CHARACTERIZING THE TIME-FREQUENCY PROPERTIES OF THE 4 Hz QUASI-PERIODIC OSCILLATION AROUND THE BLACK HOLE X-ray BINARY XTE J1550-564

SU, YI-HAO,CHOU, YI,HU, CHIN-PING,YANG, TING-CHANG,HSIEH, HUNG-EN,CHUANG, PO-SHENG,LIN, CHING-PING,LIAO, NAI-HUI The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

We present the results from analysis of the Hilbert-Huang transform (HHT) for the 4 Hz quasi-periodic oscillations (QPO) around the black hole X-ray binary XTE J1550-564. The resultant Hilbert spectra demonstrate that the QPO is composed of a series of intermittent signals appearing occasionally. From the analysis of the HHT, we further found the distribution of the lifetimes for the intermittent oscillations and the distribution for the time intervals with no significant signal (the break time). The mean lifetime is 1.45 s and 90% of the oscillation segments have lifetimes less than 3.1 s whereas the mean break time is 0.42 s and 90% of break times are less than 0.73 s. We conclude that the intermittent feature of the QPO could be explained by the Lense-Thirring precession model and rules out interpretations of continual frequency modulation.

Wave propagation in spherical and cylindrical panels reinforced with carbon nanotubes

Yi-Wen Zhang,Hao-Xuan Ding,Gui-Lin She 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.1

Based on the third-order shear deformation theory, the wave propagations in doubly curved spherical- and cylindrical- panels reinforced by carbon nanotubes (CNTs) are firstly investigated in present work. The coupled equations of wave propagation for the carbon nanotubes reinforced composite (CNTRC) doubly curved panels are established. Then, combined with the harmonic balance method, the eigenvalue technique is adopted to simulate the velocity-wave number curves of the CNTRC doubly curved panels. In the end, numerical results are showed to discuss the effects of the impact of key parameters including the volume fraction, different shell types (including spherical (R1=R2=R) and cylindrical (R1=R, R2=→∞)), wave number as well as modal number on the sensitivity of elastic waves propagating in CNTRC doubly curved shells.

Multiple damage detection of maglev rail joints using time-frequency spectrogram and convolutional neural network

Yi-Qing Ni,Su-Mei Wang,Gao-Feng Jiang,Yang Lu,Guobin Lin,Hong-Liang Pan,Junqi Xu,Shuo Hao 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.4

Maglev rail joints are vital components serving as connections between the adjacent F-type rail sections in maglev guideway. Damage to maglev rail joints such as bolt looseness may result in rough suspension gap fluctuation, failure of suspension control, and even sudden clash between the electromagnets and F-type rail. The condition monitoring of maglev rail joints is therefore highly desirable to maintain safe operation of maglev. In this connection, an online damage detection approach based on three-dimensional (3D) convolutional neural network (CNN) and time-frequency characterization is developed for simultaneous detection of multiple damage of maglev rail joints in this paper. The training and testing data used for condition evaluation of maglev rail joints consist of two months of acceleration recordings, which were acquired in-situ from different rail joints by an integrated online monitoring system during a maglev train running on a test line. Short-time Fourier transform (STFT) method is applied to transform the raw monitoring data into time-frequency spectrograms (TFS). Three CNN architectures, i.e., small-sized CNN (S-CNN), middle-sized CNN (M-CNN), and large-sized CNN (L-CNN), are configured for trial calculation and the M-CNN model with excellent prediction accuracy and high computational efficiency is finally optioned for multiple damage detection of maglev rail joints. Results show that the rail joints in three different conditions (bolt-loosenesscaused rail step, misalignment-caused lateral dislocation, and normal condition) are successfully identified by the proposed approach, even when using data collected from rail joints from which no data were used in the CNN training. The capability of the proposed method is further examined by using the data collected after the loosed bolts have been replaced. In addition, by comparison with the results of CNN using frequency spectrum and traditional neural network using TFS, the proposed TFSCNN framework is proven more accurate and robust for multiple damage detection of maglev rail joints.

Inhibition of Transient Receptor Potential Melastain 7 Enhances Apoptosis Induced by TRAIL in PC-3 cells

Lin, Chang-Ming,Ma, Ji-Min,Zhang, Li,Hao, Zong-Yao,Zhou, Jun,Zhou, Zhen-Yu,Shi, Hao-Qiang,Zhang, Yi-Fei,Shao, En-Ming,Liang, Chao-Zhao Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

Transient receptor potential melastain 7 (TRPM7) is a bifunctional protein with dual structure of both ion channel and protein kinase, participating in a wide variety of diseases including cancer. Recent researches have reported the mechanism of TRPM7 in human cancers. However, the correlation between TRPM7 and prostate cancer (PCa) has not been well studied. The objective of this study was to investigate the potential the role of TRPM7 in the apoptosis of PC-3 cells, which is the key cell of advanced metastatic PCa. In this study, we demonstrated the influence and potential function of TRPM7 on the PC-3 cells apoptosis induced by TNF-related apoptosis inducing-ligand (TRAIL). The study also found a novel up-regulated expression of TRPM7 in PC-3 cells after treating with TRAIL. Suppression of TRPM7 by TRPM7 non-specific inhibitors ($Gd^{3+}$ or 2-aminoethoxy diphenylborate (2-APB) ) not only markedly eliminated TRPM7 expression level, but also increased the apoptosis of TRAIL-treated PC-3 cells, which may be regulated by the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway accompany with up-regulated expression of cleaved Caspase-3, (TRAIL-receptor 1, death receptors 4) DR4, and (TRAIL-receptor 2, death receptors 5) DR5. Taken together, our findings strongly suggested that TRPM7 was involved in the apoptosis of PC-3 cells induced by TRAIL, indicating that TRPM7 may be applied as a therapeutic target for PCa.

Characteristics of InGaP/InGaAs pseudomophic field-effect transistors with modulated InGaAs doping channels

Yi-Ting CHAO,Pao-Sheng LIN,Syuan-Hao LIOU,Jung-Hui TSAI 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Online condition assessment of high-speed trains based on Bayesian forecasting approach and time series analysis

Zhang, Lin-Hao,Wang, You-Wu,Ni, Yi-Qing,Lai, Siu-Kai Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.5

High-speed rail (HSR) has been in operation and development in many countries worldwide. The explosive growth of HSR has posed great challenges for operation safety and ride comfort. Among various technological demands on high-speed trains, vibration is an inevitable problem caused by rail/wheel imperfections, vehicle dynamics, and aerodynamic instability. Ride comfort is a key factor in evaluating the operational performance of high-speed trains. In this study, online monitoring data have been acquired from an in-service high-speed train for condition assessment. The measured dynamic response signals at the floor level of a train cabin are processed by the Sperling operator, in which the ride comfort index sequence is used to identify the train's operation condition. In addition, a novel technique that incorporates salient features of Bayesian inference and time series analysis is proposed for outlier detection and change detection. The Bayesian forecasting approach enables the prediction of conditional probabilities. By integrating the Bayesian forecasting approach with time series analysis, one-step forecasting probability density functions (PDFs) can be obtained before proceeding to the next observation. The change detection is conducted by comparing the current model and the alternative model (whose mean value is shifted by a prescribed offset) to determine which one can well fit the actual observation. When the comparison results indicate that the alternative model performs better, then a potential change is detected. If the current observation is a potential outlier or change, Bayes factor and cumulative Bayes factor are derived for further identification. A significant change, if identified, implies that there is a great alteration in the train operation performance due to defects. In this study, two illustrative cases are provided to demonstrate the performance of the proposed method for condition assessment of high-speed trains.

Influence of Water Molecules on Polarization Behavior and Time–Frequency Dielectric Properties of Cellulose Insulation

Wen Hao,Cheng Lin,Jiang Yi,Zhu Taiyun,Chen Zhong,Dai Xize,Gao Chenyu 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

Oil-immersed power transformer plays an important role in power transmission and transformation engineering. Moisture is one of the important factors to determine its insulation performance. Molecular simulation technique is used to study the mechanism of water molecules on the micro polarization behavior of cellulose insulation materials. The number of hydrogen bonds, solubility parameters, total dipole moment and polarizability are analyzed. These characteristics explain the action mechanism of water molecules on cellulose insulation. At the same time, the time domain and frequency dielectric response of cellulose insulation materials with diff erent moisture content are explored. The dielectric modulus spectrum is introduced to replace the traditional frequency dielectric spectroscopy to characterize the micro relaxation process of cellulose insulation under diff erent moisture content. Finally, the characteristic parameters are extracted from the polarization, depolarization current and dielectric modulus spectrum curves to evaluate the moisture content of cellulose insulation materials. The results show that the number of hydrogen bonds, binding energy density, solubility parameter, total dipole moment and polarizability increase with the increase of water content. It should be noted that dielectric modulus spectroscopy can eff ectively characterize the relaxation behavior of cellulose insulation materials. The moisture content of cellulose insulation can be quantitatively evaluated by DC conductivity, insulation resistance, imaginary part relaxation peak of dielectric modulus and integral value of real part and imaginary part of dielectric modulus.

Wave propagation in a FG circular plate via the physical neutral surface concept

Gui-Lin She,Hao-Xuan Ding,Yi-Wen Zhang 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.2

In this paper, the physical neutral surface concept is applied to study the wave propagation of functionally graded (FG) circular plate, the wave equation is derived by Hamiltonian variational principle and the first-order shear deformation plate model. Then, we convert the equations to dimensionless equations. The exact solution of wave propagation problem is obtained by Laplace integral transformation, the first order Hankel integral transformation and the zero order Hankel integral transformation. The results obtained by the current model are very close to those obtained in the existing literature, which indicates the correctness and reliability of this study. Moreover, the effects of the functionally graded index parameters and pore volume fraction on the wave propagation are also discussed in detail.

Implication of hydrolysis on vanadium precipitation with acidic ammonium salt from high concentration of alkaline vanadium solution

Jiang Lin,He Wenyi,Du Guangchao,Zheng Hao,Peng Yi 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.10

Vanadium precipitation with acidic ammonium salt is widely applied in industrial practice of vanadium pentoxide production. However, the ammonia wastewater produced in the precipitation process and resultant environmental issues have been paid increasing attention. With the intention of reducing wastewater and extra cost, an enhancement in the vanadium content of basic qualified solution is the most directly effective method. Unfortunately, high vanadium concentration brings about a low precipitation rate and a high Na content in ammonium polyvanadate, as a result of hydrolysis existence in the precipitation process. The effect of hydrolytic vanadium reaction on acidic ammonium salt precipitation has rarely been reported. Therefore, the whole precipitation process, including the effect of pH value, reaction temperature and vanadium concentration on precipitation result were clarified by analyzing the thermodynamic form of vanadate radicals in this work. Simultaneously, a study on technological parameters was inquired based on the theoretical analysis. The phase composition and crystal morphology of precipitates were also inspected using XRD and SEM-EDS. The results show the negative reaction of vanadium hydrolysis cannot be eliminated in the process of vanadium precipitation with acidic ammonia salt. When vanadium content is higher than 35g/L, Na in APV is easy to exceed 0.6%. Na mainly precipitates in V2O5·H2O in the formation of amorphous body or chemical absorption. The results in this work provide a fundamental guide for the application of high concentration vanadium precipitation technology.

Regulatory Role of SFN Gene in Hepatocellular Carcinoma and Its Mechanism

Ying Hui,Hao Zeng,Yi Feng,Wenzhou Qin,Peisheng Chen,Lifang Huang,Wenfu Zhong,Liwen Lin,Hui Lv,Xue Qin 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.3

Purpose: This study aims to explore the differential expression of SFN gene and its regulatory role in different hepatocarcinoma cells, and the impact on hepatocarcinoma. Materials and Methods: High and low SFN expression cells were screened by qRT-PCR and western blotting methods. SFN over expression and interference vectors were constructed. Cell viability was detected by CCK8 kit, cell cycle and apoptosis were detected by flow cytometry. Cell invasion and migration were detected. CCNB1 and CDK1 expression levels were detected by qRT-PCR and Western blotting methods. Results: The high SFN expression BEL7402 cells and the low SFN expression Hep3B cells were screened from Hep3B, HepG2, and BEL7402 cells. The activity of Hep3B cells overexpression vector SFNpcDNA3.1(+) decreased and apoptosis increased, the ratio of G0/G1 decreased and the ratio of S phase increased. The activity of BEL7402 cells transfected with SFN siRNA decreased and apoptosis increased, the ratio of G0/G1 decreased and the ratio of G2/M increased. Interference and overexpression vectors have little effect on the invasion and migration of the two cells. The expression of CDK1 in Hep3B cells decreased significantly, the expression of CDK1 and CCNB1 in BEL7402 cells increased significantly. Conclusions: The differentially expressed SFN gene can regulate the growth of the two hepatocarcinoma cells, high expression of SFN gene can inhibit their growth. The mechanism may be achieved by regulating CCNB1 and CDK1 expression.