An Integrated Three-phase Transformer for Partial Parallel Dual Active Bridge Converter

Jiasheng Huang,Zhe Zhang,Yudi Xiao,Bainan Sun,Michael A.E. Andersen 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In this paper, an integrated three-phase transformer is utilized in the partial parallel dual active bridge (PPDAB) converter. Due to the symmetrical structure, the flux generated by the primary windings is equally distributed to the three outer legs. Given the same number of turns of the windings in each parallel modules, the ac currents can inherently balance in the parallel modules. In order to enlarge the leakage inductor to serve as the interfacing ac inductor in the PPDAB converter, the coupling between the primary windings and secondary windings is weakened by placing the primary and secondary windings on the center and outer legs, respectively. Compared to the discrete three-phase transformers, the winding loss will also decrease with the proposed structure. A 1kW 400V/50V 500 kHz prototype with an efficiency of 96.72% is built and tested to verify the theoretical analysis.

Association between STAT4 polymorphisms and risk of primary biliary cholangitis: a meta-analysis

Li Zhang,Chunming Gao,Chuanmiao Liu,Jiasheng Chen,Kuihua Xu 한국유전학회 2018 Genes & Genomics Vol.40 No.10

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease. Several studies reported that SATA4 (signal transducer and activator of transcription 4) polymorphisms were significantly associated with PBC susceptibility. In order to derive a more comprehensive estimation of the association between STAT4 and PBC risk, this meta-analysis was conducted. Thirteen eligible studies from 8 articles with a total number of 11,310 cases and 27,844 controls were included in this meta-analysis. Pooled odds ratios (OR) and 95% confidence intervals (CI) were estimated with fixed effects model or random effects model. The results showed statistically significant association between polymorphisms of rs7574865, rs3024921, rs6752770, rs7601754 and rs10168266 in STAT4 and PBC risk under the allelic effect model (rs7574865, T vs. G, OR = 1.24, 95% CI 1.14–1.35; rs3024921, T vs. A, OR = 1.65, 95% CI 1.44–1.91; rs6752770, G vs. A, OR = 1.24, 95% CI 1.11–1.39; rs7601754, A vs. G, OR = 1.35, 95% CI 1.17–1.55; and rs10168266, T vs. C, OR = 1.31, 95% CI 1.22–1.41). Furthermore, the rs7574865 polymorphism was significantly associated with PBC risk under all genotype genetic models (dominant effect model: TT + TG vs. GG, OR = 1.43, 95% CI 1.19–1.71; recessive effect: TT vs. TG + GG, OR = 1.40, 95% CI 1.24–1.58; and co-dominant effect: TT vs. GG, OR = 1.67, 95% CI 1.37–2.02). The sensitivity analysis by omitting one study at a time showed that the results were stable. No publication bias was indicated from both Begg’s test and Egger’s weighted regression. This meta-analysis suggested that polymorphisms of rs7574865, rs3024921, rs6752770, rs7601754 and rs10168266 in STAT4 were significantly associated with the risk of PBC.

Fabrication of porous Mn₂O₃ microsheet arrays on nickel foam as high–rate electrodes for supercapacitors

Xu, Jiasheng,Sun, Yudong,Lu, Mingjun,Wang, Lin,Zhang, Jie,Qian, Jianhua,Kim, Eui Jung ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.717 No.-

<P><B>Abstract</B></P> <P>Porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays on nickel foam have been prepared by a mild chemical reaction combined with a calcination process. The porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays are directly grown on the surface of the conductive nickel foam. The porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays are composed of numerous interconnected nanopores with an average size of about 16 nm. The specific surface area of the porous Mn<SUB>2</SUB>O<SUB>3</SUB> materials is 36.34 m<SUP>2</SUP> g<SUP>−1</SUP>. The fabricated electrode materials exhibit a high specific capacitance of 566.6 F g<SUP>−1</SUP> at a current density of 0.5 A g<SUP>−1</SUP> and 294.4 F g<SUP>−1</SUP> at a current density of 20 A g<SUP>−1</SUP>. The energy density of the porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet was 19.65 Wh kg<SUP>−1</SUP> at a power density of 124.85 W kg<SUP>−1</SUP> and it was reduced to 10.22 Wh kg<SUP>−1</SUP> at a power of density of 5.00 kW kg<SUP>−1</SUP>. The good electrochemical capacitance is ascribed to the interconnected porous structure of the Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet, which facilitates electrolyte diffusion and enhances electron transport. The porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays on nickel foam are a promising electrode material for supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays on nickel foam are synthesized via solution process followed with an annealing treatment. </LI> <LI> It directly utilizes as electrode materials for pseudocapacitors. </LI> <LI> A specific capacitance of 566.6 F g<SUP>−1</SUP> is achieved at a current density of 0.5 A g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Association between PNPLA3 rs738409 polymorphism and hepatocellular carcinoma risk: an updated meta-analysis

Li Zhang,Chuanmiao Liu,Kuihua Xu,Jiasheng Chen 한국유전학회 2016 Genes & Genomics Vol.38 No.9

Hepatocellular carcinoma (HCC) is a common malignant tumor and the leading cause of cancer-related death worldwide. The protein encoded by patatin-like phospholipase domain-containing protein 3 (PNPLA3) plays important roles in liver fatty metabolism. Recent studies have indicated associations of PNPLA3 rs738409 with various liver diseases, including HCC. This metaanalysis was performed to investigate and update the association between rs738409 polymorphism and the risk of HCC, and to test the association between rs738409 and HCC specifically in patients within chronic hepatitis B and/ or C infection, alcoholic liver disease, or other diseases. Studies were searched from the literature database up to March 31, 2016. The meta-analysis was conducted based on statement of preferred reporting items for systematic reviews and meta-analyses. Pooled odds ratios (OR) and 95 % confidence intervals (CI) were estimated the strength of associations between rs738409 polymorphism and HCC risk. Fifteen published studies, consisting of 2264 HCC patients (case) and 5802 without HCC individuals (control), were included in the present study. Meta-analysis revealed that rs738409 polymorphism contributed to HCC risk under the allelic effect model (C vs. G: OR 1.73; 95 % CI 1.53–1.96), the dominant effect model (CC vs. CG?GG: OR 1.61; 95 % CI 1.44–1.81), and the recessive effect model (CC?CG vs. GG: OR 2.66; 95 % CI 2.28–3.11). Furthermore, the effect of rs738409 G allele on liver oncogenesis was higher in alcoholic liver disease (OR 2.55), compared to chronic hepatitis C/B (OR 1.32) and other diseases (OR 2.27). The results suggested that rs738409 polymorphism was significantly associated with HCC risk and it could be used as one risk factor for HCC.

Facile Synthesis of Small Gold Nanoparticles Stabilized by Carbon Nanospheres for Selective Hydrogenation of 4-Nitrobenzaldehyde

Minghui Liu,Jiasheng Wang,Yingcen Liu,Rongwen Lu,Shufen Zhang 대한화학회 2019 Bulletin of the Korean Chemical Society Vol.40 No.10

We report the facile synthesis of small gold nanoparticles stabilized by carbon nanospheres (Au@C) for highly active and selective hydrogenation of 4-nitrobenzaldehyde. The formation of such a Au@C unique structure can be attributed to the high distribution of Au(III) species in the melamine-formaldehyde resin nanospheres, which were formed via the coordination of Au(III) with the abundant imino groups of melamine-formaldehyde pre-polymer. After the subsequent condensation and confined in situ reduction, small gold nanoparticles, and carbon nanospheres were formed simultaneously. Under the reaction conditions of 80 °C and 1.6 MPa, 99.3% conversion and >99% selectivity were achieved for the hydrogenation of 4-nitrobenzaldehyde to 4-aminobenzaldehyde.

Targeted capture enrichment and sequencing identifies HLA variants associated with the severity of COVID-19

Liu Chuanmiao,Zhang Li,Chen Jiasheng,Gao Yu 한국유전학회 2023 Genes & Genomics Vol.45 No.4

Background Coronavirus disease 2019 (COVID-19) is currently a global pandemic. The pathogenesis of severe COVID-19 has been widely investigated, but it is still unclear. Human leukocyte antigen (HLA) plays a central role in immune response, and its variants might be related to COVID-19 progression and severity. Objective To investigate the hypothesis that individual HLA variations could alter the course of COVID-19 and might be associated with the severity of COVID-19. Methods In this study, we conducted an HLA targeted capture enrichment and sequencing of severe COVID-19 patients matched to mild cases. A total of 16 COVID-19 patients, confirmed by SARS-CoV-2 viral RNA polymerase-chain-reaction (PCR) test and chest computed tomography (CT) scan, were enrolled in this study. The HLA targeted capture enrichment and sequencing were conducted. HLA typing was performed by comparing contigs with IPD-IMGT/HLA Database. Results In this study, 139 four-digit resolution HLA alleles were acquired. The results showed that HLA-DRB3*01:01 allele was significantly associated with the severity of COVID-19 (odds ratio [OR] = 27.64, 95% confidence interval [CI] = 1.35–560.50, P = 0.0064). And HLA-K*01:01 might be a potential risk factor for COVID-19 severity (OR = 0.11, 95% CI = 0.017–0.66, P = 0.019), but HLA-K*01:02 might be a protective factor (OR = 7.50, 95% CI = 1.48–37.92, P = 0.019). Conclusion Three non-classical HLA alleles, including HLA-DRB3*01:01, HLA-K*01:01, HLA-K*01:02 were identified to be associated with the severity of COVID-19 by comparing mild and severe patients. The current findings would be helpful for exploring the influence of HLA gene polymorphisms on the development and severity of COVID-19.

A New Modeling and Analysis Approach Based on State-Space Averaging for Converters

Zhenchuan Sun,Jiasheng Zhang 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.10

4-quadrant converters (4QCs) have been widely applied in power active VAR and harmonic compensators, FACTS, electric drive systems, and a variety of other applications. The state-space averaging model is usually quite facile and suitable for converter topologies with only two switch states, like half-bridge 4QC units. When directly used in topologies with multiple switch states, however, the modeling method becomes overly complicated. Due to this, plus the fact that multi-phase PWM 4QCs and even other varieties of converters are mostly multi-unit-symmetrical, a novel method is necessary. By researching the inner link between multi-phase topologies and half-bridge units, including inter-phase symmetry configurations, and control relations, this paper proposes a general unified modeling approach for application to multi-phase 4QCs. A series of conclusions are derived, alongside theoretical analysis of the model. The validity of the model and its theory is confirmed using single-phase and three-phase 4QCs and their numerical simulating waveforms as special cases. The proposed method may also extend to the modeling, analysis, and general research of other varieties of converter topologies.

Finite-Time Nonlinear Disturbance Observer Based Discretized Integral Sliding Mode Control for PMSM Drives

Zheng, Changming,Zhang, Jiasheng The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4

To deal with the operation performance degradation of permanent magnet synchronous machine (PMSM) drives with uncertainties and unmodeled dynamics, this paper presents a finite-time nonlinear disturbance observer (FTNDO) based discretized integral sliding mode (DISM) composite control scheme. Based on the reaching-law approach, a DISM speed controller featuring a superior dynamic quality and global robustness against disturbances is constructed. This controller can avoid the reaching phase and overlarge control action. In addition, a sliding mode differentiator based FTNDO is devised and extended to the discrete-time domain for disturbance estimation. The attractive features of the FTNDO are that it can provide a finite-time converging estimation and alleviate the chattering effect in conventional sliding mode observers, while retaining robustness to parameter variations. By feeding the estimate forward to the pre-stage DISM controller, both disturbances and chattering can be significantly suppressed. Moreover, considering the estimation error of a FTNDO caused by discrete sampling, a stability analysis of the composite controller is discussed. Experimental results validate the superiority of the presented scheme.

In situ fabrication dynamic carbon fabrics membrane with tunable wettability for selective oil–water separation

Xuejie Yue,Tao Zhang,Dongya Yang,Fengxian Qiu,Yao zhu,Jiasheng Fang 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.61 No.-

Achieving reversible wetting properties of separation membrane for on-demand separate oil/water mixture remains challenging, especially for the oil/water mixtures with complex impurities. Herein, hierarchical porous dynamic separation membranes involving primary fiber membrane and secondary nanostructures are fabricated by in situ growth ZnO nanowires on the surface of carbon fibers. Based on the effect of oxygen-related defects of ZnO nanowires coating, the as-fabricated dynamic separation membrane is capable of switching wetting property between high-hydrophobicity and superhydrophilicity via simply annealing alternatively under vacuum and air environment, achieving the switching between oil-removing mode and water-removing mode according to the type of oil/water mixtures. Moreover, the dynamic separation membrane can be extended to separate the oil/water mixtures containing suspended solids using the reconstruction of ZnO dynamic coating. Through removing the ZnO dynamic coating via soaking the clogged membrane in the hydrochloric acid–ethanol and refabricating the ZnO-dynamic coating, the membrane blocked by impurities could be readily re-formed, which effectively expand its scope of application and enhance its anti-fouling property. This work not only provides a simple and on-demand solution for pure oily wastewater, but also extends the separation membrane to separate oil/water mixtures containing suspended solids.

Finite-Time Nonlinear Disturbance Observer Based Discretized Integral Sliding Mode Control for PMSM Drives

Chang-Ming Zheng,Jiasheng Zhang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.4

To deal with the operation performance degradation of permanent magnet synchronous machine (PMSM) drives with uncertainties and unmodeled dynamics, this paper presents a finite-time nonlinear disturbance observer (FTNDO) based discretized integral sliding mode (DISM) composite control scheme. Based on the reaching-law approach, a DISM speed controller featuring a superior dynamic quality and global robustness against disturbances is constructed. This controller can avoid the reaching phase and overlarge control action. In addition, a sliding mode differentiator based FTNDO is devised and extended to the discrete-time domain for disturbance estimation. The attractive features of the FTNDO are that it can provide a finite-time converging estimation and alleviate the chattering effect in conventional sliding mode observers, while retaining robustness to parameter variations. By feeding the estimate forward to the pre-stage DISM controller, both disturbances and chattering can be significantly suppressed. Moreover, considering the estimation error of a FTNDO caused by discrete sampling, a stability analysis of the composite controller is discussed. Experimental results validate the superiority of the presented scheme.