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The reservoir lithology of the fourth Member of Dengying Formation in the north-central Sichuan Basin is complex with strong heterogeneity， which limits the gas reservoir exploration in the fourth Member of Dengying Formation. To further deepen the understanding of sedimentary facies and reservoir characteristics in Well DB1 area in north-central Sichuan， the sedimentary facies and reservoir characteristics of the fourth Member of Dengying Formation in Well DB1l area in the north-central Sichuan were studied based on the data of drilling core， thin section observation， well logging， log， physical property test， and drilling results. The results show that two sedimentary subfacies of platform margin and restricted platform are mainly developed in the fourth Member of Dengying Formation in the study area， and sedimentary microfacies such as algal mound， grain beach， and inter-beach sea were further identified. Among them， algal mound microfacies mainly develop algal clot dolomite and algal stromatolite dolomite， grain beach microfacies mainly develop calcarenite dolomite， and inter-beach sea microfacies mainly develop micritic dolomite and powder crystal dolomite. The algal mounds and grain beaches in the fourth Member of Dengying Formation in the study area are mainly developed on the side of the platform margin， and the deposition of algal mounds and grain beaches in the platform gradually decreases mainly inter-beach sea deposition. The development of algal mounds in the fourth Member of the Dengying Formation in the study area is characterized by longitudinal superposition， and the horizontal extension is relatively close. Meanwhile， the algal mounds are concentrated in the Upper Submember of the fourth Member of Dengying Formation with large monomer thickness， while the Lower Submember of the fourth Member of Dengying Formation is less developed and thinner. The reservoir rock types of the fourth Member of Dengying Formation in the study area are mainly algal clot dolomite， algal stromatolite dolomite， and calcarenite dolomite. The reservoir space is mainly algal binding framework pore， intergranular dissolved pore， and intergranular dissolved pore. The core porosity of the fourth Member of Dengying Formation in the study area is distributed between 2.02% and 6.03% with an overall average porosity of 3.11%， the core permeability is distributed between 0.007 04 and 9.78 mD， and the overall average permeability is 0.692 64 mD. The overall physical properties are characterized by low porosity and ultra-low permeability， and some samples show low porosity and high permeability due to the influence of fractures.

This work presents an in-depth examination of the Carboniferous volcanic reservoir within the CH471 well area, situated in the central portion of the Hongche fault zone on the northwestern margin of the Junggar Basin. Leveraging seismic data and well connection comparisons, we scrutinize the tectonic evolution model and elucidate the impact of the nappe structure of the Hongche fault zone on the volcanic reservoir. The study has obtained the following understanding: after the formation of Carboniferous volcanic rocks, affected by the Hongche fault structure, a series of structural superpositions from extension to extrusion and finally thrust occurred, resulting in a northwestward tilt of the volcanic rock mass, and a large number of cracks were generated inside the rock mass. At the same time, the top was uplifted and affected by weathering and leaching to form a weathering crust, eventually forming a reservoir. The northern part is located in the edge area of the eruption center, and the rock mass has good stratification. The rock strata have certain constraints on the reservoir distribution, and the reservoir is inclined along the rock mass. The southern part is close to the eruption center and features large volcanic breccia accumulation bodies with strong internal heterogeneity. The reservoir developed mainly in the superposition of the range of control of the weathering crust and dense fracture development, and the rock mass morphology does not control the area. Structure is the key to forming a volcanic rock reservoir, mainly reflected in the following aspects. First, tectonic activity is accompanied by fracture development, and fractures are densely developed in areas with strong activity, which can effectively improve the physical properties of volcanic reservoirs. Second, tectonic activity leads to the strata uplift and weathering denudation, forming a weathering crust. Within the range of control of weathering and leaching, the physical properties of volcanic rocks are improved, and it is easier to form high-quality reservoirs. Third, the distribution of volcanic rock masses is controlled by tectonic activity, which affects the reservoir controlled by the dominant lithology.

The middle Permian Maokou Formation in the Longnüsi area in the central Sichuan Basin is currently a key formation for exploration and development. The evaluation of the current in situ stress in this area is of great significance for fracture prediction, well pattern deployment, drilling and construction, and fracturing stimulation. This study clarifies the current direction and magnitude distributions of the in situ stress by evaluating the Maokou Formation in the Longnüsi area using finite-element numerical simulation, acoustic emission experiments, and logging data (including data from imaging logging, array acoustic logging, conventional logging, and cross-dipole acoustic logging). Specifically, the current maximum horizontal stress of the Maokou Formation in the Longnüsi area is mainly in the NW‒SE direction, and the stress direction is greatly affected by the local fault zone. The current minimum horizontal stress magnitude of the Maokou Formation obtained by acoustic emission experiments is between 96.29 and 114.36 MPa, the current maximum horizontal stress magnitude is between 126.01 and 145.10 MPa, and the current horizontal stress difference is between 25.59 and 32.58 MPa. The current minimum and maximum horizontal stress magnitudes both decrease from north to south. The current horizontal stress parameters calculated by Huang’s model are not significantly different from those experimentally measured: there is a difference of less than 8% in the current minimum horizontal stress magnitude, a difference of less than 9% in the maximum horizontal stress magnitude, and a difference of less than 15% in the current horizontal stress difference. Therefore, Huang’s model has good applicability in terms of calculating the current horizontal stresses in the Longnüsi area. The current horizontal stress parameters, which are numerically simulated with the finite-element method, are also not much different from those experimentally measured: there is a difference of less than 11% in the current minimum horizontal stress magnitude, a difference of less than 10% in the maximum horizontal stress magnitude, and a difference of less than 20% in the current horizontal stress difference. The numerically simulated current horizontal stress also decreases from north to south. Therefore, the simulated results are highly accurate. This study clarifies the directions and magnitudes of the current in situ stress state of the Maokou Formation in the Longnüsi area of the central Sichuan Basin and provides a basis for the formulation of exploration and development plans for the Maokou Formation reservoir in the study area.

Introduction: The prevalence of cognitive impairment and dementia in the older population is increasing, and thereby, early detection of cognitive decline is essential for effective intervention. Methods: This study included 2,288 participants with normal cognitive function from the Ma'anshan Healthy Aging Cohort Study. Forty-two potential predictors, including demographic characteristics, chronic diseases, lifestyle factors, anthropometric indices, physical function, and baseline cognitive function, were selected based on clinical importance and previous research. The dataset was partitioned into training, validation, and test sets in a proportion of 60% for training, 20% for validation, and 20% for testing, respectively. Recursive feature elimination was used for feature selection, followed by six machine learning algorithms that were employed for model development. The performance of the models was evaluated using area under the curve (AUC), specificity, sensitivity, and accuracy. Moreover, SHapley Additive exPlanations (SHAP) was conducted to access the interpretability of the final selected model and to gain insights into the impact of features on the prediction outcomes. SHAP force plots were established to vividly show the application of the prediction model at the individual level. Results: The final predictive model based on the Naive Bayes algorithm achieved an AUC of 0.820 (95% CI, 0.773–0.887) on the test set, outperforming other algorithms. The top ten influential features in the model included baseline Mini-Mental State Examination (MMSE), education, self-reported economic status, collective or social activities, Pittsburgh sleep quality index (PSQI), body mass index, systolic blood pressure, diastolic blood pressure, instrumental activities of daily living, and age. The model demonstrated the potential to identify individuals at a higher risk of cognitive impairment within 3 years from older adults. Conclusion: The predictive model developed in this study contributes to the early detection of cognitive impairment in older adults by primary healthcare staff in community settings. [ABSTRACT FROM AUTHOR]

Nearly 100 million tons of reserves have been explored in the Well 471 area of the Hongche Fault zone. The Carboniferous volcanic rock reservoir is the main oil-bearing reservoir in the well CH471 area and is the main target of exploration and development. The characteristics of the Carboniferous volcanic rock reservoir are studied through core, thin section, physical property, logging, and other data, and its main controlling factors are analyzed in combination with actual means of production. The lithologies of the volcanic reservoir in the study area are mainly volcanic breccia, andesite, and basalt. The matrix physical properties of volcanic rock reservoirs are medium-porosity and ultralow-permeability, among which volcanic breccia has the best physical properties. The reservoir space mainly comprises primary pores, secondary dissolution pores, and fractures, resulting in a dual medium pore-fracture-type reservoir. Combined with production data analysis, the lateral distribution of oil and gas is controlled by lithology and lithofacies, with explosive volcanic breccia being the best, followed by the basalt and andesite of overflow facies, which are vertically affected by weathering and leaching and distributed within 50~300 m from the top of the Carboniferous system. The area with densely developed fractures was conducive to developing high-quality reservoirs. The tectonic movement promoted the formation of weathering and controlled the development of faults. Based on a comprehensive analysis, it is believed that the formation of Carboniferous volcanic oil and gas reservoirs in the study area was controlled and influenced by the lithology, lithofacies, weathering, leaching, faults (fractures), and tectonics. [ABSTRACT FROM AUTHOR]

Natural fractures have an important relationship with shale gas production. This study selected the reservoir of the Wufeng‐Longmaxi Formation in Luzhou in southern Sichuan as an example. Based on the seismic reflection map of the formation, using the mechanical parameters obtained from the core sample experiment and using the finite element numerical simulation method, a three‐dimensional geological model is established, the tectonic stress field is inverted and the fracture distribution is predicted according to the Mohr‐Coulomb fracture criterion of the rock fracture, which provides theoretical support for the subsequent well pattern layout and is conducive to improving the efficiency of shale gas exploration and development. The analysis shows that the study area is dominated by NE reverse faults, with an inclination of more than 40°. The core observation results show that the filling degree of fractures is relatively high, and the width is mostly less than 1 mm, mainly caused by tectonic shear fractures. The tectonic stress in the sedimentary belt where the syncline structure is deeply buried is higher, the stress in the northwest and southeast tectonic ridges is relatively low, and the differential stress in the northeast tectonic ridge and near the fault is high. The NE fault and the surrounding rock mass have the highest fracture degree; the fracture proximity coefficient is >1.5 and the fractures are the most developed. The degree of fracture development in the area with a gentle structure is relatively low, but it is far from large faults, which is conducive to preserving shale gas. [ABSTRACT FROM AUTHOR]

This study aimed to explore the association between family function and sleep disturbances in preschool children in rural areas of China. Caregivers of preschool children completed sociodemographic questionnaires, the Children's Sleep Habits Questionnaire (CSHQ), the Self-rating Anxiety Scale (SAS) and the Family APGAR scale. Using sleep disturbances in children as the dependent variable, family function and other related factors as independent variables, binary logistic regression analyses were performed to examine associations between family function and sleep disturbances in children. A total of 3,636 caregivers of preschool children were enrolled in our study, and the prevalence of sleep disturbances among their preschool children was 89.4%. In our study, lower family function was associated with higher risk of sleep disturbances among preschool children. After adjusting for age (years), education level of mother, discipline attitudes of father and mother, only child status and caregivers' anxiety, the associations were statistically significant both in families of which caregivers of children are their parents or other relatives. (AOR for parents = 1.487, 95% CI:1.152–1.919, P = 0.002; AOR for other relatives = 1.963, 95% CI:1.302–2.958, P = 0.001). Our study results indicated that family function was associated with sleep disturbances in preschool children, and future high-quality cohort studies are needed to explore this topic in more detail. [ABSTRACT FROM AUTHOR]