海冰表面积雪深度是利用卫星测高技术反演海冰厚度的关键参数。基于ICESat-2和CryoSat-2测高卫星的协同观测数据（简称IS2CS），对比与评估卫星测高雪深估算的两种时空匹配方法（轨迹搜索法和格网搜索法），并对2018-2024年北极海冰生长期（10月至次年4月）积雪深度的时空分布特征进行分析。结果表明：（1）IS2CS轨迹法雪深与OIB实测数据具有较高的沿轨相关性，能够较好地捕获沿轨积雪深度的变化特征；（2）格网法雪深更适合表征大尺度积雪深度的空间分布和季节性变化特征，本文格网法雪深和GSFC雪深精度相当，在SIMBA数据的评估中本文格网法雪深性能优于GSFC雪深；（3）相比IS2CS雪深，MW99/AMSR2雪深相对偏厚，且在海冰生长期内季节性变化表征能力较弱；（4）海冰积雪深度呈现明显的时空差异，多年冰表面雪深普遍厚于一年冰表面雪深，春季雪深厚于秋冬季雪深。2018-2024年间，北极海冰表面积雪深度总体呈现减薄趋势，且多年冰区域的雪深减薄速率高于一年冰区域。研究成果为改进卫星测高雪深产品和优化海冰厚度反演算法提供了科学依据。

Employing soil improvement techniques to mitigate and prevent the detrimental effects of liquefaction on foundations often leads to a significant increase in construction costs in engineering projects. Developing simple, cost-effective, and eco-friendly liquefaction mitigation methods has always been one of the main concerns of geotechnical engineers. Researchers introduced the induced partial saturation (IPS) method to increase the liquefaction resistance of the saturated foundations, which is based on decreasing the saturation degree of the saturated sand. In this study, hollow cylinder torsional shear tests were conducted on loose saturated and desaturated calcareous sand to assess the liquefaction behavior of desaturated sand. Soil compressibility is the primary parameter affecting the liquefaction behavior of desaturated sand. As saturation degree, back pressure, and effective confining pressure significantly influence soil compressibility, their effects on the liquefaction resistance of desaturated sand were investigated. The pore pressure development during cyclic loading reveal that, unlike saturated samples, desaturated samples do not exhibit an excess pore pressure ratio reaching one, even when the double amplitude shear strain surpasses 7.5 %. Finally, the test results demonstrated a notable correlation between liquefaction resistance ratio, maximum volumetric strain, and the maximum generated excess pore pressure ratio, and a pore pressure model was proposed.

重复轨道法是利用测高卫星监测南极冰盖高程变化的重要方法。在利用重复轨道方法计算冰盖高程变化时，引入一种基于抗差估计的方法（insrtitue of geodesy and geophysicsⅢ，IGGⅢ）取代传统的最小二乘方法（least square,LS）。利用2019年3月至2021年12月的ICESat-2陆冰高程数据，分别采用LS方法和IGGⅢ方法在东南极Totten冰川流域进行了实验。结果表明，该流域分别呈现出-0.038±0.163 m/yr和-0.040±0.136 m/yr的高程降低趋势，说明IGGⅢ抗差估计方法能够在保留重复轨道方法高数据利用率的基础上，有效地减少异常数据被错误引入产生的误差。利用MEaSUREs ITS＿LIVE高程变化产品对两种方法计算的结果进行了对比，IGGⅢ方法的结果在空间分布上具有更好的一致性。

As a cost-effective and environmentally friendly technique for enhancing the liquefaction resistance of sandy soils, the air-injection method has attained widespread application in multiple soil improvement or desaturation strategies. This study reports undrained cyclic loading experiments on reconstituted, slightly desaturated sand specimens under either isotropic or anisotropic consolidation to examine the effects of the presence of injected air and initial stress anisotropy on the energy-based assessment of pore pressure and liquefaction resistance. The results exhibited three different cyclic response patterns for the saturated/desaturated specimens with distinct deformation mechanisms, revealing that the sand has a higher degree of stress anisotropy and lower degree of saturation typically being more dilative and less susceptible to cyclic liquefaction. The energy-based liquefaction potential evaluation indicates that the accumulative energy is mathematically correlated with the pore pressure, thus establishing a unified energy-pore pressure relationship for both saturated and desaturated sand. Furthermore, the energy capacity for triggering cyclic failure demonstrates a consistently rising trend with an increase in the consolidation stress ratio and a reduction in the degree of saturation, which seems closely linked to the cyclic liquefaction resistance. This result signifies the potential applicability of an energy-based approach to quantify the liquefaction susceptibility of desaturated in situ soils using strength data from conventional stress-based analyses.

Despite the emergence of recent advancements, machine learning (ML) based methods for estimating the fragility curves of structures through probabilistic ground motion selection techniques pose a challenge due to the computational cost associated with data preparation. The primary aim of this research is to reduce the data preparation time involved in estimating the fragility curves of structures using a ground motion selection approach that considers earthquake magnitude, distance from the seismic source, and shear wave velocity of soil as essential parameters. To achieve this objective, ML algorithms are employed to calculate the fragility curves of various reinforced concrete moment resisting (RC/MR) frames with different periods, utilizing codebased and generalized conditional intensity measure (GCIM) ground motion selection methods. The SMOTE-ENN technique, a data resampling method, is used to balance the training data for the ML algorithms to address potential bias resulting from imbalanced training data. To validate the fragility curves obtained through ML, analytical fragility curves are derived for a specific structure at three damage levels and compared with the ML curves. The results demonstrate that the percentage of the enclosed area between the analytical and ML curves, relative to the area under the analytical curve, is below 10 % and 5 % for the GCIM and code-based methods, respectively. Fragility curves were generated for various structures, including regular and irregular buildings, to investigate the generalizability. Results indicate that, for the specific structures analyzed in this study, excluding torsional ones, the structure's period is a sufficient structural feature for generating fragility curves.

This study formulated biodegradable, edible films with sodium alginate and varying concentrations and a combination of seed oils (watermelon seed oil, sesame seed oil) and rosehip extract. In the present study, rosehip, sesame, and watermelon seed oils, which incorporated many bioactive compounds and are known to have antioxidant properties, were incorporated into edible films to improve the film properties due to the controlled release of the active substance and thus increase the storage time. The potential to form alginate-based edible films by incorporating this extract and seed oils into alginate-based films has not been thoroughly investigated. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and mechanical, physical, thermal, and antioxidant properties characterized the edible film samples. The biodegradability by soil was also performed. Blending rosehip extract and its combination with seed oils significantly improved the films' antioxidant properties while reducing moisture content. In the study, the highest total phenolic content was recorded in the rosehip + sesame oil film (R2) sample (0.418 +/- 0.015 mg GAE/g) and the lowest total phenolic content was recorded in the control sample (0.208 +/- 0.014 mg GAE/g). Additionally, the highest % moisture value was recorded in the control sample (68.060 +/- 0.530%), and the lowest % moisture value was recorded in the rosehip + sesame oil film (R2) sample (61.223 +/- 0.881%). Watermelon seed oil blended film samples showed more homogeneity and had smooth surfaces compared to control samples. Alginate-based films incorporated with seed oils and rosehip extract may have caused color differences and whiteness index due to phenolic and bioactive compounds in their content. Soil degradation properties showed that the films were biodegradable. The elongation at break value of alginate-based films combined with rosehip extract and seed oils showed a significant increase compared to the control films. According to the results, alginate-based films combined with rosehip extract (films compounded with rosehip extract only and films compounded with rosehip and selected seed oils) improved film properties compared to control films. In addition, the incorporation of rosehip extract into the films improved the film properties compared to the films obtained using only seed oil. Based on the findings of this study, the use of rosehip extract, sesame, and watermelon seed oil in the development of composite biodegradable, edible films of sodium alginate could be used as a suitable alternative for edible food packaging.

Fluoride, a highly phytotoxic and nonessential element in higher concentrations is a major concern in decreasing wheat production. In the present study, we examined the ability of silicon, a semi-essential element which helps to mitigate the detrimental effects of various environmental stresses in overcoming fluoride-mediated toxicity in wheat cultivars. The seeds of two wheat cultivars, tolerant (Raj 4120) and susceptible (Raj 4238), were grown in soil supplemented with NaF (0, 400, and 500 mg kg-1) and then supplied with silicon (0, 200, and 300 mg kg-1) as Na2SiO3 at 10th days of germination with 160 mu mol quanta m-2 s-1 of photon density, 16-h photoperiod, and 55-60% relative humidity at 25 +/- 2 degrees C. The fluoride stress led to oxidative damage in roots, as evidenced by the significant elevation in MDA and H2O2 content in both wheat cultivars and decreased major components of the suberin and cesA4 gene expression in roots, which together can negatively impact the rigidity and strength of the cell wall. Conversely, the application of silicon had a beneficial effect in both wheat cultivars with and without fluoride stress. Silicon decreased the MDA and H2O2 content levels and increased the antioxidant defence system. Interestingly, Si was able to partially reverse F stress in both the wheat cultivars by increasing suberin deposition on the endodermis and promoting secondary cell wall synthesis gene expression in roots. The present study concluded that soil application of silicon can be a useful approach in protecting wheat from fluoride toxicity.

Root-knot nematodes (RKN; Meloidogyne spp.) are among the most damaging plant-parasitic nematodes. They parasitize almost every species of higher plant and induce the formation of galls along the plant roots, which are detrimental to plant growth. North Carolina's leading field crops are sweetpotato (Ipomoea batatas (L.) Lam.), soybean (Glycine max L. Merr), cotton (Gossypium hirsutum L.), and tobacco (Nicotiana tabacum L.), which are all hosts to several root-knot nematode species. This pathogen represents a major threat to farmers, obligating them to seek alternative crops that are non-host to root-knot nematodes that will help decrease soil populations and provide economic revenue. We tested seven sesame cultivars for their host status and potential resistance to four Meloidogyne species (M. arenaria, M. incognita, M. enterolobii, and M. hapla). We inoculated sesame seedlings with 1,000 nematode eggs of each species. Sixty days after inoculation, we harvested the plants to evaluate a visual gall severity rating, measure final egg counts, and calculate the reproductive factor (RF). All sesame cultivars had a significantly lower RF than the tomato (Solanum lycopersicum L.) cv. Rutgers control for all species of RKN except M. arenaria. The RF values for sesame cultivars inoculated with M. incognita and M. hapla were not significantly different from one another; however, there were significant differences in RF among sesame cultivars inoculated with M. enterolobii, suggesting that genetic variability of the host may play an important role in host status and conferring resistance.

Fomesafen is a herbicide with long persistence in soil, causing damage to succeeding crops. Dichlormid is a widely used safener protecting maize from chloroacetanilide and thiocarbamate injury. We found that dichlormid treatment could restore the growth of wheat seedlings exposed to fomesafen stress. To explore its molecular mechanism, RNA-Seq was conducted to analysis transcript profiles between fomesafen and fomesafen+dichlormid treated wheat seedlings. The gene expression level was determined by qRT-PCR. Results showed that the up-regulated genes by dichlormid treatment were significantly enriched in pathways related to photosynthesis. The expression level of glutamyl-tRNA reductase (GTR), protoporphyrinogen IX oxidase (PPO, target of fomesafen), and magnesium chelatase (MAG) involved in chlorophyll biosynthesis was significantly up- regulated by dichlormid. And the expression level of genes in chlorophyll binding, energy biosynthesis, gibberellin biosynthesis and salicylic acid signal pathway was also validated to be significantly up-regulated by dichlormid. The detoxification enzyme activity of cytochrome P450 or glutathione S-transferase (GSTs), and their gene expression level was found to show no significant difference between fomesafen and fomesafen+dichlormid treatment. The antioxidant enzyme activity of peroxidase, superoxide, and the content malondialdehyde content was decreased by dichlormid, while the reduced glutathione content was increased by dichlormid significantly. The metabolism of fomesafen was further validated to be not influenced by dichlormid. These results suggested that dichlormid acted by increasing the expression of fomesafen target and photosynthesis related genes to alleviate fomesafen injury to wheat, but not accelerating fomesafen metabolism.

The lunar environment is known to be characterized by complex interactions between plasma, the exosphere, dust, and the surface. However, our understanding of the environment is limited due to the lack of experimental evidence. Here, we propose a small, low-cost mission to characterize the dust and exosphere environment of the Moon. Named the Limb Pathfinder (LimPa), this is a proof-of-concept mission aimed toward understanding the coupling between plasma, dust, and tenuous neutral atmosphere. The LimPa mission was proposed to a call for the Small Mission to the Moon issued by European Space Agency in 2023. LimPa is designed to examine the dust exosphere above the lunar polar regions by using an utterly novel remote-sensing technique to measure the solar wind hydrogen atoms-the solar wind protons that are neutralized to hydrogen atoms. Its goals are (1) to detect for the first time the neutralized solar wind hydrogen produced by exospheric gas and levitated dust; (2) to measure the height profiles of the levitated dust and exospheric gas densities; and (3) to determine the emission mechanism of the horizon glow. Our baseline design of the LimPa mission is a 12U CubeSat. Three highly matured instruments are used: an energetic neutral atom camera, a proton sensor, and a camera system. The LimPa CubeSat is proposed to be inserted into a circular lunar polar orbit, with an altitude of 100 km as a baseline. The Sun-pointing attitude will allow measurements of neutralized solar wind that are produced by the exosphere and dust grains above the polar regions. The nominal lifetime is for 3 months as a pathfinder mission. The LimPa mission will open a new window to remote characterization of the lunar dust exosphere environment above the poles, and will demonstrate that this monitoring can be achieved with a simple and low-cost instrument system and spacecraft operation. The concept to be proven by the LimPa mission will enable long-term monitoring of the fragile dust exosphere environment, which substantially impacts on lunar exploration and will be significantly altered by human activities.