Electrical current induced mechanism in microstructure and nano-indention of Al–Zn–Mg–Cu (AZMC) Al alloy thin film

Fei-Yi Hung,Jiunn-Der Liao,Truan-Sheng Lui,Li-Hui Chen 한국물리학회 2011 Current Applied Physics Vol.11 No.6

In this study, the microstructural variation and nano-indention of Al-5.7Zn-2.4Mg-1.5Cu (AZMC) thin film was investigated using DC electrical current at a density of 1000 A/cm^2. The results show that microstructural changes due to the electrical current involved both the solid solubility effect and enhanced diffusion. The electrical current drove the Al atoms and Cu atoms of the matrix from the cathode to the anode. After electrical current testing, precipitation phases (Al_2Cu; CuMgAl_2) had decomposed into the cathode matrix and MgZn phases had grown in the anode zones. Meanwhile, the current also caused the hardness of the thin film to decrease and affected both the texture and dynamic strain mechanism of nano-indention.

Trans-Membrane Transport of n-Octadecane by Pseudomonas sp. DG17

Fei Hua,Hong Qi Wang,Yi Li,Yi Cun Zhao 한국미생물학회 2013 The journal of microbiology Vol.51 No.6

The trans-membrane transport of hydrocarbons is an important and complex aspect of the process of biodegradation of hydrocarbons by microorganisms. The mechanism of transport of 14C n-octadecane by Pseudomonas sp. DG17,an alkane-degrading bacterium, was studied by the addition of ATP inhibitors and different substrate concentrations. When the concentration of n-octadecane was higher than 4.54 μmol/L, the transport of 14C n-octadecane was driven by a facilitated passive mechanism following the intra/extra substrate concentration gradient. However, when the cells were grown with a low concentration of the substrate, the cellular accumulation of n-octadecane, an energy-dependent process, was dramatically decreased by the presence of ATP inhibitors, and n-octadecane accumulation continually increased against its concentration gradient. Furthermore, the presence of non-labeled alkanes blocked 14C n-octadecane transport only in the induced cells, and the trans-membrane transport of n-octadecane was specific with an apparent dissociation constant Kt of 11.27 μmol/L and Vmax of 0.96μmol/min/mg protein. The results indicated that the transmembrane transport of n-octadecane by Pseudomonas sp. DG17 was related to the substrate concentration and ATP.

AN INTELLIGENT TOOL KIT FOR EMBEDDED SAFETY-CRITICAL SOFTWARE AUTOMATIC TESTING

Yi-fei MAO,Jin-hui YANG 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

The safety-critical software (SCS) is often directly related to the safety of the people's lives and wealth; it has to undergo safety testing strictly. The fault injection approach can generate testing cases to find dangerous prone defects quickly by running the SCS under a faulty environment. A fault injection tool kit for SCS is developed to implement fault injection to enhance the safety testing ability of the existing method. The tool kit generates test cases for safety testing according to an operational profile automatically and provides a script language as interface. When this tool kit applied in the testing of interlocking software, a typical class of SCS, the level of testing automation as well as testing efficiency is improved.

Prevalence and Risk Factors of Cerebral Small Vessel Disease in a Chinese Population-Based Sample

Fei Han,Fei-Fei Zhai,Quan Wang,Li-Xin Zhou,Jun Ni,Ming Yao,Ming-Li Li,Shu-Yang Zhang,Li-Ying Cui,Zheng-Yu Jin,Yi-Cheng Zhu 대한뇌졸중학회 2018 Journal of stroke Vol.20 No.2

Background and Purpose Epidemiological data of cerebral small vessel disease (CSVD) in the general population of China are lacking. We report on the prevalence of lacunes, white matter hyperintensity (WMH), and cerebral microbleeds (CMBs) in a community-based sample in China and compare the results with those of other studies. Methods This was a cross-sectional analysis of the population-based Shunyi Study in China. A total of 1,211 stroke-free participants (mean age, 55.6±9.3 years; 37.4% men) with available 3 Tesla (3T) magnetic resonance images were included in this analysis. Demographic information and risk factor data were assessed. The overall and age-specific prevalence of lacunes, WMH, and CMBs was evaluated. Associations between cardiovascular risk factors and the presence of these lesions were analyzed by multiple logistic regression. Results Our study showed a prevalence of 14.5% for lacunes, 72.1% for periventricular hyperintensity (PVH), 65.4% for deep white matter hyperintensity (DWMH), and 10.6% for CMBs. When compared with other community-based samples, individuals in the same age group showed a higher burden of lacunes and a relatively lower prevalence of CMBs. Advanced age was independently associated with the prevalence of these CSVD markers, while the presence of hypertension increased the risk of lacunes, PVH/DWMH, and CMBs in deep or infratentorial locations. Conclusions A higher burden of lacunes but a relatively lower prevalence of CMBs was observed in this Chinese population. This notable result highlights the challenge of CSVD prevention in China. Chinese have a risk factor profile for CSVD similar to those in other populations.

An Improved Active Damping Method with Capacitor Current Feedback

Yi-Wen Geng,Ya-Wen Qi,Hai-Wei Liu,Fei Guo,Peng-Fei Zheng,Yong-Gang Li,Wen-Ming Dong 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

Proportional capacitor current feedback active damping (CCFAD) has a limited valid damping region in the discrete time domain as (0, fs/6). However, the resonance frequency (fr) of an LCL-type filter is usually designed to be less than half the sampling frequency (fs) with the symmetry regular sampling method. Therefore, (fs/6, fs/2) becomes an invalid damping region. This paper proposes an improved CCFAD method to extend the valid damping region from (0, fs/6) to (0, fs/2), which covers all of the possible resonance frequencies in the design procedure. The full-valid damping region is obtained and the stability margin of the system is analyzed in the discrete time domain with the Nyquist criterion. Results show that the system can operate stably with the proposed CCFAD method when the resonance frequency is in the region (0, fs/2). The performances at the steady and dynamic state are enhanced by the selected feedback coefficient H and controller gain Kp. Finally, the feasibility and effectiveness of the proposed CCFAD method are verified by simulation and experimental results.

Investigation of a Novel IGCT Module for DC Circuit Breaker

Qiang Yi,Yifei Wu,Yi Wu,Fei Yang,Zhihui Zhang,Chong Gao 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

Power semiconductors for DC circuit breaker (DCCB) have attracted great attentions due to their fast and arc-less operation under full-range current-breaking. Since the robustness of Integrated Gate-Commutated Thyristor (IGCT) is the highest among all full-control power semiconductors, it becomes the perfect power semiconductor candidate for DC circuit breaker. In this paper, the principle and operation of hybrid circuit breaker are introduced. Technical analysis of full-control power semiconductor is conducted and IGCT is the best choice for HCB. Then, A novel power semiconductor circuit based on two IGCTs, diode-bridge, snubber-circuit and MOV is proposed and designed both topologically and structurally. The selection of full-control power semiconductor is discussed and fast recover diode must be used to ensure reliability. Furthermore, the internal current distribution is analyzed. Finally, a test of a single-stage IGCT module prototype demonstrates successful current-breaking at over 10kA and below 4kV, which is promising in the area of fault protection in future MVDC distribution system.

Medicinal Chemistry : ARTICLE ; Regulation of T-cell activation and migration by the kinase TBK1 during neuroinflammation

( Jia Yi Yu ),( Xiao Fei Zhou ),( Mi Kyoung Chang ),( Mako Nakaya ),( Jae Hoon Chang ),( Yi Chuan Xiao ),( J. William Lindsey ),( Stephanie Dorta Estremera ),( Wei Cao ),( Anna Zal ),( Tomasz Zal ),( 영남대학교 약품개발연구소 2015 영남대학교 약품개발연구소 연구업적집 Vol.25 No.-

Development of an immune or autoimmune response involves T-cell activation in lymphoid organs and subsequent migration to peripheral tissues. Here we show that T-cell-specific ablation of the kinase TBK1 promotes T-cell activation but causes retention of effector T cells in the draininglumph node in a neuroinflammatory autoimmunity model,experimental autoimmune encephalomyelitis (EAE).Atolder ager,the T-cell-conditional TBK1-knockout mice also spontaneously accumulate T cells with activated phenotype.TBK1 contrlos the activation of AKT and its downsream kinase m TIORC1 by a mechanism involving TBK1-stimulated AKT ubiquitination and degradation. The deregulated AKT-mTORC1 signalling in turn contributes to enhanced T-cell activation and impaired effector T-cell egress from draining lymph nodes. Treatment of mice with a small-molecule inhibitor fo TBK1 inhibits EAE induction. These results suggest a role for TBK1 in regulating T-cell migration and establish TBK1 as a regulator of the AKT-mTORC1 signalling axis.

Exploration of temperature effect on videogrammetric technique for displacement monitoring

Hua-Fei Zhou,Lin-Jun Lu,Zhao-Yi Li,Yi-Qing Ni 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.2

There has been a sustained interest towards the non-contact structural displacement measurement by means of videogrammetric technique. On the way forward, one of the major concerns is the spurious image drift induced by temperature variation. This study therefore carries out an investigation into the temperature effect of videogrammetric technique, focusing on the exploration of the mechanism behind the temperature effect and the elimination of the temperature-caused measurement error. 2D videogrammetric measurement tests under monotonic or cyclic temperature variation are first performed. Features of measurement error and the casual relationship between temperature variation and measurement error are then studied. The variation of the temperature of digital camera is identified as the main cause of measurement error. An excellent linear relationship between them is revealed. After that, camera parameters are extracted from the mapping between world coordinates and pixels coordinates of the calibration targets. The coordinates of principle point and focal lengths show variations well correlated with temperature variation. The measurement error is thought to be an outcome mainly attributed to the variation of the coordinates of principle point. An approach for eliminating temperature-caused measurement error is finally proposed. Correlation models between camera parameters and temperature are formulated. Thereby, camera parameters under different temperature conditions can be predicted and the camera projective matrix can be updated accordingly. By reconstructing the world coordinates with the updated camera projective matrix, the temperature-caused measurement error is eliminated. A satisfactory performance has been achieved by the proposed approach in eliminating the temperature-caused measurement error.

Overexpression and Clinicopathological Contribution of DcR3 in Bladder Urothelial Carcinoma Tissues

Jiang, Yi-Qiang,Zhong, Teng-Fei,Dang, Yi-Wu,Zou, Ling-Song,Yang, Liu,Yang, Xia,Chen, Gang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

Background: To explore the expression of DcR3 protein and its clinicopathological significance in bladder urothelial carcinomas (BUC). Materials and Methods: Immunohistochemistry was performed to detect the expression of DcR3, caspase-3, Bcl-2, VEGF, Ki-67, PCNA and P53 in 166 BUC and 56 normal bladder tissues. Western blotting was used to detect the expression of DcR3 in the supernatants of cultured BUC cells. Results: Overexpression of DcR3 was found in BUC tissues and cell lines, with significant elevation as compared to normal bladder tissues (p<0.0001). Higher DcR3 expression was related to the status of invasion, lymph node metastasis and recurrence. Furthermore, DcR3 expression was negatively correlated with caspase-3 and positively associated with Bcl-2, VEGF, Ki-67 labeling index (LI), PCNA LI and P53 (all p<0.0001), respectively. Conclusions: DcR3 may play a crucial role as an oncogene in tumorigenesis, deterioration and progress of BUC via influencing related pathways of apoptosis, proliferation and angiogenesis. The detection of DcR3 protein in the formalinfixed and paraffin-embedded samples could assist to predict in prognosis of BUC patients.

An Improved Active Damping Method with Capacitor Current Feedback

Geng, Yi-Wen,Qi, Ya-Wen,Liu, Hai-Wei,Guo, Fei,Zheng, Peng-Fei,Li, Yong-Gang,Dong, Wen-Ming The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.2

Proportional capacitor current feedback active damping (CCFAD) has a limited valid damping region in the discrete time domain as (0, $f_s/6$. However, the resonance frequency ($f_r$) of an LCL-type filter is usually designed to be less than half the sampling frequency ($f_s$) with the symmetry regular sampling method. Therefore, ($f_s/6$, $f_s/2$) becomes an invalid damping region. This paper proposes an improved CCFAD method to extend the valid damping region from (0, $f_s/6$ to (0, $f_s/2$), which covers all of the possible resonance frequencies in the design procedure. The full-valid damping region is obtained and the stability margin of the system is analyzed in the discrete time domain with the Nyquist criterion. Results show that the system can operate stably with the proposed CCFAD method when the resonance frequency is in the region (0, $f_s/2$). The performances at the steady and dynamic state are enhanced by the selected feedback coefficient H and controller gain $K_p$. Finally, the feasibility and effectiveness of the proposed CCFAD method are verified by simulation and experimental results.