacement (after 3 × 10⁶ cycles, velocity increases by 50% vs. 8.1% for displacement); temperature rise significantly increases vibration velocity while slightly decreasing displacement. The TEHL sub-model predicts that the minimum film thickness and maximum pressure occur near the pitch point, with a temperature rise of approximately 35 K, and the friction coefficient exhibits a U-shaped distribution that shifts upward with accumulated wear. Vibration response is partially validated using vibration acceleration measurements on an FZG test rig under multiple operating conditions; the model shows consistent trends with experiments (errors < 20%), though direct validation of the tribological sub-models remains for future work. Full article

Indoor formaldehyde pollution poses a serious threat to human health, and residential layout design plays a critical role in formaldehyde diffusion. However, current research on the correlation between typical residential layout shapes and formaldehyde diffusion mechanisms remains insufficient. This study summarizes and refines five typical residential layout prototypes in Wuhan through investigation and employs CFD simulation to analyze formaldehyde diffusion patterns under three ventilation conditions: still-air condition, southeasterlies (dominant in summer), and northwesterlies (dominant in winter), with varying airflow speeds. Key indices such as the Human Health Risk Index and the removal rates are calculated, and the spatial distribution characteristics are evaluated by integrating airflow organization properties. The findings reveal that: (1) Under unventilated conditions, formaldehyde diffusion differs markedly by layout: the T-shaped layout shows more concentrated high concentrations. (2) Ventilation leads to layout-specific accumulation (dead zones, vortices), requiring tailored removal measures. (3) Most layouts achieve optimal removal efficiency at 1 m/s airflow speed (O-shaped, I-shaped, and L-shaped layouts), whereas F-shaped layouts require >0.5 m/s in summer and >1 m/s in winter; T-shaped layouts require case-specific solutions. Based on simulations, optimized ventilation strategies (targeted window-opening sequences, high-risk zone removal measures) are proposed. Results provide insights for early-stage residential design optimization in subtropical monsoon climates, improving indoor air quality. Full article

Background: Human papillomavirus (HPV) has traditionally been considered a sexually transmitted infection, yet accumulating evidence demonstrates that HPV can be acquired through multiple non-sexual routes. Understanding these alternative transmission pathways is critical for interpreting HPV detection in non-sexually active populations and for refining public health strategies. Methods: This review synthesizes current evidence on non-sexual HPV transmission routes, including vertical (transplacental, intrapartum), perinatal oropharyngeal colonization, fomite contamination, breast milk transmission, and horizontal non-sexual contact. We examine HPV prevalence data from female virgins, neonates, infants, and children, and evaluate metagenomic evidence positioning HPV as a component of the human virome across multiple body sites. Results: Published studies report that vertical transmission occurs in approximately 18.2% of HPV-positive mothers, with neonatal HPV positivity of 3.4% at birth and 100% genotype concordance in transmission pairs. Transplacental transmission has been documented in 10.2% of concordant mother–placenta–newborn triads. Reviewed studies report oropharyngeal colonization at birth reaching 58.2% following vaginal delivery, with 94.3% of colonized neonates clearing infection by 24 months. HPV DNA has been detected on fomites and medical devices, in breast milk (8.6–15%), and across body sites in healthy adults (skin 61.3%, vagina 41.5%, oral cavity 30%, gut 17.3%). Metagenomic studies identify HPV DNA in 68.9% of healthy individuals, with 109 distinct types detected. Female virgins show HPV prevalence ranging from 0–51.1% across studies. Conclusions: The reviewed evidence suggests that HPV exhibits characteristics of a ubiquitous virome component with multiple non-sexual acquisition routes. These findings have important implications for vaccination strategies, screening interpretation, infection control in healthcare settings, and counseling of pediatric cases and non-sexually active individuals. Full article

Romanian county Public Health Directorates (PHDs) were central to local COVID-19 crisis management, yet subnational differences in institutional response capacity remain insufficiently quantified. This study aimed to examine institutional characteristics associated with COVID-19 response capacity among Romanian PHDs. An observational comparative design included 20 PHDs—10 from counties with university medical centers (UC) and 10 from non-university counties (NUC)—using 2020–2022 averages derived from public activity reports and official statistical databases. Seven indicators were analyzed: county population, area, number of employees, institutional budget, personnel density, prior health crisis experience, and diversity of COVID-19 response measures. Group differences were assessed using the Mann–Whitney U test, and associations using Spearman’s rank correlation. UC PHDs had larger workforces (133 vs. 67 employees, p = 0.001), higher budgets (24.3 vs. 7.6 million RON, p = 0.001), greater prior crisis experience (2.4 vs. 0.8 crises, p = 0.001), and broader response portfolios (5.6 vs. 3.0 measure categories, p < 0.001). Personnel density did not differ significantly (17.80 vs. 18.59 employees/100,000 inhabitants, p = 0.614). Response diversity correlated strongly with workforce size (ρ = 0.87), budget (ρ = 0.88), and prior crisis experience (ρ = 0.81; all p < 0.001). These findings suggest that absolute institutional resources and accumulated experience may be more relevant to crisis response capacity than population-adjusted staffing alone. Full article

Stable drainage of coalbed methane wells is essential for reducing reservoir pressure and promoting methane desorption. However, coal fines carried by produced water tend to accumulate and deposit within the standing valves of drainage pumps. To address this common problem, this study investigates the transport characteristics of coal fines within the standing valve during the liquid-dominated water-pumping stage of the plunger upstroke, with the standing valve fully open. Theoretical calculations, numerical simulations, and settling experiments were conducted for three coal fines size fractions of 60–100, 100–200, and 200–400 mesh to validate the model’s predictive capability for coal fines motion. The results show that the RNG k–ε model has the lowest mean absolute relative error, at 14.50%. A solid–liquid two-phase flow model was employed to comparatively analyze five valve seat cone angles ranging from 105° to 165° and representative inlet velocities of 0.1–0.4 m/s. The results indicate that the mixture within the standing valve accelerates markedly while passing through the narrow clearance between the valve ball and the valve seat and then decelerates in the region above the valve ball. The region above the valve ball and the valve seat transition region are the primary locations of instantaneous coal fines enrichment. Increasing the inlet velocity generally enhances coal fines transport capacity and reduces the local maximum solid-phase volume fraction. Larger coal fines particles exhibit more pronounced inertial deviation and a higher degree of local enrichment, whereas smaller particles show stronger flow-following behavior and a more dispersed spatial distribution. The results further indicate that, within the investigated structural range, the 150° valve seat cone angle provides the best overall balance between coal fines transport capacity and hydraulic resistance. Ultimately, the findings provide a theoretical foundation and methodological reference for understanding the anti-clogging mechanisms of CBM pump standing valves, optimizing structural parameters, and guiding the blockage-resistant design of downhole flow components. Full article