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[Objective] To solve the problems such as unclear lithological variations of the Feixianguan Formation on the western side of the marine trough's southern segment and within the plateau interior of the eastern part of the Sichuan Basin, [Methods] the lithological types and characteristics of the Feixianguan Formation were studied by comprehensively using multiple geological data such as cores, drilling and logging, and an intelligent identification method of lithological logging based on machine learning was proposed, which solved the technical problems of fine identification of lithology in the old area, and revealed the lithology, distribution and evolution of the Feixianguan Formation in the area. [Results and Conclusions] (1) The Feixianguan Formation is mainly composed of lithology such as mudstone, mud crystal limestone, argillary limestone, granule limestone, granulous dolomite, mud crystal dolomite, paste dolomite, and gypsum rock; (2) Comparison found that the improved gradient-boosted decision tree algorithm, namely Stochastic Gradient Boosting Decision Tree (SGBDT), is superior to other algorithms for constructing lithology models, and is more suitable for carbonate rock complex lithology identification; (3) The granule limestone developed intensively in the area south of the Kaijiang-Liangping Sea Trough between Feixianguan I period and Feixianguan III period, and the granulous dolomite was concentrated in the Feixianguan II period and distributed and scattered; (4) The distribution of the oolitic shoal in the area exhibits significant variation. The main development of the plateau ancient geomorphological high point and the edge of the platform in the Feixianguan I period. In the Feixianguan II period, most of the the oolitic shoal at the edge of the platform were developed, and a small number of ancient landforms in the platform were developed .And the main development of the plateau ancient geomorphological high point in the Feixianguan III period. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) shows promise in tumor treatment, particularly when combined with nanotechnology. This study examines the impact of deep learning, particularly the Cellpose algorithm, on the comprehension of cancer cell responses to PDT. The Cellpose algorithm enables robust morphological analysis of cancer cells, while logistic growth modelling predicts cellular behavior post-PDT. Rigorous model validation ensures the accuracy of the findings. Cellpose demonstrates significant morphological changes after PDT, affecting cellular proliferation and survival. The reliability of the findings is confirmed by model validation. This deep learning tool enhances our understanding of cancer cell dynamics after PDT. Advanced analytical techniques, such as morphological analysis and growth modeling, provide insights into the effects of PDT on hepatocellular carcinoma (HCC) cells, which could potentially improve cancer treatment efficacy. In summary, the research examines the role of deep learning in optimizing PDT parameters to personalize oncology treatment and improve efficacy. [ABSTRACT FROM AUTHOR]

Continental shale in China is a key exploration target with regard to unconventional hydrocarbons. Systematic research on the mineral composition, organic geochemistry, and hydrocarbon mobility has been performed in the Da'anzhai (J1dn) lacustrine shale oil reservoirs, clarifying the factors controlling shale oil accumulation. The results suggest that J1dn consists of three sub-members, with an organic-rich interval developed within the second sub-member. Three types of lithological associations have developed within the organic-rich interval: Type 1 represents the interbedding relationship between shale and shell limestone and Type 2 represents shale with intercalated limestone, followed by Type 3. The brittleness index of the J1dn continental organic-rich shale is relatively low. The porosity of the Da'anzhai lacustrine shale ranges between 0.5% and 10.5% (average value of 5.89%). The porosity is predominantly due to inorganic pores, with a small amount being attributable to nanoscale microfractures and organic pores. The average porosity of the shell limestone is only 1.2%, but fractures at the micron and centimeter scales are well developed. The organic matter in the J1dn continental shale is mainly II1–II2, with maturity in the oil generation stage. The average oil saturation of the J1dn continental shale is 3.15%, with most samples having oil saturation of less than 4%. The J1dn continental shale has great exploration potential with regard to shale oil. Type 1 shale oil is affected by multiscale fractures, including bedding fractures, and has the best mobility. The high hydrocarbon generation capacity of lacustrine shale, coupled with the multiscale fractures within shell limestone and shale, is the principal controlling factor for hydrocarbon enrichment. Based on exploration practices, the Type 1 shale association may represent the optimal interval for future shale oil exploration in the Da'anzhai Member. [ABSTRACT FROM AUTHOR]

The Ediacaran Dengying Formation fourth member in Central Sichuan Basin is the deep dolomite gas reservoir with the largest natural gas reserves in China, providing an excellent example for understanding the effect of hydrothermal silicification on deep dolomite reservoir quality. By integrating petrology, geochemistry and physical property measurement, this study aims to reveal the genesis of different quartz phase and their corresponding diagenetic events, and to discuss the temporal relationship of diagenetic events and their effects on the quality of deep dolomite reservoir in Dengying fourth member. Three phases of quartz cement are identified in Ediacaran Dengying Formation deep dolomite reservoirs of Central Sichuan Basin as follows: (1) first‐stage quartz filled in primary reservoir spaces, (2) second‐stage quartz mainly filled in secondary reservoir spaces, and (3) third‐stage quartz filled in secondary reservoir spaces with Mississippi Valley‐Type minerals. By analysing petrographic and temporal relationships between these fabrics, it is suggested that the first‐stage quartz precipitated during the syndiagenetic stage, the second‐stage quartz precipitated during middle diagenetic stage, and the third‐stage quartz precipitated during middle diagenetic stage as well. Silicification during syndiagenetic stage is characterized by replacement of cryptocrystalline quartz and cementation of first‐stage quartz within matrix dolomite (MD). After syndiagenetic silicification, the mineral composition of the MD changed from magnesium calcium carbonate to silica, and the later constructive diagenetic alterations were almost ineffective. The distribution of syndiagenetic silicification during syndiagenetic stage gradually decreases from the platform‐interior to the platform‐margin. The second‐stage and third‐stage quartz cements, derived from two‐stage hydrothermal silicification in the middle stage, are both destructive for reservoir preservation. This study, combined with coeval vapour–liquid inclusions Th data and thermal‐burial models, constrains the time of the second‐stage quartz to ca. 403–408 Ma, suggesting an hydrothermal silicification related to the Caledonian movement. The time of the third‐stage quartz cement is constrained to ca. 259.4 Ma, associated with Late Permian eruption of Emeishan flood basalts. [ABSTRACT FROM AUTHOR]

The pore‐throat structure and fluid mobility are the key factors of tight sandstone reservoir classification and evaluation. Taking the Jurassic Shaximiao Formation tight sandstone reservoir in Central Sichuan Basin as an example, 19 samples were analysed by casting thin sections, scanning electron microscopy, high‐pressure mercury injection and nuclear magnetic resonance to clarify the pore‐throat structure, the fluid motility and its controlling factors. The results show that the pore type of Shaximiao Formation tight sandstone reservoir consist of intergranular pores, dissolved pores and a few microfractures. Based on the feature of capillary pressure curve, the pore‐throat structure was classified into three types, corresponding to different movable fluid characteristics. The Type I has large pore and throat radius, good pore‐throat connectivity, small fractal dimension, weak reservoir heterogeneity and strong fluid motility. The distribution range of pore‐throat radius is mainly from 0.3 to 1.1 μm and the average movable fluid porosity (MFP) and movable fluid saturation (MFS) are 6.04% and 49.93%. The Type II has poor pore‐throat sorting, weak fluid motility and the distribution range of pore‐throat radius is 0.01–0.03 μm and 0.2–0.8 μm. The average MFP and MFS of Type II are 1.13% and 14.3%. The Type III has the smallest pore‐throat radius and the largest fractal dimension, corresponding to the most complex pore‐throat structure, which lead to the worst fluid mobility. The average MFP and MFS are 0.49% and 12.76%. The fluid mobility of the tight sandstone reservoir is affected by physical properties and pore‐throat structure. The reservoirs with large pore‐throat size, good connectivity between pore and throat, and low heterogeneity have higher MFP and saturation. Moreover, the mineral compositions have different effects on fluid mobility of the tight sandstone. The feldspar positively affects fluid mobility, while the clay minerals negatively affect fluid mobility. [ABSTRACT FROM AUTHOR]

Deeply buried (>3500 m) marine shale has become a focus point for the future exploration and exploitation of shale hydrocarbon in China. Low-temperature nitrogen adsorption (LTNA), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR), and other experiments were combined to characterize the pore structure and fluid division in deep-marine shale of the southern Sichuan Basin in this study. The results suggest that the deep-marine shale had a relatively developed nanopore network, especially with honeycomb organic pores. These organic pores were largely macropores with good connectivity in three-dimensional space and constituted the major reservoir space of the deep-marine shale gas. Microfractures were predominantly clay-mineral-related fractures, and the development degree of microfractures connected with organic pores was low, which contributed to the preservation of organic pores. Within the deep-marine shale interval, the pore volumes of Section 1 and Section 3 were higher. Pore volume was predominantly contributed by pores above 10 nm, where macropores accounted for a large proportion. Based on a combination of high-speed centrifugation and gradient temperature drying, the pore fluid of deep-marine shale reservoirs was quantitatively classified into four types: clay-bound fluid, capillary-bound fluid, free-flowing fluid, and closed-pore fluid. The clay-bound fluid existed in pores of less than 4.25 nm, which cannot be exploited. Quantitative division of the shale pore system could be realized by using the pore space differences of different types of fluids. [ABSTRACT FROM AUTHOR]

Lacustrine shale oil has the potential to lead the development of China's oil and gas industry. By integrating scanning electron microscopy, low-temperature CO2 and N2 adsorption, high-pressure mercury intrusion, and nuclear magnetic resonance with centrifugation at different speeds, the pore system and pore fluid distribution of Da'anzhai Member lacustrine shale in the Sichuan Basin are studied. The results show that: (1) The reservoir space is mainly inorganic pores and micro-fractures. Nano-micron scale pores are commonly found and widely distributed in the Da'anzhai shale with multiple peaks of 28 nm, 200 nm, 900 nm, and 3.5 µm. The total pore volume ranges from 0.00849 to 0.02808 cm³/g, and the pores ranging from 100 nm to 1000 nm are the main contributors to total pore volume. (2) Pore fluid can be divided into movable oil, bound oil, and adsorption oil. The proportion of movable oil, bound oil, and adsorbed oil is 21.4%, 12.4%, and 66.2% in Da'anzhai shale, respectively. Movable oil mainly occurs in pores larger than 350 nm, bound oil is 30–350 nm, while adsorbed oil mainly exists in pores below 30 nm. (3) The higher the total organic carbon content and clay minerals content, the smaller the pore size, resulting in the low content of movable oil. The higher the content of brittle minerals such as quartz, the better the development of intergranular pores and microfractures, and the higher the content of movable oil. Through the grading evaluation of shale pore structure and pore fluid, it is conducive to guide the exploration and development of Da'anzhai shale oil, which has important theoretical and practical significance. [ABSTRACT FROM AUTHOR]

The corrosion properties of SPFC440 steel and 5052 aluminum alloy self-piercing riveting joints were studied, and the self-piercing riveting joints and adhesive bond-riveted hybrid joints were fabricated respectively. The fatigue tests of joints with different corrosion durations were carried out, and the effects of adhesive on the corrosion and fatigue properties of riveting joints were analyzed. In addition, the fatigue fracture and crack extension were analyzed by SEM and EDS. The results how that the adhesive increases the strength of riveting joints and protects the metal interface and reduces the galvanic corrosion. The maximum static loads of adhesive bond-riveted hybrid joints are decreased continuously with the increase of corrosion durations. And the maximum static loads of self-piercing riveting joints are first increased and then decreased with the increase of corrosion durations. The tensile failure mode of adhesive bond-riveted hybrid joints is similar to that of self-piercing riveting joints. The fatigue cracks of self-piercing riveting joints are mainly concentrated in the regions of the locked sheet around the rivet. Failure mode of adhesive bond-riveted hybrid joints shows the fracture of the locked sheets. Serious fretting wear exists in the contact areas between the rivet and the locked sheet, and the contact surfaces between the pierced sheet and the locked sheet. [ABSTRACT FROM AUTHOR]

As one of the most widely grown crops in the world, rice is not only a staple food but also a source of calorie intake for more than half of the world's population, occupying an important position in China's agricultural production. Thus, determining the inner potential connections between the genetic mechanisms and phenotypes of rice using dynamic analyses with high-throughput, nondestructive, and accurate methods based on high-throughput crop phenotyping facilities associated with rice genetics and breeding research is of vital importance. In this work, we developed a strategy for acquiring and analyzing 58 image-based traits (i-traits) during the whole growth period of rice. Up to 84.8% of the phenotypic variance of the rice yield could be explained by these i-traits. A total of 285 putative quantitative trait loci (QTLs) were detected for the i-traits, and principal components analysis was applied on the basis of the i-traits in the temporal and organ dimensions, in combination with a genome-wide association study that also isolated QTLs. Moreover, the differences among the different population structures and breeding regions of rice with regard to its phenotypic traits demonstrated good environmental adaptability, and the crop growth and development model also showed high inosculation in terms of the breeding-region latitude. In summary, the strategy developed here for the acquisition and analysis of image-based rice phenomes can provide a new approach and a different thinking direction for the extraction and analysis of crop phenotypes across the whole growth period and can thus be useful for future genetic improvements in rice., (Copyright © 2023 Zhixin Tang et al.)