• Title/Summary/Keyword: H atoms

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ATOMIC CARBON IN THE W 3 GIANT MOLECULAR CLOUD

  • SAKAI TAKESHI;OKA TOMOHARU;YAMAMOTO SATOSHI
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.257-260
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    • 2005
  • We have mapped the W 3 giant molecular cloud in the $C^o\;^3P_1-^3 P_o$ ([CI]) line with the Mount Fuji Submillimeter-wave Telescope. The [CI] emission is extended over the molecular cloud, having peaks at three star forming clouds; W 3(Main), W 3(OH), and AFGL 333. The [CI] emission is found to be strong in the AFGL 333 cloud. We have also observed the $C^{18}O,\;CCS,\;N_2H^+$, and $H^{13}CO^+$ lines by using the Nobeyama Radio Observatory 45 m telescope. In the AFGL 333 cloud, we find two massive cores, which are highly gravitationally bound and have no sign of active star formation. The high [$C^o$]/[CO] and [CCS]/[$N_2H^+$] abundance ratios suggest that the AFGL 333 cloud is younger than the W 3(Main) and W 3(OH) clouds.

ON THE SCHULTZ POLYNOMIAL AND HOSOYA POLYNOMIAL OF CIRCUMCORONENE SERIES OF BENZENOID

  • Farahani, Mohammad Reza
    • Journal of applied mathematics & informatics
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    • v.31 no.5_6
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    • pp.595-608
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    • 2013
  • Let G = (V, E) be a simple connected graph. The sets of vertices and edges of G are denoted by V = V (G) and E = E(G), respectively. In such a simple molecular graph, vertices represent atoms and edges represent bonds. The distance between the vertices $u$ and $v$ in V (G) of graph G is the number of edges in a shortest path connecting them, we denote by $d(u,v)$. In graph theory, we have many invariant polynomials for a graph G. In this paper, we focus on the Schultz polynomial, Modified Schultz polynomial, Hosoya polynomial and their topological indices of a molecular graph circumcoronene series of benzenoid $H_k$ and specially third member from this family. $H_3$ is a basic member from the circumcoronene series of benzenoid and its conclusions are base calculations for the Schultz polynomial and Hosoya polynomial of the circumcoronene series of benzenoid $H_k$ ($k{\geq}3$).

A Study on the Laser Aided Measurement of Salt Contamination of Porcelain Insulators (레이저를 이용한 활선 염해 측정)

  • Cho, C.H.;Lee, H.S.;Choi, Y.W.;Kweon, D.J.;Choi, I.H.;Kim, J.B.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1807-1809
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    • 1997
  • The salt contamination on the surface of the porcelain insulators used electric power systems causes flash-over accidents. Therefore the quantity of salt contamination should be monitored not to exceed a limit. In this study, we tried laser aided measurement of salt contamination. The Nd:YAG laser beam was focused on the surface of the porcelain insulators which were artificially contaminated, and we detected the D-Line (${\cong}589nm$) of spontaneous emission from the excited sodium atoms with a PMT and an oscilloscope. And we deduced the relation between the detected signals and degree of salt contamination.

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Investigation into the variation on Si wafer by RTA annealing in $H_2$ gas (RTA를 이용하여 수소 열처리한 실리콘 웨이퍼의 표면 및 근처의 변화 연구)

  • 정수천;이보영;유학도
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.1
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    • pp.42-47
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    • 2000
  • The surface structure and the crystalline features in the near surface region have been investigated for CZ(Czochralski) grown Si wafers. Si wafers were annealed by RTA (Rapid Thermal Annealing) method in H$_2$ambient after mirror polished process. The densities of COPs (Crystal Originated Particles) after RTA process were remarkably decreased at the surface and in the region of 5um depth from the surface as well. terrace type surface structure which was formed by etching and re-arrangement of Si atoms during $H_2$annealing process also has been observed.

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The Chemical Kinetics for the Reaction of O(³P) with Ethylene

  • 임종태;조경용;최창열;박호림;최중길;Simon H. Bauer
    • Bulletin of the Korean Chemical Society
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    • v.16 no.7
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    • pp.595-600
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    • 1995
  • The kinetics of the reaction between O(3P) and C2H4 was investigated by measuring time-dependent concentrations of OH resulting from the reaction by using the LIF detection. Oxygen atoms were generated by titrating microwave discharged N2/He with NO to the chemiluminescent end point. The operating pressures in the flow reactor ranged from 5 to 15 torr and the mixtures consisted of He/O(3/P)/C2H4 in the approximate ratios from 100/1/0.1 to 100/1/1. The controlled residence time prior to the detection were estimated to be 0.8-17 ms at the reactor pressure of 7 torr. Experimentally determined profiles both in shape and magnitude were compared with the computed OH density for a specified set of experimental parameters, allowing us to arrive at a complete mechanism for the reaction of O(3P) with ethylene.

3-Dimensional Terbium Coordination Polymers: [Tb4(NDC)6(H2O)5]·2H2O and [Tb2(BPDC)3(H2O)3]·H2O(NDC = 2,6-Naphthalenedicarboxylate; BPDC = 2,2'-Bipyridine-4,4'-dicarboxylate)

  • Min, Dong-Won;Lee, Soon-W.
    • Bulletin of the Korean Chemical Society
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    • v.23 no.7
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    • pp.948-952
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    • 2002
  • Three-dimensional terbium coordination polymers with the formulas of [Tb4(NDC)6(H2O)5]${\cdot}$2H2O (1) and [Tb2(BPDC)3(H2O)3]${\cdot}$H2O (2) (NDC = 2,6-naphthalenedicarboxylate; BPDC = 2,2'-bipyridine-4,4'-dicarboxy-late) were prepared by hydrothermal reactions. Both compounds were structurally characterized by X-ray diffraction. Compound 1 has a polymeric structure that contains four distinct Tb metals. Three Tb metals have a square-antiprismatic structure, and the remaining one has a 9-coordinate, triply capped trigonal-prismatic structure. Compound 2 is also a polymer with two distinct Tb metals, both of which have a square-antiprismatic structure. The pyridine nitrogen atoms of the BPDC 2- ligand do not coordinate to the metal centers in compound 2.

AN ESR STUDY OF AMINO ACID AND PROTEIN FREE RADICALS IN SOLUTION PART I. Reaction Mechanism of Free Radical Production in the Ti-$H_2O_2$ Flow System (용액에서의 아미노산 및 단백질 자유기에 관한 ESR 연구 제1보 ; Ti-$H_2O_2$ Flow System에서 자유기를 만드는 반응기구)

  • Hong Sun-Joo;L. H. Piette
    • Journal of the Korean Chemical Society
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    • v.15 no.1
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    • pp.37-44
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    • 1971
  • The reaction of amino acids and the reactive hydroxyl radical generated by $Ti^{3+}-H_2O_2$ system was studied using fast flow techniques coupled with ESR. Upon adding methionine to the 0.2M $H_2O_2$ solution (0.05M methionine after addition) and mixing with 0.01M $TiCl_3$, the low field component of the two incompletely resolved peaks, in the spectrum of $Ti^{3+}-H_2O_2$ system alone, vanished completely whereas the high field component remained almost constant and superimposed on the secondary spectrum of the methionine free radical. Similar results were obtained for other amino acids and proteins. The results strongly demonstrate that the $T^{3+}-H_2O_2$ flow system generates two different radical species, only one of which, giving rise to the low field component, is alone responsible for abstracting hydrogen atoms from substrate molecules. The effects of HCl, $H_2SO_4$ and NaOH on the system were also studied with widely varying results.

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Adsorption of H Atoms on the Si(111)$4{\times}1$-In Surface (Si(111)$4{\times}1$-In 표면에의 수소원자 흡착 연구)

  • Yu Sang-Yong;Lee Geun-Seop
    • Journal of the Korean Vacuum Society
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    • v.15 no.2
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    • pp.139-144
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    • 2006
  • Using scanning tunneling microscopy (STM) measurements, we studied the adsorption of hydrogen on the Si(111)$4{\times}1$-In surface at room temperature. The H atom features are found to be located between the two protrusions in one side of the $4{\times}1$ chain. The adsorbed H preferentially occupies one of the two zigzag In subchains, suggesting that the adsorption of H is influenced by the subsurface structure. The adsorbed H atom induces not only a localized distortion but also perturbs the distant region and results in a period-doubling modulations in the STM images. This H-induced perturbation differs from the Na-Induced perturbation on the same surface.

Spectral and Geometrical Study of Two Cadmium Complexes, mer-R,S-[Cd(aepn)2]X2 (X: I-, Cl-, aepn: N-(2-Aminoethyl)-1,3-propanediamine) Supported by Solution Experiments

  • Hakimi, Mohammad;Mardani, Zahra;Moeini, Keyvan
    • Journal of the Korean Chemical Society
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    • v.57 no.4
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    • pp.447-454
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    • 2013
  • In this research, two new complexes of N-(2-aminoethyl)-1,3-propanediamine (aepn), $[Cd(aepn)_2]I_2$ (1) and $[Cd(aepn)_2]Cl_2{\cdots}H_2O$ (2), were prepared and identified by elemental analysis, FT-IR, Raman spectroscopy and single-crystal X-ray diffraction. Geometry around the cadmium atom in two complexes by coordination of six nitrogen atoms of two aepn is distorted octahedral. If distortion in the mer-$[Cd(aepn)_2]^{2+}$ cation is disregarded, it has a $C_2$ axis and $C_2$ symmetry. The cyclic voltammetry experiments were carried out to study the complexation process. Two structural surveys on coordination modes and complexes of aepn are presented. A study was carried out using CSD data to estimate the averages of bond lengths for different types of the Cd-N bonds. It was found that the intermolecular $N-H{\cdots}I$, $C-H{\cdots}I$ hydrogen bonds in 1 and $N-H{\cdots}Cl$, $N-H{\cdots}O$, $C-H{\cdots}O$, $O-H{\cdots}Cl$ in 2 stabilized the crystal networks.

Behavior of Hydroxide Ions at the Water-Ice Surface by Low Energy Sputtering Method

  • Kim, S.Y.;Park, E.H.;Kang, H.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.338-338
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    • 2011
  • The behavior of hydroxide ions on water-ice films was studied by using $Cs^+$ reactive ion scattering (RIS), low energy sputtering (LES) and temperature-programmed desorption (TPD). A $Cs^+$ beam of a low kinetic energy (<100 eV) from $Cs^+$ ion gun was scattered at the film surface, and then $Cs^+$ projectiles pick up the neutral molecules on the surface as $Cs^+$-molecule clusters form (RIS process). In LES process, the preexisting ions on the surface are desorbed by the $Cs^+$ beam impact. The water-ice films made of a thick (>50 BL) $H_2$O layer and a thin $D_2O$ overlayer were controlled in temperatures 90~140K. We prepared hydroxide ions by using Na atoms which proceeded hydrolysis reaction either on the ice film surface or at the interface of the $H_2O$ and $D_2O$ layers.[1] The migration of hydroxide ions from the $H_2O/D_2O$ interface to the top of the film was examined as afunction of time. From this experiment, we show that hydroxide ions tend to reside at the water-ice surface. We also investigated the H/D exchange reactions of $H_2O$ and $D_2O$ molecules mediated by hydroxide ions to reveal the mechanism of migration of hydroxide to the ice surface.

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