http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Study of the growth of Au films on Si(100) and Si films on Ge(100) surface
J. H. Kim,Y. S. Lee,K. H. Lee,A. Weiss,J. H. Lee 한국진공학회(ASCT) 2002 Journal of Korean Vacuum Science & Technology Vol.6 No.3
The growth of Au films grown on a Si(100)-2x1 surface and Si films on a Ge(100)-2x1 substrate is studied using Positron-annihilation induced Auger Electron Spectroscopy(PAES), Electron induced Auger Electron Spectroscopy(EAES), and Low Energy Electron Diffraction(LEED). Previous work has shown that PAES is almost exclusively sensitive to the top-most atomic layer due to the trapping of positrons in an image potential well just outside the surface before annihilation. This surface specificity is exploited to profile the surface atomic concentrations during the growth of Au on Si(100) and Si on Ge(100) and EAES provides concentrations averaged over the top 3-10 atomic layers simultaneously. The difference in the probe-depth makes us possible to use PAES and EAES in a complementary fashion to estimate the surface and near surface concentration profiles. The results show that (ⅰ) the intermixing of Au and Si atoms occurs during the room temperature deposition, (ⅱ) the segregated Ge layer is observed onto the Si layers deposited at 300K. In addition, the prior adsorption of hydrogen prevents the segregation of Ge on top of the deposited Si and that the hydrogen adsorption is useful in growing a thermally stable structure.
First 230 GHz VLBI fringes on 3C 279 using the APEX Telescope
Wagner, J.,Roy, A. L.,Krichbaum, T. P.,Alef, W.,Bansod, A.,Bertarini, A.,Gü,sten, R.,Graham, D.,Hodgson, J.,Mä,rtens, R.,Menten, K.,Muders, D.,Rottmann, H.,Tuccari, G.,Weiss, A.,Wieching, G.,W EDP Sciences 2015 Astronomy and astrophysics Vol.581 No.-
김석규,전권수,김재홍,이종용,A.H. Weiss,M. Nadesalingam 한국물리학회 2005 새물리 Vol.51 No.4
Positron-annihilation-induced Auger electron spectroscopy (PAES) studies performed on the Fe-Cu alloy surface have demonstrated the trapping of positrons in quantum-dot-like Cu nano-particles on the Fe surface. In PAES, energetic electron emission results from Auger transitions initiated by annihilation of core electrons with positrons trapped in a surface state. The strong Fe PAES intensities obtained from a clean Fe-Cu (as quenched) alloy surface indicate that the surface was terminated by Fe atoms. This suggests that the implanted positrons are trapped at Fe sites in the top most layer of the sample. The low Fe intensity observed in PAES mesurements of a Cu-Fe (2h-aged) alloy indicates that the positrons are trapped at Cu nano-particles diffused onto the surface during heating at 550 $^\circ$C for 2 h while EAES showed no difference between the of the Fe-Cu and the Cu-Fe alloys. 양전자 소멸 유도 Auger 분광기를 이용하여 Fe-Cu alloy 시스템에서 Fe 표면에 있는 nano particle 과 같은 Cu 양자점에 양전자가 포획됨을 보였다. 본 논문에서는 최근에 개발된 Positron annihilation-induced Auger Electron Spectroscopy (PAES)를 이용하여 표면에 양전자가 포획되는 표면선택성을 이용하여 극소량의 원소를 구분 할 수 있는 결과를 보고한다. 철 표면에 증착되는 미소량의 구리 농도를 측정하였고, 0.5 ML 정도에서 95 \% 정도의 Cu 구성비를 얻었다. 반면에 기존의 전자를 이용한 표면 분석 방법으로는 10 \%정도의 Cu 구성비를 얻었다. 저에너지($\sim$ 16 eV)로 조사된 양전자는 표면에서 포획되어 최외각 원자층의 코아 전자와 소멸해서 Auger 전자를 방출한다. 급속 냉각한 Fe-Cu시료를 2시간동안 550 $^\circ$C로 가열한 후 PAES는 표면에 Cu 원자가 증가함을 보인 반면에 EAES는 변화를 볼 수 없었다.
Lee, N.K.,Kapanidis, A.N.,Koh, H.R.,Korlann, Y.,Ho, S.O.,Kim, Y.,Gassman, N.,Kim, S.K.,Weiss, S. Published for the Biophysical Society by the Rocke 2007 Biophysical journal Vol.92 No.1
We introduce three-color alternating-laser excitation (3c-ALEX), a fluorescence resonance energy transfer (FRET) method that measures up to three intramolecular distances and complex interaction stoichiometries of single molecules in solution. This tool extends substantially the capabilities of two-color ALEX, which employs two alternating lasers to study molecular interactions (through probe stoichiometry S) and intramolecular distances (through FRET efficiency E), and sorts fluorescent molecules in multi-dimensional probe-stoichiometry and FRET-efficiency histograms. Probe-stoichiometry histograms allowed analytical sorting, identification, and selection of diffusing species; selected molecules were subsequently represented in FRET-efficiency histograms, generating up to three intramolecular distances. Using triply labeled DNAs, we established that 3c-ALEX enables 1), FRET-independent analysis of three-component interactions; 2), observation and sorting of singly, doubly, and triply labeled molecules simultaneously present in solution; 3), measurements of three intramolecular distances within single molecules from a single measurement; and 4), dissection of conformational heterogeneity with improved resolution compared to conventional single-molecule FRET. We also used 3c-ALEX to study large biomolecules such as RNA polymerase-DNA transcription complexes, and monitor the downstream translocation of RNA polymerase on DNA from two perspectives within the complex. This study paves the way for advanced single-molecule analysis of complex mixtures and biomolecular machinery.