• 제목/요약/키워드: Novel technology

검색결과 5,763건 처리시간 0.037초

A Novel Virtual Space Vector Modulation Strategy for the Neutral-Point Potential Comprehensive Balance of Neutral-Point-Clamped Converters

  • Zhang, Chuan-Jin;Tang, Yi;Han, Dong;Zhang, Hui;Zhang, Xiao;Wang, Ke
    • Journal of Power Electronics
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    • 제16권3호
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    • pp.946-959
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    • 2016
  • A novel Virtual Space Vector (VSV) modulation strategy for complete control of potential neutral point (NP) issues is proposed in this paper. The neutral point potential balancing problems of multi-level converters, which include elimination of low frequency oscillations and self-balancing for NP dc unbalance, are investigated first. Then a set of improved virtual space vectors with dynamic adjustment factors are introduced and a multi-objective optimization algorithm which aims to optimize these adjustment factors is presented in this paper. The improved virtual space vectors and the multi-objective optimization algorithm constitute the novel Virtual Space Vector modulation. The proposed novel Virtual Space Vector modulation can simultaneously recover NP dc unbalance and eliminate low frequency oscillations of the neutral point. Experiment results show that the proposed strategy has excellent performance, and that both of the neutral point potential issues can be solved.

Coenzyme $Q_{10}$ Production by Sphingomonas sp. ZUTE03 with Novel Precursors Isolated from Tobacco Waste in a Two-Phase Conversion System

  • Qiu, Lequan;Wang, Weijian;Zhong, Weihong;Zhong, Li;Fang, Jianjun;Li, Xuanzhen;Wu, Shijin;Chen, Jianmeng
    • Journal of Microbiology and Biotechnology
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    • 제21권5호
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    • pp.494-502
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    • 2011
  • Coenzyme $Q_{10}$ ($CoQ_{10}$) is a widely used supplement in heart diseases treatment or antioxidative dietary. The microbial production of $CoQ_{10}$ was enhanced by addition of solanesol and novel precursors recovered from waste tobacco. The novel precursors were separated by silica gel and identified as ${\alpha}$-linolenic acid (LNA) and butylated hydroxytoluene (BHT) based on the effect on $CoQ_{10}$ production and GC-MS. The effects of novel precursors on $CoQ_{10}$ production by Sphingomonas sp. ZUTE03 were further evaluated in a two-phase conversion system. The precursor's combination of solanesol (70 mg/l) with BHT (30 mg/l) showed the best effect on the improvement of $CoQ_{10}$ yield. A maximal $CoQ_{10}$ productivity (9.5 mg $l^{-1}$ $h^{-1}$) was achieved after 8 h conversion, with a molar conversion rate of 92.6% and 92.4% on BHT and solanesol, respectively. The novel precursors, BHT and LNA in crude extracts from waste tobacco leaves, might become potential candidates for application in the industrial production of $CoQ_{10}$ by microbes.

A SDR/DDR 4Gb DRAM with $0.11\mu\textrm{m}$ DRAM Technology

  • Kim, Ki-Nam
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제1권1호
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    • pp.20-30
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    • 2001
  • A 1.8V $650{\;}\textrm{mm}^2$ 4Gb DRAM having $0.10{\;}\mu\textrm{m}^2$ cell size has been successfully developed using 0.11 $\mu\textrm{m}$DRAM technology. Considering manufactur-ability, we have focused on developing patterning technology using KrF lithography that makes $0.11{\;}\mu\textrm{m}$ DRAM technology possible. Furthermore, we developed novel DRAM technologies, which will have strong influence on the future DRAM integration. These are novel oxide gap-filling, W-bit line with stud contact for borderless metal contact, line-type storage node self-aligned contact (SAC), mechanically stable metal-insulator-silicon (MIS) capacitor and CVD Al process for metal inter-connections. In addition, 80 nm array transistor and sub-80 nm memory cell contact are also developed for high functional yield as well as chip performance. Many issues which large sized chip often faces are solved by novel design approaches such as skew minimizing technique, gain control pre-sensing scheme and bit line calibration scheme.

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A novel radiation-dependence model of InP HBTs including gamma radiation effects

  • Jincan Zhang;Haiyi Cai;Na Li;Liwen Zhang;Min Liu;Shi Yang
    • Nuclear Engineering and Technology
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    • 제55권11호
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    • pp.4238-4245
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    • 2023
  • In order to predict the lifetime of InP Heterojunction Bipolar Transistor (HBT) devices and related circuits in the space radiation environment, a novel model including gamma radiation effects is proposed in this paper. Based on the analysis of radiation-induced device degradation effects including both DC and AC characteristics, a set of empirical expressions describing the device degradation trend are presented and incorporated into the Keysight model. To validate the effective of the proposed model, a series of radiation experiments are performed. The correctness of the novel model is validated by comparing experimental and simulated results before and after radiation.

Construction of a Novel Recombinant Bombyx mori Nuclear Polyhedrosis Virus Producing the Fluorescent Polyhedra

  • Kang, Seok-Woo;Yun, Eun-Young;Woo, Soo-Dong;Goo, Tae-Won;Hwang, Jae-Sam
    • International Journal of Industrial Entomology and Biomaterials
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    • 제3권1호
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    • pp.75-81
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    • 2001
  • We have constructed a novel recombinant Bombyx mori nuclear polyhedrosis virus (BmNPV) producing the green fluorescent polyhedra. For the production of the fluorescent polyhedra, partial polyhedrin gene containing KRKK as nuclear localization site from the BmNPV polyhedrin gene and the green fluorescent protein (gfp) gene were introduced under the control of p10 promoter of BmNPV. The recombinant BmNPV was stably produced fluorescent polyhedra in the infected Bm5 cells and the morphology of the fluorescent polyhedra was similar to that of wild-type BmNPV. The fluorescent polyhedra had 32 kDa native polyhedrin and 41 kDa fusion protein. From these data, we have further developed a novel BmNPV p10-based transfer vector producing recombinant polyhedra with foreign gene Product. The novel BmNPV P10-based transfer vector is composed of partial polyhedrin gene, factor Xa, and multiple cloning sites.

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Design of a Novel Integrated L-C-T for PSFB ZVS Converters

  • Tian, Jiashen;Gao, Junxia;Zhang, Yiming
    • Journal of Power Electronics
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    • 제17권4호
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    • pp.905-913
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    • 2017
  • To enhance the zero-voltage switching (ZVS) range and power density of the phase-shift full-bridge (PSFB) ZVS converters used in geophysical exploration, an additional resonant inductor is used as a leakage inductance and a blocking capacitor which is equivalent to interlayer capacitance is integrated into a novel integrated inductor-capacitor-transformer (L-C-T). The leakage inductance and equivalent interlayer capacitance of the novel integrated L-C-T are difficult to determine by conventional methods. To address this issue, this paper presents accurate and efficient methods to compute the leakage inductance and equivalent interlayer capacitance. Moreover, the accuracy of this methodology, which is based on electromagnetic energy and Lebedev's method, is verified by an experimental analysis and a finite element analysis (FEA). Taking the problems of the novel integrated L-C-T into consideration, the losses of the integrated L-C-T are analyzed and the temperature rise of the integrated L-C-T is determined by FEA. Finally, a PSFB ZVS converter prototype with the novel integrated L-C-T is designed and tested.

Hysteretic performance of a novel composite wall panel consisted of a light-steel frame and aerated concrete blocks

  • Wang, Xiaoping;Li, Fan;Wan, Liangdong;Li, Tao
    • Steel and Composite Structures
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    • 제41권6호
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    • pp.861-871
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    • 2021
  • This study aims at investigating the hysteretic performance of a novel composite wall panel fabricated by infilling aerated concrete blocks into a novel light-steel frame used for low-rise residential buildings. The novel light-steel frame is consisted of two thin-wall rectangular hollow section columns and a truss-beam assembled using patented U-shape connectors. Two bare light-steel frames and two composite wall panels have been tested to failure under horizontal cyclic loading. Hysteretic curves, lateral resistance and stiffness of four specimens have been investigated and analyzed. Based on the testing results, it is found that the masonry infill can significantly increase the lateral resistance and stiffness of the novel light-steel frame, about 2.3~3 and 21.2~31.5 times, respectively. Failure mode of the light-steel frame is local yielding of the column. For the composite wall panel, firstly, masonry infill is crushed, subsequently, local yielding may occur at the column if loading continues. Hysteretic curve of the composite wall panel obtained is not plump, implying a poor energy dissipation capacity. However, the light-steel frame of the composite wall panel can dissipate more energy after the masonry infill is crushed. Therefore, the composite wall panel has a much higher energy dissipation capacity compared to the bare light-steel frame.

A Novel Cooperative Spectrum Sensing Algorithm in Cognitive Radio Systems

  • Zheng, Xueqiang;Wang, Jinlong;Wu, Qihui;Shen, Liang
    • Journal of Communications and Networks
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    • 제11권2호
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    • pp.115-121
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    • 2009
  • In cognitive radio (CR) systems, cognitive users can use the frequency bands when the primary users are not present. Hence, reliable detection of available spectrum is foundation of cognitive radio technology. To ensure unimpaired operation of primary users, cooperative spectrum sensing is needed. To reduce the network overhead of cooperative spectrum sensing, a novel cooperative spectrum sensing algorithm based on credibility is proposed. In particular, the close-form expressions for probability of detection and false-alarm are derived for the novel algorithm, and expression for the average overhead used for cooperation is given. The thresholds design method for the algorithm is also discussed. The conclusion is proved by computer simulations.

A Novel Wound Rotor Type for Brushless Doubly Fed Induction Generator

  • Chen, Xin;Wang, Xuefan
    • Journal of Electrical Engineering and Technology
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    • 제10권2호
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    • pp.595-602
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    • 2015
  • The rotor configuration of the brushless doubly fed induction generator (BDFIG) plays an important role in its performance. In order to make the magnetomotive force (MMF) space vector in one set rotor windings to couple both magnetic fields with different pole-pair and have low resistance and inductance, this paper presents a novel wound rotor type for BDFIG with low space harmonic contents. In accordance with the principles of slot MMF harmonics and unequal element coils, this novel rotor winding is designed to be composed of three-layer unequal-pitch unequal-turn coils. The optimal design process and rules are given in detail with an example. The performance of a 700kW 2/4 pole-pair prototype with the proposed wound rotor is analyzed by the finite element simulation and experimental test, which are also carried out to verify the effectiveness of the proposed wound rotor configuration.

Direct Palladium-Catalyzed C-4 Arylation of Tri-substituted Furans with Aryl Chlorides: An Efficient Access to Heteroaromatics

  • Yang, Hai;Zheng, Zhishuo;Zeng, Jian;Liu, Huajie;Yi, Bing
    • Bulletin of the Korean Chemical Society
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    • 제33권8호
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    • pp.2623-2626
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    • 2012
  • A series of functionalized furans were synthesized by way of a palladium-catalyzed coupling reaction of 2,3,5-trisubstituted furans with aryl chlorides through C-H bond cleavages at C-4 position. The feature of the reaction was facilitative preparation of furan derivatives with good functional group tolerance. All reactions gave the desired products in moderate to good yields in the presences of $BuAd_2P$ and t-BuOK in DMF at $120^{\circ}C$ after 15 h.