http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : H. Marchand (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
Physical and chemical changes of coal during catalytic fluidized bed gasification
Marchand, D.J.,Schneider, E.,Williams, B.P.,Joo, Y.L.,Kim, J.,Kim, G.T.,Kim, S.H. Elsevier Scientific Pub. Co 2015 Fuel processing technology Vol.130 No.-
Coal gasification was studied by analyzing samples of feedstock extracted from a fluidized bed gasifier at various times throughout the gasification process. The analysis techniques used included energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy for elemental concentrations in the bulk and at the surface, respectively; acidimetric titrations to quantify the concentration of certain oxygen functional groups; and the BET method to determine surface area and porosity. The changes in feed particle size and composition showed that the gasification reaction rate was slow compared to the gas diffusion rates inside the coal particle. Detailed analysis of the composition and oxygen functional groups showed that the catalyst was loaded in the coal by ion exchange with surface oxygen functional groups. As the gasification reaction proceeded, the oxidized carbon content increased in the coal loaded with catalyst, but decreased in the coal without catalyst. That result supports the idea that the catalyst increases the reaction rate by helping to oxidize the carbon and increasing the number of reactive sites, rather than by decreasing the energy barrier for carbon-carbon bond breakage.
-
Nanoindentation of Laterally Overgrown Epitaxial Gallium Nitride
M. Martyniuk,G. Parish,H. Marchand,P.T. Fini,S.P DenBaars,L. Faraone 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.2
Nanoindentation has been used to investigate and compare the mechanical properties of GaN grown by the lateral epitaxial overgrowth (LEO) method and the defective seed region prepared by metalorganic chemical vapour deposition. Common modulus of elasticity values (~230 GPa) and hardness values (~19 GPa) were found for both materials. The GaN response to nanoindentation was found to be purely elastic for low inden-tation loads with the onset of plasticity being marked by discontinuities or “pop-in” events in the indenter load-penetration curves. The maximum shear stress under the indenter at pop-in events for LEO GaN cor-responds well with the critical shear stress necessary for homogeneous dislocation nucleation, indicating that the defects in this region are too sparse and do not aid in dislocation nucleation.
-
Kirby, K A,Singh, K,Michailidis, E,Marchand, B,Kodama, E N,Ashida, N,Mitsuya, H,Parniak, M A,Sarafianos, S G R. Wegmann 2011 Cellular and molecular biology Vol.57 No.1
<P>4'—Ethynyl—2—fluoro—2'—deoxyadenosine (EFdA) is the most potent inhibitor of HIV reverse transcriptase (RT). We have recently named EFdA a Translocation Defective RT Inhibitor (TDRTI) because after its incorporation in the nucleic acid it blocks DNA polymerization, primarily by preventing translocation of RT on the template/primer that has EFdA at the 3'—primer end (T/PEFdA). The sugar ring conformation of EFdA may also influence RT inhibition by a) affecting the binding of EFdA triphosphate (EFdATP) at the RT active site and/or b) by preventing proper positioning of the 3'—OH of EFdA in T/PEFdA that is required for efficient DNA synthesis. Specifically, the North (C2'—exo/C3'—endo), but not the South (C2'—endo/C3'—exo) nucleotide sugar ring conformation is required for efficient binding at the primer—binding and polymerase active sites of RT. In this study we use nuclear magnetic resonance (NMR) spectroscopy experiments to determine the sugar ring conformation of EFdA. We find that unlike adenosine nucleosides unsubstituted at the 4'—position, the sugar ring of EFdA is primarily in the North conformation. This difference in sugar ring puckering likely contributes to the more efficient incorporation of EFdATP by RT than dATP. In addition, it suggests that the 3'—OH of EFdA in T/PEFdA is not likely to prevent incorporation of additional nucleotides and thus it does not contribute to the mechanism of RT inhibition. This study provides the first insights into how structural attributes of EFdA affect its antiviral potency through interactions with its RT target.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
