Current Controlled with Valley Voltage Detection Three-port Converter with Current-Pulsed Load

Zeyu. Zhu,Ping. Yang,Chaorui Liu,Songrong Wu,Wensheng Song,Jianping Xu,Xiaohui Qu 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In small power supply systems such as aircraft and ships, some loads present the characteristics of current pulse. After the pulse load is directly connected to the power supply bus, the instantaneous power of its load presents the pulse characteristic as the load current. In order to balance the difference of instantaneous power, this paper proposes a bi-directional converter to compensate for the current fluctuation caused by the pulse load characteristic, which makes the power supply bus in the state of constant voltage and constant current, and solves the problem of adaptability of pulse load and power supply. In the meanwhile, a current feedback control method with valley voltage loop is proposed to control the bi-directional converter, which is also applicable when there is any change in frequency or duty cycle of the pulse load, even the constant power load. Finally, an experimental prototype is built to verify the correctness of the theoretical analysis.

Seismic behavior of energy dissipation shear wall with CFST column elements

Hao Su,Lihua Zhu,Yaohong Wang,Lei Feng,Zeyu Gao,Yuchen Guo,Longfei Meng,Hanquan Yuan 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.43 No.1

To develop high-efficiency lateral force resistance components for high-rise buildings, a novel energy dissipation shear wall with concrete-filled steel tubular (CFST) column elements was proposed. An energy dissipation shear wall specimen with CFST column elements (GZSW) and an ordinary reinforced concrete shear wall (SW) were constructed, and experimented by low-cycle reversed loading. The mechanical characteristics of these two specimens, including the bearing capacity, ductility, energy dissipation, and stiffness degradation process, were analyzed. The finite-element model of the GZSW was established by ABAQUS. Based on this finite-element model, the effect of the placement of steel-plate energy dissipation connectors on the seismic performance of the shear wall was analyzed, and optimization was performed. The experiment results prove that, the GZSW exhibited a superior seismic performance in terms of bearing capacity, ductility, energy dissipation, and stiffness degradation, in comparison with the SW. The results calculated by the ABAQUS finite-elements model of GZSW corresponded well with the results of experiment, and it proved the rationality of the established finite-elements model. In addition, the optimal placement of the steel-plate energy dissipation connectors was obtained by ABAQUS.

Simulation of large biomass pellets in fluidized bed by DEM-CFD

Zhaoping Zhong,Lingli Zhu,Heng Wang,Zeyu Wang 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.10

An improved numerical model was proposed to solve the problem that the traditional DEM-CFD (Discrete element method-computational fluid dynamics) method was not suitable for the flow simulation of large particles. In the improved model, the large particle was regarded as an agglomerate of many small fictitious spheres. Herein, the drag force between gas and large pellets was assumed as a combined effect of that between gas and fictitious spheres by volume penalty method. Based on the proposed model, the flow of the mixtures of large biomass pellets and quartz sands in fluidized bed was simulated. It shows that the existence of the biomass pellets has a great impact on the flow field. The flow patterns and pressure drops under different working conditions in simulation results have a good agreement with that in experimental results partially, which also tests the proposed model.

Excessive Startle with Novel GLRA1 Mutations in 4 Chinese Patients and a Literature Review of GLRA1-Related Hyperekplexia

Feixia Zhan,Chao Zhang,Shige Wang,Zeyu Zhu,Guang-Chen Jiao,Mingliang Zhao,Li Cao 대한신경과학회 2020 Journal of Clinical Neurology Vol.16 No.2

Background and Purpose Hyperekplexia (HPX), a rare neurogenetic disorder, is classically characterized by neonatal hypertonia, exaggerated startle response provoked by the sudden external stimuli and followed by a shortly general stiffness. Glycine receptor alpha 1 (GLRA1) is the major pathogenic gene of the disease. We described the clinical manifestations of genetically confirmed HPX patients and made a literature review of GLRA1-related HPX to improve the early recognition and prompt the management of the disorder. Methods Extensive clinical evaluations were analyzed in 4 Chinese HPX patients from two unrelated families. Next generation sequencing was conducted in the probands. Sanger sequence and segregation analysis were applied to confirm the findings. Results All four patients including 3 males and 1 female presented with excessive startle reflex, a cautious gait and recurrent falls. Moreover, startle episodes were dramatically improved with the treatment of clonazepam in all cases. Exome sequencing revealed 2 homozygous GLRA1 mutations in the patients. The mutation c.1286T>A p.I429N has been previously reported, while c.754delC p.L252* is novel. Conclusions HPX is a treatable disease, and clonazepam is the drug of choice. By studying and reviewing the disorder, we summarized the phenotype, expanded the genotype spectrum, and discussed the possible pathogenic mechanisms to enhance the understanding and recognition of the disease. Early awareness of the disease is crucial to the prompt and proper administration, as well as the genetic counseling.

Decreased vitamin D-binding protein level portends poor outcome in acute-on-chronic liver failure caused by hepatitis B virus

Daxian Wu,Qunfang Rao,Zhongyang Xie,Xiaoqing Zhu,Jian Wu,Hainv Gao,Jingyu Zhang,Zhouhua Hou,Xiaoyu Cheng,Zeyu Sun 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.4

Background/Aims: Acute-on-chronic liver failure (ACLF) is a catastrophic illness. Few studies investigated the prognostic value of vitamin D-binding protein (VDBP) for hepatitis B virus (HBV)-related ACLF (HBV-ACLF) resulted in conflicting results. Methods: Two prospective HBV-ACLF cohorts (n=287 and n=119) were enrolled to assess and validate the prognostic performance of VDBP. Results: VDBP levels in the non-survivors were significantly lower than in the survivors (P<0.001). Multivariate Cox regression demonstrated that VDBP was an independent prognostic factor for HBV-ACLF. The VDBP level at admission gradually decreased as the number of failed organs increased (P<0.001), and it was closely related to coagulation failure. The areas under the receiver operating characteristic curve (AUCs) of the Child-Pugh-VDBP and chronic liver failuresequential organ failure assessment (CLIF–SOFA)-VDBP scores were significantly higher than those of Child-Pugh (P<0.001) and CLIF-SOFA (P=0.0013). The AUCs of model for end-stage liver disease (MELD)-VDBP were significantly higher than those of MELD (P= 0.0384) only in the case of cirrhotic HBV-ACLF patients. Similar results were validated using an external multicenter HBV-ACLF cohort. By longitudinal observation, the VDBP levels gradually increased in survivors (P=0.026) and gradually decreased in non-survivors (P<0.001). Additionally, the VDBP levels were found to be significantly decreased in the deterioration group (P=0.012) and tended to be decreased in the fluctuation group (P=0.055). In contrast, they showed a significant increase in the improvement group (P=0.036). Conclusions: The VDBP was a promising prognostic biomarker for HBV-ACLF. Sequential measurement of circulating VDBP shows value for the monitoring of ACLF progression.

Low-noise reconstruction method for coded-aperture gamma camera based on multi-layer perceptron

Rui Zhang,Xiaobin Tang,Pin Gong,Peng Wang,Cheng zhou,Xiaoxiang Zhu,Dajian Liang,Zeyu Wang 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.10

Accurate localization of radioactive materials is crucial in homeland security and radiological emergencies. Coded-aperture gamma camera is an interesting solution for such applications and can be developed into portable real-time imaging devices. However, traditional reconstruction methods cannot effectively deal with signal-independent noise, thereby hindering low-noise real-time imaging. In this study, a novel reconstruction method with excellent noise-suppression capability based on a multi-layer perceptron (MLP) is proposed. A coded-aperture gamma camera based on pixel detector and coded-aperture mask was constructed, and the process of radioactive source imaging was simulated. Results showed that the MLP method performs better in noise suppression than the traditional correlation analysis method. When the Co-57 source with an activity of 1 MBq was at 289 different positions within the field of view which correspond to 289 different pixels in the reconstructed image, the average contrast-to-noise ratio (CNR) obtained by the MLP method was 21.82, whereas that obtained by the correlation analysis method was 5.85. The variance in CNR of the MLP method is larger than that of correlation analysis, which means the MLP method has some instability in certain conditions.

MiR-200c-3p aggravates gastric cell carcinoma via KLF6

Wang Ying,Lu Kaijuan,Li Weibing,Wang Zhigang,Ding Jing,Zhu Zeyu,Li Zhipeng 한국유전학회 2021 Genes & Genomics Vol.43 No.11

Background Gastric cell carcinoma (GCC) is a common and high-incidence malignant gastrointestinal cancer that seriously threatens human life and safety. Evidences suggest that microRNAs (miRNAs) exhibit an essential role in regulating the occurrence and development of GCC, while the efects and possible mechanisms remain to be further explored. Objective This study was designed to explore whether miR-200c-3p exerted its functional role in the growth and metastasis of GCC, and investigate the possible mechanisms. Methods The expression levels of miR-200c-3p in GCC tissues and cell lines were detected by qRT-PCR analysis. The functional role of miR-200c-3p in the viability, proliferation, migration and invasion of GCC cells were evaluated by CCK-8, EdU, wound healing and Transwell assays. In addition, the candidate targets of miR-200c-3p was predicted and confrmed by dual-luciferase reporter assay. Moreover, the relationship between miR-200c-3p and target (Krüppel like factor 6, KLF6) was assessed by qRT-PCR and western blot assays. Besides, the expression levels of KLF6 in GCC cells were determined by qRT-PCR and western blot assays. Furthermore, the role of KLF6 in the viability, proliferation, migration and invasion of GCC cells mediated with miR-200c-3p mimics was evaluated by CCK-8, EdU, wound healing and Transwell assays. Results In the present study, a new tumor promoting function of miR-200c-3p was disclosed in GCC. We found that the expression of miR-200c-3p was obviously increased in clinic GCC tissues and cell lines. In addition, down-regulation of miR-200c-3p suppressed cell viability, proliferation, migration, and invasion in GCC cells. Moreover, KLF6 was verifed as a direct target of miR-200c-3p by binding its 3’-UTR. Additionally, KLF6 was remarkably decreased and was negatively associated with the miR-200c-3p expression in GCC cell lines. Furthermore, over-expression of KLF6 retarded the efects of miR-200c-3p on the growth and metastasis of GCC cell lines. Conclusions MiR-200c-3p potentially played a tumor-promoting role in the occurrence and development of GCC, which may be achieved by targeting KLF6.