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The cyclic water intrusion and stresses lead to changes in the rock pores' microstructure, which affects the rock’s seepage characteristics. This study performs a three-dimensional reconstruction of the rock specimen using the Avizo software based on the results of multiple computed tomography (CT) tests conducted on sandstone subjected to varying numbers of cyclic water intrusions. In addition, a numerical model comprising pores and grain matrix is developed, based on which stress loading and seepage simulations are carried out. The results show that the mean outlet velocity, maximum seepage pressure, and permeability of the rock samples show an exponential increase with the number of cyclic water intrusions. Stress loading of the rock samples reveals that as the stress increases, the average exit velocity and permeability decrease. It is observed that the stress sensitivity index tends to increase and subsequently decrease with the number of water intrusion cycles at the same stress level when the stress sensitivity index is calculated under different water intrusion cycles. The relationship between effective stress, porosity, and stress sensitivity index is derived, and an effective linkage between permeability and macro-mechanical parameters considering stress sensitivity is achieved. [ABSTRACT FROM AUTHOR]

Epoxy-based composites with high insulation and thermal conductivity are desirable materials for electronic and electrical applications. However, resolving the tradeoff between insulation and thermal conductivity remains challenging. Based on the functional requirement, we designed and fabricated a cactus-like double-oriented epoxy composite by combining magnetic orientation and ice-templated methods. Semiconducting SiC endowed the composite with field-grading characteristics, thus relieving local electric field stress along the horizontal direction, while BN with high thermal conductivity promoted heat dissipation along the vertical direction. The composite exhibited its highest performance with 15 vol% filler, improving the breakdown voltage and thermal conductivity by 43.7% and 1312% compared with pure epoxy, respectively, outperforming recently developed packaging materials. It is believed that this work offers an efficient strategy for the fabrication of the filler structure and provides insights on the simultaneous enhancement in insulation and thermal conductivity of polymer composites. [ABSTRACT FROM AUTHOR]

In this context, a novel recycling strategy for the upcycling of waste biodegradable plastics, specifically PBAT, has been proposed. This approach initially employs a 1,4-butanediol-alkali method to rapidly hydrolyze PBAT without introducing other impurities. Following this, a two-step synthesis process is employed to swiftly create a foam nickel-supported NiOOH electrocatalyst. This catalyst efficiently converts the hydrolyzed solution of 1,4-butanediol into the higher-value product, succinic acid, achieving a Faraday efficiency of 97.6% along with satisfactory stability. [Display omitted] • A novel method was employed for the rapid catalytic degradation of PBAT. • A versatile foam nickel-supported NiOOH electrocatalyst was synthesized quickly. • The conversion of PBAT hydrolysis solution into high-value succinic acid. • The oxidative mechanism of 1,4-butanediol by the catalyst was elucidated. Biodegradable plastics such as Poly (butylene adipate-co-terephthalate) (PBAT) have been extensively utilized in numerous fields. However, post-consumption, PBAT tends to pollute the environment and waste resources. Herein, a novel approach employing a 1,4-butanediol-alkali combined method for the hydrolysis of PBAT is introduced. At 130 °C, with a reaction time of 60 min, the hydrolysis rate of PBAT exceeds 99 %. Subsequently, a two-step synthesis rapidly produces a foam nickel-supported NiOOH catalyst for the electrocatalytic reformation of the PBAT hydrolysate into higher-value chemicals (succinate salts) at an impressive current density of 100 mA cm−2 at 1.43 V (vs. RHE) and a Faradaic efficiency of 97.6 %. Experimental results and density functional theory calculations have elucidated the active state changes of the foam nickel-supported NiOOH catalyst and the intermediates in the oxidation of 1,4-butanediol to succinate, alongside the reaction mechanism. This study offers a viable approach for the degradation of PBAT plastic through a 1,4-butanediol-alkali method and the rapid preparation of a foam nickel-supported NiOOH electrocatalyst, achieving the upgraded recycling of post-consumer biodegradable PBAT plastic. [ABSTRACT FROM AUTHOR]

With global enforcement of plastic bans and restrictions, the biodegradable plastic, e.g., polylactic acid (PLA), has been extensively employed as a primary substitute for traditional petroleum-based plastics. However, the growing problem associated with PLA waste accumulation is posing grand environmental challenges. In addition, although PLA has the degrading property under natural conditions, the degradation process takes too long and the degradation products cannot be recycled. In this context, enzymatic degradation of PLA arouses great attention in scientific communities. This study aims at selecting the most cost-effective protease from various enzymes and optimizing the enzymolysis conditions towards the degradation of PLA. We will demonstrate that under an optimal temperature of 45 °C, a pH vale of 11, and an enzyme concentration of 0.6 mg mL−1, the protease K would achieve a remarkable degradation efficiency (> 99 %) for PLA films within just 50 min. Finally, molecular dynamics (MD) simulation and molecular docking studies reveal the mechanism behind the protease-induced PLA degradation, providing a promising direction for waste treatment and resource utilization for future biodegradable plastics. [Display omitted] • A protease capable of rapidly degrading PLA films has been screened. • For the first time, the degradation mechanism has been investigated using molecular dynamics and molecular docking. • Provides a new approach for the waste treatment and resource utilization of biodegradable plastics in the future. [ABSTRACT FROM AUTHOR]

In this paper, a resin with high adhesion, easy curing, good flexibility, and high temperature resistance was prepared from polyimide fiber paper. First, in order to improve the toughness and curability of impregnating resin, epoxy resin was modified by addition of vinyl silicone resin. Subsequently, ternary resin with high temperature stability was obtained by polyimide resin addition. Among the investigated conditions, the optimal additive amount of vinyl silicone resin and polyimide resin was 30% and 5%, respectively. The prepared ternary resin has better toughness, crosslinking degree, high temperature stability (5% mass loss at 339.2 °C) and no obvious glass transition at high temperature. Finally, the polyimide fiber paper-based composite material was impregnated with modified epoxy resin and ternary resin, respectively. The results shows that the paper-based composite material impregnated with modified epoxy resin has a better fiber bonding degree, a smooth surface, and contact angle could reach up to 148.71°. Meanwhile, the paper-based composite material impregnated with ternary resin has good high temperature resistance, and the tensile index of the paper-based composite material could reach up to 35.1 N·m/g at 200 °C. [ABSTRACT FROM AUTHOR]

The glacial lakes in the Southeastern Qinghai–Tibet Plateau (SEQTP) have undergone dramatic expansion in the context of global warming, leading to several glacial lake outburst floods (GLOFs) disasters. However, there is a gap and incompleteness in glacial lake inventories across this area due to the heavy cloud cover. In this study, an updated and comprehensive glacial lake inventory was produced by object-based image analysis (OBIA) and manual vectorization based on the Sentinel-1 SAR and Sentinel-2 MSI images acquired in 2022. Detailed steps regarding the OBIA were provided, and the feature set of Sentinel-1 SAR images suitable for extracting glacial lakes was also determined in this paper. We found that the mean combination of ascending-orbit and descending-orbit images is appropriate for mapping glacial lakes. VV-polarized backscattering coefficients from ascending-orbit achieved a better performance for delineating glacial lakes within the study area. Moreover, the distribution of glacial lakes was characterized in terms of four aspects: size, type, elevation, and space. There were 3731 glacial lakes with a total area of 1664.22 ± 0.06 km2 in the study area; most of them were less than 0.07 km2. Ice-contacted lakes were primarily located in the Palongzangbo basin (13.24 ± 0.08 km2). Nyang Qu basin had the most abundant glacial lake resources (2456 and 93.32 ± 0.18 km2). A comparison with previously published glacial lake datasets demonstrated that our dataset is more complete. This inventory is useful for evaluating water resources, studying glacier–glacial lake interactions, and assessing GLOFs' susceptibility in the SEQTP. [ABSTRACT FROM AUTHOR]

Permafrost areas are sensitive to climate change and have a significant impact on energy and water cycles. Ground ice is a crucial component on the Qinghai–Tibetan Plateau (QTP). Understanding the environmental characteristics of ground ice is vital for accurately modeling its distribution and evolution. In this study, we analyzed 15 environmental characteristics of high ice-content permafrost sites. These attributes were extracted from 400 high ice-content permafrost datasets including 300 drilling boreholes and 100 thaw slumps collected throughout the entire plateau using large-scale remote sensing data and their products. The results are as follows: The mean annual air temperature in areas where high ice-content permafrost exists ranges from −5 to −3.5 °C, with an average warming rate of 0.08 °C/a. Additionally, there was an average increase in precipitation of about 25 mm/10a and an increase in soil moisture of about 4%/10a. Geomorphology strongly influences the occurrence of high ice content permafrost, with 85% of high ice-content permafrost development at altitudes between 4400 and 5100 m. Approximately 86% of high ice-content permafrost were developed in lowland or relatively flat areas, preferably in gently sloping and shady slope regions. Soils exhibit less variability in clay particles and more variability in silt and sand. Key indicators in the high ice content permafrost region include warming rate, active layer thickness, elevation, bulk density, soil thickness, clay content, precipitation, soil moisture, and NDVI. High ice-content permafrost is the result of a combination of environmental factors and is expected to undergo significant changes in the future. This study provides a foundation for comprehending the environmental changes in the high ice-content permafrost areas and modeling the distribution of ground ice. It underscores the urgent need to address the significant environmental changes faced by high ice-content permafrost regions. [ABSTRACT FROM AUTHOR]

The accurate and rapid extraction of glacier boundaries plays an important role in the study of glacier inventory, glacier change and glacier movement. With the successive launches of high-resolution remote-sensing satellites and the increasing abundance of available remote-sensing data, great opportunities and challenges now exist. In this study, we improved the DeepLab V3 + as Attention DeepLab V3 + and designed a complete solution based on the improved network to automatically extract glacier outlines from Gaofen-6 panchromatic and multispectral (PMS) images with a spatial resolution of 2 m. In the solution, test-time augmentation (TTA) was adopted to increase model robustness, and the convolutional block attention module (CBAM) was added into the atrous spatial pyramid pooling (ASPP) structure in DeepLab V3 + to enhance the weight of the target pixels and reduce the impact of superfluous features. The results show that the improved model effectively increases the robustness of the model, enhances the weight of target image elements and reduces the influence of non-target elements. Compared with deep-learning models, such as full convolutional network (FCN), U-Net and DeepLab V3 + , the improved model performs better in the test dataset. Moreover, our method achieves superior performance for glacier boundary extraction in parts of the Tanggula Mountains, the Kunlun Mountains and the Qilian Mountains based on Gaofen-6 PMS images. It could distinguish glaciers from terminal moraine lakes, thin snow and clouds, thus demonstrating excellent performance and great potential for rapid and precise extraction of glacier boundaries. [ABSTRACT FROM AUTHOR]

• Environmentally friendly super-insulating material with 3D nanoporous structure. • High breakdown field strength of the material composited with atmospheric CO 2. • Novel insulation form and carbon sequestration capacity for the future GIL. • Theoretical calculation for a substantial improvement of breakdown field strength. Gas-insulated transmission lines (GILs) play a pivotal role in facilitating the future long-distance transmission of power generated by renewable energy. However, the extensive employment of gaseous SF 6 presents formidable obstacles to scaled application of GILs, due to its relatively low breakdown strength and substantial greenhouse effect. In this work, a fantastic phenomenon was discovered that the breakdown field strength of insulating gases can be significantly enhanced under the confinement of nanostructures, based on it, the starch/polyorganosiloxane biocomposite insulating dielectric (S/PBID) with three-dimensional nanoporous structure was designed and fabricated. Specifically, insulating gases (CO 2 , N 2 , SF 6) composite with S/PBID, the breakdown field strength is significantly improved by 744.44 %, 520.74 %, and 310.95 % compared to the original gases, respectively. The relative permittivity of S/PBID (<2) is considerably lower than that of most existing insulating materials. Theoretical analysis suggests that the nanopores within S/PBID restricts electron multiplication and transport processes at the lateral scale, leading to a substantial enhancement in gas breakdown field strength. The nanoporous material is expected to be composited with atmospheric CO 2 to overturn the conventional gas–solid composite insulation form of the GILs, thereby providing a novel insulation form of high-performance, environmental-friendly, and carbon sequestration. [ABSTRACT FROM AUTHOR]

PVDF-based gas diffusion electrode is synthesized in two steps: first, PVDF-based gas diffusion layer is produced by phase inversion and subsequently the product is electrochemically polymerized with polypyrrole and reduced graphene oxide. The manufactured GO@Pr@GDE toward O2 reduction reaction is studied as air cathode to generate H2O2, which can be further used to oxidize nonbiodegradable ofloxacin in a simple cell system. Although all the GDE samples have a similar configuration, GO@Pr@GDE shows the highest catalytic activity toward H2O2 production. The exchange current density of GO@Pr@GDE in Na2SO4 solution is 2.4 × 10−8 A cm−2, which is 6 times greater than that of Pr@GDE. Results of XRD, FTIR, and SEM characterization are consistent with GDE's electrochemical behavior, revealing that pyrrole polymerized on the pristine PVDF-based GDE can supply more conductive sites, and reduced GO plays the most important role in H2O2 production and achieving 69% removal efficiency of ofloxacin. [ABSTRACT FROM AUTHOR]