Search Results (199)

To optimize the location optimization of the coalbed methane (CBM) extraction target area in abandoned mines, based on the background of the Songzao mining area in Chongqing, theoretical analysis and numerical simulation research methods were comprehensively used to systematically evaluate the potential of residual CBM resources in the goaf of the Songzao mining area. The stress-fracture evolution law and permeability enhancement characteristics of overlying strata under repeated mining of inclined multi-coal seams were deeply revealed, and the location optimization of the residual CBM extraction borehole target area was carried out. The results show that the amount of CBM resources in Songzao Coal Mine is 5.248 × 10⁷ m³, accounting for 26.57% of the total resources, which is suitable for the extraction of CBM left in goaf. The maximum height of the overburden fracture zone caused by repeated mining of K2b, K1, and K3b coal seams in Songzao Coal Mine is 72.3 m, which is basically consistent with the results of the numerical simulation (69.76 m). The fracture development of overlying strata is in the distribution form of a symmetrical trapezoid and inclined asymmetrical trapezoid, and its development height increases with an increase in coal seam mining times, and finally forms a three-dimensional ‘O’-ring fracture area, which provides a channel and enrichment area for the effective migration of CBM. The significant permeability-increasing zone of overburden rock is stable in the range of 10~40 m above the roof of the K3b coal seam and is nearly trapezoidal. According to the calculation of the height prediction model of the fracture zone in the abandoned goaf, the fracture height of the long-term compaction of the Songzao Coal Mine is reduced to 63.74 m. Based on the stress-fracture evolution characteristics of the overburden rock, combined with the permeability-increasing characteristics of the overburden rock and the migration law of the remaining CBM, it is determined that the preferred position of the remaining CBM extraction target area of the Songzao Coal Mine should be in the upper corner of the fracture development area within the range of 10~32.47 m above the K36 coal seam. Full article

Deep multi-coal seam mining is plagued by intense mining pressure, significant impacts of multi-working face mining on system roadways, and difficult surrounding rock deformation control—these issues severely threaten the safe and normal operation of roadways, creating an urgent need for effective dynamic disaster control technologies. Taking the 131,105 working face of Liuzhuang Mine (burial depth up to 740 m) as an example, this study addresses a critical research gap; existing roof cutting pressure relief technologies mostly focus on shallow/thin-coal-seam mining and fail to tackle secondary dynamic pressure induced by repeated mining in deep multi-coal seams—where the superposition of mining stress, ground stress, and goaf stress severely threatens system roadways. To fill this gap, three novel contributions are made. (1) A hierarchical “upper break and middle cut” deep-hole blasting design is proposed, distinct from single-mode roof cutting in existing studies. It achieves directional roof failure by “upper break” (damaging overlying hard rock) and “middle cut” (creating fissures between goaf and protective coal pillars), blocking stress transmission to roadways. (2) Numerical simulations specifically for deep strata (740 m) optimize key parameters: 25 m as the optimal cutting height and 35° as the optimal cutting angle, quantifying their effects on pressure relief (a gap in existing parameter optimization for deep mining). (3) A rapid sealing scheme combining AB material grouting with high-strength detonator pins is developed, solving the problem of slow hardening and poor sealing in traditional deep-hole processes (e.g., cement-only sealing), enabling blasting within 10 min after sealing. This cut off the integrity of the roof, blocked the pressure transmission of the roof stress to the existing system roadway, and achieved a 43.7% reduction in roadway surrounding rock stress (from 32 MPa to 18 MPa) and a 46.7% reduction in maximum roadway deformation (from the pre-blasting 15 cm to 8 cm). This study provides a reference for similar deep multi-coal seam projects. Field monitoring and numerical simulation results show the following. (1) The maximum deformation of the protected East Third Concentrated main roadway is only 8 cm, fully meeting normal operation requirements. (2) The “upper break and middle cut” technology effectively reduces the mining influence range (from 156 m without roof cutting to 125 m with 25 m roof cutting) and weakens roof stress transfer to roadways. This study verifies the feasibility and effectiveness of deep hole blasting for roof cutting, pressure relief, and roadway protection in deep multi-coal seam mining. It provides direct technical references and engineering application templates for similar projects facing roadway protection and dynamic disaster control challenges, contributing to the safe and efficient mining of deep coal resources. Full article

The stability of open-pit mines under low-temperature conditions is critical for safe and efficient coal extraction. However, the mechanisms of rock damage and fracture under combined temperature and stress effects remain unclear, particularly regarding the evolution of mechanical properties under repeated freeze–thaw cycles and varying peripheral pressures. This study investigates the damage and rupture behavior of coal-bearing sandstone in cold-region open-pit mines through experimental testing and theoretical modeling. The research was conducted in three stages: (1) freeze–thaw and peripheral pressure experiments to evaluate mechanical property evolution; (2) acoustic emission monitoring to analyze internal fracture initiation, propagation, and coalescence under temperature–stress coupling; (3) development of a local deterioration model to quantify post-damage strength decay considering low-temperature erosion and freeze–thaw effects. Results show that increasing freeze–thaw cycles leads to a transition from brittle to ductile behavior, while higher peripheral pressures significantly enhance ductility. Mechanical parameters are highly sensitive to peripheral pressure but largely independent of freeze–thaw cycle count. Acoustic emission signals respond strongly to temperature, and temperature–stress coupling governs the three-stage evolution of fracture germination, extension, and penetration. The local deterioration model effectively captures post-peak residual strength and damage evolution. These findings indicate that in regions with higher microcrack density, fault propagation is driven by rapid coalescence under stress concentration, whereas in lower-density regions, it is dominated by gradual fracture growth and temperature-induced expansion. The results provide theoretical guidance for stability assessment and support design in open-pit coal mines in cold environments. Full article

Plant architecture is a crucial agronomic trait significantly impacting soybean (Glycine max) yield. Traditional breeding has made some progress in optimizing soybean architecture, but it is limited in precision and efficiency. The Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein (CRISPR/Cas) system, a revolutionary gene-editing technology, provides unprecedented opportunities for plant genetic improvement. This review outlines CRISPR’s development and applications in crop improvement, focusing specifically on progress regulating soybean architecture traits affecting yield, such as node number, internode length, branching, and leaf morphology. It also discusses the technical challenges for CRISPR technology in enhancing soybean architecture, including that the regulatory network of soybean plant architecture is complex and the development of multi-omics platforms helps gene mining. The application of CRISPR enables precise the regulation of gene expression through promoter editing. Meanwhile, it is also faced with technical challenges such as the editing of homologous genes caused by genome polyploidy, the efficiency of editing tools and off-target effects, and low transformation efficiency. New delivery systems such as virus-induced genome editing bring hope for solving some of these problems. The review emphasizes the great potential of CRISPR technology in breeding next-generation soybean varieties with optimized architecture to boost yield potential. Full article

Mining activities in a quarry significantly interfere with the landscape, weaken its ecological functions, disrupt the continuity of habitats and change its natural character. The aim of this study is to present a robust, transparent, and participatory methodological framework centered on the Reclamation Quality Index, which enables a comprehensive and repeatable assessment of reclamation quality. At a time when the restoration of functional, ecologically stable and long-term sustainable landscapes is increasingly important, there is a need for reliable tools to assess the quality of restoration. This article presents an original methodology for the evaluation of quarry reclamation, which combines scientific precision with practical applicability. The proposed Reclamation Quality Index is built on multidisciplinary foundations and uses the Delphi methodology, through which expert knowledge and weighted preferences enter the evaluation process. A tool designed in this way makes it possible to quantify the quality of land restoration, identify the benefits of individual interventions, support effective planning, and strengthen the strategic management of post-mining transformation. At the same time, the Reclamation Quality Index creates space for the application of the principles of ecological stability and integration of the landscape as a living, dynamic system in the process of restoration. With its structure and philosophy, the methodology represents a prospective approach to the evaluation and planning of the post-extraction landscape. Its application goes beyond academia, as it can serve as a support for environmental policymaking, landscape planning, and assessing the quality of restoration in practice. Full article

Blasting is one of the most widely used and cost-effective techniques for rock excavation and fragmentation in open-pit mining, particularly for large-scale operations. However, repeated or poorly controlled blasting can generate excessive ground vibrations that threaten slope stability by causing structural damage, fracturing of the rock mass, and potential failure. Evaluating the effects of blast-induced vibrations is essential to ensure safe and sustainable mining operations. This study investigates the impact of blasting-induced vibrations on slope stability at the Saindak Copper-Gold Open-Pit Mine in Pakistan. A comprehensive dataset was compiled, including field-monitored ground vibration measurements—specifically peak particle velocity (PPV) and key blast design parameters such as spacing (S), burden (B), stemming length (SL), maximum charge per delay (MCPD), and distance from the blast point (D). Geomechanical properties of slope-forming rock units were validated through laboratory testing. Slope stability was analyzed using pseudo-static limit equilibrium methods (LEMs) based on the Mohr–Coulomb failure criterion, employing four approaches: Fellenius, Janbu, Bishop, and Spencer. Pearson and Spearman correlation analyses quantified the influence of blasting parameters on slope behavior, and sensitivity analysis determined the cumulative distribution of slope failure and dynamic response under increasing seismic loads. FoS values were calculated for both east and west pit slopes under static and dynamic conditions. Among all methods, Spencer consistently yielded the highest FoS values. Under static conditions, FoS was 1.502 for the east slope and 1.254 for the west. Under dynamic loading, FoS declined to 1.308 and 1.102, reductions of 12.9% and 11.3%, respectively, as calculated using the Spencer method. The east slope exhibited greater stability due to its gentler angle. Correlation analysis revealed that burden had a significant negative impact (r = −0.81) on stability. Sensitivity analysis showed that stability deteriorates notably when PPV exceeds 10.9 mm/s. Although daily blasting did not critically compromise stability, the west slope showed greater vulnerability, underscoring the need for stricter control of blasting energy to mitigate vibration-induced instability and promote long-term operational sustainability. Full article

Driver models, which provide mathematical or computational representations of human driving behavior, are crucial for intelligent driving systems by enabling stable and repeatable operations. However, existing models typically employ fixed weighting parameters to simulate preview delay, failing to reflect individual driver differences and real-time dynamic behaviors. This paper proposes a Brain-Memory Driver Model (BMDM) that emulates human brain memory mechanisms to dynamically adjust preview weights by integrating global path curvature, real-time vehicle speed, and steering torque. This emulation involves a three-stage process: capturing data in an Instantaneous Memory (IM) region, filtering data via a forgetting mechanism in a Short-Time Memory (STM) region to reduce scale, and retaining data based on correlation strength in a Long-Time Memory (LTM) region for persistent mining. By deploying a trained behavioral memory database, the model dynamically calibrates preview weights based on the driver’s state and real-time curvature variations under different road conditions. This enables the model to more accurately simulate authentic preview characteristics and improves its adaptability. Simulation results from an automated steering case study demonstrate that the improved model exhibits control performance closer to the real driving process, reproducing authentic steering behavior within the human–vehicle–road closed-loop system from an intelligent biomimetic perspective. Full article

Introduction: Huntington’s disease (HD) disrupts cortico-striato-thalamocortical circuits decades before clinical onset. Electroencephalography (EEG) offers millisecond temporal resolution, low cost, and broad accessibility, yet its mechanistic and biomarker potential in HD remains underexplored. We conducted a mechanistic review to synthesize half a century of EEG findings, identify reproducible electrophysiological signatures, and outline translational next steps. Methods: Two independent reviewers searched PubMed, Scopus, Google Scholar, ResearchGate, and the Cochrane Library (January 1970–April 2025) using the terms “EEG” OR “electroencephalography” AND “Huntington’s disease”. Clinical trials published in English that reported raw EEG (not ERP-only) in human HD gene carriers were eligible. Abstract/title screening, full-text appraisal, and cross-reference mining yielded 22 studies (~700 HD recordings, ~600 controls). We extracted sample characteristics, acquisition protocols, spectral/connectivity metrics, and neuroclinical correlations. Results: Across diverse platforms, a consistent spectral trajectory emerged: (i) presymptomatic carriers show a focal 7–9 Hz (low-alpha) power loss that scales with CAG repeat length; (ii) early-manifest patients exhibit widespread alpha attenuation, delta–theta excess, and a flattened anterior-posterior gradient; (iii) advanced disease is characterized by global slow-wave dominance and low-voltage tracings. Source-resolved studies reveal early alpha hypocoherence and progressive delta/high-beta hypersynchrony, microstate shifts (A/B ↑, C/D ↓), and rising omega complexity. These electrophysiological changes correlate with motor burden, cognitive slowing, sleep fragmentation, and neurovascular uncoupling, and achieve 80–90% diagnostic accuracy in shallow machine-learning pipelines. Conclusions: EEG offers a coherent, stage-sensitive window on HD pathophysiology—from early thalamocortical disinhibition to late network fragmentation—and fulfills key biomarker criteria. Translation now depends on large, longitudinal, multi-center cohorts with harmonized high-density protocols, rigorous artifact control, and linkage to clinical milestones. Such infrastructure will enable the qualification of alpha-band restoration, delta-band hypersynchrony, and neurovascular coupling as pharmacodynamic readouts, fostering precision monitoring and network-targeted therapy in Huntington’s disease. Full article

A narrow coal pillar in double-roadway excavation can solve the problem of working face connection and improve the resource recovery rate, but narrow coal pillars are affected by the full mining stress. Taking the 2109 double-roadway excavation of Qingwa Coal Mine as the engineering background, the roof mechanical structure model of a narrow coal pillar in a double-roadway excavation layout was established, and the bearing characteristics of different coal pillar widths under the influence of full dynamic pressure were studied. The narrow coal pillar retention width was obtained and tested through field industrial experiments. The main research results were as follows: (1) The relationship between the coal pillar bearing load and the immediate roof length was deduced, and the bearing stress of the coal pillar was divided into the steep decline stage, the transition stage, and the stabilization stage. The coal pillar within the width of the stabilization stage has a certain strength surplus capacity. (2) Under the influence of full dynamic pressure, the 5~7 m coal pillar yielded to failure, and the coal pillar of 8 m and above had a certain residual bearing capacity, compared with the first mining. After the second mining, the elastic zone in the coal pillar of each width was significantly reduced; there was no elastic grid in the coal pillar of 5 m and 6 m in width, and the grid area and proportion of the elastic zone of the coal pillars with widths of 7 m and above were very low. The optimal retention width of the narrow coal pillar was determined to be 8 m. (3) Under the influence of repeated mining, the impact of first mining on the roadway displacement of the roof and floor plate was greater, followed by the solid coal side, which had less impact on the coal pillar side. The secondary mining had a greater impact on the floor, followed by the coal pillar side and the solid coal side, which had little impact on the roadway roof. This paper also provides a significant reference for the retention of narrow coal pillars in double-roadway excavation. Full article

As a part of the mining-induced stress redistribution process during coal mining, the repeated loading and unloading process with increasing peak stresses will cause more severe deformation and damage to mining roadways, which is different from the findings in other underground engineering practices. Consequently, cyclic triaxial compression tests with increasing amplitudes were carried out to investigate the mechanical behavior, acoustic emission (AE) characteristics, and damage evolution of coal materials. It is found that peak deviatoric stress and axial residual strain at the failure of coal specimens increase with increasing confining pressures, while the changes in circumferential strain are not obvious. Moreover, the failure patterns of coal specimens exhibit shear failure due to the constraint of confining pressures while some local tensile cracks occur near the shear bands at both ends of the specimens. After that, the damage evolution of coal specimens was analyzed against the regularity of AE counts and energies to develop a damage evolution model. It is concluded that the damage evolution model can not only quantify the deformation and failure process of the coal specimens under cyclic loads with increasing amplitudes but also takes into account both the initial damage due to natural defects and the induced damage by the cyclic loads in previous cycles. Full article

In open-pit mines, substantial amounts of dust are generated at various stages. Due to the long duration, repeated mechanical disturbance, and large volume of material handled during the shoveling and loading of blasting piles, this stage is recognized as one of the primary contributors to overall dust emissions in open-pit mining operations. The objective of this study is to investigate the spatial dispersion characteristics of dust at blasting piles and evaluate the influence of wind direction on dust migration and escape behavior. This study uses a full-scale numerical model to analyze the airflow and dust migration characteristics at blasting piles under different wind directions. Simulation results show that dust particles of different sizes exhibit distinct dispersion patterns: large particles settle near the source, medium particles migrate a moderate distance, and fine particles (PM2.5 and PM10) travel further and are more likely to escape from the pit. The leeward slope and pit bottom are identified as critical zones of dust accumulation and escape. Under both dump-side and stope-side wind conditions, respirable dust (d < 5 μm) accounts for more than 50% of the escaped particles, posing potential health risks to workers. These findings establish a scientific basis for targeted dust suppression strategies, supporting safer and more sustainable mine site management. Full article

Repeated mining under insufficiently collapsed gobs is a complex process in underground mining and is associated with safety hazards such as ground collapse and subsidence. The effect of layer spacing on the fracture network evolution and fluid transport mechanisms in rock strata during this process has not been systematically studied. In this work, the discrete element method was employed to analyze the fracture development and seepage evolution of surrounding rocks in the Nanliang coal mine across varying layer spacings (5, 20, 35, 50, and 65 m). A systematic evaluation of the rock mass integrity was conducted through damage coefficient quantification. The key findings revealed that an increase in the layer spacing progressively reduced the damage coefficients in both the overburden strata above the goaf and in the interlayer formations ahead of the working face, accompanied by reduced fracture propagation intensity. Shear failure mechanisms dominated throughout the mining process. Fractal characteristics of the fractures intensified with the advance of the working face, while the hydraulic conductivity and interstitial pressure in the interlayer strata exhibited declining trends with reduced attenuation rates. Our findings provide critical insights for ensuring the safety and improving the efficiency of repeated mining under insufficiently collapsed gobs. Full article

With the increasing depth of coal mining operations, the repeated extraction of multiple coal seams has led to serious safety threats to mines, including secondary roof fracturing, interlayer separation-induced water hazards, and intense mine pressure. Due to the limited research available on the roof failure laws of gently inclined coal seam groups, this study focuses on the Yindonggou Coal Mine and employs a comprehensive approach combining theoretical analysis, numerical simulation, and field measurement. Theoretical calculations indicate that after the mining of Seam 1, the caving zone height ranges from 6.69 to 11.09 m, and the height of the water-conducting fracture zone ranges from 29.59 to 40.79 m. After Coal Seam 2 is mined, the caving zone extends 24.05–33.47 m above the roof of Coal Seam 1, and the fracture zone develops for up to 74.10–94.94 m. Following the mining of Seam 4, the caving zone expands to 30.73–40.15 m above the roof of Coal Seam 1, and the fracture zone reaches 92.26–113.10 m. The numerical simulation results show that after mining Seam 1, the caving zone height is 8.4 m, and the fracture zone reaches 36 m. After Seam 2 is mined, the caving zone extends to 27 m above the roof of Coal Seam 1 and the fracture zone extends to 89 m. After Seam 4 is mined, the caving zone expands to 40 m above the roof of Coal Seam 1 and the fracture zone develops to 112.6 m. The field measurements validate the following findings: a loss of flushing fluid during drilling indicates that after Coal Seam 4 is mined, the fracture zone develops up to 110.5 m above the roof of Coal Seam 1, and the caving zone reaches 47.5 m. Optical imaging logging shows the fracture zone developing to 114.5 m and the caving zone extending to 48.1 m above the roof of Coal Seam 1. The results demonstrate good consistency among these theoretical calculations, numerical simulations, and field measurements. This study reveals a progressive development pattern of roof failure during the repeated mining of gently inclined coal seam groups, providing a theoretical foundation for water hazard prevention and mine pressure control in deep multi-seam mining operations. Full article

The tomato leaf miner Phthorimaea (syn. Tuta) absoluta (Lepidoptera: Gelechiidae) is invasive in many agricultural regions. Its larvae feed inside leaf mines and tomato fruits, causing yield losses. Repeated sprays of insecticides disrupt agri-ecosystems. Conducting three open-field tomato experiments, we assessed whether formulations of entomopathogenic nematodes could improve the efficacy of these promising biocontrol agents or whether other nature-based agents such as pyrethrin or spinosad would be the better option(s), as compared to a standard insecticide. Steinernema carpocapsae formulated in an alkyl polyglycoside polymeric surfactant, in canola oil, or mixed in both reduced 37 to 68% of pest larvae within two weeks post-treatment, followed by the botanical pyrethrin (48%). Neither spinosad nor lambda cyhalothrin achieved sufficient control. Increasing the frequency of treatments to every two weeks moderately increased efficacy. Positively, the nematodes can, if properly formulated and applied, still be recovered alive from leaf surfaces up to two hours after spraying, indicating that they have time to enter the leaf mines. A small proportion can even be still extracted alive from the leaf mines one week later. Despite these promising results, further research is needed to improve the efficacy of nature-based management options for use against this pest, with the aim of ultimately reducing reliance on chemical insecticides and minimizing the impact on agri-ecosystems. Full article

The genus Coturnix, comprising migratory Old World quails, includes Common Quail (Coturnix coturnix) and Japanese Quail (Coturnix japonica), which are nearly indistinguishable morphologically. This similarity poses challenges in species identification, leading to conservation issues such as the illegal trade of wild Common Quail in the name of farmed Japanese Quail. To address this issue, we employed two approaches: (1) mining species-specific short sequence repeats (SSRs) and (2) designing a PCR-restriction fragment length polymorphism (PCR-RFLP) assay targeting the COX1 gene to distinguish these species. While SSR markers proved unreliable, the PCR-RFLP assay successfully distinguished between Common Quail and Japanese Quail, leveraging the unique BsaBI restriction site in the Common Quail COX1 gene. This method demonstrated high specificity and reproducibility, offering a robust tool for forensic and conservation applications. Our findings provide a reliable, efficient, and accessible technique for wildlife managers and researchers to regulate the illegal trade of Coturnix quails and support conservation efforts. Full article