Direct simulation of inhalable particle motion and collision in a standing wave field

Fengxian Fan,Xufeng Yang,Chang Nyung Kim 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.6

Motion of inhalable particles (PM10) under the effect of acoustic standing wave was numerically studied, and the inter-particle collision rate was investigated based on the direct simulation Monte Carlo (DSMC) method. The results show that the particles convergence rapidly, generating two particle number concentration peaks in a wavelength range along the wave propagation direction. Considering the inter-particle collision, it is found that when the particle size and number concentration keep constant, the collision rate first increases and then decreases with the increase of the frequency. Hence there is an optimal frequency that corresponds to the highest collision rate. As the sound intensity level increases, the collision rate increases monotonically. In cases with the same acoustic wave, the collision rate increases with the particle number concentration. The particle size is also an important factor that strongly affects the collision rate. The large inhalable particles collide more intensively than the small ones.

Production of biodiesel from soybean oil catalyzed by attapulgite loaded with C4H5O6KNa catalyst

Fengxian Qiu,Bin Ye,Yihuai Li,Chuanjia Sun,Zhenyu Zhao,Teng Ma,Dongya Yang 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.7

Biodiesel is a green, safe, renewable alternative fuel, which is of great significance to solving the problem of energy shortage and environmental pollution. A series of solid base catalysts were prepared with the support of attapulgite (ATP), the load of C4H5O6KNa by impregnation method, and were used to catalyze transesterification of soybean oil with methanol to biodiesel. The activities of prepared catalysts were investigated compared to pure ATP. The optimal conditions for the catalyst preparation were investigated: molar ratio of Na : ATP was 1.7 : 1 and calcination temperature was 400 oC. The prepared catalysts were characterized by several techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, N2 adsorption-desorption measurements,X-ray diffraction and the Hammett indicator method. The prepared solid base catalyst can be separated from reaction system effectively and easily. The effects of the molar ratio of methanol to oil, reaction temperature and amount of catalyst on the biodiesel yield were investigated. The experimental results showed that a 22 : 1 molar ratio of methanol to oil, 10.0% of catalyst amount, 65 oC of reaction temperature and 3.0 h of reaction time gave the best results. The catalyst has longer lifetime and maintained sustained activity after being used for five cycles.

Capability of Enterprise and Patterns of Technology Convergence in Firms

Fengxian YANG 한국유통과학회 2018 KODISA ICBE (International Conference on Business Vol.2018 No.-

Technology convergence has been one means of technological innovation, which integrates similar or different technology fields to create new technology in the same industry or between industries. Technology convergence can be operated in different ways, including technology trade, technological alliance, mergers and acquisitions, which are the patterns of technology convergence. Because, single company can not possess all diverse technologies and resources innovation needs, it’s necessary to obtain them from outside through market or cooperation approach. Technology convergence is essentially a means of technological innovation. The choice among different technology convergence patterns is affected by resources and capability that company has. Enterprise capability refers to the power in company and the ability to build relationship and manage innovation resources. Technology trade, technological alliance, mergers and acquisitions are three different patterns to practice convergence. This article adopts empirical research method. Firstly, bring up research hypotheses based on literature review. Secondly, design and distribute questionnaires to collect data. Finally, one way- ANOVA is used to process data analysis and hypotheses test. The results indicate that capability of enterprise have significant influence on the choice between different patterns for company, although the degree of influence each are not identical.

Preparation and characterization of L-phenylalanine-derivatized β-cyclodextrin-bonded silica and its application on chiral separation of alanine acid racemates

Fengxian Qiu,Kaichen He,Jiao Qin,Jie Yan,Dongya Yang 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.11

A chiral adsorption material, L-phenylalanine-derivatized β-cyclodextrin-bonded silica (L-Phe-CD/SiO2),was prepared and characterized by Fourier transform infrared (FT-IR), elemental analysis, field emission scanning electron microscope (FESEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) measurements. Langmuir and Freundlich isotherm models were employed to simulate the equilibrium data. The results showed that the equilibrium data were well represented by Langmuir isotherm model. Experimental data were analyzed using pseudofirst order and pseudo-second order kinetic models and the obtained results indicated that kinetics followed a pseudosecond order equation. The static adsorption experiments indicated that L-Phe-CD/SiO2 had significantly higher adsorption capacity for L-alanine (L-Ala) compared with D-alanine (D-Ala); and the selectivity coefficient is 2.53. The result shows that the prepared L-Phe-CD/SiO2 could be applied to chiral separation of the racemic alanine acid solution.

Image 3d Adaptive Algorithm Based on Graph Cut

Fengxian Tang,Yunfeng Yang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8

As a key step in the visual inspection, image to appear particularly important. Compared with the traditional algorithm, graph cut algorithm overall high precision and faster convergence speed in discontinuous area. Based on adaptive algorithm on the basis of in-depth study, this paper proposes a three-dimensional adaptation algorithm based on graph cut theory in order to realize the image matching. Experimental results show that this algorithm can well meet the requirements of high precision and high real time capability, solve the problems such as large amount of calculation in the traditional algorithm.

Numerical study on heterogeneous behavior of fine particle growth

FAN Fengxian,YANG Linjun,Yuan Zhulin,Yan Jinpei,Jo Young Min 한국입자에어로졸학회 2009 Particle and Aerosol Research Vol.5 No.4

PM2.5 is one of critical air pollutants due to its high absorbability of heavy metallic fumes, PAH and bacillary micro organisms. Such a fine particulate matter is often formed through various nucleation processes including condensation. This study attempts to find the nucleation behaviors of PM2.5 arisen from coal power stations using a classical heterogeneous Fletcher’s theory. The numerical simulation by C-language could approximate the nucleation process of PM2.5 from water vapor, of which approach revealed the required energy for embryo formation and embryo size and nucleation rate. As a result of the calculation, it was found that wetting agents could affect the particle nucleation in vapor condensation. In particular, critical contact angle relates closely with the vapor saturation. Particle condensation could be reduced by lowering the angles. The wetting agents aid to decrease the contact angle and surface tensions, thereby may contribute to save the formation energy. Key words : Particle nucleation, Fletcher’s theory, Particle wettability, Numerical simulation

중국 음악전공 대학생의 교육과정 만족과 진로준비행동간의 관계에서 자기효능감과 진로결정수준의 조절된 매개효과

하봉선(He Fengxian) 학습자중심교과교육학회 2022 학습자중심교과교육연구 Vol.22 No.4

목적 본 연구의 주요 목적은 중국 음악전공 대학생들의 교육과정과 운영체제 만족이 진로결정수준을 통해 진로준비행동에 미치는 효과가 음악적 자기효능감에 의해 조절되는지를 검증하는데 두었다. 방법 연구대상은 중국의 음악전공 대학생 472명(관현악 115명, 성악 126명, 피아노 127명, 음악교육 104명)이 선정되었다. 자료는 교육과정과 운영체제 만족, 음악적 자기효능감, 진로결정수준 및 진로준비행동을 측정하는 4개의 질문지를 통해 수집되었다. 자료분석은 기술통계, 확인적 요인분석, 신뢰도 분석, 상관분석 및 위계적 회귀분석을 이용하여 분석되었다. 결과 위계적 회귀분석의 결과는 다음과 같다. (1) 음악전공 대학생의 교육과정과 운영체제에 대한 만족은 진로결정수준을 통해서 뿐만 아니라 직접 진로준비행동에 긍정적인 영향을 준다. (2) 음악전공 대학생의 교육과정과 운영체제에 대한 만족과 음악적 자기효능감이 상호작용하여 진로결정수준에 긍정적인 영향을 준다. (3) 음악전공 대학생의 진로결정수준과 음악적 자기효능감이 상호작용하여 진로준비행동에 긍정적인 영향을 준다. 결론 이들 결과는 교육과정과 운영체제에 대한 만족도가 높은 중국 음악대학 학생들이 음악적 자기효능감과 진로결정 수준이 높을수록 진로준비행동이 높다는 사실을 시사한다. Objectives The purposes of this study was whether the career preparation behaviors moderate the mediating effect of career decision level in the relationship between Chinese university students’ satisfaction with music curriculum and administration systems. Methods Subjects were 472 Chinese undergraduate students (115 instrumental music, 126 vocal, 127 piano, 104 music education) who are majoring in music. Data were collected using a set of questionnaires measuring curriculum and administration system, musical self-efficacy, career decision level, and career preparation behaviors. Data were conducted via descriptive statistics, confirmatory factor analysis, correlation, and hierarchical regression analysis. Results The results of regression analysis were as follows: (1) University students’ satisfaction with curriculum and its administration system have positively an effect on career preparation behaviors throughout career decision level. (2) The interaction of University students’ satisfaction with curriculum and its administration system and musical self-efficacy have a positive impact on career decision level. (3) The interaction of University students’ career decision level and musical self-efficacy have a positive impact on career preparation behaviors. Conclusions These findings suggest that Chinese undergraduate students majoring in music who showed high satisfaction with their curriculum and its administration are inclined to have high career preparation behaviors when their musical self-efficacy and career decision level are high.

최승희 훈련체계의 교육적 발전 양상 : 중국 연변대학교의 사례를 중심으로

김봉선 ( Jin Fengxian ),이미령 ( Li Meiling ) 무용역사기록학회 2021 무용역사기록학 Vol.62 No.-

본 논문은 최승희 훈련체계의 교육적 발전 양상을 고찰하기 위한 연구이다. 최승희의 훈련체계를 기반으로 중국조선족무용을 계승 및 발전하고 있는 중국 연변대학교 조선족무용교육 교재의 현황을 사례로 조선족무용교육 교재의 발전 양상과 교재의 특징을 살펴보는데 연구의 목적이 있다. 연변대학교의 조선족무용교육은 초기에는 최승희 훈련체계를 기반으로 이루어 졌으며, 박용원을 통해 더욱 세분화되고 규범화된 교육체계를 구축하게 되었고 오늘날까지 그 명맥을 계승 및 발전하고 있다. 최승희 훈련체계의 교육적 발전 양상을 고찰하고자 최승희의 훈련체계를 기반으로 한 연변대학교의 조선족무용교육 교재의 발전 양상과 그 특징에 대해 실제로 연변대학 예술학원 무용학과의 조선족 무용교육에 활용되고 있는 영상교재 『조선족무용교재』(2005), 『조선족전통무용 소도구 춤 기본』(2015), 『조선족민속무용교재』(2016)를 중점적으로 살펴보았다. 연구를 토대로 살펴본 연변대학교의 조선족무용교육 교재의 특징은 다음과 같다. 첫째, 최승희 훈련체계의 교육 교재 편성방법을 기반으로 하고 있다. 둘째, 최승희의 훈련체계에서 다루지 않았던 내용까지 포괄적으로 수용하여 풍부한 교육내용으로 교재의 구체화를 이루었다. 셋째, 현재는 여성기본을 위주로 훈련체계가 정립되어 있다. 이와 같이 연변대학교의 조선족무용교육은 최승희 훈련체계를 계승하여 이어감과 동시에 그들만의 시대성을 겸비한 논리적이고 전문화된 과학적인 교육체계를 이루고 있다. 따라서 이처럼 연변대학교의조선족무용교육이 지금의 논리적인 훈련체계를 뒷받침할 수 있는 교육 교재를 구축할 수 있었던 점은 바로 계승과 발전이라는 두 근본을 원칙으로 조선족무용교육을 위해 연구에 헌신한 조선족무용 교육가들이 있었기 때문이다. 이를 계기로 현재까지 이루어낸 모든 교육 교재를 하나의 종합적이고 총체를 이루는 중국 조선족무용교재로 집필하게 된다면 진정한 교육체계의 확립을 이루게 될 것이라 사료된다. 앞으로 연변대학교 조선족무용교육이 오늘날의 성과를 이어 꾸준히 사회적 발전과 수요에 따라 적극적인 변화와 개혁을 통해 더욱더 비약적인 발전을 이룰 것이라 전망해본다. This study aims to examine the educational development of Choi Seunghee’s training system, particularly with a focus on the development patterns of Korean-Chinese dance education textbooks and characteristics of Korean-Chinese dance education textbooks at Yanbian University in China, which has inherited and developed Korean-Chinese dance based on Choi Seunghees training system. The characteristics of Yanbian University’s Korean-Chinese dance education textbooks examined in this study are as follows. First, it is based on the method of organizing educational textbooks, which was identified in Choi Seunghee’s training system. Second, the contents that were not covered by Choi Seunghee’s training system have been comprehensively adopted into the textbooks, which thus came to be loaded with abundant educational content. Third, a training system is currently established focusing on the basics of women’s dance movements. Yanbian University’s Korean-Chinese dance education was able to create educational textbooks that could support the current logical training system due to the Korean-Chinese dance educators’ devotion to research on Korean-Chinese dance education, which was based on the principle of succession and development.

Selective adsorption of L-TA/D-TA by β-cyclodextrin derivative modified with l-tryptophan: Isotherm, kinetic and thermodynamics studies

Kaichen He,Fengxian Qiu,Jiao Qin,Jie Yan,Dongya Yang 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

b-Cyclodextrin derivative modified with L-tryptophan (L-Trp-CD) was prepared for recognitive chiral separation of tartaric acid enantiomers from ethanol solution. Kinetic properties were successfully investigated by pseudo-first-order model and pseudo-second-order model. Equilibrium data were described by the Langmuir and Freundlich isotherm models. The thermodynamics parameters (positive values of DH8 and DS8, negative values of DG8) indicated that binding system for L-Trp-CD was endothermic, entropy gained and spontaneous. Selective adsorption result of L-tartaric acid (L-TA)/Dtartaric acid (D-TA) by L-Trp-CD indicated that L-Trp-CD has significantly higher adsorption capacity for L-TA compared with D-TA, and the selectivity coefficient is 3.36.

A facile hydrothermal synthesis, adsorption kinetics and isotherms to Congo Red azo-dye from aqueous solution of NiO/graphene nanosheets adsorbent

Xinshan Rong,Fengxian Qiu,Jiao Qin,Hao Zhao,Jie Yan,Dongya Yang 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.26 No.-

A series of NiO/graphene nanosheets adsorbents (NGNS) were synthesized by a facile hydrothermal method, and characterized by UV–vis, XRD, TG, TEM, HRTEM, Raman, SAED and XPS methods. The NGNS was applied to deal with wastewater solution containing Congo Red (CR); and adsorption efficiency attained 99.56% at optimum condition. The adsorption kinetic and isotherm of adsorbent toward CR were investigated. The results indicated that pseudo second-order kinetic model and the equilibrium data were well fitted by Redlich–Peterson model. The adsorbent can be separated from system effectively and easily. The prepared adsorbent has potential application for the wastewater treatment containing CR azo-dye.