Search Results (311)

Studies of Upper Permian Changxing Formation reef–shoal bodies in the Sichuan Basin have mainly focused on platform-margin belts along the Kaijiang–Liangping trough. The sequence position, diagnostic criteria, and spatial configuration of local intraplatform high-energy bodies remain insufficiently constrained. Using Well Pengshen 10 as the key well, this study integrates core, thin-section, log, wavelet, INPEFA, 3D seismic, RMS, and well-tie evidence. Three sequence boundaries, SB1, SB2, and SB3, divide the Changxing Formation into Sq1 and Sq2. High-energy reef–shoal deposition is concentrated in the highstand systems tract of Sq2. In Well Pengshen 10, the high-energy interval consists mainly of sponge framestone and bioclastic grainstone modified by dolomitization, dissolution, and fracturing. Some intervals show continuous low gamma-ray responses. Seismic profiles show a localized body with mound-shaped to lenticular geometry and weak internal reflection continuity. RMS anomalies are patchy in map view. Well-tie sections indicate that this body overlies platform-interior deposits and is separated from the continuous platform-margin belt to the east. These observations define it as a local intraplatform reef–shoal complex. The published results of gas tests demonstrate industrial gas deliverability at Well Pengshen 10. Integrated lithofacies, gamma-ray, and seismic-geometry constraints can therefore help identify comparable intraplatform targets beyond continuous platform-margin belts. Full article

Lacustrine shale oil has become an important target for increasing unconventional oil and gas reserves and production in China. However, compared with shallow to medium-depth shale oil systems, ultra-deep shale oil systems have experienced more complex burial evolution, diagenetic alteration, and fluid activities, and their large-scale enrichment mechanisms remain poorly understood. This study focuses on the ultra-deep shale oil system of the fourth member of the Paleogene Funing Formation (E₁f₄) in the Gaoyou Sag, Subei Basin. Core observations, mineralogical analyses, organic geochemical tests, scanning electron microscopy (SEM), pore structure characterization, and laser confocal microscopy were integrated to investigate shale lithofacies, organic matter characteristics, and shale oil occurrence mechanisms, and to identify the key factors controlling shale oil enrichment. The results show that five major lithofacies are developed in the E₁f₄, including laminated calcareous–dolomitic shale and laminated clay-rich mixed shale. Among them, carbonate-rich laminated lithofacies exhibit the highest organic matter abundance and the best reservoir quality. Laser confocal microscopy further reveals that heavy hydrocarbons are mainly retained within organic-rich clay laminae, whereas light hydrocarbons preferentially migrate into and accumulate within adjacent carbonate-rich and felsic laminae, forming an efficient source–reservoir association at the microscale. The integrated results indicate that abundant algal organic matter and thick high-quality source rocks provided sufficient hydrocarbon-generation potential. Differential source–reservoir associations controlled by laminated structures, together with multi-scale pore–fracture networks, promoted short-distance hydrocarbon migration and effective accumulation. In addition, thick mudstone roof and floor seals, a weak faulting background, and an overpressure system ensured long-term hydrocarbon preservation. This study reveals the enrichment mechanism of ultra-deep mixed shale oil in faulted lacustrine basins of eastern China, improves the understanding of lacustrine shale oil accumulation, and provides a theoretical basis for sweet spot evaluation and favorable area selection in similar basins. Full article

Acinetobacter baumannii is a major nosocomial pathogen characterized by multidrug resistance and persistence in hospital environments. This study evaluated antimicrobial susceptibility and biofilm-forming capacity in ten clinical A. baumannii isolates obtained from a tertiary care hospital in Northwestern Mexico to explore phenotypic traits associated with persistence. Minimum inhibitory and bactericidal concentrations were determined using broth microdilution according to Clinical and Laboratory Standards Institute guidelines. All isolates were resistant to ciprofloxacin, whereas variable resistance was observed for tobramycin (60%) and ceftazidime (20%); all strains remained susceptible to colistin. Bactericidal assays revealed heterogeneous responses across antibiotics. Biofilm formation, assessed by crystal violet staining, showed that most isolates produced weak to moderate biofilms, while three strains were non-producers. Significant variability in biofilm biomass was observed (p < 0.001). Notably, no direct association was found between antimicrobial resistance profiles and biofilm-forming capacity, indicating phenotypic heterogeneity among isolates. These findings suggest that persistence-related traits in A. baumannii may not be solely predicted by resistance patterns, highlighting the complexity of adaptive responses under antimicrobial stress. Full article

To elucidate the recharge relationships and hydrological processes among different water bodies in the Qinghai Lake Basin, precipitation, river water, groundwater, and lake water samples were collected from April to November 2024. The hydrogen and oxygen stable isotope compositions (δ²H and δ¹⁸O) were determined to characterize their spatiotemporal variations, and the MixSIAR model was applied to quantitatively evaluate the recharge contributions among different water bodies. The results show significant differences in stable isotope compositions among the various water bodies. Overall, lake water exhibited the most enriched isotopic signatures, whereas groundwater was the most depleted and isotopically stable, while precipitation displayed the largest variability. Precipitation isotopes exhibited pronounced seasonal effects. River water showed a depletion–enrichment–depletion pattern, reflecting the important recharge contributions from wet season precipitation and frozen-soil meltwater. Groundwater exhibited relatively weak seasonal variations and a distinct smoothing effect. In contrast, the isotopic composition of lake water was jointly controlled by evaporative fractionation and multiple recharge sources, with the highest enrichment occurring in spring and gradual depletion during wet season and dry season. Spatially, significant isotopic differences were observed among rivers. Groundwater was relatively enriched in the western part of the basin and depleted in the eastern part, whereas lake water exhibited an opposite pattern, characterized by enrichment in the east and depletion in the west. The Local Meteoric Water Line (LMWL) of the Qinghai Lake Basin was defined as δ²H = 8.07δ¹⁸O + 37.48 (R² = 0.96). Both the slope and intercept were higher than those of the Global Meteoric Water Line (GMWL), indicating that locally recycled evaporated moisture played an important role in regional precipitation formation. The river water line showed characteristics similar to those of the groundwater line, suggesting strong hydraulic connectivity between river water and groundwater. In contrast, the lake water line deviated markedly from the meteoric water line, indicating significant evaporative fractionation of lake water. The MixSIAR results indicate that the contributions of river water, groundwater, and precipitation to lake water were 37.5%, 33.9%, and 28.6%, respectively. These findings reveal the complex hydrological connections and transformation processes among multiple water bodies in the Qinghai Lake Basin and provide a scientific basis for water resource management and ecological environmental protection in inland basins of the Qinghai–Tibet Plateau. Full article

Natural fractures dominate fracturing effects and well production. Conventional fracturing fails to fully activate multi-scale fractures, and most simulations adopt homogeneous rock assumptions, lacking systematic analysis on fracture propagation and seepage evolution in heterogeneous fractured formations, while the natural fracture activation mechanism of pulsed fracturing remains unclear. This work constructs a pulsed fracturing model for heterogeneous fractured rock to simulate fracture growth and permeability evolution in intact rock and formations with various fracture attitudes, revealing the coupled laws of fracture propagation and seepage change. Results show rock mechanical heterogeneity determines fracture network complexity in intact rock; pulsed loading slows main fracture breakthrough and stimulates microcracks, creating a near-well dense and far-well sparse fracture distribution. Single-orientation fractures drive directional asymmetric fracture extension following near-weak-zone priority, with matrix heterogeneity merely causing local fracture deflection. Multi-orientation fractures display layered activation: low-angle and near-well fractures initiate first, and cross-fracture interactions raise network complexity and coverage. Fracture growth is jointly governed by weak bedding, pulse fatigue damage and matrix properties. Pulsed fracturing achieves remote non-contact activation of natural fractures, with fracture-permeability evolution showing strong spatiotemporal coupling; main fracture breakthrough triggers abrupt permeability growth. Serving as both mechanical weak planes and preferential flow paths, natural fractures build composite seepage systems of main channels and micro flow zones. This study provides theoretical support for parameter optimization and efficient permeability improvement in fractured reservoirs. Full article

Due to system interactions, the formation and maintenance of dual squall lines are more complex than for single squall lines. In this study, we use upper-air soundings, ERA5 reanalysis data, high-density surface automatic weather station observations, and Doppler radar data to analyze a dual squall-line system that occurred over North China on 13 June 2022 under the Northeast China Cold Vortex. We focus on the differences between the two squall lines in mesoscale environments, convective triggering mechanisms, and maintenance processes. The main results are as follows: (1) The dual squall-line event occurred in different sectors of the Northeast China Cold Vortex, with both lines exhibiting a “dry-cold aloft, warm-moist below” stratification. However, significant spatiotemporal differences in mesoscale thermodynamic and dynamic conditions across Hebei and Shandong provinces led to distinct evolutionary pathways between the two squall lines. (2) Squall Line 1 (SL1) was triggered by the superposition of cold-pool outflow from convective cells over the Bohai Bay and convergence lines associated with surface cyclonic circulations. Squall Line 2 (SL2) was triggered by the thermal instability in the overlapping region of the temperature and dew-point fronts on the eastern slope of the Taihang Mountains, in conjunction with topographic uplift driven by the easterly flow. (3) This case study shows that squall-line maintenance depends not only on environmental CAPE and vertical wind shear but may also be closely related to the coordinated interplay between local thermal conditions and low-level shear. SL1, situated in a high-CAPE, low-LCL warm-moist environment, experienced relatively weak low-level shear; however, the ratio of cold-pool propagation speed to low-level shear remained near the RKW optimum, favoring persistence. Additionally, cold-pool spreading on the southern flank triggered new convection that merged into the southern end of the squall line, enhancing the cold pool via evaporative cooling and further promoting longevity. By contrast, SL2 displayed a pronounced north–south disparity: the northern segment failed to satisfy RKW balance due to insufficient cold-pool propagation relative to shear, leading to rapid echo dissipation; the southern segment, featuring an overly strong cold pool and low-CAPE, high-LCL conditions, inhibited deep convection. As a result, SL2 gradually split due to the spatial mismatch of thermodynamic and dynamic conditions along its north–south extent. Full article

The escalation of antimicrobial resistance (AMR) represents a serious global threat to public health, with AMR-associated mortality estimated to increase by 70% by 2050. As pathogens evolve through enzymatic inactivation, target modification, efflux-mediated clearance, biofilm formation, and broader genetic adaptation, conventional therapies are increasingly compromised, while the antibiotic development pipeline remains critically constrained by high discovery and development costs, weak commercial incentives, and the escalating complexity of resistance mechanisms. This review comprehensively synthesizes advanced pharmacological and biotechnological innovations designed to circumvent these entrenched resistance mechanisms. We highlight the development of novel therapeutic classes, particularly lariocidin, which disrupts bacterial protein synthesis via a previously unexploited ribosomal-binding site. Moreover, we critically evaluate molecular interventions, emphasizing CRISPR/Cas-based gene silencing and genome editing as precise tools to neutralize specific resistance determinants, such as the mecA gene in methicillin-resistant Staphylococcus aureus (MRSA). Concurrently, we explore the integration of engineered nanoparticles to revitalize existing antimicrobials by overcoming biofilm barriers, improving drug solubility, and enabling targeted delivery. Collectively, mastering the evolving AMR landscape requires a multidimensional framework that seamlessly integrates these novel molecular targets with advanced rapid diagnostics and robust international governance. Full article

Teixobactin is a promising antibiotic that targets cell wall biosynthesis in Gram-positive bacteria and displays a low propensity for resistance; however, its structural complexity presents challenges for analogue development and optimisation. In this study, we investigated the effects of macrocycle size and replacement of the native depsipeptide linkage with an amide bond on antibacterial activity using a simplified Leu₁₀-teixobactin scaffold. An amide-based macrocyclisation strategy was developed for efficient lactam formation using readily accessible amino acid building blocks, avoiding reliance on synthetically demanding modified diamino acids employed in other approaches. Two complementary synthetic routes provided access to a series of ten analogues, comprising linear and macrocyclised variants with systematic variation at position 8. Antibacterial activity was evaluated against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant clinical isolates. While linear analogues exhibited weak or no measurable antibacterial activity, macrocyclised analogues retained measurable antibacterial activity, indicating that macrocyclisation is essential within this scaffold, whereas moderate expansion of the macrocycle was tolerated. The structure–activity relationships identified here demonstrate the suitability of a simplified Leu₁₀-teixobactin framework and provide a platform for further optimisation of teixobactin-inspired antibiotics. Full article

Mudstone hydration is a critical factor contributing to casing failure during water injection operations in oilfield development. However, the relationship between hydration-induced stress evolution and casing failure mechanisms remains insufficiently understood. In this study, a three-dimensional fluid–solid coupling numerical model of the casing–cement sheath-formation system was developed, based on the nonlinear correlation between mudstone water content and its mechanical properties. Experiment results indicate that increasing the water content from 2% to 8% reduces the shear strength of mudstone by 89.7%. The axial shear strain distribution along the casing exhibits a pattern of lowvalues in the central section and high values at both ends. With increasing water content, the shear strain response evolves through three stages: weak localization at 2–3%, enhanced localization at 4–5%, and pronounced ring-shaped localization at 8%. Furthermore, localization analysis identifies lithological interfaces as high-risk zones, where strain gradient reversals occur within both the cement sheath and casing. By integrating simulation with observed casing failure data, this study elucidates the progression of casing failure mechanisms in the studied oilfield, providing a mechanistic basis for identifying and mitigating casing failure in waterflood-developed oilfields with extensive mudstone intervals and complex geology. Full article

The recycling of spent lithium-ion batteries and selected complex electronic waste fractions is commonly evaluated using isolated metrics such as leaching yield, metal removal efficiency, and reagent consumption. However, this approach fails to address the central challenge of sustainable valorization: integrating upstream conversion with downstream selective recovery without shifting environmental and separation burdens. This review focuses specifically on spent LIBs as the primary model system, while also drawing insights from related e-waste streams (e.g., printed circuit boards and polymer-containing residues) where the interface-driven framework applies. It examines how key interfaces—solid–fluid, polymer–metal–fluid, membrane–solution, electrode–electrolyte, and crystal–solution—govern metal mobilization, selectivity, effluent quality, product purity, and scalability. Emphasis is placed on hydrothermal and supercritical water processing, PVC/CPVC (Polyvinyl Chloride/Chlorinated Polyvinyl Chloride)-assisted metal mobilization and membrane-based recovery techniques, including nanofiltration, membrane distillation, membrane distillation crystallization, ion exchange, and electrochemical methods. Supercritical water and membrane processes are complementary only when upstream chemistry is designed to facilitate downstream separation. PVC-rich waste is reconsidered as a reactive chlorine source, provided that corrosion, HCl formation, and salt precipitation are controlled. Critical gaps include incomplete mass balances, limited multicomponent studies, weak integration between process stages, and scarce techno-economic and life-cycle analyses. A roadmap is proposed for scalable, integrated hydrothermal–membrane systems enabling efficient resource recovery and water reuse. Full article

To address severe stress concentration, excessive convergence, and instability of the roadside backfill body (RBB) in gob-side entry retaining (GER) under thick and hard roof conditions, this study investigates the control mechanism of main roof fracture position on surrounding rock stability, using the 3⁻¹01 working face of Huoluowan Coal Mine as a case study. A combined approach integrating theoretical analysis, numerical simulation, and field investigation is adopted. A statically indeterminate mechanical model based on masonry beam theory is established to characterize the lateral roof fracture behavior. The deflection and bending moment distributions are derived, and a criterion for fracture position determination is developed based on the maximum bending moment condition. The theoretical results indicate that the natural fracture position is located approximately 9.4–11.2 m inside the gob boundary. Numerical simulations using UDEC Trigon under different fracture positions (−2 m, 1 m, 5 m, and 9 m) show that fracture location significantly affects the mechanical response of GER. Fractures occurring above the roadway or RBB induce large deformation levels and more extensive plastic zones, while gob-side fracture conditions correspond to relatively lower disturbance levels and improved structural stability. The RBB exhibits shear-dominated failure characteristics, and the displacement distribution is non-uniform along height, with larger deformation in the middle-to-upper region. To improve stability, a coordinated control strategy combining anchor cable reinforcement and directional long-distance hydraulic fracturing (HF) is proposed to regulate the main roof fracture position through the formation of artificial weak planes. Field monitoring results show that the maximum displacements of the roof, floor, and ribs are 558 mm, 233.5 mm, and 71.3 mm, respectively, with a convergence ratio of 19.8%. Borehole imaging confirms the development of hydraulic fractures within the designed roof stratum, supporting the effectiveness of the proposed control approach. These results demonstrate that the fracture position of the main roof plays a key role in controlling GER stability, and its regulation provides an effective means for improving roadway performance under complex geological conditions. Full article

Single-cell omics technologies have transformed the study of cellular heterogeneity, enabling high-resolution analysis of tissue development and complex traits. In sheep and goats, these approaches have been applied to skin, hair follicles, reproductive organs, metabolic tissues, and adipose tissue, revealing cell type-specific regulatory programs underlying traits such as wool quality, fertility, growth, and fat deposition. However, most studies rely on single-cell RNA sequencing (scRNA-seq) and are limited by incomplete genome annotation, insufficient coverage of production traits, and weak integration with population genetics, restricting their application in molecular breeding. This review summarizes advances in single-cell omics in sheep and goats, focusing on tissue development and trait formation. We further discuss emerging strategies that integrate single-cell multi-omics, spatial transcriptomics, and population genetics to resolve regulatory mechanisms in a cell type-specific and spatially informed context. Finally, we discuss CRISPR/Cas9-based validation to link genotype and phenotype, accelerating gene discovery and precision breeding in small ruminants. Full article

Tight oil and gas reservoirs have become an important alternative to conventional hydrocarbon resources worldwide. They are characterized by dense formations, strong heterogeneity, and the low natural productivity of individual wells, making well pattern deployment and injection–production parameter optimization highly challenging. In real development, tight oil and gas fields usually involve hundreds or even thousands of wells. If each well is analyzed and optimized individually, a large amount of computation is required. Meanwhile, uncertainty in geological models further increases the complexity of development scheme design. Traditional manual adjustment methods based on engineering experience are inefficient and make it difficult to obtain an optimal well pattern suitable for the efficient development of tight oil and gas reservoirs under complex constraints, thus showing obvious limitations. To address these problems, this study first analyzes the strengths, weaknesses, and applicability of existing well placement optimization methods. Based on this analysis, we propose an optimization design method that integrates numerical simulation software for tight oil and gas reservoirs with modern intelligent optimization algorithms, enabling rapid and effective integrated optimization of horizontal well placement and fracturing in tight reservoirs. After being applied to Block X of a tight oil field, this optimization method achieved favorable field results, with an average cumulative oil and gas equivalent production of 31,400 metric tons per well, providing a new approach for the effective development of similar tight oil and gas reservoirs. Full article

As RFID systems become increasingly widespread, the limitations imposed by tag collisions on system performance are becoming more evident. Parallel decoding has attracted significant attention due to its ability to improve channel utilization and throughput. However, existing schemes often perform poorly when decoding weak signals. Several challenges remain, including the assumption of ideal channel conditions, difficulty in detecting tag state transitions, and the complexity of state cluster formations in the In-phase and Quadrature (IQ) domain. To address the above issues, this paper first experimentally verifies the ability of middle state points to segment tag states, and proposes a time-window-based pre-processing method to improve the density of state clusters in the IQ domain. Second, by leveraging the high vertical resolution of the reader, we propose an ideal magnitude calculation method and a matching strategy for combined state clusters under weak signal conditions. Finally, we propose MagMap, a parallel decoding scheme based on middle state points and magnitude extraction. Experimental results demonstrate that, under weak signal conditions, MagMap reduces the decoding BER (Bit Error Ratio) of received packets by more than 60% compared to the state-of-the-art. Full article

Geological observations, excavation performance records, field monitoring data, and support applications obtained during construction were examined in relation to excavation-induced structural behavior. Monitoring systems, including tiltmeters, extensometers, and distomat measurements, were used to evaluate deformation behavior in buildings located near the tunnel alignment. This study additionally discusses the differences between the preliminary FEM-based deformation predictions reported during the design stage and the structural behavior observed during excavation. The results indicate that groundwater-sensitive claystone sections generated significant excavation and stability problems despite controlled excavation and support measures. High groundwater inflow (30–35 L/s) caused base instability, unfavorable excavation conditions, and increased deformation risks. Field observations indicated substantially greater deformation behavior than the preliminary FEM-based predictions reported during the design stage. The findings demonstrate that shallow urban tunneling in weak and groundwater-sensitive formations may generate more complex ground–structure interactions than those represented in preliminary numerical assessments. This study highlights the importance of continuous field monitoring, adaptive support strategies, groundwater control measures, and observational excavation management practices for improving tunnel safety and reducing risks to nearby urban structures. Full article