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In the early stage of offshore oilfield development, due to the lack of drilling, limited data admission, and lack of dynamic data, there is great uncertainty in the understanding of oilfield reserves. With increased degree of development, production is usually inconsistent with reserves, and reserve re-evaluation is an important way to resolve this problem. In order to improve the development efficiency and reduce costs, offshore oilfields are dominated by horizontal wells, resulted in limited data acquisition. Therefore, new horizontal well data has become the key to obtainnew geological reservoir parameters and improve the accuracy of reserve estimation. In order to further obtain reliable reserve evaluation results and resolve the dynamic and static contradictions of the oilfield, based on analyzing the main controlling parameters of reserve change in the Pearl River Mouth Basin, this study fully excavates the role of horizontal development wells in improving the accuracy of primary controlling parameters.Our results show that the oil-bearing area and effective thickness are the most uncertain in the reserve assessment, and cause the change of reserves. Horizontal development well is critical in improving the production capacity of the oilfield, determining the lower limit of effective thickness, investigating microstructure, and identifying lithological boundary and fluid interface, etc. In the case of limited data access, the utilizationof horizontal development wells can effectively improve the accuracy of major controlling parameters to obtain relatively reasonable geological reserves, and solve the dynamic contradictions of oilfield production. It also points out the direction for late exploration and development of oilfields. Application examples from multiple oil fields in the eastern South China Sea also confirm this understanding.

In fire investigations, the most important aspect is determining the presence of a liquid accelerant at the fire scene. The presence or absence of accelerants is critical evidence during trials for fire cases. Upon exposure to high temperatures, metallic substances undergo oxidation, which can be imparted by accelerants in the fire. Oxides and substrates found on metal surfaces offer valuable information on the characteristics of fire, including exposure temperature, duration, and involvement of a liquid accelerant. In this study, we investigated the oxidation behavior of copper at high temperatures in a simulated flame environment using ethanol combustion. After oxidation, the morphological, oxide phase composition, and microstructural features of specimens were characterized by observation, X-ray diffraction, X-ray photoelectron energy spectroscopy, transmission electron microscopy, and scanning electron microscopy with energy-dispersive spectroscopic analysis. The elemental carbon with a hexagonal structure deposited on the sample’s surface was found, which may be incomplete combustion and the chemical composition of ethanol. Copper has a preferred orientation of oxide on the (111) crystal plane, which differs from oxidation in ordinary hot air that is related to the large Coulomb force of the (111) crystal plane. Hot air convection due to combustion may cause large areas of oxide layer on the copper surface to crack and peel. Oxide properties and surface state of metals strongly depended on oxidation duration, temperature, and atmosphere. These data shall offer reference information for determining the presence of combustion accelerants at fire scenes.

Abstract Background Acupuncture at Neiguan (PC6) has long been used for treating cardiovascular diseases, but its antiarrhythmic effect and the underlying mechanisms have not yet been well investigated, especially regarding premature ventricular complexes (PVCs) that occur post-myocardial infarction (MI). The purpose of this study was to study the antiarrhythmic effect of manual acupuncture applied to PC6 for a relatively long period (28 days) and to elucidate the mechanism in mice. Methods An MI mouse model was generated by ligating the left anterior descending coronary artery in male C57/BL6 mice (n = 31). Manual acupuncture at PC6 was applied seven times weekly for 4 weeks. The state of myocardial injury was characterized by electrocardiography (ECG) and echocardiography. Inflammation was detected by ELISA and immunohistochemical stanning. Fibrosis was evaluated by Masson’s trichrome staining. RNA sequencing was used to explore the differentially expressed genes (DEGs) among the different groups after treatment. Results Acupuncture at PC6 lowered the incidence of spontaneous PVCs after MI injury (1/9, 11%) compared to that in mice without acupuncture treatment (6/9, 67%) and improved the ejection fraction from 31.77% in the MI mice to 44.18% in the MI + PC6 mice. Fibrosis was reduced after PC6 treatment. RNA-seq showed many DEGs involved in the immune system and inflammatory response pathway. Further studies confirmed that inflammation at the circulation level and cardiac tissue was inhibited in MI + PC6 mice, accompanied by suppressed sympathetic activation. Conclusions In conclusion, 28-day treatment of acupuncture at PC6 reduced spontaneous PVCs and improved systolic function, possibly by suppressing inflammatory response-mediated fibrosis and sympathetic hyperactivity.

The acoustoelastic technique shows considerable potential for in situ stress measurement in concrete. However, the current technology is not fully developed, and challenges primarily arise from the intricate nature of concrete, along with various factors affecting its acoustoelastic properties, such as material strength, aggregate size, porosity, temperature, and humidity. A comprehensive understanding of how these factors influence the acoustoelastic characteristics of concrete is essential for advancing acoustoelastic technology in engineering applications. This study specifically focuses on the material strength, a pivotal factor influencing the quality of concrete, and explores its correlation with the acoustoelastic coefficient (AEC). An initial theoretical investigation was conducted to establish a theoretical model between the two factors, involving two steps: (1) integrating the empirical formula correlating material strength and Young's modulus into the acoustoelastic equations for bulk waves to derive the formula connecting AECs and concrete strengths; (2) applying qualitative analysis and statistical methods to assess the monotonic properties of the formula within its defined domain. To validate the accuracy of the theoretical model, acoustoelastic tests were conducted on prismatic concrete specimens with five different strength levels under axial compressive stress. The findings revealed a consistent pattern, demonstrating that the AECs of concrete decrease with an increase in material strength under axial compressive stress. The outcomes of this study make a substantial contribution to establishing a theoretical foundation for the development of concrete stress monitoring technology based on the ultrasonic method. Practical Applications: The safety of concrete structures is paramount. Currently, structural performance assessment relies primarily on on-site inspections and evaluations by professionals to detect visible cracks and deformations. Typically, cracks become apparent only once the damage has reached a critical level. Failure to identify deterioration processes before reaching this critical stage necessitates significant repairs to prevent premature failure of concrete structural components. If the in situ stress information of structures can be nondestructively obtained would be highly beneficial for warning the early deterioration, tracking the evolution of crack or damage, and forecasting the remaining service life of structures. Acoustoelastic techniques have demonstrated significant potential in achieving this objective. Nonetheless, concrete acoustoelastic effects are influenced by various factors, such as material strength, aggregate size, porosity, and environmental conditions, which impede further advancement of this technology. Therefore, this study investigated the dependence of concrete acoustoelastic effects on material strength. Correlation equations between concrete strength and acoustoelastic coefficients have been formulated. The application of these equations in practice can mitigate the impact of material strength on acoustoelastic measurements. This research contributes to advancing the engineering applications of acoustoelastic techniques in concrete stress assessment. [ABSTRACT FROM AUTHOR]

Iron tailing porous concrete (ITPC) is a type of foamed concrete material that uses iron ore tailings powder to partially replace cement. As a relatively new concrete-like material, only very limited research on the dynamic material property of ITPC under high strain rates has been performed. To supplement the material properties for its practical applications, in this study, splitting Hopkinson pressure bar (SHPB) tests were carried out to measure the dynamic properties of ITPC specimens with a density range of 600 kg/m3–1,200 kg/m3 in a strain rate range of about 120 s−1–250 s−1. The influences of strain rate and density on the impact resistance performance of ITPC were analyzed based on the failure modes, stress–strain relations, compressive strengths, elastic moduli, peak strains, and dynamic increase factors (DIFs). The microstructures of ITPC after impact were also observed and characterized by scanning electron microscopy (SEM). Moreover, the energy dissipation characteristics were discussed and analyzed. The test results indicate that the dynamic properties of ITPC exhibit significant strain rate effects and density dependence. The dynamic compressive strength of ITPC increases quadratically and linearly with density and strain rate, respectively. Moreover, the empirical formulas for dynamic compressive strength, DIF, energy dissipation ratio, and energy dissipation capacity of ITPC as functions of strain rate and material density are proposed based on the experimental data; the variation trends of these key dynamic mechanical parameters of ITPC are analyzed and discussed in detail. [ABSTRACT FROM AUTHOR]

Polyoxometalate (POM)-based materials are ideal candidates for implementing molecular memories, and rational POM molecule design is key to higher resistive switching (RS) performance. In this work, in order to obtain a deep structure–property correlation of POM-based memristors, three Anderson-based hybrids, i.e. two-component hybrids (MV)3(MnMo6O18L2)2·4DMF (1) and (MV)2[Cu(DMF)2](MnMo6O18L1)2·6DMF (2), and the three-component one (MV)2(Cu2I3)(MnMo6O18L2)·4CH3CN (3) (L = 2-(hydroxymethyl)-2-(pyridine-4-yl)-1,3-propanediol) have been structurally determined. These hybrids together with the precursors (methyl viologen (MV2+), CuI, and (MnMo6O18L2)) were further fabricated as memristors with the structure of ITO/active layer/Ag. Interestingly, three precursors are RS silent or have bad RS performance, but the incorporation of MV2+ in 1 and 2 can trigger the RS performances, and the further decoration of iodocuprate in 3 can render enhanced RS behavior (ON/OFF ratio: 2.32 × 102) with high thermal-tolerance temperature (240 °C) and extremely long-term stability. The RS mechanism could be assigned to the valence change (VC) induced by oxygen vacancy migrations. The presence of air-stable (MnMo6O18L2)3−-MV2+ donor–acceptor couples can stabilize the oxygen vacancies, which not only trigger the RS behaviors in ITO/1/Ag and ITO/2/Ag, but also result in extremely long-term stability in ITO/3/Ag. Besides, the oxygen vacancies can also be stabilized by Cu2I3 with intense cuprophilic interactions, which corresponds to enhanced RS properties in ITO/3/Ag. This mechanism could be validated by the following structural characters in 3: the stronger POM-MV2+ interactions, the better planarity of MV2+, the very short Cu⋯Cu distances and the ABAB-type packing fashion. The structure–property correlation in this work can provide a new strategy for the development of highly efficient and reliable memristors. [ABSTRACT FROM AUTHOR]

From June 2008 to August 2013, approximately 67 kt of CO2 was injected into a deep saline formation at the Ketzin pilot CO2 storage site. During injection, 3D seismic surveys have been performed to monitor the migration of sequestered CO2. Seismic monitoring results are limited by the acquisition and signal-to-noise ratio of the acquired data. The multiphysical reservoir simulation provides information regarding the CO2 fluid behavior, and the approximated model should be calibrated with the monitoring results. In this work, property models are delivered from the multiphysical model during 3D repeated seismic surveys. The simulated seismic data based on the models are compared with the real data, and the results validate the effectiveness of the multiphysical inversion method. Time-lapse analysis shows the trend of CO2 migration during and after injection. [ABSTRACT FROM AUTHOR]

Cannabis is now one of the most commonly used illicit substances among pregnant women. This is particularly concerning since developmental exposure to cannabinoids can elicit enduring neurofunctional and cognitive alterations. This study investigates the mechanisms of learning and memory deficits resulting from prenatal cannabinoid exposure (PCE) in adolescent offspring. The synthetic cannabinoid agonist WIN55,212-2 was administered to pregnant rats, and a series of behavioral, electrophysiological, and immunochemical studies were performed to identify potential mechanisms of memory deficits in the adolescent offspring. Hippocampal-dependent memory deficits in adolescent PCE animals were associated with decreased long-term potentiation (LTP) and enhanced long-term depression (LTD) at hippocampal Schaffer collateral-CA1 synapses, as well as an imbalance between GluN2A- and GluN2B-mediated signaling. Moreover, PCE reduced gene and protein expression of neural cell adhesion molecule (NCAM) and polysialylated-NCAM (PSA-NCAM), which are critical for GluN2A and GluN2B signaling balance. Administration of exogenous PSA abrogated the LTP deficits observed in PCE animals, suggesting PSA mediated alterations in GluN2A- and GluN2B- signaling pathways may be responsible for the impaired hippocampal synaptic plasticity resulting from PCE. These findings enhance our current understanding of how PCE affects memory and how this process can be manipulated for future therapeutic purposes.