18 research outputs found

    Improved Model for Beam-Wave Interaction with Ohmic Losses and Reflections of Sheet Beam Traveling Wave Tubes

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    In this article, an improved model for the beam-wave interaction of sheet beam in traveling wave tubes (TWTs) considering ohmic losses and reflections is presented. The ohmic losses are obtained by field analysis and equivalent method. The space charge magnetic field is derived from the active Helmholtz's equation. An algorithm to obtain the S-matrix by the equivalent circuit method is presented. The relativistic Boris method is applied to accelerate macroparticles. The exchanged power is computed by the work the electromagnetic field applied to the macroparticles. The theoretical model is applied for validation to a G-band staggered double vane TWT and validated in comparison with CST Particle Studio and simulations without losses and reflections. The convergence of this algorithm is also discussed. The simulation time of the model is substantial faster than 3-D particle-in-cell (PIC) simulations

    Study on Selection of Wheat Varieties for Noodle Production in Hebei Province and Factors Affecting the Processing Quality

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    [Objectives] To screen out the specific wheat varieties for noodle production in Hebei Province and analyze the factors affecting the processing quality of noodle. [Methods] The quality characteristics of grains, flour and noodle of major medium gluten wheat varieties in Hebei Province were detected and analyzed. [Results] The sensory score of noodle is significantly positively correlated with wet gluten content of medium gluten wheat flour, and extensile length, cohesiveness, resilience, elasticity, gumminess, chewiness and extensile distance of TPA of noodle, and is significantly negatively correlated with softening degree. TPA of noodle can indirectly reflect sensory quality of noodle. [Conclusions] Han 7086, Xingmai 4, Liangxing 66, Shiyou 17, Heng 5229 and Liangxing 99 are suitable for producing high-quality noodle, and they can be used as noodle-specific varieties promoted in Hebei Province

    All-Solid-State Lithium Organic Battery with Composite Polymer Electrolyte and Pillar[5]quinone Cathode

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    The cathode capacity of common lithium ion batteries (LIBs) using inorganic electrodes and liquid electrolytes must be further improved. Alternatively, all-solid-state lithium batteries comprising the electrode of organic compounds can offer much higher capacity. Herein, we successfully fabricated an all-solid-state lithium battery based on organic pillar[5]quinone (C35H20O10) cathode and composite polymer electrolyte (CPE). The poly(methacrylate) (PMA)/poly(ethylene glycol) (PEG)-LiClO4-3 wt % SiO2 CPE has an optimum ionic conductivity of 0.26 mS cm(-1) at room temperature. Furthermore, pillar[5]quinine cathode in all-solid-state battery rendered an average operation voltage of similar to 2.6 V and a high initial capacity of 418 mAh g(-1) with a stable cyclability (94.7% capacity retention after 50 cycles at 0.2C rate) through the reversible redox reactions of enolate/quinonid carbonyl groups, showing favorable prospect for the device application with high capacity

    MYB-CC transcription factor, TaMYBsm3, cloned from wheat is involved in drought tolerance

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    Abstract Background MYB-CC transcription factors (TFs) genes have been demonstrated to be involved in the response to inorganic phosphate (Pi) starvation and regulate some Pi-starvation-inducible genes. However, their role in drought stress has not been investigated in bread wheat. In this study, the TaMYBsm3 genes, including TaMYBsm3-A, TaMYBsm3-B, and TaMYBsm3-D, encoding MYB-CC TF proteins in bread wheat, were isolated to investigate the possible molecular mechanisms related to drought-tolerance in plants. Results TaMYBsm3-A, TaMYBsm3-B, and TaMYBsm3-D were mapped on chromosomes 6A, 6B, and 6D in wheat, respectively. TaMYBsm3 genes belonged to MYB-CC TFs, containing a conserved MYB DNA-binding domain and a conserved coiled–coil domain. TaMYBsm3-D was localized in the nucleus, and the N-terminal region was a transcriptional activation domain. TaMYBsm3 genes were ubiquitously expressed in different tissues of wheat, and especially highly expressed in the stamen and pistil. Under drought stress, transgenic plants exhibited milder wilting symptoms, higher germination rates, higher proline content, and lower MDA content comparing with the wild type plants. P5CS1, DREB2A, and RD29A had significantly higher expression in transgenic plants than in wild type plants. Conclusion TaMYBsm3-A, TaMYBsm3-B, and TaMYBsm3-D were associated with enhanced drought tolerance in bread wheat. Overexpression of TaMYBsm3-D increases the drought tolerance of transgenic Arabidopsis through up-regulating P5CS1, DREB2A, and RD29A

    All-Solid-State Lithium Organic Battery with Composite Polymer Electrolyte and Pillar[5]quinone Cathode

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    The cathode capacity of common lithium ion batteries (LIBs) using inorganic electrodes and liquid electrolytes must be further improved. Alternatively, all-solid-state lithium batteries comprising the electrode of organic compounds can offer much higher capacity. Herein, we successfully fabricated an all-solid-state lithium battery based on organic pillar[5]­quinone (C<sub>35</sub>H<sub>20</sub>O<sub>10</sub>) cathode and composite polymer electrolyte (CPE). The poly­(methacrylate) (PMA)/poly­(ethylene glycol) (PEG)-LiClO<sub>4</sub>-3 wt % SiO<sub>2</sub> CPE has an optimum ionic conductivity of 0.26 mS cm<sup>–1</sup> at room temperature. Furthermore, pillar[5]­quinine cathode in all-solid-state battery rendered an average operation voltage of ∼2.6 V and a high initial capacity of 418 mAh g<sup>–1</sup> with a stable cyclability (94.7% capacity retention after 50 cycles at 0.2C rate) through the reversible redox reactions of enolate/quinonid carbonyl groups, showing favorable prospect for the device application with high capacity

    Ultrathin 2D TiS2 Nanosheets for High Capacity and Long-Life Sodium Ion Batteries

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    Sodium ion batteries are now attracting great attention, mainly because of the abundance of sodium resources and their cheap raw materials. 2D materials possess a unique structure for sodium storage. Among them, transition metal chalcogenides exhibit significant potential for rechargeable battery devices due to their tunable composition, remarkable structural stability, fast ion transport, and robust kinetics. Herein, ultrathin TiS2 nanosheets are synthesized by a shear-mixing method and exhibit outstanding cycling performance (386 mAh g−1 after 200 cycles at 0.2 A g−1). To clarify the variations of galvanostatic curves and superior cycling performance, the mechanism and morphology changes are systematically investigated. This facile synthesis method is expected to shed light on the preparation of ultrathin 2D materials, whose unique morphologies could easily enable their application in rechargeable batteries

    Ultrathin 2D TiS2 nanosheets for high capacity and long-life sodium ion batteries

    No full text
    Sodium ion batteries are now attracting great attention, mainly because of the abundance of sodium resources and their cheap raw materials. 2D materials possess a unique structure for sodium storage. Among them, transition metal chalcogenides exhibit significant potential for rechargeable battery devices due to their tunable composition, remarkable structural stability, fast ion transport, and robust kinetics. Herein, ultrathin TiS2 nanosheets are synthesized by a shear-mixing method and exhibit outstanding cycling performance (386 mAh g(-1) after 200 cycles at 0.2 A g(-1)). To clarify the variations of galvanostatic curves and superior cycling performance, the mechanism and morphology changes are systematically investigated. This facile synthesis method is expected to shed light on the preparation of ultrathin 2D materials, whose unique morphologies could easily enable their application in rechargeable batteries

    All Carbon Dual Ion Batteries

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    Dual ion batteries based on Na+and PF6-received considerable attention due to their high operating voltage and the abundant Na resources. Here, cheap and easily obtained graphite that served as a cathode material for dual ion battery delivered a very high average discharge platform (4.52 V vs Na+/Na) by using sodium hexafluorophosphate in propylene carbonate as electrolyte. Moreover, the all-carbon dual ion batteries with graphite as cathode and hard carbon as anode exhibited an ultrahigh discharge voltage of 4.3 V, and a reversible capacity of 62 mAh·g-1at 40 mA·g-1. Phase changes have been investigated in detail through in situ X-ray diffraction and in situ Raman characterizations. The stable structure provides long life cycling performance, and the pseudocapacitance behavior also demonstrates its benefits to the rate capability. Thus, dual ion batteries based on sodium chemistry are very promising to find their applications in future
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