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# An implementation of multigrid for 2D edge elements

Pollack Periodica
Authors: Chao Chen and Oszkár Bíró

This paper deals with the numerical solution of a two-dimensional (2-D) magnetostatic field problem. Thereby, a finite element method (FEM) with the magnetic vector potential as field variable and a discretization with edge elements is used. For the efficient solution of the obtained matrix equation system, a geometric multigrid solver (MG) is presented which reduces the number of iterations considerably.

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# Edge element multigrid for time-harmonic 3-D eddy-current problems

Pollack Periodica
Authors: Chao Chen and Oszkár Bíró

A geometric multigrid method for the efficient solution of time-harmonic 3-D eddy-current problems is presented. A finite element method with a scalar potential and a vector potential is used to describe the problem. Numerical examples show that using the right smoother in the multigrid, a good convergence of solutions, which does not deteriorate for bad quality meshes can be obtained. The computation time for solving the eddy-current problem of the multigrid method is much faster than that of the conjugate gradient method with incomplete Cholesky factorization as preconditioner.

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# Inequalities involving gamma and digamma functions

Studia Scientiarum Mathematicarum Hungarica
Authors: Horst Alzer and Chao-Ping Chen

We prove:

1. (A) Let
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage{bbm} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\Delta _c (x) = \log \frac{{\Gamma (x + 1)}}{{\sqrt {2\pi } (x/e)^x }} - \frac{1}{2}\psi (x + c) (x > 0; c \geqq 0).$$ \end{document}
1. (i) −Δc is completely monotonic on (0, ∞) if and only if c ≧ 2/3.
2. (ii) Δc is completely monotonic on (0, ∞) if and only if c = 0.
2. (B) The inequalities
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage{bbm} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\frac{1}{2}\psi (x + a_0 ) < \log \frac{{\Gamma (x + 1)}}{{\sqrt {2\pi } (x/e)^x }} < \frac{1}{2}\psi (x + b_0 )$$ \end{document}
hold for all x > 0 with the best possible constants a 0 = 0.52660… and b 0 = 2/3.

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# Evaluation of minimum detectable amounts of iodine in biological samples by neutron activation analysis

Journal of Radioanalytical and Nuclear Chemistry
Authors: J. Chao, H. Lee, C. Tseng, C. Chen, and Y. Wei

## Abstract

Evaluation of minimal detectable amounts (MDA) of iodine in various or specified irradiation and measurement conditions is described. Interfering contributions due to Na and Cl to the spectral background as well as the dead time of detection system were calculated in details based on an experimental approach. The MDA of iodine for some important biological samples with various Na and Cl concentrations can be evaluated and predicted according to the specified irradiation and measurement arrangements to meet the requirement of analytical purposes.

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# Research on the N-alkylation of morpholine with alcohols catalyzed by CuO–NiO/γ–Al2O3

Reaction Kinetics, Mechanisms and Catalysis
Authors: Xinzhi Chen, Hu Luo, Chao Qian, and Chaohong He

## Abstract

The N-alkylation of morpholine with alcohols in gas–solid phase was investigated in a fixed-bed reactor over CuO–NiO/γ–Al2O3 catalyst prepared by the impregnation method. The N-methylation of morpholine with methanol gave a 95.3% conversion with a 93.8% selectivity of N-methylmorpholine under the optimum reaction condition, and the corresponding apparent activation energy is 46.20 kJ mol−1. The present catalytic system is also applicable to other low-carbon primary alcohols. However, secondary alcohols enjoy relatively low product selectivity for the resulting ketone is a poorer electrophile than an aldehyde. For cyclohexanol, the low conversion and selectivity are mainly due to steric effects. The catalyst shows a high catalytic activity without obvious fluctuation during a long period of 120 h.

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# Neuroscience output of China: A MEDLINE-based bibliometric study

Scientometrics
Authors: Wei Xu, Yi-Zhang Chen, and Zhi-Chao Shen

## Abstract

Neuroscience is one of the most active research fields in many countries including China, an economically and scientifically emerging country, where a rapid development has been occurred since the 1970s. In this study, a MEDLINE-based bibliometric analysis of Chinese international output in neuroscience was conducted for the period from 1984 through 2001. An attempt was made to identify the pattern of the growth and to obtain some quantitative indicators over the literature studied in order to review at the developing steps of neuroscience in China during the period.

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# Association between Internet gaming disorder and generalized anxiety disorder

Authors: Chao-Yang Wang, Yu-Chen Wu, Chen-Hsiang Su, Pai-Cheng Lin, Chih-Hung Ko, and Ju-Yu Yen

### Introduction

This study evaluates the association between generalized anxiety disorder (GAD) and Internet gaming disorder (IGD) and the role of behavior inhibition in young adults.

### Methods

We recruited 87 people with IGD and a control group of 87 people without a history of IGD. All participants underwent a diagnostic interview based on the fifth edition of Diagnostic and Statistical Manual of Mental Disorders, IGD and GAD criteria, and completed a questionnaire on behavior inhibition, depression, and anxiety.

### Results

Logistic regression revealed that adults with GAD were more likely (odds ratio = 8.11, 95% CI = 1.78−37.09) to have IGD than those without it. The OR decreased when controlling for behavior inhibition. IGD subjects with GAD had higher depressive and anxiety score than those without GAD.

### Conclusions

GAD was associated with IGD. Comorbid GAD can contribute to higher emotional difficulty. GAD should be well-assessed and interventions planned when treating young adults with IGD. Behavioral inhibition confounds the association between GAD and IGD. Further study is necessary to evaluate how to intervene in behavioral inhibitions to attenuate the risk of GAD and IGD comorbidity.

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# Positive outcome expectancy mediates the relationship between social influence and Internet addiction among senior high-school students

Authors: Min-Pei Lin, Jo Yung-Wei Wu, Chao-Jui Chen, and Jianing You

### Background and aims

Based on the foundations of Bandura’s social cognitive theory and theory of triadic influence (TTI) theoretical framework, this study was designed to examine the mediating role of positive outcome expectancy of Internet use in the relationship between social influence and Internet addiction (IA) in a large representative sample of senior high-school students in Taiwan.

### Methods

Using a cross-sectional design, 1,922 participants were recruited from senior high schools throughout Taiwan using both stratified and cluster sampling, and a comprehensive survey was administered.

### Results

Structural equation modeling and bootstrap analyses results showed that IA severity was significantly and positively predicted by social influence, and fully mediated through positive outcome expectancy of Internet use.

### Discussion and conclusions

The results not only support Bandura’s social cognitive theory and TTI framework, but can also serve as a reference to help educational agencies and mental health organizations design programs and create policies that will help in the prevention of IA among adolescents.

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# A simple HPLC method for the determination of butorphanol tartrate and ondansetron hydrochloride in patient-controlled analgesia solution

Acta Chromatographica
Authors: Bao-xia Fang, Lin-hai Wang, Fu-chao Chen, Peng Li, and Xiao-ya Shi

A simple and rapid high-performance liquid chromatographic (HPLC) method was established for simultaneous determination of butorphanol tartrate and ondansetron hydrochloride in analgesic mixture samples used for patient-controlled analgesia (PCA). The separation of butorphanol tartrate and ondansetron hydrochloride in PCA solution was carried out on phenomenex C18 column (4.6 mm × 150 mm, 5 μm) using 50 mM sodium acetate (pH 4.0) buffer and acetonitrile (72:28, v/v). Flow rate was 1.0 mL min−1 with a column temperature of 30 °C, and detection wavelength was carried out at 280 nm and 306 nm. Validation of the method was made in terms of specificity, linearity, accuracy, and intra- and inter-day precision, as well as quantification and detection limits. The developed method was successfully used to evaluate the chemical stability of butorphanol tartrate and ondansetron hydrochloride in analgesic mixtures at the usual concentration used for PCA.

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# Study on the effect of supplementation of ironfortified food to Chinese juvenile athletes by nuclear analysis techniques and blood analysis

Journal of Radioanalytical and Nuclear Chemistry
Authors: Q. Qian, W. Feng, J. Chen, P. Zhang, C. Chai, J. Pan, Y. Wu, S. Zheng, X. Liu, and Z. Chao

## Abstract

The iron contents in the hair and blood samples of 37 juvenile athletes who were supplemented with 0, 8 and 16 mg Fe/day, respectively, in the food of ferrous gluconatecontaining chocolate for 3 months were determined before and after the supplementation by INAA, SRXRF and blood analysis. The experimental results showed that after supplementation of the iron-fortified food, the normal ferritin level in the blood of the male athletes was attained and the iron content in the hair was increased with supplementation, but both are not in the positive proportion. Most of the female athletes had similar results. It is suggested that supplementation of 8 mg iron/day to juvenile athletes may be desirable.

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