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The lithologic combinations in lacustrine shale strata in China are complex, and shale oil content varies significantly across different combinations. Identifying favorable lithologic combinations will assist in locating shale oil-rich zones. This study takes the shale strata of the second submember of the Da'anzhai Member (Da 2 submember) in Jurassic of the central Sichuan Basin as a case study. Using mineral composition analysis and core observation, four primary lithologies were identified: shell limestone, shale with interbedded shell layers, shell-bearing shale, and pure shale. Various types of pores and fractures develop in each lithology, with bedding-parallel microfractures being more developed in shell-bearing shale and pure shale. To further reveal the pore and fracture system in the shale strata, the proportion of oil-wet and water-wet pores and fractures in the rock (pore and fracture configuration) were determined through one-dimensional nuclear magnetic resonance (NMR) experiments. The pore and fracture configuration values of shell limestone and shale with interbedded shell layers exceeded 60%, indicating restricted oil and gas migration. Due to the development of bedding-parallel microfractures, the pore and fracture configuration values in shell-bearing shale and pure shale were less than 60%, indicating that these lithologies provided more favorable migration channels for oil and gas. Furthermore, influenced by the hydrocarbon supply capacity and the resistance in oil and gas migration, rocks with total organic carbon (TOC) content greater than 1.0% as well as pore and fracture configuration values greater than 60% possessed more residual oil and exhibited better mobility than those with pore and fracture configuration values smaller than 60% (S1ranging from 0.86 to 2.19 mg/g, with an average of 1.42 mg/g; OSI values ranging from 65.96 to 123.21 mg/g, with an average of 91.98 mg/g). Finally, based on the characteristics of organic matter enrichment, the favorable lithologic combinations for shale oil enrichment in the Da 2 submember in the study area were clarified.

Based on the oil and gas exploration in the Sichuan Basin, combined with data such as seismic, logging and geochemistry, the basic geological conditions, hydrocarbon types, hydrocarbon distribution characteristics, source- reservoir relationship and accumulation model of the Upper Triassic–Jurassic continental whole petroleum system in the basin are systematically analyzed. The continental whole petroleum system in the Sichuan Basin develops multiple sets of gas-bearing strata, forming a whole petroleum system centered on the Triassic Xujiahe Formation source rocks. The thick and high-quality source rocks in the Upper Triassic Xujiahe Formation provide sufficient gas source basis for the continental whole petroleum system in the basin. The development of conventional-unconventional reservoirs provides favorable space for hydrocarbon accumulation. The coupling of faults and sandbodies provides a high-quality transport system for gas migration. Source rocks and reservoirs are overlapped vertically, and there are obvious differences in sedimentary environment, reservoir lithology and physical properties, which lead to the orderly development of inner-source shale gas, near-source tight gas, and far-source tight–conventional gas in the Upper Triassic–Jurassic, from bottom to top. The orderly change of geological conditions such as burial depth, reservoir physical properties, formation pressure and hydrocarbon generation intensity in zones controlled the formation of the whole petroleum system consisting of structural gas reservoir in thrust zone, shale gas-tight gas reservoir in depression zone, tight gas reservoir in slope zone, and tight gas–conventional gas reservoir in uplift zone on the plane. Based on the theory and concept of the whole petroleum system, the continental shale gas and tight gas resources in the Sichuan Basin have great potential, especially in the central and western parts with abundant unconventional resources.

The abundance of petroleum resource is influenced by various factors and involves complex parameters and extensive data. Consequently, traditional geostatistical methods often lack precision in quantitative prediction. To address this issue, this study focuses on the third member of Paleogene Shahejie Formation (member Es3) in the Wenliu area of the Dongpu Sag and utilizes a multi-layer perceptron neural network (MLP) for predicting petroleum resource abundance and employed the Boosting ensemble learning algorithm to optimize the prediction model. The MLP and MLP-Boosting algorithm models were test on 66 sample groups, yielding correlation coefficients of 0.789 and 0.989 for the training set, 0.618 and 0.825 for the validation set and 0.689 and 0.845 for the test set. The analysis identified effective thickness, average permeability and effective porosity are the most significant geological factors influencing petroleum resource abundance, with importance coefficients of 33.93%, 20.12% and 19.53%, respectively. Other factors such as trap area, surface crude oil density and sedimentary facies assignment were found to be less influential. Overall, the Boosting ensemble learning algorithm significantly enhanced the prediction accuracy of the multi-layer perceptron model, offering valuable insights for target optimization, exploration planning and petroleum resource evaluation in other blocks in the sag.

Taking the Lower Permian Fengcheng Formation shale in Mahu Sag of Junggar Basin, NW China, as an example, core observation, test analysis, geological analysis and numerical simulation were applied to identify the shale oil micro-migration phenomenon. The hydrocarbon micro-migration in shale oil was quantitatively evaluated and verified by a self-created hydrocarbon expulsion potential method, and the petroleum geological significance of shale oil micro-migration evaluation was determined. Results show that significant micro-migration can be recognized between the organic-rich lamina and organic-poor lamina. The organic-rich lamina has strong hydrocarbon generation ability. The heavy components of hydrocarbon preferentially retained by kerogen swelling or adsorption, while the light components of hydrocarbon were migrated and accumulated to the interbedded felsic or carbonate organic-poor laminae as free oil. About 69% of the Fengcheng Formation shale samples in Well MY1 exhibit hydrocarbon charging phenomenon, while 31% of those exhibit hydrocarbon expulsion phenomenon. The reliability of the micro-migration evaluation results was verified by combining the group components based on the geochromatography effect, two-dimension nuclear magnetic resonance analysis, and the geochemical behavior of inorganic manganese elements in the process of hydrocarbon migration. Micro-migration is a bridge connecting the hydrocarbon accumulation elements in shale formations, which reflects the whole process of shale oil generation, expulsion and accumulation, and controls the content and composition of shale oil. The identification and evaluation of shale oil micro-migration will provide new perspectives for dynamically differential enrichment mechanism of shale oil and establishing a “multi-peak model in oil generation” of shale.

Based on the analysis of Upper Paleozoic source rocks, source-reservoir-caprock assemblage, and gas accumulation characteristics in the Ordos Basin, the gas accumulation geological model of total petroleum system is determined. Then, taking the Carboniferous Benxi Formation and the Permian Taiyuan Formation and Shanxi Formation as examples, the main controlling factors of gas accumulation and enrichment are discussed, and the gas enrichment models of total petroleum system are established. The results show that the source rocks, faults and tight reservoirs and their mutual coupling relations control the distribution and enrichment of gas. Specifically, the distribution and hydrocarbon generation capacity of source rocks control the enrichment degree and distribution range of retained shale gas and tight gas in the source. The coupling between the hydrocarbon generation capacity of source rocks and the physical properties of tight reservoirs controls the distribution and sweet spot development of near-source tight gas in the basin center. The far-source tight gas in the basin margin is mainly controlled by the distribution of faults, and the distribution of inner-source, near-source and far-source gas is adjusted and reformed by faults. Generally, the Upper Paleozoic gas in the Ordos Basin is recognized in four enrichment models: inner-source coalbed gas and shale gas, inner-source tight sandstone gas, near-source tight gas, and far-source fault-transported gas. In the Ordos Basin, inner-source tight gas and near-source tight gas are the current focuses of exploration, and inner-source coalbed gas and shale gas and far-source gas will be important potential targets in the future.

Granite residual soil (GRS) exhibits favorable engineering properties in its natural state. However, a hot and rainy climate, combined with vibrations generated during mechanical construction, can cause a notable decrease in its strength. In this study, the evolution of stress–strain curves and strength parameters (cohesion c and internal friction angle φ), unconfined compression strength (UCS) under drying and wetting(DW) cycles and vibration were investigated by means of direct shear test and UCS test. Furthermore, modified formulas for calculating shear strength and UCS under DW cycles and vibration were proposed, and their accuracy was verified. The results are as follows: The stress–strain curve of shear strength exhibits strain-hardening characteristics, and the shear compressibility of the sample increases with the number of DW cycles and vibration time. However, the stress–strain curve of UCS shows strain-softening properties, and the peak strength shifts forward with the number of DW cycles and vibrations. With the increase in the number of DW cycles and the vibration time, c shows a non-linear degradation, with a maximum degradation of 58.6%. φ fluctuates and increases due to the densification effect of DW cycles, but the influence of vibration on φ decreases with the increase in the number of DW cycles. UCS rapidly decreases and gradually stabilizes after DW cycles and vibration, with a maximum degradation of 81.1%. This study can serve as a reference for the stability analysis of GRS pits subjected to long-term influences of hot and rainy climates and mechanical vibration, providing valuable insights for future research.

A micro-nano pore three-dimensional visualized real-time physical simulation of natural gas charging, in-situ pore-scale computation, pore network modelling, and apparent permeability evaluation theory were used to investigate laws of gas and water flow and their distribution, and controlling factors during the gas charging process in low-permeability (tight) sandstone reservoir. By describing features of gas-water flow and distribution and their variations in the micro-nano pore system, it is found that the gas charging in the low permeability (tight) sandstone can be divided into two stages, expansion stage and stable stage. In the expansion stage, the gas flows continuously first into large-sized pores then small-sized pores, and first into centers of the pores then edges of pores; pore-throats greater than 20 μm in radius make up the major pathway for gas charging. With the increase of charging pressure, movable water in the edges of large-sized pores and in the centers of small pores is displaced out successively. Pore-throats of 20–50 μm in radius and pore-throats less than 20 μm in radius dominate the expansion of gas charging channels at different stages of charging in turn, leading to reductions in pore-throat radius, throat length and coordination number of the pathway, which is the main increase stage of gas permeability and gas saturation. Among which, pore-throats 30–50 μm in radius control the increase pattern of gas saturation. In the stable stage, gas charging pathways have expanded to the maximum, so the pathways keep stable in pore-throat radius, throat length, and coordination number, and irreducible water remains in the pore system, the gas phase is in concentrated clusters, while the water phase is in the form of dispersed thin film, and the gas saturation and gas permeability tend stable. Connected pore-throats less than 20 μm in radius control the expansion limit of the charging pathways, the formation of stable gas-water distribution, and the maximum gas saturation. The heterogeneity of connected pore-throats affects the dynamic variations of gas phase charging and gas-water distribution. It can be concluded that the pore-throat configuration and heterogeneity of the micro-nanometer pore system control the dynamic variations of the low-permeability (tight) sandstone gas charging process and gas-water distribution features.

Dietary fiber (DF) is believed to provide important health benefits and it has become a research hotspot. DF exists in most natural foods, including fruits (16.74%–91.24%), vegetables (6.53%–85.19%), grains (9.76%–69.20%) and so on. DF has different physicochemical properties such as water holding capacity (WHC) (2.01–25.03 g/g), water swelling capacity (WSC) (0.95–23.90 mL/g), oil holding capacity (OHC) (0.65–29.00 g/g), glucose adsorption capacity (GAC) (0.17–4.65 mmol/g), cholesterol adsorption capacity (CAC) (0.03–37.10 mg/g) and viscosity, which make it exhibits different physiological functions such as reducing the risk of obesity, diabetes, cancer, and intestinal diseases. On the basis of consulting related databases, the physicochemical properties of DF and its derived physiological functions are reviewed. It is found that DF has effect on the prevention and treatment of obesity due to good WHC, WSC, OHC and CAC. Good GAC can relieve the symptoms of diabetes. The physicochemical properties of WHC and WSC can reduce the risk of cancer. The WHC, WSC and viscosity are beneficial to intestinal health.

The permanent strain is one of the most important dynamic properties of the granite residual soil. To systematically study the dynamic deformation characteristics of granite residual soil (GRS) under the drying-wetting (D-W) cycles, a series of dynamic triaxial tests is carried out to obtain the stress-strain relationship of GRS with various fine particle contents subjected to D-W cycles. The experimental results show that the growth of permanent strain consists of two stages, namely, compaction stage and compression stage. The main effect of D-W cycles is reflected in the compression stage. On the other hand, the influence of fine particle contents on the permanent strain occurs mainly at the compaction stage, which can be classified as the lubrication, densification, and asphyxiation, respectively. Subsequently, a new criterion to characterize the permanent strain of GRS is deduced from the experimental results, which accounts for both strains and rates of strains. This criterion illustrates that with the increase of D-W cycles number, the permanent strain evaluation pattern of GRS is gradually changing from plastic stabilization to plastic creep. Finally, a quadratic function model referring to the log-log scale is proposed to fit well the relationship between the permanent strain and loading cycle number of GRS under D-W cycles. It is found that the parameters of the proposed model can physically represent the strain rate, the compression strain, and the compaction strain.

Abstract Norepinephrine (NE), acting as both a neurotransmitter and hormone, plays a significant role in regulating the action of the brain and body. Many studies have demonstrated a strong correlation between mental disorders and aberrant NE levels. Therefore, it is of urgent demand to develop in vivo analytical methods of NE for diagnostic assessment and mechanistic investigations of mental diseases. Herein, we report a 19F MRI probe (NRFP) for sensing and imaging NE, which is constructed by conjugating a gadolinium chelate to a fluorine‐containing moiety through a NE‐responsive aromatic thiocarbonate linkage. The capacity and specificity of NRFP for detecting NE is validated with in vitro detecting/imaging experiments. Furthermore, the feasibility of NRFP for visualizing NE in animals is illustrated by ex vivo and in vivo imaging experiments, demonstrating the promising potential of NRFP for selective detection and specific imaging of NE in deep tissues of living subjects.

In southern China, granite residual soil (GRS) is widely used as road base material. Thus, it is important to study the effects of hot and rainy climates and cyclic loads generated by trains on the dynamic properties of GRS. In this work, by means of dynamic triaxial tests, the effects of the number of drying and wetting (D–W) cycles, fines content and number of load cycles on the hysteresis curve, dynamic shear modulus Gd and damping ratio λ of GRS are systematically investigated. The experimental results illustrate the changes in the morphology of the hysteresis curve and dynamic parameters with the numbers of load and D–W cycles, as well as the fines content. Namely, the area S, center offset d, and residual strain εsp of the hysteresis curve decrease with the increase of load cycle number, increase with the growth of fines content, and first decrease with the increase of D–W cycle number, then slowly increase to stabilized values. However, the major axis gradient k exhibits exactly the opposite relationships. Meanwhile, the dynamic shear modulus Gd increases with the growing load cycles and decreases with the addition of fines content, and the damping ratio λ shows the opposite behavior. It is also shown that Gd and λ vary linearly with respect to logN, where N is the number of D–W cycles. The dynamic properties of GRS are mostly affected by the number of load cycles, which is followed by the fines content and then the number of D–W cycles. The influence of the latter two factors on the dynamic properties of GRS may be primarily due to contact form changes between soil particles.

Recently, increasing numbers of oil and gas reservoirs have been discovered in the Wenchang Depression, western Pearl River Mouth Basin, South China Sea, revealing prospects for hydrocarbon exploration. The Enping Formation (E 3 e) is a key target layer for the development of source rocks. However, previous work has only focused on lacustrine swamp source rocks of E 3 e in the Wenchang A Sag, without a systematic study of shallow lacustrine source rocks. In this study, the quality of E 3 e shallow lacustrine source rocks is reevaluated, and the hydrocarbon generation and expulsion characteristics are analyzed using relevant geological data and constructing a conceptual model. The results show that the E 3 e 2 source rocks have greater thickness (50–600 m) and similar organic matter abundance (0.5–2.5%) compared with the E 3 e 1 source rocks (50–500 m and 0.5–2.5%). On the whole, the E 3 e source rocks were deposited in the continental environment and are dominated by Type II and Type III kerogen. Meanwhile, the E 3 e source rocks of the Wenchang A Sag are in the stage of mature to over mature, while those of the Wenchang B Sag are in the stage of low mature. Vertically, the hydrocarbon generation potential of the E 3 e 2 source rocks is greater than E 3 e 1 . Also, the cumulative hydrocarbon production of steep slope in the Wenchang A Sag is larger than that in the Wenchang B Sag. In addition, the corresponding vitrinite reflectances of hydrocarbon expulsion threshold and peak are 0.72 and 0.96%, respectively. Horizontally, four hydrocarbon generation and expulsion centers were mainly concentrated in different subsags of the Wenchang A and B Sags for E 3 e. The maximum values of hydrocarbon generation and expulsion intensity for E 3 e 1 are 1500 × 10 4 t/km 2 and 1000 × 10 4 t/km 2 , respectively, while those for E 3 e 2 are 1800 × 10 4 t/km 2 and 1200 × 10 4 t/km 2 , respectively, with the expulsion efficiency of 75%.

Anthocyanins have great health benefits, especially malvidin. Vitis amurensis Rupr are rich in malvidin, and malvidin-3-O-glucoside (Mv3G) monomer is the most abundant. However, natural anthocyanins are unstable, which limits their wide application in the food field. Soybean insoluble dietary fiber (SIDF) has high stability, and it can be used as an inert substrate to construct a stable system, which may improve the stability of anthocyanins. The optimal condition to construct a stable system of SIDF and Mv3G at pH 3.0 was determined by an orthogonal experiment. The results indicated that SIDF effectively improved the stability of Mv3G under different pH values (1.0~7.0), high temperature (100 °C for 100 min), and sunlight (20 ± 2 °C for 30 d) conditions. The absorption peak intensity of the UV–VIS spectrum of SIDF-Mv3G was enhanced, which indicated that there was interaction between SIDF and Mv3G. Fourier transform infrared spectroscopy analyses revealed that the -OH stretching vibration peak of SIDF-Mv3G was changed, which indicated that the interaction between SIDF and Mv3G was due to hydrogen bonding. X-ray diffraction analysis showed that the crystalline morphology of SIDF was opened, which was combined with Mv3G, and SIDF made Mv3G change to a more stable state. Scanning electron microscope analysis showed that SIDF and Mv3G were closely combined to form an inclusion complex. Overall, this study provides valuable information for enhancing the color stability of anthocyanins, which will further expand the application of anthocyanins in the food field.

The Lufeng Sag and Huizhou Sag, both located in the Zhu-1 Depression, have similar geographical locations, but their reservoir characteristics in the Paleogene Wenchang Formation show obvious differences. Primary intergranular pores are mainly developed in the Lufeng Sag. However, secondary pores are the main reservoir space in the Huizhou depression. Overall, the reservoir properties of the Lufeng Sag are better than those of the Huizhou Sag. To analyse the differences between the Paleogene reservoirs in these two areas, this study mainly uses assay data, such as rock thin sections, scanning electron microscope images, drilling, and logging, to analyse the differential development mechanisms of high-quality reservoirs, and two types of reservoir development models were concluded. The results show that the anti-compaction primary porosity preservation mode is mainly developed in the Lufeng Sag. High compositional maturity quartz sandstone is the congenital condition of primary porosity development. The top and bottom calcareous cementation formed of the large set of thick sand bodies increases the rock’s anti-compaction ability. The early shallow burial slows down the compaction action of overlying strata. Under the low geothermal temperature, it can delay the time for deep reservoirs to enter the middle diagenetic stage. The reservoirs in the Huizhou Sag are developed with the secondary dissolution pore development model. The Wenchang Formation reservoir in the Huizhou Sag has a large area of contact with source rocks, and organic acids can migrate to sandstone reservoirs for dissolution. Additionally, the secondary dissolution pores are more developed because the Wenchang Formation reservoirs in the Huizhou Sag contain more easily dissolved substances.

Anthocyanins are abundant in purple corn and beneficial to human health. Soybean protein isolate-7s (SPI-7s) could enhance the stability of anthocyanins. The stable system of soybean protein isolate-7s and delphinidin-3-O-glucoside complex (SPI-7s-D3G) was optimized using the Box–Behnken design at pH 2.8 and pH 6.8. Under the condition of pH 2.8, SPI-7s effectively improved the sunlight-thermal stabilities of delphinidin-3-O-glucoside (D3G). The thermal degradation of D3G conformed to the first order kinetics within 100 min, the negative enthalpy value and positive entropy value indicated that interaction was caused by electrostatic interaction, and the negative Gibbs free energy value reflected a spontaneous interaction between SPI-7s and D3G. The interaction of SPI-7s-D3G was evaluated by ultraviolet visible spectroscopy, circular dichroism spectroscopy and fluorescence spectroscopy. The results showed that the maximum absorption peak was redshifted with increasing the α-helix content and decreasing the β-sheet contents, and D3G quenched the intrinsic fluorescence of SPI-7s by static quenching. There was one binding site in the SPI-7s and D3G stable system. The secondary structure of SPI-7s had changed and the complex was more stable. The stabilized SPI-7s-D3G will have broad application prospects in functional foods.

The effects of Zn2+ incorporation on the phase formation, thermal expansion, phase transition, and vibrational properties of HfMg1−xZnxMo3O12 are investigated by XRD, dilatometry, and Raman spectroscopy. The results show that (i) single phase formation is only possible for x ≤ 0.5, otherwise, additional phases of HfMo2O8 and ZnMoO4 appear; (ii) The phase transition temperature from monoclinic to orthorhombic structure of the single phase HfMg1−xZnxMo3O12 can be well-tailored, which increases with the content of Zn2+; (iii) The incorporation of Zn2+ leads to an pronounced reduction in the positive expansion of the b-axis and an enhanced negative thermal expansion (NTE) in the c-axes, leading to a near-zero thermal expansion (ZTE) property with lower anisotropy over a wide temperature range; (iv) Replacement of Mg2+ by Zn2+ weakens the Mo–O bonds as revealed by obvious red shifts of all the Mo–O stretching modes with increasing the content of Zn2+ and improves the sintering performance of the samples which is observed by SEM. The mechanisms of the negative and near-ZTE are discussed.

Based on the distribution features of present formation pressure, analysis on logging data, and genetic mechanisms of abnormal pressure, the overpressure evolution was reconstructed using numerical basin simulation and other quantitative analysis methods. The phase differences of pressure increasing mechanisms, enhancement differences among different mechanisms, and the control of geopressure evolution on gas migration and accumulation were discussed. The causes of overpressure in the Xujiahe Formation include under-compaction (from early Late Triassic to the end of the Jurassic), hydrocarbon generation (from end of the Early Jurassic to the Neogene) and tectonic compression (since the Cretaceous). It is suggested that tectonic compression and hydrocarbon generation are the principal factors of the present overpressure in the Xujiahe Formation. Overpressure transmission is the main cause of overpressure in the Jurassic strata which occurred during the intense tectonic activity periods since the Cretaceous. The overpressure is the main force for hydrocarbon migration and overpressure-related microfractures are the major pathways for gas migration. Fault transport and overpressure driving caused the formation of Jurassic secondary gas reservoirs with distant sources. The areas with high pressure coefficient in the Jurassic and high-overpressure zones in the Xujiahe Formation are optimum targets for exploration. Key words: abnormal pressure, under-compaction, hydrocarbon generated overpressure, tectonic compression, overpressure transmission, hydrocarbon accumulation, Western Sichuan Depression

The fine characterization of the micro pore structure of low-permeability sandstone has become the key technology for the efficient development of this kind of reservoir. In this study, the micro fine modeling of three-dimensional pore structure is established through the micro-CT scanning, and quantitative parameter characterization analysis is carried out combined with the image processing technology. Based on this, the digital rock electrical experiments of gas/water two-phase saturated low permeability sandstone is carried out, and the influence of internal factors such as wettability, saturation and micro pore throat structure parameters on the rock electrical characteristics is analyzed. The experimental results show that the porosity-based image segmentation method is used to binarize the digital image of low permeability sandstone and establish the pore network model, which can retain the real topology of pore space to the greatest extent. Rock electrical three-dimensional simulation technology of porescale has certain applicability for complex reservoirs such as low permeability sandstone. The wettability, pore throat structure and other microscopic factors have an important influence on the rock electrical characteristics. The resistivity of water-wet reservoir is lower than that of gas-wet reservoir, and the difference is more obvious in the stage of low water saturation. Among the micro pore throat structure parameters, the throat radius and pore throat ratio show a good positive correlation with the resistivity index. With the increase of coordination number, the resistivity index decreases, which is particularly prominent under low water saturation. [ABSTRACT FROM AUTHOR]