Grazing Incidence X - ray Diffraction (GIXRD) Studies of the Structure of Si₁_xGex / Si Surface Alloy

Y. Shi,R. Zhao,C. Z. Jiang,X. J. Fan 한국진공학회(ASCT) 2002 Journal of Korean Vacuum Science & Technology Vol.6 No.2

The Si_(1-x)Ge_x/Si surface alloy (x = 0.3, 0.4 and 0.5), which are prepared by solid source MBE and have the SiGe epilayer thickness of 50Å, are annealed with different parameters. The surface structure analyses of the heterostructure samples are made on a triple-axis X-ray diffractometer in grazing incidence X-ray diffraction (GIXRD) geometry. It has been found that with different annealing time (1.5h, 18h, 64h) and annealing temperature (550℃, 750℃), the SiGe epilayer experienced different strain relaxation process, which was deduced from the GIXRD measurements of the in-plane (220) diffraction peak of Si(001) substrate and the relevant (220) surface diffraction of SiGe epilayer. The results show that the stress relieving and the lateral strain relaxation in the SiGe/Si heterostructure can be promoted by correct annealing, which is very helpful for the preparation of SiGe/Si strained superlattice with fine strain crystallization.

한국과 중국의 간호재학생들의 비판적 사고성향과 전문직관 비교연구

이향련 ( H Y Lee ),김윤희 ( Y H Kim ),강현숙 ( H S Kim ),이지아 ( J Lee ),( Fan X ),( Ling M ),YuanQ 경희대학교 동서의학연구소 2007 동서간호학연구지 Vol.13 No.2

본 연구는 간호교육성과 평가를 위해 한국간호평가원에서 정한 5개의 영역인 비판적 사고력,전문직관, 지도력,의사소통능력, 간호수행능력 중 비판적 사고 성향과 전문직관에 대하여 한국과 중국의 간호대학생을 대상으로 평가 비교하였다. 한국과 중국의 간호학 생의 교육성과를 비교 분석함으로써 중국유학생의 기준을 확인 할 수 있으며 미래 간호인력 활용에 있어 서도 본 연구 결과를 활용하고자 하였다.본 연구결과 한국의 간호교육과정이 주로 3년제와 4년제로 구분되어있는 것에 비하여 중국의 경우 4년 제와 5년제로 구분되었고 입학자격이 일반적으로 중 학교 졸업 이상임을 알게 되었다. 본 연구의 대상인 중국의 간호대학은5년제 과정이었으며 교과과정에서 비판적 사고나 전문직관이 포함되어 있지 않았고 한국의 간호대학의 경우 2학년 교과과정에 ‘비판적 사 고와 간호,가 전공 선택으로 포함되었다. 따라서 관련 교과목의 선수경험을 조사한 결과 비판적 사고가 전문직관보다 양국기간에 더 큰 유의한 차이를 나타내었다 양국기간의 비판적 사고성향 비교에서 한국은 97. 06점 (l35점 만점) 이었고, 중국은 88. 61점으로 나타나 두 집단 간에 유의한 차이가 있었다 (t=以286, p<.001).이는 한국학생들의 43. 3% 가 비판적 사고와 관련된 과목을 수강한 경험이 있는 반면 중국의 경우 8. 7% 안이 관련과목을 수강하였다고 보고하였음을 감안할 때 국가 간의 차이보다는 교육의 효과가 좀 더 반영되었다고 볼 수 있으며 실제로 본 연구에서 한국 측 대학과정에서 비판적 사고의 과목이 2학년의 선택 과목으로 개설되고 있었다. 선행연구인 Yoon (2004) 의 95. 55와 비교하면 본 연구의 한국학생 대상자 군의 점 수가 더 높았다. 한편, Yoon (2004) 의 연구에서는 대상 자들의 비판적 사고관련 과목의 선수경험여부를 보고 하지 않았지만 교과과정에 비판적 사고라는 교과목이 개설되지 않은 상태이며 l학년과 4학년의 점수가 95. 09과 974로 235의 차이가 있는 반면 한국의 경 우 1학년과 4학년의 점수가 94. 10점과 103. 22정으로 좀 더 큰 점수차이인 9.12점 이였음을 고려할 때 비판 적 사고를 주제로 한 교과과목의 수강경험이 비판적 사고성향 함양에 큰 영향을 주었음을 알 수 있다. 급 속히 변화하는 임상환경에 효과적으로 대처할 수 있는 능력을 위해 본 연구의 한국측 간호대학에서는 학 생들의 비판적 사고 능력함양에 관심을 갖게 되어 ‘비판적 사고와 간호· 라는 교과목을 개설하여 운영하고 있었다. 실제로 임상현장은 끊임없이 문제해결과 의사결정을 요구하고 있으며 비판적 사고 없이 이루 어지는 간호행위는 없다고 해도 과언이 아니다. 따라 서 비판적 사고력을 증진시킬 수 있는 교과목 혹은 관련 교과목을 교과과정에 포함시켜 간호학생들이 임상현장을 접하기 전에 비판적 사고성향을 기르도록 하여 임상현장에 잘 적응할 수 있게 해야 할 것이다. 또 하나의 교육성과 측정영역인 전문직관을 분석한 결과 한국학생은 65. 44점 (95점 만점) 이었고 중국학생 은 72. 14점으로 중국학생이 한국학생보다 유의하게 높은 점수를 보고하였다 (논 - 4. 876, P<, o이). 이는 Kim등신999) 의 연구에서 간호전문대학을 졸업한 현직 간 호사를 위한 2년의 편입과정 (RN- BㄴN) 학생들을 대상으로 한 조사에서 입학 시 점수인 91. 2叩33점 만점)을 95점 만점으로 환산한 점수인 입학시 65. 14점보다 높았고 졸업 시 점수인 70. 83보다는 한국학생은 낮은 점수를 중국학생은 더 높은 점수를 나타냈다. 본 연 구에서 저학년학생들과 고학년학생들을 비교했을 때 한국 의 경우 l학년은 61. % 점이었고 4학년은 70. 17점으로 4학년이 l학년보다 821점이 더 높았다. 이는 교육과 함께 병용된 체계화된 임상실습경험이 학부생인 l학 년과 4학년의 점수차이에 크게 좌우된 것으로 보인 다. 중국의 경우에서도 임상실습경험이 없는 1학년에 서 4학년까지의 점수 범위가 67. 10점에서 71. 50점인 반면 임상실습을 경험한 5학년의 경우 77.7점로 4학 년보다 α 27점이 더 높았다. 그러나 전문직관과 관련된 선수과목의 경험여부는 점수에 별로 큰 영향을 주지 못했다. 즉, 관련과목 경험학생들의 전문직관이 70. 03점이었고 경험하지 않은 학생들은 68. 27점으로 유의한 차이가 없었다 (t= 1. 033, p=272). 본 연구에서 한국과 중국 양 대학에 전문직 관을 중점적으로 다루는 과목이 없었고, 간호전문직 관을 측정하기 위해 사용한 도구가 간호수행과 관련 된 전문성, 직업윤리 및 감정이입의 수준을 파악하였기 때문에 간호수행을 실습하는 현장실습인 임상실습 의 경험여부가 긍정적인 전문직관 형성에 영향을 준 것으로 보인다. Jeong (2007) 의 연구에서도 임상에서 간호전문직관에 따라 간호수행능력이 달라지므로 간호전문직관을 긍정적으로 향상시키기 위한 계속 교육 의 필요성을 강조하였다. 이상의 연구결과는 한국과 중국의 교육성과 평가에 대한 지속적인 국제연구교류를 위해 일차적으로 중국 의 간호교육 환경을 중국의 간호역사와 함께 이해하며 교과과정을 분석하는 선행연구의 필요성을 제시하고 있다. 본 연구에서는 교육성과 평가를 위해 한국 교육평가원에서 제시한 5개 영역 중 먼저 2개 영역을 평가하며 중국과 한국학생들을 비교할 뿐만 아니라 중국과의 지속적인 연구교류의 가능성을 파악하였다. 여전히 언어와 문화의 차이로부터 오는 상대방을 이 해하는 어려움이 있었지만 본 대학으로서는 처음으로 중국 현지 연구팀과 협력관계를 유지하며 시도한 공동연구로서 앞으로 지속적인 국제연구교류를 위한 기초자료를 제시하는 연구였다. Purpose: The aim of this study was to examine the differences in critical thinking and professionalism between Korean and Chinese nursing students. Critical thinking and professionalism were a part of five domains to evaluate nursing education: critical thinking, professionalism, leadership, communication, and nursing practice from the Korean Accreditation Board of Nursing. Methods: Data were collected from 207 college nursing students: 104 students from the 4-year degree program in Korea and 103 from the 5-year degree program in China from September 2006 to September 2007. The instruments for Chinese students were translated in Chinese and re-translated to check accuracy. The data were analyzed by using the SPSS/ PC+ Win 12.0 Version. The x2-test to compare general characteristics and the t-test to examine the differences of the study variables were conducted. Results: Korean nursing students reported significantly higher scores of critical thinking than did Chinese students while Chinese students reported significantly higher scores of professionalism. Students took previous courses associated with critical thinking reported significantly higher scores than did those without previous courses taken. There was no significant difference in scores of professionalism whether students had previous experience of related courses or not. Rather than, students with clinical practice reported higher scores of professionalism than did those without clinical practice. Conclusion: Levels of critical thinking were influenced by course focusing on critical thinking while professionalism was improved by combination of associated courses and clinical practice. For follow-up study, there is needed to examine nursing curriculum between Korea and China.

Microstructure and Properties of the Cr–Si–N Coatings Deposited by Combining High-Power Impulse Magnetron Sputtering (HiPIMS) and Pulsed DC Magnetron Sputtering

Wang, T. G.,Dong, Y.,Gebrekidan, B. A.,Liu, Y. M.,Fan, Q. X.,Kim, K. H. Springer Science + Business Media 2017 Acta metallurgica sinica Vol.30 No.7

<P>The Cr-Si-N coatings were prepared by combining system of high-power impulse magnetron sputtering and pulsed DC magnetron sputtering. The Si content in the coating was adjusted by changing the sputtering power of the Si target. By virtue of electron-probe microanalysis, X-ray diffraction analysis and scanning electron microscopy, the influence of the Si content on the coating composition, phase constituents, deposition rate, surface morphology and microstructure was investigated systematically. In addition, the change rules of micro-hardness, internal stress, adhesion, friction coefficient and wear rate with increasing Si content were also obtained. In this work, the precipitation of silicon in the coating was found. With increasing Si content, the coating microstructure gradually evolved from continuous columnar to discontinuous columnar and quasi-equiaxed crystals; accordingly, the coating inner stress first declined sharply and then kept almost constant. Both the coating hardness and the friction coefficient have the same change tendency with the increase of the Si content, namely increasing at first and then decreasing. The Cr-Si-N coating presented the highest hardness and average friction coefficient for an Si content of about 9.7 at.%, but the wear resistance decreased slightly due to the high brittleness. The above phenomenon was attributed to a microstructural evolution of the Cr-Si-N coatings induced by the silicon addition.</P>

Optical properties of amorphous $Si_xC_yN_z$ ternary thin films prepared by plasma enhanced chemical vapor deposition

Zhang, Z.H.,Fan, X.J.,Guo, H.X.,Zhang, W.,Zhang, C.Y.,Luo, F.Y. The Korean Vacuum Society 1998 Applied Science and Convergence Technology Vol.7 No.1

Amorphous ternary $Si_xC_yN-z$ thin films were obtained by plasma enhanced chemical vapor deposition(PECVD) using $N_2, SiH_4 \;and \;C_2H_4$ as the reaction sources. The chemical state were characterized by x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy(FTIR). The optical properties of the thin films were investigated by UV-visible spectrophotometer and ellipsometer, and the optical band gaps of thin films were determined from corresponding transmittance spectra following Tauc equation.

Structural studies of Mn+ implanted GaN film

Y. Shi,L. Lin,C. Z. Jiang,X. J. Fan 한국진공학회(ASCT) 2003 Applied Science and Convergence Technology Vol.12 No.S1

Wurtzite GaN films are grown by low-pressure MOCVD on (0001)-plane sapphire substrates. The GaN films have a total thickness of 4 ㎛ with a surface Mg-doped p-type layer, which has a thickness of 0.5 ㎛. 90k eV Mn^+ ions are implanted into the GaN films at room temperature with doses ranging from 1×10^(15) to 1×10^(16) ㎝-². After an annealing step at 770℃ in flowing N₂, the structural characteristics of the Mn^+ implanted GaN films are studied by X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and atomic force microscopy (AFM). The structural and morphological changes brought about by Mn^+ implantation and annealing are characterized.

Magnetic Characteristics and Structure Studies of Mn-Implanted p-type GaN Films

Y. Shi,C. Z. Jiang,D. J. Fu,L. Lin,강태원,X. J. Fan 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

Wurtzite GaN ¯lms are grown by low-pressure MOCVD on (0001)-plane sapphire substrates. The GaN ¯lms have a total thickness of 4 ¹m with a surface Mg-doped p-type layer which has a thickness of 0.5 ¹m. 90-keV Mn+ ions are implanted into the GaN ¯lms at room temperature with doses ranging from 1 £ 1015 cm¡2 to 5 £ 1016 cm¡2. After an annealing step at about 800 ±C in °owing N2, the magnetism of the Mn-implanted GaN ¯lms is investigated by superconducting-quantum-interference device (SQUID). Despite the diamagnetic background of the undoped sample, the Mn-implanted GaN ¯lms show paramagnetism with dose of 1£1015 cm¡2 and ferromagnetism with a dose of 5 £ 1015 cm¡2 » 5 £ 1016 cm¡2. Combined with the structural characteristics given by X-ray diraction (XRD) and scanning electron microscopy (SEM), the magnetism of the Mn-implanted p-type GaN ¯lms is discussed.

Structural studies of $Mn^+$ implanted GaN film

Shi, Y.,Lin, L.,Jiang, C.Z.,Fan, X.J. The Korean Vacuum Society 2003 Applied Science and Convergence Technology Vol.12 No.1

Wurtzite GaN films are grown by low-pressure MOCVD on (0001)-plane sapphire substrates. The GaN films have a total thickness of 4 $\mu$m with a surface Mg-doped p-type layer, which has a thickness of 0.5 $\mu$m. 90k eV $Mn^{+}$ ions are implanted into the GaN films at room temperature with doses ranging from $1 \times10^{15}$ to $1 \times 10^{16}\textrm{cm}^{-2}$. After an annealing step at $770^{\circ}C$ in flowing $N_2$, the structural characteristics of the $Mn^{+}$ implanted GaN films are studied by X-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and atomic force microscopy (AFM). The structural and morphological changes brought about by $Mn^{+}$ implantation and annealing are characterized.

Simulation of Neutron irradiation Corrosion of Zr-4 Alloy Inside Water Pressure reactors by Ion Bombardment

Bai, X.D.,Wang, S.G.,Xu, J.,Chen, H.M.,Fan, Y.D. The Korean Vacuum Society 1997 Applied Science and Convergence Technology Vol.6 No.1

In order to simulate the corrosion behavior of Zr-4 alloy in pressurized water reactors it was implanted (or bombarded) with 190ke V $Zr^+\; and \;Ar^+$ ions at liquid nitrogen temperature and room temperature respectively up to a dose of $5times10^{15} \sim 8\times10^{16} \textrm{ions/cm}^2$ The oxidation behavior and electrochemical vehavior were studied on implanted and unimplanted samples. The oxidation kinetics of the experimental samples were measured in pure oxygen at 923K and 133.3Pa. The corrosion parameters were measured by anodic polarization methods using a princeton Applied Research Model 350 corrosion measurement system. Auger Electron Spectroscopy (AES) and X-ray Photoelectric Spectroscopy (XPS) were employed to investigate the distribution and the ion valence of oxygen and zirconium ions inside the oxide films before and after implantation. it was found tat: 1) the $Zr^+$ ion implantation (or bombardment) enhanced the oxidation of Zircaloy-4 and resulted in that the oxidation weight gain of the samples at a dose of $8times10^{16}\textrm{ions/cm}^2$ was 4 times greater than that of the unimplantation ones;2) the valence of zirconium ion in the oxide films was classified as $Zr^0,Zr^+,Zr^{2+},Zr^{3+}\; and \;Zr^{4+}$ and the higher vlence of zirconium ion increased after the bombardment ; 3) the anodic passivation current density is about 2 ~ 3 times that of the unimplanted samples; 4) the implantation damage function of the effect of ion implantation on corrosion resistance of Zr-4 alloy was established.

Polymorphism of Ghrelin Gene in Twelve Chinese Indigenous Chicken Breeds and Its Relationship with Chicken Growth Traits

C. C. Li,K. Li,J. Li,D. L. Mo,R. F. Xu,G. H. Chen,Y. Z. Qiangba,S. L. Ji,X. H. Tang,B. Fan,M. J. Zhu,T. A. Xiong,X. Guan,B. Liu 아세아·태평양축산학회 2006 Animal Bioscience Vol.19 No.2

A 2,656 bp fragment of chicken ghrelin gene was cloned and SNPs were detected by PCR-RFLP and Allele Specific PCR (ASP) in 12 Chinese indigenous chicken breeds and a commercial chicken population. The results showed that there were 23 base variations and an amino acid change (Gln->Arg) in cloned chicken ghrelin gene. Three SNPs were confirmed in 13 populations and associations between this gene and growth traits of Tibetan chicken (TC) and Recessive White chicken (RW) were investigated. The results of haplotype analysis revealed that 26 haplotype genotypes were composed of eight haplotypes. The results of x2 tests indicated that there were significant differences between genotypes or haplotype genotype frequencies in some of the breeds or sexes at 0.05 or 0.01 levels. The results of ANOVA revealed that there were significant differences between genotypes or haplotype genotypes on some growth traits of TC and RW chicken breeds at 0.05 or 0.01 levels. Multiple comparisons showed that there were significant associations between genotype CT at site 71 and some growth traits of two chicken breeds and between genotype AG at site 1,215 and body weight at 16 wk of two chicken breeds, and there was a significant association between haplotype genotype CAA/CAG and body weight and shank girth at 16 wk of two chicken breeds.

ELECTROMAGNETIC VALVE TRAIN FOR GASOLINE ENGINE EXHAUST SYSTEM

X. Y. FAN,L. LIU,S. Q. CHANG,J. T. XU,J. G. DAI 한국자동차공학회 2016 International journal of automotive technology Vol.17 No.3

Electromagnetic valve train (EMVT) in camless engine offers large potential for both part load fuel economy and high load engine torque. However, it is more difficult to be applied on exhaust system than intake system. Because the gas pressure brings high demands for driving force, especially at high engine speed and full load. Based on the working characters of actuator, a method by increasing the transient currents in windings during valve’s opening motion is suggested to overcome the gas pressure. But this will cause more energy losses and heat. In order to make the EMVT used on exhaust system better, quantitative analysis is carried out against the additional power consumption caused by gas pressure under different conditions. Furthermore, an approach is introduced to define the optimal exhaust valve opening motion at full load conditions. It aims at making a better compromise between the engine power output and exhaust valves’ power consumption, thus both the efficiency of EMVT and engine performance are enhanced.