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Since reservoirs with permeability less than 10 mD are characterized by high injection difficulty, high-pressure drop loss, and low pore throat mobilization during the water drive process, CO2 is often used for development in actual production to reduce the injection difficulty and carbon emission simultaneously. However, microfractures are usually developed in low-permeability reservoirs, which further reduces the injection difficulty of the driving medium. At the same time, this makes the injected gas flow very fast, while the gas utilization rate is low, resulting in a low degree of recovery. This paper conducted a series of studies on the displacement effect of CO2-soluble foaming systems in low-permeability fractured reservoirs (the permeability of the core matrix is about 0.25 mD). For the two CO2-soluble blowing agents CG-1 and CG-2, the effects of the CO2 phase state, water content, and oil content on static foaming performance were first investigated; then, a more effective blowing agent was preferred for the replacement experiments according to the foaming results; and finally, the effects of the blowing agents on sealing and improving the recovery degree of a fully open fractured core were investigated at different injection rates and concentrations, and the injection parameters were optimized. The results show that CG-1 still has good foaming performance under low water volume and various oil contents and can be used in subsequent fractured core replacement experiments. After selecting the injection rate and concentration, the blowing agent can be used in subsequent fractured cores under injection conditions of 0.6 mL/min and 2.80%. In injection conditions, the foaming agent can achieve an 83.7% blocking rate and improve the extraction degree by 12.02%. The research content of this paper can provide data support for the application effect of a CO2-soluble blowing agent in a fractured core. [ABSTRACT FROM AUTHOR]

The conventional production technique employed for low-permeability tight reservoirs exhibits limited productivity. To solve the problem, an acetate-type supercritical carbon dioxide (scCO2) thickener, PVE, which contains a large number of microporous structures, was prepared using the atom transfer radical polymerization (ATRP) method. The product exhibited an ability to decrease the minimum miscibility pressure of scCO2 during a solubility test and demonstrated a favorable extraction efficiency in a low-permeability tight core displacement test. At 15 MPa and 70 °C, PVE-scCO2 at a concentration of 0.2% exhibits effective oil recovery rates of 5.61% for the 0.25 mD core and 2.65% for the 5 mD core. The result demonstrates that the incorporation of the thickener PVE can effectively mitigate gas channeling, further improve oil displacement efficiency, and inflict minimal damage to crude oil. The mechanism of thickening was analyzed through molecular simulation. The calculated trend of thickening exhibited excellent agreement with the experimental measurement rule. The simulation results demonstrate that the contact area between the polymer and CO2 increases in direct proportion to both the number of thickener molecules and the viscosity of the system. The study presents an effective strategy for mitigating gas channeling during scCO2 flooding and has a wide application prospect. [ABSTRACT FROM AUTHOR]

With the rapid development of electronic equipment and communication technology, radiation pollution caused by electromagnetic waves has become a serious social nuisance. Based on this, the development of high-performance electromagnetic wave-absorbing materials has become a research hotspot. Among them, Fe3O4, as a traditional ferrite-based wave-absorbing material, has the advantages of abundant natural resources, low environmental pollution, and deep wave-absorbing strength. Therefore, the direct utilization of Fe3O4 as a wave-absorbing material or as a raw material for the preparation of wave-absorbing materials has become a research direction for researchers. This paper first introduces the basic theories and evaluation parameters related to wave absorption and then reviews the research progress of pure Fe3O4 wave-absorbing materials with key structural dimensions below 500 nm and related composite wave-absorbing materials by summarizing the reports of electromagnetic wave-absorbing materials related to Fe3O4 in recent years. Finally, the development prospect of Fe3O4-based wave-absorbing materials is introduced. [ABSTRACT FROM AUTHOR]

The lithology of conglomerate is rich and variable, the pore structure is complex, the classification of reservoir tvpe is difficult, without standardized evaluation parameters. Taking the conglomerate reservoirs of the Lp-per-Lower Karamav Formation in District Min-7 of Karamav Oilfield of Xinjiang as the object of study, based on the high-pressure mercur injection data of the reservoir rocks of the Formation 106, the classification scheme of the conglomerate reservoirs was established by using the clustering analysis method; the classification parameters of the conglomerate reservoirs were simplified and clarified by the methods such as the variance calculation and the va-lidity of this method was verified by the use of the discriminant analysis in the end. The results show that the non-homogeneity of the conglomerate reservoir in the study area is strengthened as the physical properties become better and the pore-throat size becomes larger, reflecting the complexity of the conglomerate pore structure; the clustering analysis after data preprocessing can effectively classify the reservoirs, and there are significant differences between the classes; based on the quantification of parameter centralization and dispersion, six parameters for reservoir classification, such as the median pressure and the average pore-throat radius, are preferred; after the validation of the discriminant analysis, the accuracy of classification is still as high as 95.80% after the parameter preference, indi-cating that the method has high classification accuracy and is not geographically restricted, which makes it valuable for generalization. [ABSTRACT FROM AUTHOR]

Following the growth of infotech and electronic industries, electromagnetic-wave-absorbing materials play an essential role in the traction of the need for high-precision weaponry and intelligent electronic equipment. The exploitation of high-performance electromagnetic-wave-absorbing materials has emerged as a strategic challenge to be solved in the upgrading of military equipment and civil electromagnetic security. The more maturely studied absorbing materials (carbon, ferrite, etc.) have a single loss mechanism and poor resistance matching, which are already not enough to cover the basic needs. To explore absorbing materials that satisfy both impedance matching and attenuation balance, dielectric nanomaterials have come to the fore. They can realize light weight, thin layer, broad band, and multiband, which have great application prospects. In this review, we start with a summary of typical dielectric loss mechanisms (interfacial polarization, dipole polarization, and conduction loss). Next, diverse carbides, oxides, sulfides, and their composites with dielectric or magnetic materials are described, and the nanostructure advantages and wave-absorbing performance advantages are investigated. Then, the applications of wave-absorbing materials are depicted. Lastly, the challenges faced by dielectric-type materials are outlined, and future development trends are foreseen. Overall, this review offers an overview of the advances in the study of dielectric nanoabsorbing materials. [ABSTRACT FROM AUTHOR]

Research into electromagnetic radiation enhancement and frequency band broadening is growing in popularity with the advance of 5G connected communication technology. As such, there is an urgent need for wave-absorbing materials that meet both the broadband and strong absorption requirements. Dielectric materials, as a class of lightweight materials with controllable morphology, are one of the many candidates, but their inherent properties make it tough to simultaneously match impedance and strong attenuation, so they cannot meet both broadband and strong absorption requirements. Here, we compensate for the intrinsic properties of dielectric materials by means of shape modulation, which can achieve a win–win situation of impedance and attenuation. When the response time is 8 h, the material studied achieves robust absorption (reflection loss value reaches −45.6 dB) and a wide frequency band (6.08 GHz) at 2.6 mm. Given that the material has a multi-vacancy embroidered spherical structure, it allows multiple reflections of electromagnetic waves and improves the conductive loss. Also, the nanosheet cross-stacking builds multiple interfaces, and the resulting interfacial polarization becomes the most important part of the dielectric loss. Meanwhile, it can be further demonstrated by simulation and radar scattering area solution that the interfacial polarization constructed from the embroidery spherical structure leads to exceptional wave absorption performance. This work suggests a concept for the preparation of practical absorbing materials with strong absorption, a wide frequency band and multiple interfaces. [ABSTRACT FROM AUTHOR]

Summary: With advanced sequencing technology, dozens of complex polyploid plant genomes have been characterized. However, for many polyploid species, their diploid ancestors are unknown or extinct, making it impossible to unravel the subgenomes and genome evolution directly.We developed a novel subgenome‐phasing algorithm, SubPhaser, specifically designed for a neoallopolyploid or a homoploid hybrid. SubPhaser first searches for the subgenome‐specific sequence (k‐mer), then assigns homoeologous chromosomes into subgenomes, and further provides tools to annotate and investigate specific sequences.SubPhaser works well on neoallopolyploids and homoploid hybrids containing subgenome‐specific sequences like wheat, but fails on autopolyploids lacking subgenome‐specific sequences like alfalfa, indicating that SubPhaser can phase neoallopolyploid/homoploid hybrids with high accuracy, sensitivity and performance.This highly accurate, highly sensitive, ancestral data free chromosome phasing algorithm, SubPhaser, offers significant application value for subgenome phasing in neoallopolyploids and homoploid hybrids, and for the subsequent exploration of genome evolution and related genetic/epigenetic mechanisms. [ABSTRACT FROM AUTHOR]

Osimertinib is the first third-generation epithelial growth factor receptor (EGFR) inhibitor, and it has been approved as a first-line medication for metastatic non-small cell lung cancer (NSCLC). Recently, the clinical use of osimertinib has revealed the emergence of new mutations, L792F, L792Y, and L792H (L792X), which endow lung cancer cells with the ability to escape drug inhibition. However, the binding mode between osimertinib and these mutants as well as the resistance mechanisms remains poorly understood. Here, we investigated the inhibitory process associated with EGFR T790M (sensitive to osimertinib) and EGFR T790M/L792X (resistant to osimertinib) by modeling the recognition step and the dissociation step using an integrated computational approach. Using molecular mechanics/generalized Born surface area (MM/GBSA) free energy calculations, the results indicated that the L792X mutation from a hydrophobic amino acid to a hydrophilic amino acid might be the main reason for the difference in binding free energy of each mutant. Per-residue binding free energy decomposition analysis showed that the binding energy contribution of residues Met-793 and Gly-796, and the mutant residues, is most strongly affected by the L792X mutation. Moreover, umbrella sampling (US) simulations revealed that the resistance effect conferred by the L792X mutation is mainly caused by a decreased interaction between osimertinib and the hinge region of EGFR. Our research results provided new insights into drug resistance caused by the L792X mutation and gave valuable guidance for the development of more effective inhibitors. [ABSTRACT FROM AUTHOR]