Analytical and Experimental Validation of Parasitic Components Influence in SiC MOSFET Three-Phase Grid-connected Inverter

Liu, Yitao,Song, Zhendong,Yin, Shan,Peng, Jianchun,Jiang, Hui The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

With the development of renewable energy, grid-connected inverter technology has become an important research area. When compared with traditional silicon IGBT power devices, the silicon carbide (SiC) MOSFET shows obvious advantages in terms of its high-power density, low power loss and high-efficiency power supply system. It is suggested that this technology is highly suitable for three-phase AC motors, renewable energy vehicles, aerospace and military power supplies, etc. This paper focuses on the SiC MOSFET behaviors that concern the parasitic component influence throughout the whole working process, which is based on a three-phase grid-connected inverter. A high-speed model of power switch devices is built and theoretically analyzed. Then the power loss is determined through experimental validation.

Compressive behavior of circular hollow and concrete-filled steel tubular stub columns under atmospheric corrosion

Shan Gao,Zhen Peng,Xuanding Wang,Jiepeng Liu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.33 No.4

This paper aims to study the compressive behavior of circular hollow and concrete-filled steel tubular stub columns under simulated marine atmospheric corrosion. The specimens after salt spray corrosion were tested under axial compressive load. Steel grade and corrosion level were mainly considered in the study. The mechanical behavior of circular CFST specimens is compared with that of the corresponding hollow ones. Design methods for circular hollow and concrete-filled steel tubular stub columns are modified to consider the effect of marine atmospheric corrosion. The results show that linear fitting curves could be used to present the relationship between corrosion rate and the mechanical properties of steel after simulated marine atmospheric corrosion. The ultimate strength of hollow steel tubular and CFST columns decrease with the increase of corrosion rate while the ultimate displacement of those are hardly affected by corrosion rate. Increasing corrosion rate would change the failure of CFST stub column from ductile failure to brittle failure. Corrosion rate would decrease the ductility indexes of CFST columns, rather than those of hollow steel tubular columns. The confinement factor <i>ξ</i> of CFST columns decreases with the increase of corrosion rate while the ratio between test value and nominal value shows an opposite trend. With considering marine atmospheric corrosion, the predicted axial strength of hollow steel tubular and CFST columns by Chinese standard agree well with the tested values while the predictions by Japanese standard seem conservative.

Applicability research of round tube CHF mechanistic model in rod bundle channel

Liu, Wei,Peng, Shinian,Shan, Jianqiang,Jiang, Guangming,Liu, Yu,Deng, Jian,Hu, Ying Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.2

In view of the complex geometric structure of the rod bundle channel and the limitation of the current CHF visualization experiment technology, it is very difficult to obtain the rod bundle CHF mechanism directly through the phenomenon of the rod bundle CHF visualization experiment. In order to obtain the applicable CHF mechanism assumption for rod bundle channel, firstly, five most representative DNB type round tube CHF mechanistic models are obtained with evaluation and screening. Then these original round tube CHF mechanistic models based on inlet conditions are converted to local conditions and coupled with subchannel analysis code ATHAS. Based on 5 × 5 full-length rod bundle CHF experimental data independently developed by Nuclear Power Institute of China (NPIC), the applicability research of each model for CHF prediction performance in rod bundle channel is carried out, and the commonness and difference of each model are comparatively studied. The CHF mechanism assumption of superheated liquid layer depletion that is most likely to be applicable for the rod bundle channel is selected and two directions that need to be improved are given. This study provides a reference for the development of CHF mechanistic model in rod bundle channel.

Propagation characteristics of longitudinal wave, shear wave and bending wave in porous circular nanoplates

Wubin Shan,Zulu Deng,Hao Zhong,Hu Mo,Ziqiang Han,Zhi Yang,Chengyu Xiang,Shuzhou Li,Peng Liu 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.4

On the basis of nonlocal strain gradient theory, considering the material properties of porous FGM changing with thickness and the influence of moment of inertia, the wave equation of FG nano circular plate is derived by using the first-order shear deformation plate theory, by introducing dimensionless parameters, we transform the equations into dimensionless wave equations, and the dispersion relations of bending wave, shear wave and longitudinal wave are obtained by Laplace and Hankel integral transformation method. The influence of nonlocal parameter, porosity volume fraction, strain gradient parameters and power law index on the propagation characteristics of bending wave, shear wave and longitudinal wave in FG nano circular plate.

Analytical and Experimental Validation of Parasitic Components Influence in SiC MOSFET Three-Phase Grid-connected Inverter

Yitao Liu,Zhendong Song,Shan Yin,Jianchun Peng,Hui Jiang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

With the development of renewable energy, grid-connected inverter technology has become an important research area. When compared with traditional silicon IGBT power devices, the silicon carbide (SiC) MOSFET shows obvious advantages in terms of its high-power density, low power loss and high-efficiency power supply system. It is suggested that this technology is highly suitable for three-phase AC motors, renewable energy vehicles, aerospace and military power supplies, etc. This paper focuses on the SiC MOSFET behaviors that concern the parasitic component influence throughout the whole working process, which is based on a three-phase grid-connected inverter. A high-speed model of power switch devices is built and theoretically analyzed. Then the power loss is determined through experimental validation.

Prevalence and Age, Gender and Geographical Area Distribution of Esophageal Squamous Cell Carcinomas in North China from 1985 to 2006

Feng, Xiao-Shan,Yang, Yan-Tong,Gao, She-Gan,Ru, Yi,Wang, Gong-Ping,Zhou, Bo,Wang, Yu-Feng,Zhang, Peng-Fei,Li, Pu-Yu,Liu, Yong-Xuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.5

Objective: To establish the prevalence and distribution profile of esophageal squamous cell carcinomas (ESCCs) over a 22-yr period in North China. Methods: Using endoscopy for primary diagnosis and histological analysis for the further confirmation, a total of 74,854 ESCC patients aged 20-89 between January 1985 and December 2006 were investigated to analyze the epidemiological profile including prevalence rates, distribution of age-of-onset, gender and geographical area of ESCC in Luoyang, the highest incidence area of North China. Results: A total of 4092 cases of ESCC were finally diagnosed among 74,854 patients who had their first endoscopies. The prevalence among males was higher than that among females (p<0.01), resulting in an overall male:female OR of 1.2 (95%CI, 1.2-1.3). The prevalence in rural areas was higher than in urban areas (p<0.01), resulting in an overall rural:urban OR of 2.6 (95%CI, 2.4-2.9). The rural:urban ORs and the 95% CI increased continuously from 2.6, 2.3-3.0 to 2.7, 2.2-3.3, respectively, for 4 consecutive periods during the 22-yr study period. Moreover, the median age of onset among females was higher than that among males (p<0.01). For both sexes and in both areas, the prevalence rates declined and the median age of onset rose for 4 consecutive periods in the 22-yrs time frame (p<0.01). Conculsions: These data reveal the epidemiological profile of ESCC in the area of North China, and suggest that urban areas and rural people account for a growing proportion of the ESCC patients although the prevalence of ESCC significantly declined and the median age-of-onset postponed over the 22-yrs period. Moreover, the prevalence status of ESCC in rural areas also underlines the need for public health initiatives aimed at reducing risk factors of this fatal disease.

An intelligent hybrid methodology of on-line system-level fault diagnosis for nuclear power plant

Min-jun Peng,Hang Wang,Shan-shan Chen,Genglei Xia,Yong-kuo Liu,Xu Yang,Abiodun Ayodeji 한국원자력학회 2018 Nuclear Engineering and Technology Vol.50 No.3

To assist operators to properly assess the current situation of the plant, accurate fault diagnosis methodologyshould be available and used. A reliable fault diagnosis method is beneficial for the safety ofnuclear power plants. The major idea proposed in this work is integrating the merits of different faultdiagnosis methodologies to offset their obvious disadvantages and enhance the accuracy and credibilityof on-line fault diagnosis. This methodology uses the principle component analysis-based model andmulti-flow model to diagnose fault type. To ensure the accuracy of results from the multi-flow model, amechanical simulation model is implemented to do the quantitative calculation. More significantly,mechanism simulation is implemented to provide training data with fault signatures. Furthermore, oneof the distance formulas in similarity measurementdMahalanobis distancedis applied for on-line failuredegree evaluation. The performance of this methodology was evaluated by applying it to the reactorcoolant system of a pressurized water reactor. The results of simulation analysis show the effectivenessand accuracy of this methodology, leading to better confidence of it being integrated as a part of thecomputerized operator support system to assist operators in decision-making.

Elevated TRAF4 expression impaired LPS-induced autophagy in mesenchymal stem cells from ankylosing spondylitis patients

Jinteng Li,Peng Wang,Zhongyu Xie,Rui Yang,Yuxi Li,Xiaohua Wu,Hongjun Su,Wen Deng,Shan Wang,Zhenhua Liu,Shuizhong Cen,Yi Ouyang,Yanfeng Wu,Huiyong Shen 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Ankylosing spondylitis (AS) is a type of autoimmune disease that predominantly affects the spine and sacroiliac joints. However, the pathogenesis of AS remains unclear. Some evidence indicates that infection with bacteria, especially Gram-negative bacteria, may have an important role in the onset and progression of AS. Recently, many studies have demonstrated that mesenchymal stem cells (MSCs) dysfunction may contribute to the pathogenesis of many rheumatic diseases. We previously demonstrated that MSCs from AS patients exhibited markedly enhanced osteogenic differentiation capacity in vitro under non-inflammatory conditions. However, the properties of MSCs from AS patients in an inflammatory environment have never been explored. Lipopolysaccharide (LPS), a proinflammatory substance derived from the outer membrane of Gram-negative bacteria, can alter the status and function of MSCs. However, whether MSCs from AS patients exhibit abnormal responses to LPS stimulation has not been reported. Autophagy is a lysosome-mediated catabolic process that participates in many physiological and pathological processes. The link between autophagy and AS remains largely unknown. The level of autophagy in ASMSCs after LPS stimulation remains to be addressed. In this study, we demonstrated that although the basal level of autophagy did not differ between MSCs from healthy donors (HDMSCs) and ASMSCs, LPS-induced autophagy was weaker in ASMSCs than in HDMSCs. Specifically, increased TRAF4 expression in ASMSCs impaired LPS-induced autophagy, potentially by inhibiting the phosphorylation of Beclin-1. These data may provide further insight into ASMSC dysfunction and the precise mechanism underlying the pathogenesis of AS.

Influence of internal pores and graphene platelets on vibration of non-uniform functionally graded columns

Wen-qi Liu,Shan-jun Liu,Ming-yu Fan,Wei Tian,Ji-peng Wang,Vahid Tahouneh 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.35 No.2

This paper deals with free vibration analysis of non-uniform column resting on elastic foundations and subjected to follower force at its free end. The internal pores and graphene platelets (GPLs) are distributed in the matrix according to different patterns. The model is proposed with material parameters varying in the thickness of column to achieve graded distributions in both porosity and nanofillers. The elastic modulus of the nanocomposite is obtained by using Halpin-Tsai micromechanics model. The differential quadrature method as an efficient and accurate numerical approach is used to discretize the governing equations and to implement the boundary conditions. It is observed that the maximum vibration frequency obtained in the case of symmetric porosity and GPL distribution, while the minimum vibration frequency is obtained using uniform porosity distribution. Results show that for better understanding of mechanical behavior of nanocomposite column, it is crucial to consider porosities inside the material structure.

Positive Association Between IL-16 rs11556218 T/G Polymorphism and Cancer Risk: a Meta-analysis

Mo, Cui-Ju,Peng, Qi-Liu,He, Yu,Wang, Jian,Xie, Li,Li, Tai-Jie,Li, Shan,Qin, Xue Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11

Background: Interleukin-16 (IL-16) is a multifunctional cytokine which plays a key role in inflammatory and autoimmune diseases as well as in cancer. Genetic polymorphisms of IL-16 have been implicated in susceptibility to cancer. However, associations remain inconclusive. The present meta-analysis was therefore carried out to establish a more conclusive association of IL-16 polymorphisms with cancer risk. Materials and Methods: Relevant studies were searched through the PubMed, Embase, Web of Science, Google Scholar and Wan fang electronic databases updated in October 2013. Odds ratios (OR) and 95% confidence intervals (95% CI) were used to assess the association between IL-16 polymorphisms and cancer risk. Results: Eight eligible studies (rs4778889 T/C: 8, rs11556218 T/G: 7, rs4072111 C/T: 6) that met our selection criteria were included. The meta-analysis indicated that rs11556218 T/G was associated with a significant increased risk of cancer (G vs. T, OR=1.321, 95% CI=1.142-1.528, P<0.001; TG vs. TT, OR=1.665, 95% CI=1.448-1.915, P<0.001; GG+TG vs. TT, OR=1.622, 95% CI=1.416-1.858, P<0.001),as well as nasopharyngeal carcinoma and colorectal cancer. Furthermore, in the subgroup of Chinese, significant associations were found between rs11556218 polymorphism and cancer risk. There was no statistically significant association between the other two variants (rs4778889, rs4072111) and risk of cancer. Conclusions: This meta-analysis suggests that the IL-16 rs11556218 polymorphism is associated with increased cancer risk. Large well-designed studies involving various cancer types and different populations are now needed.