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Abstract To systematically analyze the damage caused by bedrock and overburden layer slope under seismic action, a set of large-scale shaking table test was designed and completed. Interpolation of the acceleration amplification coefficient, Hilbert–Huang transform and transfer function was adopted. The damage mechanisms of the bedrock and overburden layer slopes under seismic action are systematically summarized in terms of slope displacement, acceleration field, vibration amplitude, energy, vibration frequency, and damage level. The results show a significant acceleration amplification effect within the slope under seismic action and a localized amplification effect at the top and trailing edges of the slope. With an increase in the input seismic intensity, the difference in the vibration amplitude between the overburden layer and bedrock increased, low-frequency energy of the overburden layer was higher than that of the bedrock, and the vibration frequency of the overburden layer was smaller than that of the bedrock. These differences cause the interface to experience cyclic loading continuously, resulting in the damage degree of the overburden layer at the interface being larger than that of the bedrock, reduction of the shear strength, and eventual formation of landslides. The displacement in the middle of the overburden is always greater than that at the top. Therefore, under the action of an earthquake and gravity, the damage mode of the bedrock and overburden layer slope is such that the leading edge of the critical part pulls and slides at the trailing edge, and multiple tensile cracks are formed on the slope surface.

Abstract Lysine crotonylation (Kcr) is a recently discovered histone acylation modification that is closely associated with gene expression, cell proliferation, and the maintenance of stem cell pluripotency and indicates the transcriptional activity of genes and the regulation of various biological processes. During cell culture, the introduction of exogenous croconic acid disodium salt (Nacr) has been shown to modulate intracellular Kcr levels. Although research on Kcr has increased, its role in cell growth and proliferation and its potential regulatory mechanisms remain unclear compared to those of histone methylation and acetylation. Our investigation demonstrated that the addition of 5 mM Nacr to cultured bovine fibroblasts increased the expression of genes associated with Kcr modification, ultimately promoting cell growth and stimulating cell proliferation. Somatic cell nuclear transfer of donor cells cultured in 5 mM Nacr resulted in 38.1% blastocyst development, which was significantly greater than that in the control group (25.2%). This research is important for elucidating the crotonylation modification mechanism in fibroblast proliferation to promote the efficacy of somatic cell nuclear transfer.

Abstract In the realm of photovoltaics, organometallic hybridized perovskite solar cells (PSCs) stand out as promising contenders for achieving high‐efficiency photoelectric conversion, owing to their remarkable performance attributes. Nevertheless, defects within the perovskite layer, especially at the perovskite grain boundaries and surface, have a substantial impact on both the overall photoelectric performance and long‐term operational stability of PSCs. To mitigate this challenge, we propose a method for water‐induced condensation polymerization of small molecules involving the incorporation of 1,3‐phenylene diisocyanate (1,3‐PDI) into the perovskite film using an antisolvent technique. Subsequent to this step, the introduction of water triggers the polymerization of [P(1,3‐PDI)], thereby facilitating the in situ passivation of uncoordinated lead defects inherent in the perovskite film. This passivation process demonstrates a notable enhancement in both the efficiency and stability of PSCs. This approach has led to the attainment of a noteworthy power conversion efficiency (PCE) of 24.66% in inverted PSCs. Furthermore, based on the P(1,3‐PDI) modification, these devices maintain 90.15% of their initial efficiency after 5000 h of storage under ambient conditions of 25°C and 50 ± 5% relative humidity. Additionally, even after maximum power point tracking for 1000 h, the PSCs modified with P(1,3‐PDI) sustain 82.05% of the initial PCE. Small molecules can rationally manipulate water and turn harm into benefit, providing new directions and methods for improving the efficiency and stability of PSCs.

Precipitation strengthening is a key strengthening method for metallic materials. However, the temperature effect on precipitation strengthening is still unclear to date. Based on dislocation theory, a thermally-activated precipitation strengthening model is built by considering the competition between shear and bypass mechanisms. For medium-sized precipitate particles, the thermally-activated shear mechanism dominates the precipitation strengthening, resulting in a plateau region. While, for large or very fine precipitate particles, the thermally-activated bypass mechanism dominates the precipitation strengthening, leading to the strengthening or weakening regions. Moreover, the effects of precipitate phase volume fraction, temperature, shear modulus, strain rate, and mobile dislocation density on precipitation strengthening are also investigated. This study not only provides new insights into precipitation strengthening from the perspective of thermal activation but also offers clear guidance for the design of new materials.

Under the repeated action of residual stress and wheel load caused by welding, fatigue cracks easily occur on the top plate-U rib welding of an orthotropic bridge deck (OBD). These affect the service life. To study the influence of different full-penetration welding methods on the residual stress and fatigue of OBD, this study compared the residual stress, welding deformation, and fatigue performance of full-penetration single- and double-sided welding through finite element analysis. The welding temperature and residual stress fields were simulated based on Goldak's double ellipsoid heat source model using the thermal elastic-plastic method. The numerical results were verified using measured data from relevant literature, and the two were in good agreement. The results showed that the longitudinal residual stress of the double-sided welded U-rib was larger than that of the single-sided welded U-rib, primarily in the compressive stress range, and the maximum deviation reached 99.44 MPa. The longitudinal displacement of single-sided welding along the weld direction was 0.060 mm lesser than that of double-sided welding, and the maximum vertical displacement perpendicular to the weld direction was 2.457 mm lesser than that of double-sided welding. For the same frequency of fatigue load (wheel load), the fatigue strength of single-sided welding was larger than that of double-sided welding, and the fatigue life increased by 29.7%. In this study, analysis models of the full-penetration single-sided and full-penetration double-sided welding were established, which could provide a reference for structural fatigue assessment using the two full-penetration welding techniques under the influence of residual stress.

An efficient method was discovered for catalyzing the esterification under air using Novozym 435 to obtain pyridine esters. The following conditions were found to be optimal: 60 mg of Novozyme 435, 5.0 mL of n-hexane, a molar ratio of 2:1 for nicotinic acids (0.4 mmol) to alcohols (0.2 mmol), 0.25 g of molecular sieve 3A, a revolution speed of 150 rpm, a reaction temperature of 50 °C, and reaction time of 48 h. Under nine cycles of Novozym 435, the 80 % yield was consistently obtained. Optimum conditions were used to synthesize 23 pyridine esters, including five novel compounds. Among them, gas chromatography-mass spectrometry-olfactometry (GC-MS-O) showed phenethyl nicotinate (3g), (E)-hex-4-en-1-yl nicotinate (3m), and octyl nicotinate (3n) possessed strong aromas. Thermogravimetric analysis (TG) revealed that the compounds 3g, 3m and 3n exhibited stability at the specified temperature. This finding provides theoretical support for adding pyridine esters fragrance to high-temperature processed food.

Abstract After undergoing metabolic reprogramming, tumor cells consume additional glutamine to produce amino acids, nucleotides, fatty acids, and other substances to facilitate their unlimited proliferation. As such, the metabolism of glutamine is intricately linked to the survival and progression of cancer cells. Consequently, targeting the glutamine metabolism presents a promising strategy to inhibit growth of tumor cell and cancer development. This review describes glutamine uptake, metabolism, and transport in tumor cells and its pivotal role in biosynthesis of amino acids, fatty acids, nucleotides, and more. Furthermore, we have also summarized the impact of oncogenes like C-MYC, KRAS, HIF, and p53 on the regulation of glutamine metabolism and the mechanisms through which glutamine triggers mTORC1 activation. In addition, role of different anti-cancer agents in targeting glutamine metabolism has been described and their prospective applications are assessed.

Automatic detection of pitting on Ball Screw Drive (BSD) is essential to ensure normal production activities. However, the scarcity of defective samples and precisely labeled data poses a significant challenge. To address this, we propose an efficient double self-supervised model that operates at both the image and pixel levels, aiming to construct a high-performance model trained with defect-free data for detecting unknown defects in BSD images. By incorporating global and local information and extracting features at multiple hierarchical levels, the model’s generalization performance is enhanced. The image-level self-supervised representation is first learned by classifying normal images from the PasteNoise, a data augmentation approach by pasting noise patches at random locations in normal images. Meanwhile, the pixel-level self-supervised representation is learned by segmenting the noise patch to locate abnormal regions. Then, we introduce a novel feature masking strategy in a masking and prediction task for accurate defect localization. In addition, we use Histogram of Oriented Gradients (HOG) features with local contrast normalization as prediction targets to capture local shapes and appearances to improve the robustness of the model. The proposed method achieves competitive receiver operating characteristic curves of 97.42 (image-level) and 94.57 (pixel-level) on the BSD dataset. In experiments on the MVTec AD, the proposed model shows good performance, indicating the broad adaptability of our approach.

Few-shot image classification, whose goal is to generalize to unseen tasks with scarce labeled data, has developed rapidly over the years. However, in traditional few-shot learning methods with CNNs, non-local features and long-rang dependencies of the image may be lost, and this leads to a poor generalization of the trained model. With the advantage of the self-attention mechanism of Transformer, researchers have tried to use vision transformer to improve few-shot learning recently. However, these methods are more complicated and take up a lot of computing resources, and there is no baseline to measure their effectiveness. We propose a new method called ViTFSL-baseline. We take advantage of vision transformer and train our model on all train set without episodic training. Meanwhile, we design a new nearest-neighbor classifier to used for few-shot image classification. Furthermore, in order to narrow the gap between difference of same class, we introduce centroid calibration in classifier after the feature extraction of backbone. We run the experiments on popular benchmarks to show that our method is a simple and effective for few-shot image classification. Our approach could be taken as the baseline upon vision transformer for few-shot learning.

Abstract Ancient whole-genome duplication (WGD) or polyploidization is prevalent in plants and has played a crucial role in plant adaptation. However, the underlying genomic basis of ecological adaptation and subsequent diversification after WGD are still poorly understood in most plants. Here, we report a chromosome-scale genome assembly for the genus Orinus (Orinus kokonorica as representative) and preform comparative genomics with its closely related genus Cleistogenes (Cleistogenes songorica as representative), both belonging to a newly named subtribe Orininae of the grass subfamily Chloridoideae. The two genera may share one paleo-allotetraploidy event before 10 million years ago, and the two subgenomes of O. kokonorica display neither fractionation bias nor global homoeolog expression dominance. We find substantial genome rearrangements and extensive structural variations (SVs) between the two species. With comparative transcriptomics, we demonstrate that functional innovations of orthologous genes may have played an important role in promoting adaptive evolution and diversification of the two genera after polyploidization. In addition, copy number variations and extensive SVs between orthologs of flower and rhizome related genes may contribute to the morphological differences between the two genera. Our results provide new insights into the adaptive evolution and subsequent diversification of the two genera after polyploidization.

Coilia nasus is a species of anadromous migratory fish, which predominantly lives in the sea. During the breeding season, the reproductive population migrates from the sea to rivers to reproduce and clusters to form a fishing season. The Yangtze Estuary is an important migration channel for this species. In recent years, due to the influence of upstream dam construction, water conservancy projects along the Yangtze River, environmental pollution and overfishing, the populations of this species in the Yangtze River are on the verge of extinction. In order to better protect C. nasus in the Yangtze River, a large number of studies on the conservation and management of its resources, migration habits, genetic structure, and the effects of resource recovery on this species have been conducted. As for the nutritional composition of C. nasus, studies have been conducted on the different sources, ecotypes, breeding methods, and stages of gonad development. These studies have mainly focused on the muscle nutrition of C. nasus from the Yangtze River; however, none have investigated the nutritional composition of different tissues of the reproductive populations from the Yangtze Estuary. This study is the first to determine the nutritional status of the reproductive population that migrates to the Yangtze Estuary with mature ovaries, and to compare and analyze the distribution characteristics of total lipids and fatty acids in different tissues, and provides reference information for ascertaining the nutritional status and reproductive performance of this species in the Yangtze Estuary. In this study, the contents of moisture, total lipid, and fatty acid composition in muscle, liver, and ovary tissues of adult female C. nasus with gonad development stage Ⅳ were measured and analyzed using standard GB methods. The results indicated that: The moisture content declined successively in muscle, liver, and ovary tissues, with measurements of (77.91±1.61)%, (75.01±1.33)%, and (46.77±5.58)%, respectively. The total lipid content of dry matter increased successively in muscle, liver, and ovary tissues, with measurements of (16.21±1.09)%, (21.94±1.23)%, and (55.21±1.35)%, respectively. The saturated fatty acids (SFA) content was (29.89±0.81)%, (37.60±3.06)%, and (18.33±1.61)% in the muscle, liver, and ovaries, respectively, with the highest in the liver and the lowest in the ovaries. There were significant differences in SFA contents among the three tissues (P0.05). The ratio of UFA/SFA in muscle, liver, and ovary tissues was 2.35, 1.67, and 4.49, respectively, and the ratio of n3-PUFA/n6-PUFA in the same three tissues was 4.94, 3.87, and 5.13, respectively. These ratios were highest in the ovary, followed by the muscle, and were the lowest in the liver. In summary, the total lipid, PUFA, EPA, DHA, and n3-PUFA contents and the ratios of UFA/SFA and n3-PUFA/n6-PUFA were highest in ovary tissues, and the distribution characteristics of the corresponding composition in different tissues was closely related to the reproductive habits of this species during gonad development stage Ⅳ. The accumulation of rich lipids and reasonable essential fatty acid nutrition in the ovary can improve the reproductive performance of C. nasus in this stage and provide sufficient nutrition and energy sources for the development of eggs and larvae in the subsequent stage. In this study, it was found that the lipid and polyunsaturated fatty acid nutrition of C. nasus adults with ovarian development to stage Ⅳ selectively accumulated in the ovary, which is an adaptation to the reproductive activities of this species at this stage. The results provide basic data for determining the differences in nutritional demands of C. nasus adults at different ovarian development stages and the mechanisms for the synthesis and transformation of essential fatty acids. Additionally, this study lays a foundation for further exploration of the relationship between ovarian nutritional status and egg quality. Relevant data can enrich the reproductive biology knowledge of this species and provide theoretical guidance for protecting the reproductive population and the maintenance of C. nasus spawning grounds in the waters adjacent to the Yangtze Estuary.

Abstract Fish dietary niche is a core focus, and it reflects the diversity of resources, habitats, or environments occupied by a species. However, whether geographic segregation among different populations triggers dietary diversification and concomitant fish niche shift remains unknown. In the present study, we selected the Black Amur bream (Megalobrama terminalis) is a migratory fish species that plays an important role in the material transfer and energy cycling of river ecosystems, inhabiting southern China drainage with multiple geographic populations. Here, we utilized the combined analyses of 18S rDNA high‐throughput sequencing in fish gut contents and fatty acid (FA) in muscle tissues to evaluate potential spatial patterns of habitat and resource use for M. terminalis in three rivers of southern China. Our results showed that prey items of the Xijiang (XR) population (Pearl River) exhibited the highest species diversity and richness among the three geographic populations. Moreover, diet composition of M. terminalis was affected by spatial differences associated with geographic segregation. Analyses of FA biomarkers indicated that the highest levels of C16:0, C18:3n‐3, and C18:2n‐6c were found in Wanquan (WS) population (Wanquan River). The XR population exhibited a distinct FA profile characterized by higher amounts of arachidonic acid (ARA) and docosahexaenoic acid (DHA). The Moyang (MY) population (Moyang River) acted as the linkage between WS and XR populations and consisted of middle levels of saturated FAs (SFAs) and polyunsaturated FAs (PUFAs). The XR population displayed a greater FA niche width compared with WS population. Furthermore, we observed a close positive relationship between the niche width and α‐diversity indices of dietary resources for FA proflies. Our study provides valued information to develop different conservation strategies among different populations and improve fisheries management for M. terminalis and other endemic species in local rivers.

Abstract When manually polishing blades, skilled workers can quickly machine a blade by observing the characteristics of the polishing sparks. To help workers better recognize spark images, we used an industrial charge-coupled device (CCD) camera to capture the spark images. Firstly, the spark image region detected by yolo5, then segment from the background. Secondly, the target region was further segmented and refined in a fully connected conditional random field (CRF), from which the complete spark image obtained. Experimental results showed that this method could quickly and accurately segment whole spark image. The test results showed that this method was better than other image segmentation algorithms. Our method could better segment irregular image, improve recognition and segmentation efficiency of spark image, achieve automatic image segmentation, and replace human observation.

Abstract Excitons in monolayer semiconductors, benefitting from their large binding energies, hold great potential towards excitonic circuits bridging nano-electronics and photonics. However, achieving room-temperature ultrafast on-chip electrical modulation of excitonic distribution and flow in monolayer semiconductors is nontrivial. Here, utilizing lateral bias, we report high-speed electrical modulation of the excitonic distribution in a monolayer semiconductor junction at room temperature. The alternating charge trapping/detrapping at the two monolayer/electrode interfaces induces a non-uniform carrier distribution, leading to controlled in-plane spatial variations of excitonic populations, and mimicking a bias-driven excitonic flow. This modulation increases with the bias amplitude and eventually saturates, relating to the energetic distribution of trap density of states. The switching time of the modulation is down to 5 ns, enabling high-speed excitonic devices. Our findings reveal the trap-assisted exciton engineering in monolayer semiconductors and offer great opportunities for future two-dimensional excitonic devices and circuits.