770 research outputs found

    Analysis on Strengthening the Construction of School Spirit in Private Independent Colleges and Universities

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    Private independent colleges and universities shoulder the responsibility of training application-oriented talents. Teaching atmosphere, learning atmosphere, research atmosphere is not only related to the quality of talent training and the level of school running, but also related to the healthy development of independent colleges and universities themselves. This paper analyzes and discusses the core connotation and index system of the school spirit construction of China’s private independent colleges and universities: using the method of literature, investigation and research, inclusion and summary and logical analysis, strengthening the construction of the study style, advocating scientific research, and constructing three-dimensional figures of “finding problems, analyzing problems, and solving problems”. Taking nanjing tech university pujiang institute as the research object, this paper puts forward some ideas and countermeasures to strengthen the construction of school spirit. It provides some theoretical and practical guidance for the evaluation system of campus atmosphere construction of private independent colleges in China

    Explore the Origin of SSB from Adaptive Perturbation Method

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    Spontaneous symmetry breaking occurs when the underlying laws of a physical system are symmetric, but the vacuum state chosen by the system is not. The (3+1)d ϕ4\phi^4 theory is relatively simple compared to other more complex theories, making it a good starting point for investigating the origin of non-trivial vacua. The adaptive perturbation method is a technique used to handle strongly coupled systems. It has been successful in strongly coupled QM and is being generalized to scalar field theory to analyze the system in the strong-coupling regime. The unperturbed Hamiltonian does not commute with the usual number operator. However, the quantized scalar field admits a plane-wave expansion when acting on the vacuum. While quantizing the scalar field theory, the field can be expanded into plane-wave modes, making the calculations more tractable. However, the Lorentz symmetry, which describes how physical laws remain the same under certain spacetime transformations, might not be manifest in this approach. The proposed elegant resummation of Feynman diagrams aims to restore the Lorentz symmetry in the calculations. The results obtained using this method are compared with numerical solutions for specific values of the coupling constant λ=1,2,4,8,16\lambda = 1, 2, 4, 8, 16. Finally, we find evidence for quantum triviality, where self-consistency of the theory in the UV requires λ=0\lambda = 0. This result implies that the ϕ4\phi^4 theory alone does not experience SSB, and the ⟨ϕ⟩=0\langle \phi\rangle = 0 phase is protected under the RG-flow by a boundary of Gaussian fixed-points.Comment: 14 pages, 6 figures, minor change

    Chemical syntheses of the cochliomycins and certain related resorcylic acid lactones

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    The cochliomycins (7–12) are a group of six resorcylic acid lactones that have recently been isolated from culture broths of marine fungi found in the South China Sea. These natural products have attracted attention as synthetic targets because of (in certain instances) their novel structural features and their capacities to suppress biofouling. This short review summarizes the synthesis of these and some related compounds that have been reported to date, including those developed in the authors’ laboratories.The authors thank the Australian Research Council and the Institute of Advanced Studies at the Australian National University for ongoing support. YZ is the grateful recipient of a stipend from the China Scholarship Council of the People’s Republic of China while XM thanks the Guangdong Province’s GEP for the provision of a scholarship

    Unrevealing hardening and strengthening mechanisms in high-entropy ceramics from lattice distortion

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    Revealing the hardening and strengthening mechanisms is crucial for facilitating the design of superhard and high-strength high-entropy ceramics (HECs). Here, we take high-entropy diborides (HEB2_2) as the prototype to thoroughly investigate the hardening and strengthening mechanisms of HECs. Specifically, the equiatomic 4- to 9-cation single-phase HEB2_2 ceramics (4-9HEB2_2) are fabricated by an ultra-fast high-temperature sintering method. The as-fabricated 4-9HEB2_2 samples possess similar grain sizes, comparable relative densities (up to ~98%), uniform compositions, and clean grain boundaries without any impurities. The experimental results show that the hardness and flexural strength of the as-fabricated 4-9HEB2_2 samples have an increasing tendency with the increase of metal components. The first-principles calculations find that lattice distortion is essential to the hardness and strength of HEB2_2. With the increase of metal components, an aggravation of lattice distortion accompanied by B-B bond strengthening is determined, resulting in the enhancement of the hardness and flexural strength. Moreover, the correlation between other potential indicators and the hardness/flexural strength of HEB2_2 has been disproved, including valence electron concentration, electronegativity mismatch, and metallic states. Our results unravel the hardening and strengthening mechanisms of HECs by intensifying lattice distortion, which may provide guidance for developing superhard and high-strength HECs

    Simvastatin Blocks Blood-Brain Barrier Disruptions Induced by Elevated Cholesterol Both In Vivo and In Vitro

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    Background. Hypercholesterolemia and disruptions of the blood brain barrier (BBB) have been implicated as underlying mechanisms in the pathogenesis of Alzheimer's disease (AD). Simvastatin therapy may be of benefit in treating AD; however, its mechanism has not been yet fully understood. Objective. To explore whether simvastatin could block disruption of BBB induced by cholesterol both in vivo and in vitro. Methods. New Zealand rabbits were fed cholesterol-enriched diet with or without simvastatin. Total cholesterol of serum and brain was measured. BBB dysfunction was evaluated. To further test the results in vivo, rat brain microvascular endothelial cells (RBMECs) were stimulated with cholesterol in the presence/absence of simvastatin in vitro. BBB disruption was evaluated. Results. Simvastatin blocked cholesterol-rich diet induced leakage of Evan's blue dye. Cholesterol content in the serum was affected by simvastatin, but not brain cholesterol. Simvastatin blocked high-cholesterol medium-induced decrease in TEER and increase in transendothelial FITC-labeled BSA Passage in RBMECs. Conclusions. The present study firstly shows that simvastatin improves disturbed BBB function both in vivo and in vitro. Our data provide that simvastatin may be useful for attenuating disturbed BBB mediated by hypercholesterolemia

    3D-SeqMOS: A Novel Sequential 3D Moving Object Segmentation in Autonomous Driving

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    For the SLAM system in robotics and autonomous driving, the accuracy of front-end odometry and back-end loop-closure detection determine the whole intelligent system performance. But the LiDAR-SLAM could be disturbed by current scene moving objects, resulting in drift errors and even loop-closure failure. Thus, the ability to detect and segment moving objects is essential for high-precision positioning and building a consistent map. In this paper, we address the problem of moving object segmentation from 3D LiDAR scans to improve the odometry and loop-closure accuracy of SLAM. We propose a novel 3D Sequential Moving-Object-Segmentation (3D-SeqMOS) method that can accurately segment the scene into moving and static objects, such as moving and static cars. Different from the existing projected-image method, we process the raw 3D point cloud and build a 3D convolution neural network for MOS task. In addition, to make full use of the spatio-temporal information of point cloud, we propose a point cloud residual mechanism using the spatial features of current scan and the temporal features of previous residual scans. Besides, we build a complete SLAM framework to verify the effectiveness and accuracy of 3D-SeqMOS. Experiments on SemanticKITTI dataset show that our proposed 3D-SeqMOS method can effectively detect moving objects and improve the accuracy of LiDAR odometry and loop-closure detection. The test results show our 3D-SeqMOS outperforms the state-of-the-art method by 12.4%. We extend the proposed method to the SemanticKITTI: Moving Object Segmentation competition and achieve the 2nd in the leaderboard, showing its effectiveness
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