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Research on Voltage Stability Boundary under Different Reactive Power Control Mode of DFIG Wind Power Plant

  • Ma, Rui;Qin, Zeyu;Yang, Wencan;Li, Mo
    • Journal of Electrical Engineering and Technology
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    • v.11 no.6
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    • pp.1571-1581
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    • 2016
  • A novel method is proposed to construct the voltage stability boundary of power system considering different Reactive Power Control Mode (RPCM) of Doubly-Fed Induction Generator (DFIG) Wind Power Plant (WPP). It can be used for reflecting the static stability status of grid operation with wind power penetration. The analytical derivation work of boundary search method can expound the mechanism and parameters relationship of different WPP RPCMs. In order to improve the load margin and find a practical method to assess the voltage security of power system, the approximate method of constructing voltage stability boundary and the critical points search algorithms under different RPCMs of DFIG WPP are explored, which can provide direct and effective reference data for operators.

Compression-Friendly Low Power Test Application Based on Scan Slices Reusing

  • Wang, Weizheng;Wang, JinCheng;Cai, Shuo;Su, Wei;Xiang, Lingyun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.4
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    • pp.463-469
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    • 2016
  • This paper presents a compression-friendly low power test scheme in EDT environment. The proposed approach exploits scan slices reusing to reduce the switching activity during shifting for test scheme based on linear decompressor. To avoid the impact on encoding efficiency from resulting control data, a counter is utilized to generate control signals. Experimental results obtained for some larger ISCAS'89 and ITC'99 benchmark circuits illustrate that the proposed test application scheme can improve significantly the encoding efficiency of linear decompressor.

Synthesis and Characterization of Lactobionic Acid Grafted Phenylalanyl-Glycyl-Chitosan

  • Li, He-Ping;Li, Shan;Wang, Zhou-Dong;Qin, Long
    • Journal of the Korean Chemical Society
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    • v.55 no.6
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    • pp.978-982
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    • 2011
  • In order to enhance the target action of chitosan-based drug, this paper firstly prepared phenylalanyl-glycylchitosan (Phe-Gly-CS) by grafting the key intermediate, bromoacetyl-phenylalanine (BA-Phe) onto chitosan. Then the target sugar molecule, lactobionic acid (LA), was grafted to Phe-Gly-CS and the topic compound lactobionic acid grafted phenylalanyl-glycyl-chitosan (Phe-Gly-CS-LA) was finally obtained in a yield of 78.8%. The product were characterized by FTIR, MS and 1H NMR. The preparing condition of BA-Phe was optimized as follows: the best pH was 10-11, the optimum temperature was $-4^{\circ}C$, the reaction time was 1.5 h.

Preparation and In Vitro Release of Ramose Chitosan-Based-5-Fluorouracil Microspheres

  • Li, He-Ping;Li, Hui;Wang, Zhou-Dong;Zhang, Juan-Juan;Deng, Man-Feng;Chen, San-Long
    • Journal of the Korean Chemical Society
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    • v.57 no.1
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    • pp.88-93
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    • 2013
  • In order to construct a controlled release system of drugs and to reduce toxic side effects of 5-fluorouracil, the novel ramose chitosan-based-5-fluorouracil microspheres (CS-FU-MS) were prepared. Firstly, using chitosan (CS) as carriers and 5-fluorouracil (5-FU) as a model drug, ramose chitosan-based-5-fluorouracil (CS-FU) was efciently synthesized by chemical crosslinking method through microwave irradiation, drug loading was 10.6%; Secondly, CS-FU-MS were prepared by CS-FU self-assembled under the dialysis conditions and the free 5-FU was encapsulated further at the same time. The size dispersivity of particles is uniform, and the average diameter of the CS-FU-MS was $4{\mu}m$. The drug encapsulation efficiency was 76.1%, and the drug loading was increased to 26.22%. CS-FU-MS maintain the zero-order release time in PBS (pH = 7.4) and HCl/KCl (pH = 1.2) dialysis medium was 40h and 34h respectively, and the cumulative release were 58.89% and 79.33% in 182 h. The results showed that CS-FU-MS have excellent sustained release properties.

Paeonol accelerates skin wound healing by regulating macrophage polarization and inflammation in diabetic rats

  • Zuyang Zhang;Tianhua Chen;Wei Liu;Jiepeng Xiong;Liangdong Jiang;Mingjiang Liu
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.5
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    • pp.437-448
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    • 2023
  • Diabetic ulcer is usually seen in people with uncontrolled blood sugar. Reportedly, many factors such as impaired glucose metabolism, and macrovascular and microvascular diseases caused angiogenesis disorders and delayed the healing of diabetic ulcers, thus affecting the body's metabolism, nutrition, and immune function. This study aimed to explore the effect of paeonol on skin wound healing in diabetic rats and the related mechanism. A rat model of diabetic ulcer was established. High glucose-treated mouse skin fibroblasts were co-cultured with M1 or M2-polarized macrophages treated with or without paeonol. H&E and Masson staining were used to reveal inflammatory cell infiltration and collagen deposition, respectively. Immunohistochemistry visualized the expression of Ki67, CD31, and vascular endothelial growth factor (VEGF). Western blot was used to detect interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-4, IL-10, CD31, VEGFA, and collagen I/III. The expression of iNOS and arginase 1 was revealed by immunofluorescence staining. Paeonol treatment augmented collagen deposition and the expression of Ki67, CD31, VEGF, and macrophage M2 polarization markers (IL-4 and IL-10) and reduced wound area, inflammatory cell infiltration, and macrophage M1 polarization markers (IL-1β and TNF-α) in the ulcerated area. In vitro, paeonol treatment promoted M2-polarization and repressed M1-polarization in macrophages, thereby improving the repair of cell damage induced by high glucose. Paeonol accelerates the healing of diabetic ulcers by promoting M2 macrophage polarization and inhibiting M1 macrophage polarization.

Reduce on the Cost of Photovoltaic Power Generation for Polycrystalline Silicon Solar Cells by Double Printing of Ag/Cu Front Contact Layer

  • Peng, Zhuoyin;Liu, Zhou;Chen, Jianlin;Liao, Lida;Chen, Jian;Li, Cong;Li, Wei
    • Electronic Materials Letters
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    • v.14 no.6
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    • pp.718-724
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    • 2018
  • With the development of photovoltaic industry, the cost of photovoltaic power generation has become the significant issue. And the metallization process has decided the cost of original materials and photovoltaic efficiency of the solar cells. Nowadays, double printing process has been introduced instead of one-step printing process for front contact of polycrystalline silicon solar cells, which can effectively improve the photovoltaic conversion efficiency of silicon solar cells. Here, the relative cheap Cu paste has replaced the expensive Ag paste to form Ag/Cu composite front contact of silicon solar cells. The photovoltaic performance and the cost of photovoltaic power generation have been investigated. With the optimization on structure and height of Cu finger layer for Ag/Cu composite double-printed front contact, the silicon solar cells have exhibited a photovoltaic conversion efficiency of 18.41%, which has reduced 3.42 cent per Watt for the cost of photovoltaic power generation.