Dislocation Density-Based Constitutive Model and Processing Map for T2 Copper During Isothermal and Time-Variant Deformation

Gang Chen,Yu Jin,Jing Wang,Cheng Zhang,Qiang Chen,Hongming Zhang,Xingjian Zhao,Zhiyong Li,Changhai Xie,Zhiming Du 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

Isothermal compression tests were carried out to study the hot deformation behavior of T2 copper under various conditions. The deformation parameters, such as temperature and strain rate, have strong influence on flow stress and microstructureevolution of the alloy. A unified dislocation density-based model considering dynamic recovery and recrystallization wasestablished. And material parameters of the developed model were optimized by genetic algorithm. Comparisons betweenthe experimental and model data demonstrates that the developed model can precisely describe the flow behavior at quitewide range of deformation conditions. Meanwhile, the designed iterative procedure allows the model to be applied in timevariantdeformation conditions. Processing map and microstructure examination were constructed to optimize the processingwindow of the studied alloy. According to the processing maps, flow instability mainly appeared at low temperatures of500–650 °C and strain rates higher than 0.1 s−1. The optimum deformation parameters of T2 copper was concluded as thetemperature range of 700–800 °C and the strain rate of 0.1–1 s−1.

혈관외피종 -1증례 보고-

강유미,지미경,양기화,강석진,김병기,김선무,정수일 대한병리학회 1990 Journal of Pathology and Translational Medicine Vol.25 No.5

혈관외피종 -1증례 보고-

강유미,지미경,양기화,강석진,김병기,김선무,정수일 대한병리학회 1990 Journal of Pathology and Translational Medicine Vol.24 No.2

임용 후보자 선정 경쟁시험에 대한 초등 특수교사의 인식 및 개선 요구

정평강,김유리 이화여자대학교 교과교육연구소 2017 교과교육학연구 Vol.21 No.4

본 연구의 목적은 초등 특수교사를 선발하는 임용시험에 대한 초등 특수교사의 인식 및 요구를 알아보고, 이를 토대로 초등 특수교사 임용제도가 역량 있는 특수교사를 선발하는 타당한 절차로 정착되는 데 필요한 기초 자료를 제공하는 데 있다. 이를 위해 임용시험을 통해 국·공립학교에 배치되어 근무하고 있는 초등 특수교사 9명을 대상으로 개별 심층면담을 실시하였으며, 면담자료는 연속적 비교분석법을 이용하여 분석되었다. 분석 결과 임용시험의 타당성, 개선요구라는 대주제 2개가 도출되었으며 대주제별로 하위주제 3개씩 총 6개의 하위주제가 드러났다. 연구결과를 바탕으로 초등 특수교사 임용시험을 개선하기 위한 시사점이 논의되었으며, 이와 함께 후속연구를 위한 제언이 제시되었다. 초등 특수교사의 관점에서 바라본 초등 임용시험에 대한 더 깊은 이해는 앞으로 임용시험 문항의 내용이나 절차, 제도를 개선하는 데 중요한 기초 자료를 제공할 것으로 사료된다 The purpose of the present study was to explore the perceptions of elementary special education teachers on the national teacher exam. In-depth interviews were conducted with each of the 9 elementary special teachers and the interview data were analyzed using the constant comparative method. Two main themes and 6 sub-themes emerged from the data analysis. Based on the findings, practical implications on how to improve the national teacher exam are discussed and future areas for research are suggested. A better understanding of the teacher exam based on perspectives of elementary special teachers seems to provide essential basic information that assists the improvement of its process and systems.

Multi-Mode Semantic Cues Based on Hidden Conditional Random Field in Soccer Video

Yu Wang,Yu Cao,Miao Wang,Gang Liu 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.10

A new framework based on multi- modal semantic clues and HCRF (Hidden Conditional Random Field) for soccer wonderful event detection. Through analysis of the structural semantics of the wonderful event videos, define nine kinds of multi- modal semantic clues to accurately describe the included semantic information of the wonderful events. After splitting the video clips into several physical shots, extract the multi- modal semantic clues from the key frame of each shot to get the feature vector of the current shots, and compose the observed sequence of the feature vectors of all shots in the test video clips. Using the above observed sequence as HCRF model input in the case of small-scale training samples, establish wonderful event detection HCRF model effectively. Experiments show that the average recall of this paper reaches 95.3%, the average precision rate reaches 96%, the performance of this paper is obviously superior to the contrast method.

A Shared Channel Design for the Power and Signal Transfers of Electric-field Coupled Power Transfer Systems

Yu-Gang Su,Wei Zhou,Aiguo Patrick Hu,Chun-Sen Tang,Rong Hua 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

Electric-field coupled power transfer (ECPT) systems have been proposed as an alternative wireless power transfer (WPT) technology in recent years. With the use of capacitive plates as a coupling structure, ECPT systems have many advantages such as design flexibility, reduced volume of the coupling structure and metal penetration ability. In addition, wireless communications are effective solutions to improve the safety and controllability of ECPT systems. This paper proposes a power and signal shared channel for electric-field coupled power transfer systems. The shared channel includes two similar electrical circuits with a band pass filter and a signal detection resistor in each. This is designed based on the traditional current-fed push-pull topology. An analysis of the mutual interference between the power and signal transmission, the channel power and signal attenuations, and the dynamic characteristic of the signal channel are conducted to determine the values for the electrical components of the proposed shared channel. Experimental results show that the designed channel can transfer over 100W of output power and data with a data rate from 300bps to 120 kbps.

Characterization, Cloning, and Heterologous Expression of a Subtilisin-Like Serine Protease Gene VlPr1 from Verticillium lecanii

Gang Yu,Jin-Liang Liu,Li-Qin Xie,Xue-Liang Wang,Shi-Hong Zhang,Hong-Yu Pan 한국미생물학회 2012 The journal of microbiology Vol.50 No.6

The entomopathogenic fungus Verticillium lecanii is a wellknown biocontrol agent. V. lecanii produces subtilisin-like serine protease (Pr1), which is important in the biological control activity of some insect pests by degrading insect cuticles. In this study, a subtilisin-like serine protease gene VlPr1 was cloned from the fungus and the VlPr1 protein was expressed in Escherichia coli. The VlPr1 gene contains an open reading frame (ORF) interrupted by three short introns, and encodes a protein of 379 amino acids. Protein sequence analysis revealed high homology with subtilisin serine proteases. The molecular mass of the protease was 38 kDa, and the serine protease exhibited its maximal activity at 40°C and pH 9.0. Protease activity was also affected by Mg2+ and Ca2+ concentration. The protease showed inhibitory activity against several plant pathogens, especially towards Fusarium moniliforme.

Study on an Optimal Control Method for Energy Injection Resonant AC/AC High Frequency Converters

Yu-Gang Su,Xin Dai,Zhi-Hui Wang,Chun-Sen Tang,Yue Sun 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

In energy injection resonant AC-AC converters, due to the low frequency effect of the AC input envelope and the low energy injection losses requirement, the constant and steady control of the high frequency AC output envelope is still a problem that has not been solved very well. With the aid of system modeling, this paper analyzes the mechanism of the envelope pit on the resonant AC current. The computing methods for the critical damping point, the falling time and the bottom value of the envelope pit are presented as well. Furthermore, this paper concludes the stability precondition of the system AC output. Accordingly, an optimal control method for the AC output envelope is put forward based on the envelope prediction model. This control method can predict system responses dynamically under different series of control decisions. In addition, this control method can select best series of control decisions to make the AC output envelope stable and constant. Simulation and experimental results for a contactless power transfer system verify the control method.

The Blood Oxygenation T2* Values of Resectable Esophageal Squamous Cell Carcinomas as Measured by 3T Magnetic Resonance Imaging: Association with Tumor Stage

Yu-lian Tang,Xiao-ming Zhang,Zhi-gang Yang,Yu-cheng Huang,Tian-wu Chen,Yan-li Chen,Fan Chen,Nan-lin Zeng,Rui Li,Jiani Hu 대한영상의학회 2017 Korean Journal of Radiology Vol.18 No.4

Objective: To explore the association between the blood oxygenation T2* values of resectable esophageal squamous cell carcinomas (ESCCs) and tumor stages. Materials and Methods: This study included 48 ESCC patients and 20 healthy participants who had undergone esophageal T2*-weighted imaging to obtain T2* values of the tumors and normal esophagi. ESCC patients underwent surgical resections less than one week after imaging. Statistical analyses were performed to identify the association between T2* values of ESCCs and tumor stages. Results: One-way ANOVA and Student-Newman-Keuls tests revealed that the T2* value could differentiate stage T1 ESCCs (17.7 ± 3.3 ms) from stage T2 and T3 tumors (24.6 ± 2.7 ms and 27.8 ± 5.6 ms, respectively; all ps < 0.001). Receiver operating curve (ROC) analysis showed the suitable cutoff T2* value of 21.3 ms for either differentiation. The former statistical tests demonstrated that the T2* value could not differentiate between stages T2 and T3 (24.6 ± 2.7 ms vs. 27.8 ± 5.6 ms, respectively, p > 0.05) or between N stages (N1 vs. N2 vs. N3: 24.7 ± 6.9 ms vs. 25.4 ± 4.5 ms vs. 26.8 ± 3.9 ms, respectively; all ps > 0.05). The former tests illustrated that the T2* value could differentiate anatomic stages I and II (18.8 ± 4.8 ms and 26.9 ± 5.9 ms, respectively) or stages I and III (27.3 ± 3.6 ms). ROC analysis depicted the same cutoff T2* value of 21.3 ms for either differentiation. In addition, the Student’s t test revealed that the T2* value could determine grouped T stages (T0 vs. T1–3: 17.0 ± 2.9 ms vs. 25.2 ± 6.2 ms; T0–1 vs. T2–3: 17.3 ± 3.0 ms vs. 27.1 ± 5.3 ms; and T0–2 vs. T3: 18.8 ± 4.2 ms vs. 27.8 ± 5.6 ms, all ps < 0.001). ROC analysis indicated that the T2* value could detect ESCCs (cutoff, 20 ms), and discriminate between stages T0–1 and T2–3 (cutoff, 21.3 ms) and between T0–2 and T3 (cutoff, 20.4 ms). Conclusion: The T2* value can be an additional quantitative indicator for detecting ESCC except for stage T1 cancer, and can preoperatively discriminate between some T stages and between anatomic stages of this tumor.

Inhibition of RIPK1-dependent regulated acinar cell necrosis provides protection against acute pancreatitis via the RIPK1/NF- κB/AQP8 pathway

Gang Wang,Peng-yu Duan,Yuan Ma,Xi-na Li,Feng-zhi Qu,Liang Ji,Xiao-yu Guo,Wang-jun Zhang,Fan Xiao,Le Li,Ji-sheng Hu,Bei Sun 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

Currently, preliminary results have confirmed the existence of receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL)-dependent necroptosis of pancreatic acinar cells during early acute pancreatitis (AP), which might be a potential target for the effective regulation of necroinflammatory injury. However, the exact effect of receptor-interacting protein kinase 1 (RIPK1)-dependent regulated acinar cell necrosis on AP is still uncertain. In our study, we first explored the changes in the degree of local and systemic inflammation in AP rats when the activation of acinar cell RIPK1 was inhibited. The RIPK1 inhibitor Nec-1 was used to treat rats, and the levels of related inflammatory markers, necrosis indicators and apoptotic indicators were measured. Changes in pancreatic nuclear factor κB (NF-κB) and aquaporin 8 (AQP8) expression were noted. Next, the expression of AQP8 in AR42J cells was inhibited, and the degree of cell necrosis and inflammatory damage was found to be significantly reduced. Most importantly, we demonstrated that the RIPK1/NF-ĸB/AQP8 axis might be a potential regulatory pathway mediating RIPK1-dependent regulated acinar cell necrosis in early AP. Finally, we used the NF-κB inhibitor PDTC and Nec-1 to treat rats in different groups and measured the degree of pathological pancreatic injury, the activation of RIPK1, and the expression of NF-κB and AQP8. In summary, we hypothesized that there might be a RIPK1/NF-ĸB/AQP8 pathway controlling RIPK1-dependent regulated necrosis of acinar cells in AP, which might be a promising therapeutic target against AP-related injury.