In desert, Gobi, and mountain front areas, seismic data often suffer from wide frequency band noises with poor linearity and strong energy that is ten to ten thousand times stronger than the energy of the effective signal. These noises are often distributed within the near-offset triangle area, making subsequent data processing, such as, amplitude processing, deconvolution, static correction, and even migration imaging very difficult. In order to resolve this issue, a data-driving self-adaptive frequency-decomposition method is proposed to detect and suppress such noises. Using the statistical time-varying effective signal energy outside the “black triangle” as a reference, this method automatically identifies the type of noises, calculates the weighted value of each sample point, attenuates the noise, and maximizes the effective signals across different frequency bands. The method accounts for all types of strong energy interferences within the “black triangle”, such as surface waves, scattered waves, and vibration noise, and has been extensively applied to real data processing, significantly improved the quality of seismic imaging.

This paper first gives a brief review of the historical development of shear-wave splitting and P-wave azimuthal anisotropy in oil and gas seismic exploration, and focuses mainly on their distribution in the upper crust, the link between them, and their application requirements for seismic fracture detection. When a shear-wave enters a rock containing vertically aligned fractures, it splits into two travelling with different speeds, which is referred to as shear-wave splitting, or birefringence. Forty years of researches and applications of shear-wave splitting reveal that shear-wave splitting occurs widely in the upper crust, but most of the splitting is concentrated in the near surface (< 1200 m). While P-wave azimuthal anisotropy in the upper crust varies considerably from weak to strong and shows no consistence. When applied to predict fractures, P-wave azimuthal anisotropy is only sensitive to gas-saturated fractures, and very insensitive to other fluid-saturated fractures. For fracture detection, theoretical analyses and experiment studies of the link between shear-wave splitting and P-wave azimuthal anisotropy verify that, it is essential to correct the near surface effects, which might limit the application to some extents. It is important to select target areas with relatively simple structure and relatively flat surface, as well as relatively thick reservoirs. Non-zero offset vertical seismic profiles (VSPs) or Walkaround P- or S-wave VSPs are also required to correct the near-surface effects and calibrate the reservoir response. In summary, the multi-component seismic data quality, the near-surface and reservoir conditions are three key factors affecting the application of shear-wave splitting and P-wave azimuthal anisotropy for fracture detection in oil and gas exploration.

In this paper, the SS wave splitting correction method for multi fracture layers (Yue et al, 2020) was further illustrated for the case of depth-variant fracture orientation and was simplified to an easier-to-implement version for the case of fracture orientation doesn’t vary with depth but time difference does. The simplified version was tested on the 4C SS wave data of a real 3D9C dataset using the same fracture orientations during 4C SS1/SS2 separation and time differences obtained from SS1 (Ss1Rs1) and SS2 (Ss2Rs2) stack sections, and the SS wave splitting effect was eliminated in the created 4C dataset (SrRr’, SrRt’, StRr’ and StRt’). The so created SrRr’ (SV) and StRt’ (SH) achieve good imaging results with StRt’ particularly prominent, and SH shows much better reflections on the large incidence angle portion than the already good results of SS1 and SS2.

As a high precision underground velocity model building method, full-waveform inversion has been widely concerned in seismic exploration since it was proposed. However, in the time domain full-waveform inversion, the calculation of gradient needs to reconstruct or store the source wavefield to cross-correlate, which leads to extra storage, as well as the problem of wavefield reconstruction, which seriously restricts the practical application of full-waveform inversion. In this paper, a method of full-waveform inversion based on local storage strategy is proposed. According to the Nyquist sampling theorem, the storage interval is set to calculate the gradient by storing the effective wave field in the finite time interval of each spatial grid point, so as to reduce the storage of source wave field data, avoid wavefield reconstruction and improve efficiency. Compared with other methods, this method does not need to reconstruct the source wavefield and the required memory size is not affected by finite-difference accuracy and recording duration. The inversion results of 2D overthrust model as well as 3D overthrust model show that the proposed method can guarantee the accuracy and signal-to-noise ratio of inversion results without the source wavefield reconstruction, improve effectively the computational efficiency, and reduce significantly the requirement of computer memory.

The anisotropic ray tracing equations of elastic waves are derived for calculating the central ray's travel time, trajectory, and parameters P and Q. Based on the anisotropic ray tracing algorithm, we proposed a transversely isotropic elastic dynamically focused beam migration for two dimensional media. Based on the two dimensional Kirchhoff -Helmholtz integral of elastic waves, the elastic imaging weight coefficients are used to reduce the crosstalk noise. Then, based on the previous research, we introduced a sign function to eliminate the effect of polarity reversal in qPqSV wave migration. Through model tests, it can be found that the proposed method can process the multicomponent seismic data and image the complex structures for anisotropic media. The optimized dynamic ray tracing algorithm is superior to the conventional one in computational efficiency. Furthermore, the proposed method eliminates the limitations of the Gaussian beam imaging. This method not only does not affect the accuracy of shallow imaging, but also enhances the energy focusing and the amplitude of deep layers. The model tests have shown the accuracy and effectiveness of our proposed method.

Seismic interpretation of gas hydrates requires the assistance of rock physics. Changes in gas hydrate saturation can alter the elastic properties of formations, and this relationship can be considerably influenced by the occurrence state of gas hydrates. Pore-filling, load-bearing, and cementing types are three single gas hydrate occurrence states commonly considered in rock-physics investigations. However, many gas hydrate-bearing formations are observed to have mixed occurrence states, and their rock-physics properties do not fully conform to models of single occurrence states. We develop a generalized rock-physics model for gas hydrate-bearing formations with three mixed occurrence states observed in the field or laboratory experiments: coexisting pore-filling-type and matrix-forming-type gas hydrates (case 1); pore-filling type when [Formula: see text] (gas hydrate saturation) < [Formula: see text] (critical saturation) and pore-filling + matrix-forming type when [Formula: see text] (case 2); and matrix-forming type when [Formula: see text] and matrix-forming + pore-filling type when [Formula: see text] (case 3). Instead of initial porosity, the apparent porosity (the volume fraction of an effective pore filler) [Formula: see text] represents the influence of occurrence states on the pore space. These three mixed occurrence states can be modeled using a unified workflow, in which the volume fractions of various gas hydrate types are expressed in general forms in terms of the apparent porosity. In addition, the model considers the effect of a pore filler on shear modulus. The developed model is validated through calibration with real well-log data and published experimental data corresponding to five gas hydrate-bearing formations. The model effectively interprets the influences of gas hydrate saturation and occurrence state on these formations. Thus, the generalized model provides a theoretical basis for the analysis of sensitive elastic parameters and quantitative interpretation for gas hydrate reservoirs.

Effective amelioration of ischemia/reperfusion (I/R)‐induced intestinal injury and revealing its mechanisms remain the challenges in both preclinic and clinic. Potential mechanisms of naringin in ameliorating I/R‐induced intestinal injury remain unknown. Based on pre‐experiments, I/R‐injured rat intestine in vivo and hypoxia–reoxygenation (H/R)‐injured IEC‐6 cells in vitro were used to verify that naringin‐alleviated I/R‐induced intestinal injury was mediated via deactivating cGAS‐STING signaling pathway. Naringin improved intestinal damage using hematoxylin and eosin staining and decreased alanine aminotransferase and aspartate aminotransferase contents in plasma. Naringin decreased inflammation characterized by reducing IL‐6, IL‐1β, TNF‐α, and IFN‐β contents in both plasma and IEC‐6 cells. Naringin mitigated oxidative stress via recovering superoxide dismutase, glutathione, and malondialdehyde levels in the I/R‐injured intestine. Naringin reduced the expression of apoptotic proteins, including Bax, caspase‐3, and Bcl‐2, and reduced terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick‐end labeling‐positive cells both in vivo and in vitro, and decreased Hoechst 33342 signals in vitro. cGAS, STING, p‐TBK1, p‐IRF3, and NF‐κB expressions were up‐regulated both in vivo and in vitro respectively and the up‐regulated indexes were reversed by naringin. Transfection of cGAS‐siRNA and cGAS‐cDNA significantly down‐regulated and up‐regulated cGAS‐STING signaling‐related protein expressions, respectively, and partially weakened naringin‐induced amelioration on these indexes, suggesting that deactivation of cGAS‐STING signaling is the crucial target for naringin‐induced amelioration on I/R‐injured intestine.

目前,油气地震勘探主要利用了纵波(PP波)的信息,在地层多参数反演、复杂和非常规油气储层预测、流体识别等方面存在着不确定性.近年来,横波(SV-SV波和SH-SH波)可控震源技术的发展大幅提高了资料的品质,为横波勘探技术的发展和广泛应用提供了必要条件.然而,与传统的PP波、PP与PS波联合反演相比,横波的反演能力尚不明确.为此,对比、分析不同弹性参数表示的纵波、转换横波(PSV波)和横波反射系数近似公式的精度,然后利用反射系数近似公式构建针对不同弹性参数的线性反演框架,结合反演协方差矩阵和反演条件数对比,分析纵、横波在反演不同弹性参数时的不确定性、不适定性.分析结果表明:利用PP波反演剪切模量和密度的不确定性最大,即使采用大角度数据PP波反演依然具有较高的不适定性;PSV波反演可有效降低反演的不适定性,但难以独立应用于实际资料;PP波和PSV波联合反演可有效降低反演的不确定性、不适定性,但反演效果依赖于纵、横波匹配精度;SH-SH波和SV-SV波在反演横波阻抗、横波速度、剪切模量和密度时具有明显的优势,可有效降低对输入数据角度的需求.该成果可为横波反演方法研究提供理论依据.

At present, there are many static correction methods for converted waves, which have become an indispensable part of multi-component exploration. However, these methods still face some practical problems:（1） The surface wave inversion method faces the problem of surface wave divergence and low signal-to-noise ratio of surface wave in complex exploration areas, and it has difficulty in determining dispersion period and picking up dispersion curves.（2） In the static correction method for the first arrival wave, the first-arrival signal-to-noise ratio of converted waves by tomography inversion and refraction method is low, and it is difficult to pick up the first arrival, especially in complex exploration areas.（3） The structural constraint method of common detector gather stacking longitudinal wave requires that the change in underground reflection interface should be relatively gentle or horizontal. Therefore, the above methods are not suitable for static correction of converted waves in complex exploration areas. As a result, a static correction method for converted waves based on complex structures is proposed. The specific steps are as follows:（1） We eliminate the structural items in the static correction of converted waves by horizon flattening to overcome the limitation of the horizontal interface. First, we pick up the structural horizon with a high signal-to-noise ratio in P-P wave CMP stacking, calculate the horizon flattening projection moveout, and use the moveout to flatten the pre-stack data.（2） We convert the flattened horizon data to the common receiver point domain and complete the velocity analysis of the P-P wave of the common receiver point again so that each common receiver point trace has the same velocity. This process eliminates the inter-trace dynamic correction error caused by the drastic change in lateral velocity in complex structures and the low accuracy of velocity analysis. It can not only enable the common receiver points to realize in-phase stacking and improve the signal-to-noise ratio but also reduce the impact of a low velocity accuracy on the residual static correction of seismic traces.（3） We convert the projection moveout of the flattened P-P wave structural horizon into to P-SV domain to flatten the pre-stack data of the P-SV wave, restart the velocity analysis of the P-SV wave in the common receiver point domain, improve the stacking signal-to-noise ratio and resolution of P-SV wave common detector gather, and finally enhance the stacking horizon picking accuracy and efficiency of P-SV wave common detector gather. Through structural horizon flattening and velocity analysis in the common receiver point domain, we further use the static correction method for converted waves with P-P wave structural constraints to improve the calculation accuracy and efficiency of static correction of converted waves based on complex structures.

Effective chemotherapy for clinical treatment of brain diseases is still lacking due to the poor penetration of the blood-brain barrier (BBB). The aim of this study was to construct a folate modified pterostilbene (Pt) loaded polymeric micellar delivery system (F-Pt/M) with mPEG-PCL as carrier material to aim at penetrating the BBB for brain tissue targeting via receptor-mediated endocytosis. In this study, F-Pt/M was prepared using thin-film hydration method and then optimized by response surface methodology (RSM) with the entrapment efficiency (EE), drug loading (DL) and hydrodynamic diameter (HD) as indexes. The average hydrodynamic diameter and zeta potential of optimal F-Pt/M were 133.2 nm and 24.6 mV, respectively. DL (18.3%) and EE (98.6%) made the solubility of Pt in water about 25 times higher than that of crude Pt. Results of DSC evaluation revealed that drugs were successfully encapsulated inside the polymeric micelles. TEM images showed that homogeneous spherical micellar structures with a narrow size distribution were developed. The release result in vitro showed that F-Pt/M presented sustained release behavior compared to control free Pt solution. Compared to non-targeted Pt/M, F-Pt/M had a significantly higher cytotoxicity against FR-overexpressing A172 cells. In vitro cellular uptake tests illustrated that the micellar delivery system could significantly improve the accumulation of drugs in target cells via receptor-mediated endocytosis. BBB penetration value (P) of F-Pt/M was about 4 folds higher than that of free Pt group. In addition, drug targeting index (DTI) was calculated to determine targeting of F-Pt/M to the brain which was found to be 4.89, implying improved brain targeting was achieved. Hence, the developed F-Pt/M exhibited great potential for delivering more drug molecules across the BBB for the treatment of brain diseases.

At present, the velocity spectrum picking needs a lot of manual operation by experienced processors, which is time-consuming and inefficient, and is easily affected by human experience. By taking the advantages of artificial intelligence technology in the field of image processing, this paper designs an automatic velocity spectrum picking method based on object detection, and applies neural network model named FCOS (Fully Convolutional One-Stage Object Detection) (Tian et al., 2019) to implement the automatic velocity spectrum picking. In this method, the velocity spectrum is processed as an image, and the energy heap at the specific position of the point to be picked up in the velocity spectrum is detected as an object. Through the trained model, the time-velocity sequence is predicted and output, and the results of manual picking and intelligent prediction are compared and evaluated on a field data. The research shows that the prediction results are accurate in the data with medium and high SNR, and the network model can quickly pick the time-velocity sequence, improve the efficiency of velocity spectrum picking.

Non-alcoholic fatty liver disease (NAFLD) has become a predictive factor of death from many diseases. The purpose of the present study is to investigate the protective effect of glycyrrhizic acid (GA), a natural triterpene glycoside, on NAFLD induced by a high-fat diet (HFD) in mice, and further to elucidate the mechanisms underlying GA protection. GA treatment significantly reduced the relative liver weight, serum ALT, AST activities, levels of serum lipid, blood glucose and insulin. GA suppressed lipid accumulation in liver. Further mechanism investigation indicated that GA reduced hepatic lipogenesis via downregulating SREBP-1c, FAS and SCD1 expression, increased fatty acids β-oxidation via an increase in PPARα, CPT1α and ACADS, and promoted triglyceride metabolism through inducing LPL activity. Furthermore, GA reduced gluconeogenesis through repressing PEPCK and G6Pase, and increased glycogen synthesis through an induction in gene expression of PDase and GSK3β. In addition, GA increased insulin sensitivity through upregulating phosphorylation of IRS-1 and IRS-2. In conclusion, GA produces protective effect against NAFLD, due to regulation of genes involved in lipid, glucose homeostasis and insulin sensitivity.

In this paper, the combined compact difference scheme (CCD) and the combined supercompact difference scheme (CSCD) are used in the numerical simulation of the shear-wave equation. According to the Taylor series expansion and shear-wave equation, the fourth-order discrete scheme of the displacement field is established; then, the CCD and CSCD schemes are used to calculate the spatial derivative of the displacement field. Additionally, the accuracy, dispersion, and stability of the CCD and CSCD are analyzed, and numerical simulation analyses are carried out using 1D uniform models. Lastly, based on the processing of artificial boundary reflection using PML boundary conditions, shear-wave reverse-time migrations are carried out using synthetic data. The results show that (1) CCD and CSCD have smaller truncation errors, higher simulation precision, and lower numerical dispersion than other normal difference schemes; (2) CCD and CSCD can use the coarse grid and larger time step to calculate, with less memory and high computational efficiency; (3) finally, the result of the shear-wave reverse-time migration of the 2D synthetic data model show that the reverse-time migration imaging is clear, and the proposed method for shear-wave reverse-time migration is practical and effective.

Nonalcoholic fatty liver disease (NAFLD), a metabolic disease, has received wide attention worldwide. However, there is no approved effective drug for NAFLD treatment. In the study, H&E and Oil Red O staining were employed to detect liver histopathological changes and the accumulation of lipid droplets. Quantitative real‐time PCR, Western blot, bioinformatics, luciferase assay, immunofluorescence staining, reactive oxygen species (ROS), and siRNA were used to further elucidate the mechanism of isoliquiritigenin (ISL) against NAFLD. The results showed that ISL significantly reduced the liver‐to‐body weight ratios and biochemical index. And the staining results showed that ISL remarkedly ameliorated liver histopathological changes of NAFLD. Furthermore, ISL significantly increased the levels of PPARα, CPT1α, and ACADS, which were involved in lipid metabolism, and inhibited the ROS, TNF‐α, IL‐1β, and IL‐6 expression by activating PGC‐1α. Bioinformatics and luciferase assay analysis confirmed that miR‐138‐5p might bind to PGC‐1α mRNA in NAFLD. Importantly, the expression of miR‐138‐5p was increased in the NAFLD, which was significantly decreased by ISL. In addition, the miR‐138‐5p inhibitor also promoted lipid metabolism and inhibited inflammatory response in NAFLD via PGC‐1α activation. The above results demonstrate that ISL alleviates NAFLD through modulating miR‐138‐5p/PGC‐1α‐mediated lipid metabolism and inflammatory reaction in vivo and in vitro.

Vancomycin (VCM)'s nephrotoxicity limits its application and therapeutic efficiency. The aim of this study was to determine the protective effect of rhein against VCM-induced nephrotoxicity (VIN). VIN models were established in rats and NRK-52E cells. Rhein up-regulated the expressions of renal organic anion transporter (Oat) 1, Oat3, organic cation transporter 2 (Oct2), multidrug resistance-associated protein 2 (Mrp2), mammal multidrug and toxin extrusion proteins 1 (Mate 1) and P-glycoprotein (P-gp) to facilitate the efflux of plasma creatinine, blood urea nitrogen (BUN), and plasma indoxyl sulfate. Rhein increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) to regulate the expression of Mrp2, P-gp, and Mate 1. The increased level of superoxide dismutase (SOD), decreased level of malondialdehyde (MDA) and reduced number of apoptosis cells were observed after treatment of rhein. Rhein decreased the number of apoptosis cells as well as increased the expression of B-cell lymphoma-2 (Bcl-2) and decreased expressions of Bcl-2-like protein 4 (Bax). ML385, as a typical inhibitor of Nrf2, reversed the protective effects of rhein in cells. Rhein oriented itself in the site of Keap1, inhibiting the Keap1-Nrf2 interaction. Rhein ameliorated VIN mainly through regulating the expressions of renal transporters and acting on Nrf2 pathway.

Multiple studies have confirmed the significance of microRNA (miR)-122a in disease regulation. However, its impact on ischaemia/reperfusion (I/R) injury is unknown. In this study, we propose that the promoting role of miR-122a exists in I/R injuries. Two models, including hypoxia/reoxygenation (H/R)-injured IEC-6 cells in vitro and ischemia/reperfusion (I/R)-injured C57BL/6 mice intestinal tissues in vivo, were used to verify our purpose. Applying dual-luciferase reporter assays and transfection tests, the regulatory impacts of miR-122a were examined by promoting pyroptosis on intestinal I/R injury via targeting epidermal growth factor receptor (EGFR)-NOD-, LRR-, and pyrin domain-containing 3 (NLRP3) signaling pathway. Both H/R-injured IEC-6 cells and I/R-injured mice intestinal tissues had elevated miR-122a expression, which targeted EGFR directly. Increased miR-122a expression significantly inhibited EGFR activity, decreased EGFR mRNA and protein expression, increased NLRP3 mRNA and protein expression, and up-regulated caspase 1, N-GSDMD, ASC, IL-1β, and IL-18 protein expression to promote pyroptosis. Furthermore, in IEC-6 cells, a miR-122a inhibitor and an EGFR-overexpression plasmid significantly reduced pyroptosis and alleviated intestinal I/R injury via activating the EGFR-NLRP3 signaling pathway, showing that miR-122a is very essential for regulating intestinal I/R injury. In brief, miR-122a promotes pyroptosis by inhibiting the EGFR-NLRP3 signaling pathway, which should be evaluated as a therapeutic target for intestinal I/R injury.

针对由涡轮增压和进/排气双可变气门正时(VVT)构成的复杂进气系统,以缸内直喷汽油机为研究对象,采用对比态原理,通过理论推导和数据分析,提出了可变气门正时权重因子的概念,并对构成缸内充量的各种气量进行了机理-数据混合工程化建模.结果表明:该建模方法能够准确计算缸内新鲜充量和扫气量,用进/排气气门角度全因子扫描时,94％以上的数据点计算误差小于±5％;用目标进/排气气门角度进行数据验证时,全部数据点计算误差小于±5％;满足车辆应用对发动机充气模型的计算精度要求.

The downward propagating energy from a horizontal vibrator is mainly in the form of shear waves especially at near offsets. With the increase of offset, the energy of shear wave converted P-wave (SVP) increases and thus the SVP wave is another practical choice for converted-wave exploration. Like what in PSV wave, the SVP wave from azimuthal anisotropic medium is also subjected to the influence of shear wave splitting, and this makes it a practical issue for SVP wave processing. In this paper, what we did for dealing with this issue is shown: a least square method (Bale, 2012) was used to calculate subsurface fracture orientations which are used in S1P and S2P separation; and for shear wave splitting correction, a strategy that picking horizons on S1P and S2P stacked sections is adopted for obtaining the depth-variant time difference between fast- and slow-shear waves. And both synthetic and field SVP data tests are shown.

二十一世纪初,由于中国石油集团东方地球物理勘探有限责任公司(以下简称"东方物探")大力实施国际化发展战略,国际业务迅速扩大,国外主要竞争对手感觉到潜在威胁,在物探核心软件上采取了严格限售甚至禁售策略,希望以此来制约东方物探强劲的发展势头.为了打破技术封锁,在中国石油天然气集团有限公司(以下简称"中国石油")的支持下,2003年开始立项研发GeoEast软件,经过十多年的持续研发与完善,GeoEast处理解释应用系统由V1.0发展到V3.0,有效应对了从常规三维到宽方位三维、从叠后偏移到逆时偏移、从构造解释到综合解释等物探技术的飞速发展,具备了数万道、百TB的数据管理能力,可高效管理和调度数百节点的异构计算机集群,提供了传统的软件开发接口,可支持批处理、并行计算和交互操作等软件的研发,实现了处理解释数据的统一管理,支持处理解释一体化运行,基本满足了目前地震勘探的需求.