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DC Injection Control for Grid-Connected Single-Phase Inverters Based on Virtual Capacitor

  • Wang, Wei;Wang, Ping;Bei, Taizhou;Cai, Mengmeng
    • Journal of Power Electronics
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    • v.15 no.5
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    • pp.1338-1347
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    • 2015
  • DC injection is a critical issue in transformerless grid-connected inverters. DC injection control based on virtual capacitor has the advantages of low cost, low loss, high accuracy and easy implementation. In this paper, the principle of DC injection control based on virtual capacitor was analyzed. In addition, the applicable conditions, working process, steady state error and advantages were also discussed in detail. The design of the control parameters based on virtual capacitor was proposed in a grid-connected inverter with LCL filter. The robustness of the control parameters was also discussed. Simulation and experimental results verify the validity of the analysis and demonstrate that this research has a certain value in engineering applications.

Digital Control of Secondary Active Clamp Phase-Shifted Full-Bridge Converters

  • Che, Yanbo;Ma, Yage;Ge, Shaoyun;Zhu, Dong
    • Journal of Power Electronics
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    • v.14 no.3
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    • pp.421-431
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    • 2014
  • A DSP-based self-adaptive proportional-integral (PI) controller to control a DC-DC converter is proposed in this paper. The full-bridge topology is adopted here to obtain higher power output capability and higher conversion efficiency. The converter adopts the zero-voltage-switching (ZVS) technique to reduce the conduction losses. A parallel secondary active clamp circuit is added to deal with the voltage overshoot and ringing effect on the transformer's secondary side. A self-adaptive PI controller is proposed to replace the traditional PI controller. Moreover, the designed converter adopts the constant-current and constant-voltage (CC-CV) output control strategy. The secondary active clamp mechanism is discussed in detail. The effectiveness of the proposed converter was experimentally verified by an IGBT-based 10kW prototype.

Complete Mitochondrial Genome of the Chagas Disease Vector, Triatoma rubrofasciata

  • Dong, Li;Ma, Xiaoling;Wang, Mengfei;Zhu, Dan;Feng, Yuebiao;Zhang, Yi;Wang, Jingwen
    • Parasites, Hosts and Diseases
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    • v.56 no.5
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    • pp.515-519
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    • 2018
  • Triatoma rubrofasciata is a wide-spread vector of Chagas disease in Americas. In this study, we completed the mitochondrial genome sequencing of T. rubrofasciata. The total length of T. rubrofasciata mitochondrial genome was 17,150 bp with the base composition of 40.4% A, 11.6% G, 29.4% T and 18.6% C. It included 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and one control region. We constructed a phylogenetic tree on the 13 protein-coding genes of T. rubrofasciata and other 13 closely related species to show their phylogenic relationship. The determination of T. rubrofasciata mitogenome would play an important role in understanding the genetic diversity and evolution of triatomine bugs.

Molecular Characterization, Chromosomal Localizations, Expression Profile, and Association Analysis of the Porcine PECI Gene with Carcass Traits

  • Gao, H.;Fan, B.;Zhu, M.J.;Liu, Bang
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.1
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    • pp.7-12
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    • 2010
  • The full-length cDNA of the porcine peroxisomal ${\Delta}^3$,${\Delta}^2$-enoyl-CoA isomerase (PECI) gene encodes a monofunctional peroxisomal ${\Delta}^3$,${\Delta}^2$-enoyl-CoA isomerase. Cloning and sequencing of the porcine PECI cDNA revealed the presence of an 1185-base pair open reading frame predicted to encode a 394-amino acid protein by the 5'rapid amplification of cDNA ends (5'RACE) and EST sequences. The porcine PECI gene was expressed in seven tissues (heart, liver, spleen, lung, kidney, skeletal muscle, fat) which was revealed by reverse transcriptase-polymerase chain reaction (RT-PCR). The porcine PECI was mapped to SSC71/2 p11-13 using the somatic cell hybrid panel (SCHP) and the radiation hybrid panel (RH) (LOD score 12.84). The data showed that PECI was closely linked to marker S0383. A C/T single nucleotide polymorphism in PECI exon 10 (3'UTR) was detected as a PvuII PCR-RFLP. Association analysis in our experimental pig population showed that different genotypes of PECI gene were significantly associated with the Average Backfat thickness (ABF) (p<0.05) and Buttock backfat thickness (p<0.01).

Full-length cDNA, Expression Pattern and Association Analysis of the Porcine FHL3 Gene

  • Zuo, Bo;Xiong, YuanZhu;Yang, Hua;Wang, Jun
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.10
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    • pp.1473-1477
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    • 2007
  • Four-and-a-half LIM-only protein 3 (FHL3) is a member of the LIM protein superfamily and can participate in mediating protein-protein interaction by binding one another through their LIM domains. In this study, the 5'- and 3'- cDNA ends were characterized by RACE (Rapid Amplification of the cDNA Ends) methodology in combination with in silico cloning based on the partial cDNA sequence obtained. Bioinformatics analysis showed FHL3 protein contained four LIM domains and four LIM zinc-binding domains. In silico mapping assigned this gene to the gene cluster MTF1-INPP5B-SF3A3-FHL3-CGI-94 on pig chromosome 6 where several QTL affecting intramuscular fat and eye muscle area had previously been identified. Transcription of the FHL3 gene was detected in spleen, liver, kidney, small intestine, skeletal muscle, fat and stomach, with the greatest expression in skeletal muscle. The A/G polymorphism in exon II was significantly associated with birth weight, average daily gain before weaning, drip loss rate, water holding capacity and intramuscular fat in a Landrace-derived pig population. Together, the present study provided the useful information for further studies to determine the roles of FHL3 gene in the regulation of skeletal muscle cell growth and differentiation in pigs.

Bacterial Species and Biochemical Characteristic Investigations of Nostoc flagelliforme Concentrates during its Storage

  • Yue, Lifang;Lv, Hexin;Zhen, Jing;Jiang, Shengping;Jia, Shiru;Shen, Shigang;Gao, Lu;Dai, Yujie
    • Journal of Microbiology and Biotechnology
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    • v.26 no.4
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    • pp.648-658
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    • 2016
  • Preservation of fresh algae plays an important role in algae seed subculture and aquaculture. The determination and examination of the changes of cell viability, composition, and bacterial species during storage would help to take suitable preservation methods to prolong the preservation time of fresh algae. Nostoc flagelliforme is a kind of edible cyanobacterium with important herbal and dietary values. This article investigated the changes of bacterial species and biochemical characteristics of fresh N. flagelliforme concentrate during natural storage. It was found that the viability of cells decreased along with the storage time. Fourteen bacteria strains in the algae concentrate were identified by PCR-DGGE and were grouped into four phyla, including Cyanobacteria, Firmicutes, Proteobacteria, and Bacteroidetes. Among them, Enterococcus viikkiensis may be a concern in the preservation. Eleven volatile organic compounds were identified from N. flagelliforme cells, in which geosmin could be treated as an indicator of the freshness of N. flagelliforme. The occurrence of indole compound may be an indicator of the degradation of cells.

An optimization design study of producing transuranic nuclides in high flux reactor

  • Wei Xu;Jian Li;Jing Zhao;Ding She;Zhihong Liu;Heng Xie;Lei Shi
    • Nuclear Engineering and Technology
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    • v.55 no.8
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    • pp.2723-2733
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    • 2023
  • Transuranic nuclides (such as 238Pu, 252Cf, 249Bk, etc.) have a wide range of application in industry, medicine, agriculture, and other fields. However, due to the complex conversion chain and remarkable fission losses in the process of transuranic nuclides production, the generation amounts are extremely low. High flux reactor with high neutron flux and flexible irradiation channels, is regarded as the promising candidate for producing transuranic nuclides. It is of great significance to increase the conversion ratio of transuranic nuclides, resulting in higher efficiency and better economy. In this paper, we perform an optimization design evaluation of producing transuranic nuclides in high flux reactor, which includes optimization design of irradiation target and influence study of reactor core loading. It is demonstrated that the production rate increases with appropriately determined target material and target structure. The target loading scheme in the irradiation channel also has a significant influence on the production of transuranic nuclides.

MicroRNA 449c Mediates the Generation of Monocytic Myeloid-Derived Suppressor Cells by Targeting STAT6

  • Han, Xiaoqing;Luan, Tao;Sun, Yingying;Yan, Wenyi;Wang, Dake;Zeng, Xianlu
    • Molecules and Cells
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    • v.43 no.9
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    • pp.793-803
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    • 2020
  • Myeloid-derived suppressor cells (MDSCs) promote tumour progression by contributing to angiogenesis, immunosuppression, and immunotherapy resistance. Although recent studies have shown that microRNAs (miRNAs) can promote the expansion of MDSCs in the tumour environment, the mechanisms involved in this process are largely unknown. Here, we report that microRNA 449c (miR-449c) expression was upregulated in myeloid progenitor cells upon activation of C-X-C motif chemokine receptor 2 (CXCR2) under tumour conditions. MiR-449c upregulation increased the generation of monocytic MDSCs (mo-MDSCs). The increased expression of miR-449c could target STAT6 mRNA in myeloid progenitor cells to shift the differentiation balance of myeloid progenitor cells and lead to an enhancement of the mo-MDSCs population in the tumour environment. Thus, our results demonstrate that the miR-449c/STAT6 axis is involved in the expansion of mo-MDSCs from myeloid progenitor cells upon activation of CXCR2, and thus, inhibition of miR-449c/STAT6 signalling may help to attenuate tumour progression.