26 research outputs found

    Magneto-optical-electric joint-measurement scanning imaging system for identification of two-dimensional vdW multiferroic

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    As an advanced imaging system, the magneto-optical-electric joint-measurement scanning imaging system (MOEJSI) brings spectroscopic techniques with unmatched spatial resolution to very low temperature, high magnetic field and high electric field measurements. It was developed for investigating the magnetic and ferroelectric properties and their mutual control through magneto-optical-electric joint-measurements, besides Raman and photoluminescence features. In particular, the reflective magnetic circular dichroism (RMCD) loops and imaging, linear dichroism (LD) imaging and polarization-electric field hysteresis loop can be achieved when simultaneously applied high magnetic field (7 T) and electric field (100 V) at low temperature of 10 K.Comment: 3 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:2302.1348

    Dilemma in All-optical Characterization of Single-layer NiI2 Multiferroics

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    Matters Arising in Nature on "Evidence for a single layer van der Waals multiferroic". The search for two dimensional multiferroic materials is an exciting yet challenging endeavor. Recently, Song reported the exciting discovery of type II multiferroic order in an antiferromagnetic (AFM) NiI2 single layer and concluded the ferroelectric (FE) polarization induced by a helical magnetic order1. Their finding was presented from all optical experimental evidence, based on the methods of second harmonic generation (SHG) and linear dichroism (LD). However, the all optical characterizations cannot serve as unanimous evidence of the FE existence, particularly in conjunction with magnetic orders in a single layer NiI2 multiferroic. We have designed and built a Magneto-Optical-Electric Joint-measurement Scanning Imaging system (MOEJSI) for identification of two-dimensional vdW multiferroic.Comment: 7 page

    MaskOCR: Text Recognition with Masked Encoder-Decoder Pretraining

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    Text images contain both visual and linguistic information. However, existing pre-training techniques for text recognition mainly focus on either visual representation learning or linguistic knowledge learning. In this paper, we propose a novel approach MaskOCR to unify vision and language pre-training in the classical encoder-decoder recognition framework. We adopt the masked image modeling approach to pre-train the feature encoder using a large set of unlabeled real text images, which allows us to learn strong visual representations. In contrast to introducing linguistic knowledge with an additional language model, we directly pre-train the sequence decoder. Specifically, we transform text data into synthesized text images to unify the data modalities of vision and language, and enhance the language modeling capability of the sequence decoder using a proposed masked image-language modeling scheme. Significantly, the encoder is frozen during the pre-training phase of the sequence decoder. Experimental results demonstrate that our proposed method achieves superior performance on benchmark datasets, including Chinese and English text images

    Observation of unconventional van der Waals multiferroics near room temperature

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    The search for two-dimensional (2D) van der Waals (vdW) multiferroics is an exciting yet challenging endeavor. Room-temperature 2D vdW few-layer multiferroic is a much bigger insurmountable obstacle. Here we report the discovery of an unconventional 2D vdW multiferroic with out-of-plane ferroelectric polarization and long-range magnetic orders in trilayer NiI2 device from 10 K to 295 K. The evolutions of magnetic domains with magnetic field, and the evolutions between ferroelectric and antiferroelectric phase have been unambiguously observed. More significantly, we realize a robust mutual control of magnetism and ferroelectricity at room temperature. The magnetic domains are manipulated by a small voltage ranging from 1 V to 6 V at 0 T and 295 K. This work opens opportunities for exploring multiferroic physics at the limit of few atomic layers.Comment: 4 figure

    Plant biomass allocation and driving factors of grassland revegetation in a Qinghai-Tibetan Plateau chronosequence

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    Biomass allocation is a key factor in understanding how ecosystems respond to changing environmental conditions. The role of soil chemistry in the above- and belowground plant biomass allocation in restoring grassland is still incompletely characterized. Consequently, it has led to two competing hypotheses for biomass allocation: optimal partitioning, where the plants allocate biomass preferentially to optimize resource use; and the isometric hypothesis, which postulates that biomass allocation between roots and shoots is fixed. Here we tested these hypotheses over a chronosequence of alpine grasslandsion undergoing restoration in the Qinghai-Tibetan Plateau, these range from severely degraded to those with 18 years of revegetation with an intact grassland (as a reference). A high proportion of biomass was allocated to the roots in the revegetated grasslands, and more biomass to shoots in the degraded and intact grasslands. The grasslands gradually decreased their root to shoot ratio as revegetation continued, with the lowest value in year 18 of revegetation. Our results showed that aboveground biomass (AGB) was increased by available phosphorus (P), soil moisture, and negatively related to bulk density, while belowground biomass (BGB) was positively impacted by total P and negatively by nitrate nitrogen (N). The trade-off between them was positively associated with available P and nitrate-N, and soil nutrient availability is more linked to increased AGB relative to BGB. Our study indicates that biomass allocation is highly variable during the revegetation period from degraded grassland, and is linked with soil properties, thus supporting the optimal partitioning hypothesis.</p

    Autophagy-Based Unconventional Secretory for AIM2 Inflammasome Drives DNA Damage Resistance During Intervertebral Disc Degeneration

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    Intervertebral disc degeneration (IDD) is the primary cause of low back pain. Stress-induced DNA damage is closely relevant to the pathogenesis of IDD; however, the underlying mechanisms remain unclear. This study investigated the role of the absent in melanoma 2 (AIM2) inflammasome as a DNA damage sensor in nucleus pulposus (NP) cells. We found that the level of AIM2 increased in degenerated discs and was correlated to the degree of IDD. Knockdown of AIM2 ameliorated H2O2-induced DNA damage and apoptosis in NP cells in vitro, and retarded the progression of IDD in vivo. Furthermore, the induction of autophagy protected against cellular DNA damage via the unconventional secretion of AIM2. We further identified the Golgi re-assembly and stacking protein 55 (GRASP55) as mediator of the transport and secretion of AIM2 via an autophagic pathway. Taken together, our researches illustrate the role and regulatory mechanism of the AIM2 inflammasome during IDD. Targeting the AIM2 inflammasome may offer a promising therapeutic strategy for patients with IDD

    Reduced vibration and Model validation of DFIG for wind turbine

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    The vibration system of wind turbine doubly-fed induction generator (DFIG) includes generator, elastic support and frame. The work in this paper was conceived to test whether the elastic support change could change the vibration severity. So establish the Simpack simulation model and modified theoretical model to research the vibration of 4 elastic support and 5 kinds rotor mass unbalanced condition. At the same time, the experiment was carried out on the drive train test rig, experimental results are basically consistent to simulation results, and it is proved that the research in the paper is correct. Meanwhile, it proved that modified theoretical analysis model can be use to vibration analysis in frequency domain and the Simpack simulation model can be use to vibration analysis in time domain(such as trend analysis) for the rotor unbalance

    Reduced vibration and Model validation of DFIG for wind turbine

    No full text
    The vibration system of wind turbine doubly-fed induction generator (DFIG) includes generator, elastic support and frame. The work in this paper was conceived to test whether the elastic support change could change the vibration severity. So establish the Simpack simulation model and modified theoretical model to research the vibration of 4 elastic support and 5 kinds rotor mass unbalanced condition. At the same time, the experiment was carried out on the drive train test rig, experimental results are basically consistent to simulation results, and it is proved that the research in the paper is correct. Meanwhile, it proved that modified theoretical analysis model can be use to vibration analysis in frequency domain and the Simpack simulation model can be use to vibration analysis in time domain(such as trend analysis) for the rotor unbalance

    Recent progress and challenges in screening and characterization of UGT1A1 inhibitors

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    Uridine-diphosphate glucuronosyltransferase 1A1 (UGT1A1) is an important conjugative enzyme in mammals that is responsible for the conjugation and detoxification of both endogenous and xenobiotic compounds. Strong inhibition of UGT1A1 may trigger adverse drug/herb-drug interactions, or result in metabolic disorders of endobiotic metabolism. Therefore, both the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) have recommended assaying the inhibitory potential of drugs under development on the human UGT1A1 prior to approval. This review focuses on the significance, progress and challenges in discovery and characterization of UGT1A1 inhibitors. Recent advances in the development of UGT1A1 probes and their application for screening UGT1A1 inhibitors are summarized and discussed in this review for the first time. Furthermore, a long list of UGT1A1 inhibitors, including information on their inhibition potency, inhibition mode, and affinity, has been prepared and analyzed. Challenges and future directions in this field are highlighted in the final section. The information and knowledge that are presented in this review provide guidance for rational use of drugs/herbs in order to avoid the occurrence of adverse effects via UGT1A1 inhibition, as well as presenting methods for rapid screening and characterization of UGT1A1 inhibitors and for facilitating investigations on UGT1A1-ligand interactions. (C) 2019 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.Peer reviewe

    Comparison of Different Home/Commercial Washing Strategies for Ten Typical Pesticide Residue Removal Effects in Kumquat, Spinach and Cucumber

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    Home processing can reduce pesticide residues in agricultural products, and the common forms of treatment include washing, peeling, blanching, and cooking. In this study, the removal effects of tap water, micron calcium solution, alkaline electrolyzed water (AlEW), ozone water, active oxygen, and sodium bicarbonate on 10 typical pesticide residues in kumquat, cucumber, and spinach were investigated. The residue magnitudes were determined by chromatography&#8315;tandem mass spectrometry (GC-MS/MS, LC-MS/MS), combined with the QuEChERS pretreatment method. The model tests showed that the results of soaking and greenhouse were close. The removal effects of pesticide residues in kumquat and cucumber washing by alkaline electrolyzed water with a high pH value, micron calcium, and active oxygen solution were better than other washing solutions. The sodium bicarbonate solution, ozone water, and active oxygen solution were more effective in reducing pesticide residues in spinach than others. Active oxygen solution showed a better removal efficiency for the 10 pesticides than other treatments because of its alkalinity and oxidizability. Among the ten pesticides, pyrethroid pesticides had a higher removal rate. Additionally, chlorpyrifos were the most difficult to remove. For the majority of pesticides, the pesticide residue magnitudes showed a gradual reduction when increasing the washing time. The results indicated that alkaline solutions were effective for the reduction of pesticide residues when the washing time was longer than 15 min
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