5,120 research outputs found

    Nonlinear modelling and adaptive fuzzy control of PEMFC

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    To improve the stability and performance of fuel cells, the operating temperature of proton exchange membrane fuel cells (PEMFC) should be controlled within a specified range. However, most existing mathematical models of PEMFC are too complex to be applied effectively in the control process. In this paper, adaptive fuzzy identification and control models of PEMFC are developed based on input-output sampled data and experts\u27 experience. The parameters of the identifier and controller are regulated by an adaptive learning algorithm, the network structure and the rule database are modified by adjusting the parameters. In the end, the simulation results of the online control model are presented and show the effectiveness

    Reduced glutamine synthetase activity alters the fecundity of female Bactrocera dorsalis (Hendel)

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    Glutamine synthetase (GS) is a key enzyme in glutamine synthesis and is associated with multiple physiological processes in insects, such as embryonic development, heat shock response, and fecundity regulation. However, little is known about the influence of GS on female fecundity in the oriental fruit fly, Bactrocera dorsalis. Based on the cloning of BdGSs, mitochondrial BdGSm and cytoplasmic BdGSc, we determined their expressions in the tissues of adult B. dorsalis. BdGSm was highly expressed in the fat body, while BdGSc was highly expressed in the head and midgut. Gene silencing by RNA interference against two BdGSs isoforms suppressed target gene expression at the transcriptional level, leading to a reduced ovarian size and lower egg production. The specific inhibitor L-methionine S-sulfoximine suppressed enzyme activity, but only the gene expression of BdGSm was suppressed. A similar phenotype of delayed ovarian development occurred in the inhibitor bioassay. Significantly lower expression of vitellogenin and vitellogenin receptor was observed when GS enzyme activity was suppressed. These data illustrate the effects of two GS genes on adult fecundity by regulating vitellogenin synthesis in different ways

    BIOMECHANICAL MEASUREMENT AND EVALUATION FOR WUSU COMPULSORY PROGRAM

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    INTRODUCTION: The Wusu compulsory program is a new form of competition. It differs from the Wusu optional program in that all the athletes must execute the same compulsory program. Following this, judges asses the level of expertise of athletes, by scores gained, based on their performance. The comparability and objectivity in grading a compulsory program is better than in an optional program. So it is feasible to analyze technique of the Wusu compulsory program using a biomechanical measuring method. The compulsory exercise described as, “the turn about for flying kick on the right“, was measured and analyzed quantitatively in this paper. With the calculations from this study, a new evaluation factor and advanced development of competitive Wusu wasdeveloped

    Topological superconductivity and large spin Hall effect in the kagome family Ti6X4 (X = Bi, Sb, Pb, Tl, In)

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    Topological superconductors (TSC) become a focus of research due to the accompanying Majorana fermions. However, the experimentally reported TSC are extremely rare. The recent experiments reported the kagome TSC AV3_{3}Sb5_{5} (A=K, Rb, Cs), which exhibit unique superconductivity, topological surface states (TSS), and Majorana bound states. More recently, the first titanium-based kagome superconductor CsTi3 _{3} Bi5 _{5} with nontrivial topology was successfully synthesized as a perspective TSC. Given that Cs contributes little to the electronic structures of CsTi3 _{3} Bi5 _{5} and binary compounds may be easier to be synthesized, here, by density functional theory calculations, we predict five stable non-magnetic kagome compounds Ti6 _{6} X4 _{4} (X = Bi, Sb, Pb, Tl, In) which exhibit superconductivity with critical temperature Tc = 3.8 - 5.1 K, nontrivial Z\mathbb{Z}2_2 band topology, and TSS close to the Fermi level. In addition, the large intrinsic spin Hall effect is obtained in Ti6 _{6} X4 _{4} , which is caused by gapped Dirac nodes and nodal lines due to a strong spin-orbit coupling. This work offers new platforms for TSC and spintronic devices

    Enhanced surface acceleration of fast electrons by using sub-wavelength grating targets

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    Surface acceleration of fast electrons in intense laser-plasma interaction is improved by using sub-wavelength grating targets. The fast electron beam emitted along the target surface was enhanced by more than three times relative to that by using planar target. The total number of the fast electrons ejected from the front side of target was also increased by about one time. The method to enhance the surface acceleration of fast electron is effective for various targets with sub-wavelength structured surface, and can be applied widely in the cone-guided fast ignition, energetic ion acceleration, plasma device, and other high energy density physics experiments.Comment: 14 pages, 4figure
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