117 research outputs found

    Study of Valve Motion in Reciprocating Refrigerator Compressors based on the 3-D Fluid–structure Interaction Model

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    Â Abstract: In this paper, a 3-D fluid-structure interaction model was established to investigate the working process of the small reciprocating refrigeration compressors. According to the numerical calculation, the working process of the small reciprocating refrigeration compressor, the motion of valve and the impact velocity and the contact stress of discharge valve and suction valve were given. Experiments on a small reciprocating refrigeration compressor for testing the p-v graph were carried out .Experimental results agree well with the numeric model. The result provides a guidance to research and design the small reciprocating refrigeration compressors

    Ascher syndrome

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    AbstractAscher syndrome is a rare, benign skin disorder characterized by a double upper lip, blepharochalasis, and nontoxic enlargement of the thyroid gland. The exact cause is unknown, but it is considered to be a hereditary disease with an autosomal dominant trait. We report here a case of forme fruste Ascher syndrome in a 29-year-old man

    Learning Robust Representations for Continual Relation Extraction via Adversarial Class Augmentation

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    Continual relation extraction (CRE) aims to continually learn new relations from a class-incremental data stream. CRE model usually suffers from catastrophic forgetting problem, i.e., the performance of old relations seriously degrades when the model learns new relations. Most previous work attributes catastrophic forgetting to the corruption of the learned representations as new relations come, with an implicit assumption that the CRE models have adequately learned the old relations. In this paper, through empirical studies we argue that this assumption may not hold, and an important reason for catastrophic forgetting is that the learned representations do not have good robustness against the appearance of analogous relations in the subsequent learning process. To address this issue, we encourage the model to learn more precise and robust representations through a simple yet effective adversarial class augmentation mechanism (ACA), which is easy to implement and model-agnostic. Experimental results show that ACA can consistently improve the performance of state-of-the-art CRE models on two popular benchmarks.Comment: Accepted by EMNLP 202

    Comparative Proteomic Analysis of Panax ginseng C. A. Meyer × Panax quinquefolius L. Leaves and Parental Lines

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    Heterosis refers to the superior performance of heterozygous F1 hybrid plants with respect to those of their genetically distinct parents. Despite its wide use in crops, heterosis is seldom applied in the Panax genus, and its molecular basis remains unclear. Thus, this study is aimed to obtain hybrid F1s and identify the proteins associated with heterosis. Hybrid F1 plants and parental inbred lines were obtained using the embryo rescue technique, and the proteomes of their leaves were analyzed using two‐dimensional gel electrophoresis. A total of 236 differentially expressed proteins were found, among which 84 nonadditive proteins indicated a heterosis pattern in the hybrid. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analysis revealed that photosynthesis, carbohydrate metabolism, and protein and amino acid synthesis were the most abundant classes of nonadditive proteins. Of the proteins in these categories, 10, 6, and 4 proteins, respectively, showed above high parent expression in the hybrid leaves. These results imply that the increment in photosynthetic capacity, carbohydrate decomposition, and nitrogen fixation might be related to the heterosis of the hybrid biomass and ginsenoside production in the hybrid leaves. This study could provide a basis for hybrid breeding of the Panax genus

    Fast growth of monolayer organic 2D crystals and their application in organic transistors

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    Growth of monolayer 2D organic crystal has been an interesting topic in recent years owing to their promising properties. However, it is still a tough challenge to obtain the 2D organic crystal with precise thickness control and uniform morphology. Herein, we reported the fabrication of 2D crystals of alkane molecules C44H90 with only monolayer thickness and tunable size through the simple dip-coating process. Benefitted from the low solubility of the C44H90 and the isotropic Van der Waals interaction, quadrilateral-shape monolayer 2D crystals with size from several micrometers to nearly hundreds of micrometers can be achieved in the dip-coating process. Utilized the X-ray diffraction and high resolution atomic force microscopy, we obtained the clear packing mode of these monolayer crystals. In addition, these smooth 2D crystals show promising application in the thin film transistors by acting as a molecular template layer. It leads to an increment of about one magnitude on the charge mobility owing to the decreasing of both morphology defects and interface traps.</p
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