• 호남수학학술지
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• 제31권2호
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• pp.185-201
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• 2009

Let M be a real hypersurface with almost contact metric structure $({\phi},{\xi},{\eta},g)$ of a nonflat complex space form whose structure Jacobi operator $R_{\xi}=R({\cdot},{\xi}){\xi}$ is ${\xi}$-parallel. In this paper, we prove that the condition ${\nabla}_{\xi}R_{\xi}=0$ characterize the homogeneous real hypersurfaces of type A in a complex projective space $P_n{\mathbb{C}}$ or a complex hyperbolic space $H_n{\mathbb{C}}$ when $g({\nabla}_{\xi}{\xi},{\nabla}_{\xi}{\xi})$ is constant.

• 한국결정학회지
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• 제15권1호
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• pp.9-17
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• 2004

Trigonal system에 屬한 25個 space group들 中 18個는 hexagonal axes만을 나타내는 lattice letter p로 表示되고, 나머지 7個의 rhombohedral space groups R3(146), $R\={3}$(148), R32(155), R3m(160), R3c(161), $R\={3}m$(166), $R\={3}c$(167)은 첫째 3개의 lattice points (0, 0, 0), (2/3, 1/3, 1/3), (1/3, 2/3, 2/3)를 갖는 hexagonal cell in obverse setting과 둘째 primitive rhombohedral cell의 두 가지로 表示된다. 本 論文에서는 space group $R\={3}c$(167)에 대하여 論한 後 이 space group에 屬한 化合物인 tris(1,2,3,4-tetraphenylbuta-1,3-dienyl)cyclotriphosphazene, $C_{84}H_{60}N_3P_3$의 構造를 hexagonal 및 rhombohedral cell 의 양쪽으로 糾明하여 發表하였다.

• 한국결정학회지
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• 제13권3_4호
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• pp.148-151
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• 2002

X-선 회절법을 이용하여 metalaxy1, C/sub15/H/sub21/NO₄의 분자 및 결정 구조를 규명하였다. 화합물의 결정학 자료 : 단사정계 공간군 P2₁/c, a=7.849(4) Å, b=13.081(5) Å, c= 15.100(3) Å, β=101.8(2)°, V=1517.6(3) Å₃, Z=4. 분자 구조는 직접법으로 풀었고 완전최소자승법으로 정밀화하여 1694(F/sub 0//sup 2/>4σ(F/sub 0//sup 2/))인 독립회절반전에 대하여 최종 신뢰도 값 R= 0.067을 얻었다. 구조 해석 결과, Cl2-Hl2A…O1의 분자 내 수소 결합을 이루고 있었다.

• 한국세라믹학회지
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• 제40권6호
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• pp.513-518
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• 2003

La/sub 2/3-x/Li/sub 3x/□/sub 1/3-2x/TiO₃ compounds with x=0.13 and 0.12 were prepared by slow cooling (x=0.13) and rapid quenching (x=0.12) into the liquid nitrogen after sintering at 1350℃ for 6 h. Their crystal structure has been determined by Rietveld refinement of both the powder neutron and X-ray diffraction data. From neutron diffraction data, we found that the main phase was not tetragonal (P4/mmm), but trigonal (R3cH). The refinement of neutron diffraction for the slow cooled samples were in a good agreement with a new model; a mixture of trigonal (R3cH, 45.7 wt％), tetragonal (p4/mmm, 37.0 wt％), and Li/sub 0.57/Ti/sub 0.86/O₂(pbnm, 17.2 wt%), but the quenched sample was found not to contain tetragonal (p4/mmm). X-ray diffraction data couldn't be well fitted because of the Poor scattering factor of lithium ions and the similar reflection patterns among trigonal (R3cH), tetragonal (p4/mmm), and cubic (Pm3m). We also knew that one transport bottlenecks is destroyed by one La vacancy in the case of trigonal (R3cH).

• 한국재료학회지
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• 제1권4호
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• pp.184-190
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• 1991

고분해능 전자에너지손실과 자외선광전자분광법을 사용하여 단결정 ZrC(111)면의 산소흡착을 연구하였다. 산소는 낮은 산소노출량에서 $(\sqrt{3}{\times}\sqrt{3})R30^{\circ}$ 구조로 흡착된다. 노출량이 승가하면 $1{\times}1$ 구조로 바뀌는데 이때 흡착하는 산소원자는 $(\sqrt{3}{\times}\sqrt{3})R30^{\circ}$ 구조에서보다 흡착높이가 낮으며 3-fold hollow site의 중심에 놓이지 않고 bridge site에 가까와진다. 서로 다른 산소흡착 거동은 개끗한 ZrC(111) 표면에서 두개의 표면전자상태에 기인한다.

• Journal of Microbiology and Biotechnology
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• 제13권2호
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• pp.236-242
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• 2003

A culture-independent and -dependent survey of the bacterial community structure in the rhizosphere and soil samples from hot pepper plants was conducted using 16S rDNA clone library and FAME analyses. Out of the 78 clones sequenced, 56% belonged to Proteobacteria, 4% to high G+C Gram- positive group, 3% to Cytophyga-Flexibacter-Bacreroides, and 32% could not be grouped with any known taxonomic division. Among the 127 FAME isolates identified, 66% belonged to low G+C Gram-positive bacteria (Baciilus spp.) and 26% to high G+C Gram-positive bacteria. In a cluster analysis, the results for both methods were found to be strikingly dissimilar. The current study is the first comparative study of FAME and 165 rDNA clonal analyses performed on the same set of soil, rhizosphere soil, and root samples.

• Journal of Photoscience
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• 제9권2호
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• pp.110-113
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• 2002

We demonstrate here a dynamic structure of bacteriorhodopsin (bR) as revealed by $^{13}$ C NMR studies on [3_$^{13}$ C]_,[1-$^{13}$ C]Ala- and/or Val-labeled wild type and a variety of site-directed mutants at ambient temperature. For this purpose, well-resolved (up to twelve) I$^{13}$ C NMR peaks were assigned with reference to the displacement of peaks due to the conformation-dependent I$^{13}$ C chemical shifts and reduced peak-intensities due to site-directed mutations. Revealed bR structure was not rigid as anticipated from 2D crystals of hexagonal array but a dynamically heterogeneous, undergoing a variety of local fluctuations depending upon specific site with frequency range of 10$^2$ -10$^{8}$ Hz. In particular, dynamics- dependent suppression of peaks turned out to be very sensitive to the motion of 10$^{-4}$ s and 10$^{-5}$ s interfered with frequency of magic angle spinning and proton decoupling, respectively. It is also noteworthy that such dynamic feature is strongly dependent upon the manner of 2D crystalline packing: $^{13}$ C NMR peaks of monomeric bR yielded either highly broadened or completely suppressed signals, depending upon the type of $^{13}$ C-labeled amino-acid residues.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권10호
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• pp.495-499
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• 2004

Characteristics of ohmic Ni/Si/Ni contacts to n-type 4H-SiC are investigated systematically. The ohmic contacts were formed by annealing Ni/Si/Ni sputtered sequentially The annealings were performed at 950℃ using RTP in vacuum ambient and N₂ ambient, respectively. The specific contact resistivity(p/sub c/), sheet resistance(R/sub s/), contact resistance (R/sub c/) transfer length(L/sub T/) were calculated from resistance(R/sub T/) versus contact spacing(d) measurements obtained from TLM(transmission line method) structure. While the resulting measurement values of sample annealed at vacuum ambient were p/sub c/ = 3.8×10/sup -5/Ω㎠, R/sub c/ = 4.9 Ω and R/sub T/ = 9.8 Ω, those of sample annealed at N₂ ambient were p/sub c/ = 2.29×10/sup -4/Ω㎠, R/sub c/ = 12.9 Ω and R/sub T/ = 25.8 Ω. The physical properties of contacts were examined using XRD 3nd AES. The results showed that nickel silicide was formed on SiC and Ni was migrated into SiC. This result indicates that Ni/Si/Ni ohmic contact would be useful in high performance electronic devices.

• 통합자연과학논문집
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• 제9권4호
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• pp.261-267
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• 2016

The crystal structure of the saliciline derivatives 4-chloro-2{[(2-hydroxy-5-methylphenyl)amino]methyl}5-methylphenol ($C_{15}H_{15}ClNO_2$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group P21/c with unit cell dimension $a=11.5241(2){\AA}$, $b=8.733(2){\AA}$ and $c=13.649(2){\AA}$ [${\alpha}=90^{\circ}$, ${\beta}=130.876(2)^{\circ}$ and ${\gamma}=90^{\circ}$]. the title compound are essentially planar conformation. The compound lies across a crystallographic inversion centre and adopts E configurations with respect to the C-N bonds. The crystal packing of the molecules of compound is stabilized through weak O-H...O inter molecular interactions.

• 한국결정학회지
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• 제17권1호
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• pp.10-13
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• 2006

Ethylenediammonium chromate, $C_2H_{10}N_2{\cdot}CrO_4$ 결정구조는 a=6.667(2), b=8.845(2), c=11.827(2) ${\AA}$, 사방정계(Orthorhombic), 공간군 $P2_12_12_1$, 공간군 번호 19이며, Z=4, V=697.4(3) ${\AA}{^3},\;Dc=1.696gcm^{-3},\;{\mu}=1.594mm^{-1}$이었다. 구조분석은 중금속법으로 풀었으며, 최소 자승법으로 정밀화하였고, 최종 신뢰도 값들은 1204개의 회절반점에 대하여 $R_1=0.0254,\;R_w=0.070,\;R_{all}=0.0255$, S=1.133이었다. 두가지 이온들의 자료들은 기존 유사물질들의 자료에 상응하였으며, Ethylenediammonium 이온은 trans 구조로써 주위의 음이온과 사이에 많은 수소결합으로 연결되어 있다.