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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]

To meet the special insulation demand of the DC transmission system with the highest voltage in the world, a new kind of ±1 100 kV DC voltage divider is designed. The reliability of the new structure voltage divider under the action of lightning impulse is studied. To achieve the voltage and electric field strength distribution of the voltage divider, a 3D transient electric field calculation model is established and a lightning impulse test for the prototype is carried out. The results reveal that (1)The voltage and electric field strength distributing on the voltage divider changing with time show a cumulative effect. (2)The maximum electric field strength occurs at the junction where the first grading ring connecting to the internal bushing. (3)The maximum current of resistance occurs at the peak voltage of lightning impulse with the corresponding time is 1.2 µs. (4)The voltage distributing on the capacitance imply that the capacitance really does play the role of equalisation voltage when the voltage divider suffering lightning impulse. (5)The prototype of HVDC voltage divider passing through the lightning impulse test successfully strongly demonstrates the correctness and reliability of the new structure ±1 100 kV voltage divider voltage.

This paper focus on the research about the probability and practicability of 330 kV GIS structure design with three phase in one tank， which represents the miniaturisation and compact developing trend of GIS. The design principle is proposed according to the volume of three phase in one tank (structure A) is generally smaller than that of the sum volume of three single phase (structure B). Then, the dimension size of 330 kV GIS with structure A is presented. To solve the weak insulation-level problem between phases of structure A, which prevents it from being used in high-voltage power system especially above 330 kV, an electromagnetic-temperature-flow multi-physical field coupling model considering eddy effect and skin effect is established to analyse the influencing factors on the insulation level of internal GIS. Therefore， the insulation level between the phases of structure A is calculated under the condition of power frequency and short circuit, respectively. The results show that the insulation margin of 330 kV GIS with structure A is enough and completely meet the insulation requirement of GIS. Furthermore, compared with structure B, structure A has lower temperature rise and energy consumption.

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]

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]

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]