Topology, Modeling and Transient Current Transfer Analysis of DC Hybrid Vacuum Circuit Breaker Based on SiC Module

Jiang Wentao,Liu Xiaoming,Chen Hai,Li Peiyuan,Zhang Yaqian 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

A topology and main parameters based on the SiC Modules are analyzed for a 1140 V/630 A/1 kA direct current (DC) hybrid vacuum circuit breaker. The current transfer characteristic has great signifi cance for avoiding the contact ablation and realizing arcless breaking. In this paper, the model of the DC hybrid vacuum circuit breaker is established by using the combination of Mayr arc model and the arc parameters obtained from the experiment. And the infl uence of arcless breaking conditions and diff erent external circuit parasitic parameters is analyzed. Simulation results show that the transient transfer time can be controlled within 1 ms using the SiC Modules. There exists a contradictory relationship between arcless commutation capability and arc voltage. The transient characteristics of the arc voltage and current will be aff ected by stray inductance. And it is necessary to minimize the stray inductance in the circuitry.

A Deep Investigation of the Thermal Decomposition Process of Supported Silver Catalysts

Jiang, Jun,Xu, Tianhao,Li, Yaping,Lei, Xiaodong,Zhang, Hui,Evans, D.G.,Sun, Xiaoming,Duan, Xue Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.6

A deep understanding of the metallic silver catalysts formation process on oxide support and the formation mechanism is of great scientific and practical meaning for exploring better catalyst preparing procedures. Herein the thermal decomposition process of supported silver catalyst with silver oxalate as the silver precursor in the presence of ethylenediamine and ethanolamine is carefully investigated by employing a variety of characterization techniques including thermal analysis, in situ diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, and X-ray diffraction. The formation mechanism of supported silver particles was revealed. Results showed that formation of metallic silver begins at about $100^{\circ}C$ and activation process is essentially complete below $145^{\circ}C$. Formation of silver was accompanied by decomposition of oxalate group and removal of organic amines. Catalytic performance tests using the epoxidation of ethylene as a probe reaction showed that rapid activation (for 5 minutes) at a relatively low temperature ($170^{\circ}C$) afforded materials with optimum catalytic performance, since higher activation temperatures and/or longer activation times resulted in sintering of the silver particles.

Electrochemical properties of stacked-nanoflake Li4Ti5O12 spinel synthesized by a polymer-pyrolysis method

Xiaoming Zhu,Xiaoyu Jiang,Haiyan Lu,Xinping Ai,Hanxi Yang,Yuliang Cao 한국물리학회 2014 Current Applied Physics Vol.14 No.4

Stacked-nanoflake Li4Ti5O12 spinel was synthesized via the pyrolysis of a LieTi copolymeric precursor formed by in situ polymerization of LiOH and [Ti(OC4H9)4] and acrylic acid. XRD and SEM characterization shows that the powders calcined at 700 C for 3 h was well-crystallized particles with submicron diameter. Chargeedischarge measurement showed the Li4Ti5O12 electrode had displayed excellent rate capability and delivered reversible capacity of 171, 158, 148, 138 and 99 mAh g1 at rates of 0.1C, 0.5C, 1C, 2C and 4C, respectively. The test electrode also showed excellent cyclability as the capacity retains 96.1% after 60 cycles between 0.5 and 2.5 V.

Acetate attenuates inflammasome activation through GPR43-mediated Ca2+-dependent NLRP3 ubiquitination

Xiaoming Deng,Zhengyu Jiang,Changli Wang,Na Li,Lulong Bo,Yanping Zha,Jinjun Bian,Yan Zhang,Mengda Xu 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Acetate has been indicated to be elevated and to regulate inflammation in inflammatory and metabolic diseases. The inflammasome serves as a key component of immune homeostasis, and its dysregulation can lead to various inflammatory disorders. However, little is known about the effects of acetate on inflammasome activation and the underlying mechanism. Here, we demonstrate that acetate attenuates inflammasome activation via GPR43 in a Ca2+-dependent manner. Through binding to GPR43, acetate activates the Gq/11 subunit and subsequent phospholipase C-IP3 signaling to decrease Ca2+ mobilization. In addition, acetate activates soluble adenylyl cyclase (sAC), promotes NLRP3 inflammasome ubiquitination by PKA, and ultimately induces NLRP3 degradation through autophagy. In vivo, acetate protects mice from NLRP3 inflammasome-dependent peritonitis and LPS-induced endotoxemia. Collectively, our research demonstrates that acetate regulates the NLRP3 inflammasome via GPR43 and Ca2+-dependent mechanisms, which reveals the mechanism of metabolite-mediated NLRP3 inflammasome attenuation and highlights acetate as a possible therapeutic strategy for NLRP3 inflammasome-related diseases.

Nanophase ZnV2O4 as stable and high capacity Li insertion electrode for Li-ion battery

Xiaoming Zhu,Xiaoyu Jiang,Lifen Xiao,Xinping Ai,Hanxi Yang,Yuliang Cao 한국물리학회 2015 Current Applied Physics Vol.15 No.4

Spinel ZnV2O4 nanoparticles are synthesized by a hydrothermal method and its properties are characterized using XRD, SEM, TEM, and electrochemical test. The structural and morphological characterizations show that ZnV2O4 sample has high purity and well crystallization with crystal size less than 20 nm. The as prepared electrode shows stable capacity over 660 mAh g-1 in the voltage range of 0.01-3.0 V at 50 mA g-1. The reaction mechanism with lithium ion is also investigated through ex-XRD and -TEM. It shows that the pristine ZnV2O4 is transformed to isostructural spinel LixV2O4 (x close to 7.6) and metal Zn phase during the first lithiation process. Then the spinel LixV2O4 seems to perform a topotactic intercalation reaction mechanism and that the in-situ formed LixV2O4 can still keep its spinel matrix while allowing more than 5.7 lithium reversibly into/out over 50 cycles.

L-arginine and N-carbamoylglutamic acid supplementation enhance young rabbit growth and immunity by regulating intestinal microbial community

Sun, Xiaoming,Shen, Jinglin,Liu, Chang,Li, Sheng,Peng, Yanxia,Chen, Chengzhen,Yuan, Bao,Gao, Yan,Meng, Xianmei,Jiang, Hao,Zhang, Jiabao Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.1

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

A Deep Investigation of the Thermal Decomposition Process of Supported Silver Catalysts

Jun Jiang,Tianhao Xu,Yaping Li,Xiaodong Lei,Hui Zhang,D. G. Evans,Xiaoming Sun,Xue Duan 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.6

A deep understanding of the metallic silver catalysts formation process on oxide support and the formation mechanism is of great scientific and practical meaning for exploring better catalyst preparing procedures. Herein the thermal decomposition process of supported silver catalyst with silver oxalate as the silver precursor in the presence of ethylenediamine and ethanolamine is carefully investigated by employing a variety of characterization techniques including thermal analysis, in situ diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, and X-ray diffraction. The formation mechanism of supported silver particles was revealed. Results showed that formation of metallic silver begins at about 100 oC and activation process is essentially complete below 145 oC. Formation of silver was accompanied by decomposition of oxalate group and removal of organic amines. Catalytic performance tests using the epoxidation of ethylene as a probe reaction showed that rapid activation (for 5 minutes) at a relatively low temperature (170 oC) afforded materials with optimum catalytic performance, since higher activation temperatures and/or longer activation times resulted in sintering of the silver particles.

Calendar anomaly in China emerging market using stochastic domenance analysis

Gao Xiaoming,Xia Weili,Jiang Jijiao 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

With stochastic dominance approach, this paper gives empirical analysis for calendar anomalies in China stock market using Shanghai Stock Composite lndex during 1993 and 2008. Compared with other methods used in previous literatures, stochastic dominance avoids biased conclusion resulted from non-normality in return distribution. Our study shows that there exists a day-of-the-week effect, with the highest return of Friday and the lowest of Monday; and within-month effect with significant higher returns for the first week in a month than other three weeks. In addition, we find February effect instead of January exists in China stock market.

Transcriptome analysis in different chieh‑qua cultivars provides new insights into drought‑stress response

Min Wang,Xiaoming He,Biao Jiang,Wenrui Liu,Yu’e Lin,Dasen Xie,Zhaojun Liang,Lihui Chen,Qingwu Peng 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.6

Drought, one of the crucial environmental constraints, seriously threats the quality and yield in chieh-qua. Therefore, cultivat-ing drought-tolerant variety is greatly necessary for its normal growth under water deficiency. However, at present, molecular knowledge on drought resistance is mostly unclear in chieh-qua. In the study, characteristics of two diverse genetic chieh-qua variety, A39 (drought-resistance) and H5 (drought-sensitivity), were analyzed. Under drought stress, H5 exerted high water loss rate, increased malonaldehyde (MDA) content, and decreased enzyme activity of glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD) compared with A39. In addition, based on the transcriptome results, we obtained a total of 1821 (511 up-regulated and 1310 down-regulated) and 2114 (1282 up-regulated and 832 down- regulated) differentially expressed genes (DEGs) in the A39 versus H5 under normal and water-deficiency stress, respectively. Several DEGs involved in the cuticle synthesis (cytochrome P450 genes: CYP94A2, CYP86B1, CYP86A7), carbohydrate metabolism, and plant hormone signal transduction (small auxin-up RNA genes: SAUR32, SAUR72; JA-induced genes: TIFY 10A, TIFY 10C; ABA related genes: PYL2, PYL4) were explored and related to drought resistance. These expression patterns observed in the RNA-seq data were further confirmed with quantitative real-time PCR (qRT-PCR). In all, these results not only provided a new insight into analyzing genes of drought response, but also laid a foundation for isolating crucial genes involved in drought stress in chieh-qua.

Catalytic Ozonation of Phenol in Aqueous Solution by Co₃O₄ Nanoparticles

Dong, Yuming,Wang, Guangli,Jiang, Pingping,Zhang, Aimin,Yue, Lin,Zhang, Xiaoming Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.10

The degradation efficiencies of phenol in aqueous solution were studied by semi-continuous experiments in the processes of ozone alone, ozone/bulky $Co_3O_4$ and ozone/$Co_3O_4$ nanoparticles. Catalyst samples (bulky $Co_3O_4$ and $Co_3O_4$ nanoparticles) were characterized by X-ray diffraction and transmission electron microscopy. The Brunauer-Emmett-Teller surface area, $pH_{pzc}$ and the density of surface hydroxyl groups of the two catalyst samples were also measured. The catalytic activity of $Co_3O_4$ nanoparticles was investigated for the removal of phenol in aqueous solutions under different reaction temperatures. Tert-butyl alcohol had little effect on the catalytic ozonation processes. Based on these results, the possible catalytic ozonation mechanism of phenol by $Co_3O_4$ nanoparticles was proposed as a reaction process between ozone molecules and pollutants.