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      • KCI등재

        Study of the Band-gap Structure of a 1D-photonic Crystal by Using Different Numerical Approaches

        Liang-Yao Chen,Jian-Bo Chen,Yue-Rui Chen,Yan Shen,Wei-Xi Zhou,Jiu-Chun Ren,Yu-Xiang Zheng 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.4

        Comparative studies between the transfer matrices method (TMM) and plane wave method (PWM) approaches have been performed on 1D photonics crystal under different conditions to show the differences between these two kinds of calculations. TMM is suitable for the design of 1D photonic crystal device with high precision and is in good agreement with experimental results, but is not suitable for the 2D and 3D photonic structures which are limited by the complicated boundary conditions at micro interfaces. The result based on the PWM approach to deal approximately with the photonic structure in approximation has not yet been strictly verified by experiment, not even for 1D photonic crystal structures. More efforts will be required to explore its validation under all physical conditions to enhance its application.

      • Clinical and Histopathological Analysis of 66 Cases with Cardiac Myxoma

        Zheng, Jian-Jie,Geng, Xi-Gang,Wang, Hai-Chen,Yan, Yang,Wang, Hong-Yan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

        Background and Purpose: Cardiac myxoma is a major primary heart tumor which often causes unexpected symptoms or sudden death. This present study was designed to investigate its clinical pathological features and biological behavior. Methods: A retrospective analysis of the clinical pathologic and immunohistochemical features of 66 cases with cardiac myxoma was conducted. Results: In 66 patients with cardiac myxoma, 61 cases had involvement of the left atrium, one case in both the right ventricular and left atria. The female: male ratio was 2.7:1. Patients had symptoms of blood flow obstruction and systemic alterations with performance of arterial embolization. Tumors were spherical, lobulated or irregular in shape, and soft and brittle. Immunohistochemical markers of vimentin and CD34 in tumor cells were positive. Conclusion: Cardiac myxoma always exists in the left atrium and is more common in women, with diverse clinical manifestations and pathomorphism. Although proliferative activity and the recurrence rate are low, in addition to thorough surgical resection, strengthened review is important for young patients.

      • Dose-Dependent Associations between Wine Drinking and Breast Cancer Risk - Meta-Analysis Findings

        Chen, Jia-Yan,Zhu, Hong-Cheng,Guo, Qing,Shu, Zheng,Bao, Xu-Hui,Sun, Feng,Qin, Qin,Yang, Xi,Zhang, Chi,Cheng, Hong-Yan,Sun, Xin-Chen Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.3

        Purpose: To investigate any potential association between wine and breast cancer risk. Materials and Methods: We quantitatively assessed associations by conducting a meta-analysis based on evidence from observational studies. In May 2014, we performed electronic searches in PubMed, EmBase and the Cochrane Library to identify studies examining the effect of wine drinking on breast cancer incidence. The relative risk (RR) or odds ratio (OR) were used to measure any such association. Results: The analysis was further stratified by confounding factors that could influence the results. A total of twenty-six studies (eight case-control and eighteen cohort studies) involving 21,149 cases were included in our meta-analysis. Our study demonstrated that wine drinking was associated with breast cancer risk. A 36% increase in breast cancer risk was observed across overall studies based on the highest versus lowest model, with a combined RR of 1.0059 (95%CI 0.97-1.05) in dose-response analysis. However, 5 g/d ethanol from wine seemed to have protective value from our non-linear model. Conclusions: Our findings indicate that wine drinking is associated with breast cancer risk in a dose-dependent manner. High consumption of wine contributes to breast cancer risk with protection exerted by low doses. Further investigations are needed for clarification.

      • KCI등재

        New triterpenoids from Staphylea bumalda flower buds and their neuroprotective activity against H2O2-induced injury in vitro

        Zheng-Xi Zhang,Kun Feng,Xian-Jin Sui,Wen-Shu Wang,Lin Wang,Dong-Hong Wang,Xiao-Min Luo,Xiao-Fei Chen 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

        Four new acylated triterpene glycosides with aliphatic chains (4–7) as well as five known triterpenoids were isolated from the flower buds of Staphylea bumalda with bioassay guidance. Their structures were determined on the basis of spectral techniques, including IR, 1D and 2D NMR, and HR-APCI-MS. Most compounds (except 8) were isolated from S. bumalda for the first time. Additionally, the neuroprotective effects of 1 and 4–9 on suckling rat primary cultured hippocampal neurons against H2O2-induced injury were evaluated in vitro. The four new triterpenoids (4–7) showed neuroprotective effects, which increased the cell viability to over 74% at different concentrations, which was higher than the negative control (59%), while compounds 1 and 8–9 exhibited cytotoxic activity.

      • A Novel Synchronous Switch Method Based on Kalman Filter

        Zheng Guilin,Chen Xi 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2

        In order to create the idea of AC switch without electric arc and inrush voltage to the power system, the study of accurately catches AC zero crossing of a mechanical relay is put forward in this paper. It is the key to make the switch act at the right predicted time which realizes switch on or off exactly at the AC zero crossing point. However, the action time of a mechanical switch is affect by many factors such as driving voltage, ambient temperature, age of the mechanic structure. Aim at the discrete measurements of latching relay action time, the Kalman filter mathematic model is introduced in this paper to eliminate the dynamic noise and measurement noise which affects the bias time drift from the zero voltage or zero current point. Simulation result by matlab and group data get from experiments of a realized multichannel switch indicate that Kalman filter algorithm can overcome the discreteness of latching relay action time measurements. Also confirmed by statistical experiments that synchronous switch action precisely and reliably at AC zero point which can ensure the ability of suppress electric arc and high frequency inrush current.

      • KCI등재

        Sensing formic acid with a water-based chitosan lanthanide luminescence film

        Xu Zheng,Xi Chen,Xudong Yu,Yifan Yang 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

        A sensitive and selective formic acid sensor could be useful in detecting this corrosive acid in industrial,medical, and environmental settings. Herein, we present a film for detection of formic acid. We introducedchitosan as a film-forming factor to creatively overcome the problem that chitosan dissolves inacids. A carboxylic acid-carbon dot solution was used to replace the strong acid solution and prepare aluminescent film in which the color changed from green to blue when it was exposed to formic acid. Integrated data analysis of the film was used to distinguish vapor from formic acid/water solutions at differentconcentrations and with a detection limit of 0.01% v/v. The selectivity of the sensor was also investigated. After fumigation with ethanol and other common solvents, there was no response similar to thatfor formic acid. It is believed that films based on lanthanide complexes and chitosan could prevent corrosionand injury from formic acid.

      • Dietary Factors and Risk of Pancreatic Cancer: a Multi-Centre Case-Control Study in China

        Liu, Shu-Zheng,Chen, Wan-Qing,Wang, Ning,Yin, Meng-Meng,Sun, Xi-Bin,He, Yu-Tong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

        Background: Pancreatic cancer is the sixth leading cause of cancer death with an increasing trend in China. Dietary intake is believed to play an important role in pancreatic cancer carcinogenesis. The aim of this paper was to evaluate associations between some dietary factors and risk of pancreatic cancer in a multi-centre case-control study conducted in China. Materials and Methods: Cases (n=323) were ascertained from four provincial cancer hospitals. Controls (n=323) were randomly selected from the family members of patients without pancreatic cancer in the same hospitals, 1:1 matched to cases by gender, age and study center. Data were collected with a questionnaire by personal interview. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated using conditional logistic regression. Results: Tea intake (OR =0.49; 95%CI: 0.30-0.80) was associated with a half reduction in risk of pancreatic cancer. Reduced vegetable consumption (P trend: 0.04) was significant related to pancreatic cancer. Although no significant association was found for meat and fruit, ORs were all above or below the reference group. A protective effect was found for fruit (OR=1.73 for consumption of 1-2 times/week vs more than 3 times/week; 95%CI: 1.05-2.86). A high intake of meat was associated to a higher risk of pancreatic cancer (OR=0.59 for consumption of 1-2 times/week vs. more than 3 times/week; 95%CI: 0.35-0.97). Conclusions: The present study supports fruit consumption to reduce pancreatic cancer risk and indicates that high consumption of meat is related to an elevated risk. Direct inverse relations with tea and vegetable intake were also confirmed.

      • KCI우수등재

        MICROSTRUCTURE AND TRIBOLOGY OF $TiB_2$ AND $TiB_2$-TiN DOUBLE-LAYER COATINGS

        Yang, Yunjie,Chen, Lizhi,Zheng, Zhihong,Wang, Xi,Liu, Xianghuai The Korean Vacuum Society 1995 Applied Science and Convergence Technology Vol.4 No.s2

        $TiB_2$-TiN double-layer coating have been prepared by ion beam enhanced deposition. AES, XRD, TEM and HRTEM were employed to characterize the $TiB_2$ layer. The microhardness of the coatings was evaluated by an ultra low-load microhardness indenter system, and the tribological behavior was examined by a ball-on-disc tribology wear tester. It was found that in a single titanium diboride layer, the composition is uniform along the depth of the film, and it is mainly composed of nanocrystalline $TiB_2$ with hexagonal structure, which resulted from the ion bombardment during the film growth. The hardness of the $TiB_2$ films increases with increasing ion energy, and approaches a maximum value of the $TiB_2$ films increases with increasing ion energy, and approaches a maximum value of 39 Gpa at ion energy of 85 keV. The tribological property of the TiB2 films is also improved by higher energy of 85keV. The tribological property of the $TiB_2$ films is also improved by higher energy ion beam bombardment. There is no major disparity in the mechanical properties of double-layer $TiB_2$/TiN coatings and TiN/$TiB_2$ coatings. Both show an improved wear resistance compared with single-layer $TiB_2$ films. The adhesion of double-layer coatings is also superior to that of single-layer films.

      • SCIESCOPUSKCI등재
      • KCI등재

        Comparison Study of the Band-gap Structure of a 1D-Photonic Crystal by Using TMM and FDTD Analyses

        Jian-Bo Chen,Yan Shen,Wei-Xi Zhou,Yu-Xiang Zheng,Hai-Bin Zhao,Liang-Yao Chen 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.42

        A variety of numerical methods has been developed to demonstrate the nature of photons propagating in an artificially-composed periodic structure. Differences will be generated by different kinds of numerical approaches. In this work, we carry out two types of numerical calculations, TMM (transfer matrix method) and FDTD (finite different time domain) calculations. In terms of the 1D-photonic crystal structures with two different structures, we illustrate the energy band spectra, and the results show dispersive characteristics for the optical transmission and reflection of the crystal material. Through a discussion of the mechanism, detailed comparison studies are preformed based on the different physical conditions. The results given in the work will help in better understanding the ways in which photons propagate in an artificially-composed periodic structure.

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