Theory Analysis of Harmonic Current Generation and Harmonic Current Extraction of Three-phase Grid-connected Inverter

Shaohua Sun,Hongqi Ben,Yingge Li,Leyi Wang,Shuai Yu 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Theory of the harmonic current generation of three-phase grid-connected inverter under unbalanced grid conditions is analyzed in detail in this paper. Based on the characteristic of three-phase currents, the structure of three adaptive notch filter(ANF) cells collaborating with fast positive and negative sequence decomposition(FPNSD) cell is proposed, which employs for the extraction of harmonic current. The main function of this harmonic current extraction method is to provide harmonic current for voltage regulation and power control of inverter. Moreover, this method is capable of extracting a selective order of harmonic where elimination of certain harmonic is of concern. The performance and analysis of the proposed structure in this study are verified through experimental cases.

Gene expression profile of NFκB repressing factor(NKRF) knockdown cells by microarray analysis

Sun Yaqiong,Zheng Dan,Gu Shaohua,Mao Yumin,Xie Yi 한국바이오칩학회 2012 BioChip Journal Vol.6 No.3

Human NFκB repressing factor(NKRF) is a negative regulation transcription factor, which is able to repress transcription by binding to the negative regulatory element(NRE) near the NFκB binding site in certain genes’ promoters. Current researches reveals that NKRF represses the activation of IFN-β, IL-8,hiNOS and HIV-1 by NFκB. We used optical fiber beadchip to analysis the different gene expression patterns of RNAi mediated NKRF knockdown HEK293 cells and found that several genes showed significant change of expression levels. Real-time PCR was performed to verify the changes of expression of candidate genes. We analyzed the function of candidate genes by searching the gene ontology databases and publications and revealed that these genes functioned in cell cycle, cell proliferation, apoptosis, cell migration, DNA repair, transcription, metabolism, response to stimulus and signal transduction. This study provides new perspectives on NKRF’s potential multiple functions.

Paired-Associate Second Language Vocabulary Learning: The Role of L1 Translation Familiarity

Hanzhong Sun,Shaohua Fang 아시아테플 2022 The Journal of Asia TEFL Vol.19 No.1

First language (L1) use has always been a subject of debate in second language (L2) vocabulary learning, generating two main research lines. The first line concerns whether L1 use is advisable, and the second relates to how its use can be more beneficial. The current study contributes to the latter strand by probing the effect L1 familiarity had on L2 vocabulary gains using paired-associate learning paradigm. Two groups of English as a foreign language (EFL) learners with comparable L2 proficiency were recruited to learn three L2 word sets varying in L1 familiarity status (high/low), and accordingly three conditions were created (High: all L2 words with high L1 familiarity; Low: all low; Mixed: half high and half low). In the treatment session, both groups of participants studied each set separately, while made aware of, and then completing one of the two tests differing in depth of processing (either meaning recognition or meaning recall). At the testing phase, an unannounced one- week delayed posttest which measured meaning recognition was administered to both groups to examine the retention of vocabulary knowledge. The results showed that similar patterns were observed across two groups, such that High displayed an advantage over Low and Mixed did not exhibit striking differences compared to High. Additionally, recall group outperformed recognition group on all word sets. Therefore, our findings offer direct experimental support to the principle of learning burden (Nation, 1990, 2013), and highlight both the importance and the complexity of L1 familiarity. We conclude with pedagogical implications in relation to those findings.

Functionalized moso bamboo powder adsorbent for Cd(II) complexes with citric acid/tartrate acid: characterization, adsorptive performance, and mechanism

Qinju Sun,Shaohua Lin,Guohua Liu,Yue Xuan,Liping Gao,Pingping Li 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.5

A new amine group functionalized moso bamboo powder adsorbent (AMBP) was prepared using a facile procedure to remove Cd(II) complexes with citric acid (CA) and tartrate acid (TA). The properties of the AMBP were characterized using SEM, FTIR, XPS, BET, and an elemental analysis. The adsorptive performances of the AMBP toward Cd(II)-CA/TA were investigated. The results indicated that amine group was successfully introduced, and the AMBP with a BET specific surface area of 0.463 ㎡/g was effective in adsorbing Cd(II)-CA/TA under pH 4.0–10.0. The removal of Cd(II) increased significantly when the Cd(II)/ligand molar ratio changed from 1:0.5 to 1:2. The adsorption processes of Cd(II)-CA/TA were endothermic and fit well with the pseudo-second-order kinetic model (R² > 0.999). The Langmuir model (qmax of 14.41 and 7.58 mg/g for Cd(II)-CA and Cd(II)-TA, respectively) fit the isotherms better than the Freundlich model. The AMBP could be regenerated by HCl and reused at least 4 times. The uptake mechanisms of Cd(II)-CA/TA were proposed to be physisorption and the chemisorption of the coordination between –NH₂/–NH and the Cd(II). This work shows that the AMBP is an adsorbent with high practical value to remove Cd(II) in water or wastewater containing CA/TA.

Industrial test on coal re-burning at a 600MW utility boiler and NOx reduction

Penghua Qiu,Shaohua Wu,Shaozeng Sun,Hui Liu,Longbin Yang,Guozhong Wang 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.4

research conducts a series of industrial tests on coal reburning of a 600 MW pulverized coal boilerfiring lignite, which is one part of a coal reburning demonstration project. When running steadily under 60 MW load,the boiler has an average NOx emission of 274 mg/m3 (O2 content in flue gas is converted to 6% ), the NOx emissionis reduced by 65.36% . In the meanwhile, loss of ignition (LOI) under coal reburning rarely increases. Three operationconditions - traditional air feeding, air staging and coal reburning - are realized, respectively, during the industrial tests,and the results indicate that coal reburning has the lowest NOx emission, while the traditional air feeding has the highestNOx x controlcan reach.

Fabrication of MnFe2O4 and MnCO3 Nanoparticles Anchored on Amorphous Carbon-Coated Carbon Nanotubes for High-Performance Lithium Batteries and Supercapacitors

Quanwu Wen,Shaohua Zhang,Mingwei Sun,Rencheng Jin 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.5

Transition metal oxides as Li-ion batteries (LIBs) anodes have attracted much attention because of their high theoretical capacity. However, the large volume change and low electrical conductivity still hinder their application in LIBs. In this work, a new strategy is proposed to enhance the electrochemical performance by anchoring ultrafine MnFe2O4 and MnCO3 (~5 nm) on amorphous carbon-coated carbon nanotubes. Benefiting from the unique structure, the electrode displays excellent cyclability with a reversible specific capacity of 1012mAh g -1 at 0.1A g -1 after 100 cycles and outstanding rate performance accompanied by a high specific capacity of 568mAh g -1 at 5A g -1 as anode for lithium batteries. When evaluated as supercapacitors, the electrode delivers the specific capacitance of 588.9 F g -1 at a current density of 1A g -1 and maintains the capacitance retention 94.7% after 4000 cycles at 5A g -1.

Mass transfer and reaction process of the wet desulfurization reactor with falling film by cross-flow scrubbing

Juncong Sai,Shaohua Wu,Rui Xu,Rui Sun,Yan Zhao,Yukun Qin 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.3

the present study, a series of wet flue gas desulfurization experiments have been carried out in com-parison with diferent slurry feeding ways, i.e., by series connection and by parallel connection, by means of cross-flow scrubbing with faling film. The experiment results show that there is optimal desulfurization performance forfer by cross-flow scrubbing model have been developed. The pH values of the outlet slurry inside the reactor and theion concentration distributions of H2SO3, HSO3 and SO32 along the axial direction of the tubes were obtained by an-alyzing and calculating the models. The calculation values agree well with the experimental values. It shows that themodels can predict well the ion concentration distributions along the axial direction of the tubes.

A Concise Design for Irradiating U-10Zr Metallic Fuel at Very Low Burnup

Haibing Guo,Wei Zhou,Yong Sun,Dazhi Qian,Jimin Ma,Jun Leng,Heyong Huo,Shaohua Wang 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.4

In order to investigate the swelling behavior and fuelecladding interaction mechanism ofUe10Zr alloy metallic fuel at very low burnup, an irradiation experiment was conciselydesigned and conducted on the China Mianyang Research Reactor. Two types of irradiationsamples were designed for studying free swelling without restraint and the fuelecladdinginteraction mechanism. A new bonding material, namely, pure aluminum powder, wasused to fill the gap between the fuel slug and sample shell for reducing thermal resistanceand allowing the expansion of the fuel slug. In this paper, the concise irradiation rig designis introduced, and the neutronic and thermalehydraulic analyses, which were carried outmainly using MCNP (Monte Carlo N-Particle) and FLUENT codes, are presented. Out-of-piletests were conducted prior to irradiation to verify the manufacturing quality and hydraulicperformance of the rig. Nondestructive postirradiation examinations using cold neutronradiography technology were conducted to check fuel cladding integrity and swellingbehavior. The results of the preliminary examinations confirmed the safety and effectivenessof the design.

Comparative genomic and functional analysis of Akkermansia muciniphila and closely related species

Juyuan Xing,Xiaobo Li,Yingjiao Sun,Juanjuan Zhao,Shaohua Miao,Qin Xiong,Yonggang Zhang,Guishan Zhang 한국유전학회 2019 Genes & Genomics Vol.41 No.11

Background Akkermansia muciniphila is an important bacterium that resides on the mucus layer of the intestinal tract. Akkermansia muciniphila has a high abundance in human feces and plays an important role in human health. Objective In this article, 23 whole genome sequences of the Akkermansia genus were comparatively studied. Methods Phylogenetic trees were constructed with three methods: All amino acid sequences of each strain were used to construct the first phylogenetic tree using the web server of Composition Vector Tree Version 3. The matrix of Genome-to- Genome Distances which were obtained from GGDC 2.0 was used to construct the second phylogenetic tree using FastME. The concatenated single-copy core gene-based phylogenetic tree was generated through MEGA. The single-copy genes were obtained using OrthoMCL. Population structure was assessed by STRU CTU RE 2.3.4 using the SNPs in core genes. PROKKA and Roary were used to do pan-genome analyses. The biosynthetic gene clusters were predicted using antiSMASH 4.0. IalandViewer 4 was used to detect the genomic islands. Results The results of comparative genomic analysis revealed that: (1) The 23 Akkermansia strains formed 4 clades in phylogenetic trees. The A. muciniphila strains isolated from different geographic regions and ecological niches, formed a closely related clade. (2) The 23 Akkermansia strains were divided into 4 species based on digital DNA-DNA hybridization (dDDH) values. (3) Pan-genome of A. muciniphila is in an open state and increases with addition of new sequenced genomes. (4) SNPs were not evenly distributed throughout the A. muciniphila genomes. The genes in regions with high SNP density are related to metabolism and cell wall/membrane envelope biogenesis. (5) The thermostable outer-membrane protein, Amuc_1100, was conserved in the Akkermansia genus, except for Akkermansia glycaniphila PytT. Conclusion Overall, applying comparative genomic and pan-genomic analyses, we classified and illuminated the phylogenetic relationship of the 23 Akkermansia strains. Insights of the evolutionary, population structure, gene clusters and genome islands of Akkermansia provided more information about the possible physiological and probiotic mechanisms of the Akkermansia strains, and gave some instructions for the in-depth researches about the use of Akkermansia as a gut probiotic in the future.

Complete Genome Sequencing of Bacillus velezensis WRN014, and Comparison with Genome Sequences of other Bacillus velezensis Strains

( Junru Wang ),( Juyuan Xing ),( Jiangkun Lu ),( Yingjiao Sun ),( Juanjuan Zhao ),( Shaohua Miao ),( Qin Xiong ),( Yonggang Zhang ),( Guishan Zhang ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.5

Bacillus velezensis strain WRN014 was isolated from banana fields in Hainan, China. Bacillus velezensis is an important member of the plant growth-promoting rhizobacteria (PGPR) which can enhance plant growth and control soil-borne disease. The complete genome of Bacillus velezensis WRN014 was sequenced by combining Illumina Hiseq 2500 system and Pacific Biosciences SMRT high-throughput sequencing technologies. Then, the genome of Bacillus velezensis WRN014, together with 45 other completed genome sequences of the Bacillus velezensis strains, were comparatively studied. The genome of Bacillus velezensis WRN014 was 4,063,541bp in length and contained 4,062 coding sequences, 9 genomic islands and 13 gene clusters. The results of comparative genomic analysis provide evidence that (i) The 46 Bacillus velezensis strains formed 2 obviously closely related clades in phylogenetic trees. (ii) The pangenome in this study is open and is increasing with the addition of new sequenced genomes. (iii) Analysis of single nucleotide polymorphisms (SNPs) revealed local diversification of the 46 Bacillus velezensis genomes. Surprisingly, SNPs were not evenly distributed throughout the whole genome. (iv) Analysis of gene clusters revealed that rich gene clusters spread over Bacillus velezensis strains and some gene clusters are conserved in different strains. This study reveals that the strain WRN014 and other Bacillus velezensis strains have potential to be used as PGPR and biopesticide.