Optical Properties of Zinc-oxide Films Determined Using Spectroscopic Ellipsometry with Various Dispersion Models

Zhong-Hong Dai,Jie Shao,Yi-Ming Chen,Yu-Xiang Zheng,Jia-Da Wu,Liang-Yao Chen,Rong-Jun Zhang 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.3

In this work, we have studied the optical properties of wurtizite zinc-oxide films grown on silicon (100) substrates by means of pulsed laser deposition (PLD). Spectroscopic ellipsometry and three dispersion models, namely, the Sellmeier, Cauchy, and Forouhi-Bloomer models, were applied for determining the optical constants of the ZnO thin films. A comparison was made between two samples that were deposited for 30 minutes (sample I) and 60 minutes (sample II), respectively. X-ray diffraction analysis indicates that there are two types of preferred-orientation, i.e., (101) and (100) orientations for sample I and II, respectively. Results show that the Cauchy model gives the best fit for the samples with least root mean square error (RMSE) whereas the Forouhi-Bloomer model is most suitable for the data analysis in both the transparent and the absorption regions. The optical properties extracted from different dispersion models have been compared with the data reported in the literature. The results given in this work show that different dispersion models should be applied to obtain the optical constants In this work, we have studied the optical properties of wurtizite zinc-oxide films grown on silicon (100) substrates by means of pulsed laser deposition (PLD). Spectroscopic ellipsometry and three dispersion models, namely, the Sellmeier, Cauchy, and Forouhi-Bloomer models, were applied for determining the optical constants of the ZnO thin films. A comparison was made between two samples that were deposited for 30 minutes (sample I) and 60 minutes (sample II), respectively. X-ray diffraction analysis indicates that there are two types of preferred-orientation, i.e., (101) and (100) orientations for sample I and II, respectively. Results show that the Cauchy model gives the best fit for the samples with least root mean square error (RMSE) whereas the Forouhi-Bloomer model is most suitable for the data analysis in both the transparent and the absorption regions. The optical properties extracted from different dispersion models have been compared with the data reported in the literature. The results given in this work show that different dispersion models should be applied to obtain the optical constants

Genetic diversity of two Tibetan macaque (Macaca thibetana) populations from Guizhou and Yunnan in China based on mitochondrial DNA D-loop sequences

Li-Jing Zhong,Ming-Wang Zhang,Yong-Fang Yao,Qing-Yong Ni,Jun Mu,Chong-Qing Li,Huai-Liang Xu 한국유전학회 2013 Genes & Genomics Vol.35 No.2

Tibetan macaque (Macaca thibetana), an endangered species endemic to China, is categorized as a Category II species under the Chinese Wild Animal Protection Law and listed in Appendix II of the Convention on International Trade in Endangered Species. To further assess genetic diversity and population structure within this species,populations, revealing that variations occured among populations mainly. Further analysis demonstrated that significant genetic differentiation (Fst = 0.83628, P\0.01) and poor gene flow (Nm\1) had occurred among these four populations. On the phylogenetic tree and haplotype network plot, 22 haplotypes cluster together according to their geographical origins, exhibiting an obvious phylogeographic pattern. We speculate that the significant genetic differentiation among these macaque populations might result from long-term geographic barrier and human activity. In particular,Yangtze River probably play a vital role in population differentiation of Tibetan macaques. we sequenced 477 bp of mitochondrial DNA control region in 30 Tibetan macaques from the Guizhou (GZ) and Yunnan (YN) of China and conducted population genetic analysis, along with 15 previously described haplotype sequences representing 55 individuals from Sichuan (SC)and Anhui (AH). 87 polymorphic sites were detected in the alignment of 45 sequences and defined 22 haplotypes, of which 9 were newly identified. Haplotype diversity (h),nucleotide diversity (p) and average number of nucleotide differences (K) is 0.911 ± 0.015, 0.06090 ± 0.00126 and 28.32, respectively, indicating higher genetic diversity in the whole Tibetan macaque population. Analysis of molecular variance (AMOVA) partitioned the total variation into 83.63 % among populations and 16.37 % within populations, revealing that variations occured among populationsmainly. Further analysis demonstrated that significantgenetic differentiation (Fst = 0.83628, P\0.01) andpoor gene flow (Nm\1) had occurred among these fourpopulations. On the phylogenetic tree and haplotype networkplot, 22 haplotypes cluster together according to their geographicalorigins, exhibiting an obvious phylogeographicpattern. We speculate that the significant genetic differentiationamong these macaque populations might result fromlong-term geographic barrier and human activity. In particular,Yangtze River probably play a vital role in populationdifferentiation of Tibetan macaques.

β-elemene Induces Caspase-dependent Apoptosis in Human Glioma Cells in vitro through the Upregulation of Bax and Fas/FasL and Downregulation of Bcl-2

Li, Chen-Long,Chang, Liang,Guo, Lin,Zhao, Dan,Liu, Hui-Bin,Wang, Qiu-Shi,Zhang, Ping,Du, Wen-Zhong,Liu, Xing,Zhang, Hai-Tao,Liu, Yang,Zhang, Yao,Xie, Jing-Hong,Ming, Jian-Guang,Cui, Yu-Qiong,Sun, Ying Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: ${\beta}$-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of ${\beta}$-elemene against glioma cells remains unclear. In the present study, we assessed effects of ${\beta}$-elemene on human glioma cells and explored the underlying mechanism. Materials and Methods: Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of ${\beta}$-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of ${\beta}$-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and ${\beta}$-elemne treatment group. Results: With increase in the concentration of ${\beta}$-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability ($IC_{50}$) was $48.5{\mu}g/mL$ for 24h. ${\beta}$-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with ${\beta}$-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by ${\beta}$-elemene in a time and does-dependent manner. Conclusions: Our results indicate that ${\beta}$-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.

MACC1 Expression Correlates with PFKFB2 and Survival in Hepatocellular Carcinoma

Ji, Dong,Lu, Zhong-Tang,Li, Yao-Qing,Liang, Zhe-Yong,Zhang, Peng-Fei,Li, Chao,Zhang, Jun-Li,Zheng, Xin,Yao, Ying-Min Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Objective: To validate the relationship between MACC1 and 6-phosphofructo-2-kinase/fructose 2, 6 bisphosphatase (PFKFB2) expression as well as its clinicopathological features and prognostic significance in hepatocellular carcinoma. Methods: By using immunohistochemistry, we investigated the MACC1 and PFKFB2 protein expression in 60 pairs of hepatocellular carcinoma and corresponding non-tumor tissues. Using the Mann-Whitney U test, the Chi-square test, Kaplan-Meier survival analysis, Cox proportional hazard regression analysis and Spearman analysis, we studied the relationship between MACC1 and PFKFB2 protein expression and postoperative overall survival (OS) of the HCC patients. Results: MACC1 and PFKFB2 positive staining rates were significantly higher in hepatocellular carcinoma than in the corresponding nontumor tissues (P=0.012 and 0.04, respectively). The clinicopathological features evaluation revealed that positive expression of MACC1 was associated with a high Edmondson classification (P=0.007) and advanced TNM stage (P=0.027). Similar findings were evident for PFKFB2 expression (P=0.002 and P=0.027). MACC1 and PFKFB2 positive expression was associated with a lower OS rate (P=0.004 and 0.03, respectively). Kaplan-Meier survival and Cox proportional hazard regression analyses revealed MACC1 positive expression to be a prognostic factor for postoperative OS, but PFKFB was not. Conclusion: Highly expressed MACC1 and PFKFB2 protein were associated with TNM stage, Edmondson-Steier classification and overall survival. MACC1 may affect tumor metabolism partly through expression and phophorylation of PFKFB2.

A prediction model of the sum of container based on combined BP neural network and SVM

Min-jie Ding,Shao-zhong Zhang,Haidong Zhong,Yao-hui Wu,Liang-bin Zhang 한국정보처리학회 2019 Journal of information processing systems Vol.15 No.2

The prediction of the sum of container is very important in the field of container transport. Many influencingfactors can affect the prediction results. These factors are usually composed of many variables, whosecomposition is often very complex. In this paper, we use gray relational analysis to set up a proper forecastindex system for the prediction of the sum of containers in foreign trade. To address the issue of the lowaccuracy of the traditional prediction models and the problem of the difficulty of fully considering all the factorsand other issues, this paper puts forward a prediction model which is combined with a back-propagation (BP)neural networks and the support vector machine (SVM). First, it gives the prediction with the data normalizedby the BP neural network and generates a preliminary forecast data. Second, it employs SVM for the residualcorrection calculation for the results based on the preliminary data. The results of practical examples show thatthe overall relative error of the combined prediction model is no more than 1.5%, which is less than the relativeerror of the single prediction models. It is hoped that the research can provide a useful reference for theprediction of the sum of container and related studies.

An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Lin, Yu-Zhang,Shi, Li-Bao,Yao, Liang-Zhong,Ni, Yi-Xin,Qin, Shi-Yao,Wang, Rui-Ming,Zhang, Jin-Ping The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

A reduced time-varying model for a long beam on elastic foundation under moving loads

Guiming Mei,Caijin Yang,Shulin Liang,Jiangwen Wang,Dong Zou,Weihua Zhang,Yunshi Zhao,Zhong Huang,Shuqi Song,Mengying Tan,Yao Cheng,Bingrong Miao 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.9

Dynamics of a long beam on the elastic foundation subjected to moving loads is studied in the present paper. The sliding window technique is used to dynamically truncate the long beam and a reduced time-varying beam system is obtained. The Hamilton’s principle is employed to establish the equations of motion of the reduced system. The variable separation method is adopted to solve dynamical responses of the reduced system. Examples of a long simply supported Timoshenko beam on the nonlinear foundation subjected to a single moving load and multiple loads are included. Numerical results of the reduced model compared with the ones obtained from the moving element model adapted in literature are carried out to show the validity and the good efficiency of the method proposed in the present paper.

Effects of Wind Generation Uncertainty and Volatility on Power System Small Signal Stability

Shi, Li-Bao,Kang, Li,Yao, Liang-Zhong,Qin, Shi-Yao,Wang, Rui-Ming,Zhang, Jin-Ping The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

This paper discusses the impacts of large scale grid-connected wind farm equipped with permanent magnet synchronous generator (PMSG) on power system small signal stability (SSS) incorporating wind generation uncertainty and volatility. Firstly, a practical simplified PMSG model with rotor-flux-oriented control strategy applied is derived. In modeling PMSG generator side converter, the generator-voltage-oriented control strategy is utilized to implement the decoupled control of active and reactive power output. In modeling PMSG grid side converter, the grid-voltage-oriented control strategy is applied to realize the control of DC link voltage and the reactive power regulation. Based on the Weibull distribution of wind speed, the Monte Carlo simulation technique based is carried out on the IEEE 16-generator-68-bus test system as benchmark to study the impacts of wind generation uncertainty and volatility on small signal stability. Finally, some preliminary conclusions and comments are given.

An Analytical Solution for Voltage Stability Studies Incorporating Wind Power

Yu-Zhang Lin,Li-Bao Shi,Liang-Zhong Yao,Yi-Xin Ni,Shi-Yao Qin,Rui-Ming Wang,Jin-Ping Zhang 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

Voltage stability is one of the most critical security issues which has not yet been well resolved to date. In this paper, an analytical method called PQ plane analysis with consideration of the reactive power capability of wind turbine generator and the wake effect of wind farm is proposed for voltage stability study. Two voltage stability indices based on the proposed PQ plane analysis method incorporating the uncertainties of load-increasing direction and wind generation are designed and implemented. Cases studies are conducted to investigate the impacts of wind power incorporation with different control modes. Simulation results demonstrate that the constant voltage control based on reactive power capability significantly enhances voltage stability in comparison of the conventional constant power factor control. Some meaningful conclusions are obtained.

Effects of Wind Generation Uncertainty and Volatility on Power System Small Signal Stability

Li-Bao Shi,Li Kang,Liang-Zhong Yao,Shi-Yao Qin,Rui-Ming Wang,Jin-Ping Zhang 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

This paper discusses the impacts of large scale grid-connected wind farm equipped with permanent magnet synchronous generator (PMSG) on power system small signal stability (SSS) incorporating wind generation uncertainty and volatility. Firstly, a practical simplified PMSG model with rotor-flux-oriented control strategy applied is derived. In modeling PMSG generator side converter, the generator-voltage-oriented control strategy is utilized to implement the decoupled control of active and reactive power output. In modeling PMSG grid side converter, the grid-voltageoriented control strategy is applied to realize the control of DC link voltage and the reactive power regulation. Based on the Weibull distribution of wind speed, the Monte Carlo simulation technique based is carried out on the IEEE 16-generator-68-bus test system as benchmark to study the impacts of wind generation uncertainty and volatility on small signal stability. Finally, some preliminary conclusions and comments are given.