334 research outputs found

    FPGA-based Digital Baseband Transmission System Performance Tester Research and Design

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    Communication System Transmission Performance Tester, as a digital communication system design and testing equipment, plays an important role in the construction and daily maintenance of the communication system. The paper presents a kind of tester, which is designed using Cyclone IV FPGA (Field Programmable Gata Array) and VHDL (Very High Speed Integrated Circuits Hardware Description Language). According to the features in the eye diagram, the system performance can intuitively and qualitatively evaluated. The results prove that the system accurately displayed the eye diagram, thereby reflected the performance of the baseband transmission system truthfull

    3D multilayered Bi4O5Br2 nanoshells displaying excellent visible light photocatalytic degradation behaviour for resorcinol.

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    High-ordered three-dimensional multilayered Bi4O5Br2 nanoshells have been fabricated successfully via a green ultrasound-assisted anion exchange reaction followed by a calcination treatment approach. The products are characterised by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV–vis diffuse reflectance spectrum and N2 adsorption/desorption isotherms. The results reveal that ternary Bi4O5Br2 nanoshells possess a pure monoclinic phase with the average thickness of ca. 12 nm, and the walls are of 10–12 layers constructed by nanograins with 10 nm in size. The specific surface is measured to be 36.18 m2 g-1 and the band gap energy E g value is calculated to be 2.52 eV. The possible formation process for Bi4O5Br2 nanoshells is simply proposed. According to the photocatalytic degradation for resorcinol under visible light irradiation, the as-prepared Bi4O5Br2 nanoshells exhibit excellent photocatalytic performance, which is not only far beyond the degradation rate of BiOBr precursor nanosheets but also superior to that of other reported Bi4O5Br2 architectures, suggesting a practical application for the treatment of organic pollutants.This work was supported by the Program of Study Abroad for Excellent Young Scholar of Anhui Province (gxfxZD2016221), the Key Projects of Support Program for Outstanding Young Talents of Anhui Province (gxyqZD2016151), the Natural Science Foundation of Anhui Province (1808085MB40), the Natural Science Foundation of Anhui Province Educational Committee (KJ2014ZD08, KJ2015A145), and the Special Foundation for Scientists of Hefei University (15CR06)

    A Hybrid Model Based on Support Vector Machine for Bus Travel-Time Prediction

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    Effective bus travel time prediction is essential in transit operation system. An improved support vector machine (SVM) is applied in this paper to predict bus travel time and then the efficiency of the improved SVM is checked. The improved SVM is the combination of traditional SVM, Grubbs’ test method and an adaptive algorithm for bus travel-time prediction. Since error data exists in the collected data, Grubbs’ test method is used for removing outliers from input data before applying the traditional SVM model. Besides, to decrease the influence of the historical data in different stages on the forecast result of the traditional SVM, an adaptive algorithm is adopted to dynamically decrease the forecast error. Finally, the proposed approach is tested with the data of No. 232 bus route in Shenyang. The results show that the improved SVM has good prediction accuracy and practicality

    Research Progress in Molecular Biology of Fish Immunoglobulin M (IgM)

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    Immunoglobulin (Ig) is a type of globulin produced by B lymphocytes during pathogenic infection of vertebrates. It has immune functions and can realize specific recognition and neutralization of corresponding antigens. As IgM is reported first in fish, IgM is the first antibody produced during immune responses and plays a vital role in systemic and mucosal immune tissues. IgM molecules have two forms: membrane-bound IgM (mIgM) and secreted IgM (sIgM). The latter is produced by plasmacytes and secreted into body fluid, existing as immunological effect molecules. The former embeds into B cytomembrane and exists as an antigen receptor. It binds with assistant molecules to form cell receptor compounds. This study reviews research progress on the structures and production processes of IgM genes in different fish species and the distribution characteristics of IgM on B cells, mediated signal pathways, and functions. It aims to enrich basic theoretical knowledge of fish immunology and provide some scientific references for disease control in fishes

    Research Progress on the Fish Complement C3 Gene

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    Complement (C) is a serum protein with immunity-related functions and enzymatic activities. It can induce inflammatory responses and antibody formation following activation by substances such as pathogens. Moreover, it is a crucial molecule in the congenital immune defense system. Complement manifests earlier than immunoglobulin in the evolutionary process of fish's immune system. Therefore, the complement system of fish is vital for congenital and acquired immunities. A complement system is a polymolecule system comprising more than 30 soluble proteins, membrane-bound proteins, and complement receptors. It can be activated through three pathways for immunoregulation, the clearance of the immune complex, etc. The liver primarily produces the fish complement C3, which is a significant component of the complement system of fishes. C3 is the hub of three activation pathways. Research works concerning the structure, generation process, expression, and functions of C3 in fishes are reviewed in this study
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