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971.
R.Q. Guo J. Nishimura M. Matsumoto M. Higashihata D. Nakamura J. Suehiro T. Okada 《Applied physics. B, Lasers and optics》2008,90(3-4):539-542
Ordered ZnO nanowire arrays have been fabricated in N2 background gas by catalyst-free nanoparticle-assisted pulsed-laser deposition. A single ZnO nanowire was collected in an
electrode gap by dielectrophoresis. Under the optical pumping above an exciting laser (λ= 355 nm) threshold of ∼ 334 kW/cm2, ultraviolet lasing action in a single ZnO nanowire was observed at room temperature, indicating that the as-synthesized
nanowires in pure N2 background gas are of high quality. The crystalline facets of both ends of the nanowire acted to form an optical cavity.
Therefore, the mode spacings corresponding to cavity lengths of the respective nanowires were observed in photoluminescence
spectra.
PACS 78.66.Hf; 81.07.Bc; 78.67.-n; 81.16.Mk 相似文献
972.
M. Matsumoto Y. Inayoshi E. Miyamoto S. Nakajima Y. Toyoshima 《Applied Surface Science》2008,254(19):6208-6210
Silicon nitride (SiNX) film fabrication on polyethylene terephthalate (PET) substrates has been achieved at a low temperature (∼100 °C) by plasma enhanced chemical vapor deposition operated at near atmospheric pressures. A short-pulse based power system was employed to maintain a stable discharge of SiH4, H2 and N2 in near atmospheric pressures without the use of any inert gases such as He. The deposited films were characterized by X-ray photoelectron spectroscopy. Cross sections of the films were observed by scanning electron microscope (SEM). Despite the use of N2 in place of NH3, a high deposition rate (290 nm/min) was obtained by this near-atmospheric-pressure plasma. 相似文献
973.
Hironobu Hojo Eiichiro HaginoyaYoshiyuki Matsumoto Yoshiaki NakaharaKazuki Nabeshima Bryan P. TooleYasushi Watanabe 《Tetrahedron letters》2003,44(14):2961-2964
Peptide thioester carrying N-linked core pentasaccharide was prepared by the Fmoc solid-phase method with a combination of the benzyl-protection strategy at the carbohydrate portion. The obtained peptide thioester was successfully used for the synthesis of the first Ig domain of emmprin composed of 61 amino acid residues. 相似文献
974.
Effects of the surface hydrophilicity of styrene-2-hydroxyethyl methacrylate (S-HEMA) copolymer microspheres on the adsorption immobilization of trypsin and on its enzymatic activity were discussed. In the case of a polystyrene (PS) microsphere, the amount of adsorption was large, whereas the enzymatic activity of the adsorbed trypsin was low. On the other hand, in the case of an S-HEMA copolymer microsphere whose HEMA content was 10 mole %, the maximum specific activity of trypsin adsorbed was nearly equal to that of free trypsin, although the amount of adsorption decreased to about 65 % of that in PS. Accordingly, total activity, which is the product of the amount of adsorption and the specific activity, could be enhanced by controlling the surface hydrophilicity of the microsphere.Part LXXXVII of the series Studies on Suspension and Emulsion. 相似文献
975.
Takumi Mizuno Manabu Matsumoto Ikuzo Nishiguchi Tsuneaki Hirashima 《Heteroatom Chemistry》1993,4(5):455-458
Urea derivatives were readily synthesized in good yields under quite mild conditions, i.e., at ambient pressure and room temperature by sulfur-assisted carbonylation of primary amines with carbon monoxide followed by oxidation of the resulting ammonium thiocarbamates with molecular oxygen. 相似文献
976.
Low-melting, low-viscous, hydrophobic ionic liquids: aliphatic quaternary ammonium salts with perfluoroalkyltrifluoroborates 总被引:2,自引:0,他引:2
A novel class of low-melting, hydrophobic ionic liquids based on relatively small aliphatic quaternary ammonium cations ([R(1)R(2)R(3)NR](+), wherein R(1), R(2), R(3) = CH(3) or C(2)H(5), R = n-C(3)H(7), n-C(4)H(9), CH(2)CH(2)OCH(3)) and perfluoroalkyltrifluoroborate anions ([R(F)BF(3)](-), R(F) = CF(3), C(2)F(5), n-C(3)F(7), n-C(4)F(9)) have been prepared and characterized. The important physicochemical and electrochemical properties of these salts, including melting point, glass transition, viscosity, density, ionic conductivity, thermal and electrochemical stability, have been determined and comparatively studied with those based on the corresponding [BF(4)](-) and [(CF(3)SO(2))(2)N](-) salts. The influence of the structure variation in the quaternary ammonium cation and perfluoroalkyltrifluoroborate ([R(F)BF(3)](-)) anion on the above physicochemical properties is discussed. Most of these salts are liquids at 25 degrees C and exhibit low viscosities (58-210 cP at 25 degrees C) and moderate conductivities (1.1-3.8 mS cm(-1)). The electrochemical windows of these salts are much larger than those of the corresponding 1,3-dialkyimidazolium salts. Additionally, a number of [R(F)BF(3)](-) salts exhibit plastic crystal behavior. 相似文献
977.
[structure: see text] An enantioselective total synthesis of aspidophytine is described. The indole fragment bearing a cis-alkene substituent was efficiently prepared through radical cyclization of a 2-alkenylphenylisocyanide followed by Sonogashira coupling of the generated 2-iodoindole derivative with a functionalized acetylene unit. After formation of the 11-membered cyclic amine, the aspidosperma skeleton and lactone ring were constructed to complete the total synthesis. 相似文献
978.
Five rare hexoses, which are components of antibiotics or cardiac glycosides, have been synthesized as methyl glycosides through a common intermediate methyl 2,3-dehydro-2,3,6-trideoxy-α-dl glucopyranoside (7). Epoxidation and subsequent treatment with dimethylamine of7 afforded methyl α-dl-mycaminoside (9). The addition reaction of MeOH to12 gave methyl α-dl-oleandroside (15) and methyl β-dl-cymaroside (17). The hydroxymercuration and subsequent reduction of12 afforded methyl α-dl-chromoside C (19) and methyl β-dl-tyveloside (25). 相似文献
979.
Mathematical models for the apparent masses of standing subjects exposed to vertical whole-body vibration 总被引:1,自引:0,他引:1
Y. Matsumoto 《Journal of sound and vibration》2003,260(3):431-451
Linear lumped parameter models of the apparent masses of human subjects in standing positions when exposed to vertical whole-body vibration have been developed. Simple models with a single degree-of-freedom (d.o.f.) and with two (d.o.f.) were considered for practical use. Model parameters were optimised using both the mean apparent mass of 12 male subjects and the apparent masses of individual subjects measured in a previous study. The calculated responses of two (d.o.f.) models with a massless support structure showed best agreement with the measured apparent mass and phase, with errors less than 0.1 in the normalised apparent mass (i.e., corresponding to errors less than 10% of the static mass) and errors less than 5° in the phase for a normal standing posture. The model parameters obtained with the mean measured apparent masses of the 12 subjects were similar to the means of the 12 sets of parameters obtained when fitting to the individual apparent masses. It was found that the effects of vibration magnitude and postural changes on the measured apparent mass could be represented by changes to the stiffness and damping in the two (d.o.f.) models. 相似文献
980.
Hiroaki Saito Kousuke Inoue Keiji Matsumoto Makoto Tadokoro Yukio Nakamura 《Journal of Cluster Science》1998,9(2):145-164
The oxidative addition reaction of 2,6-bis(bromomethyl)pyridine to Ru3(CO)12 gave scarcely soluble {Ru2Br2(-Q)(CO)4}
n
, 1, [Q=C5H3N-2-C(O)CH2-6-CH2] or a mixture of 1 and the mononuclear complex RuBr(Q)(CO)3, 2, [Q=C5H3N-2-C(O)CH2-6-CH2Br] according to the reactant's mole ratio. Further reactions of 1 with some N- and P-donor ligands (L) afforded readily soluble dinuclear complexes, Ru2(-Br)(-Q)Br(CO)
n
(L)
m
[n=4, m=1, L=PPh3
3a, or py 3b; n=3, m=2, L=PPh3
5a, or PPh2(o-tolyl) 5b]. In this paper, the characterization of these products by the elemental analyses and the spectroscopic methods are described. The X-ray crystal structures of Ru2(-Br) (-Q)Br(CO)4(PPh3)(MeOH), 4, which was obtained by crystallization of 3a from MeOH, and of 5a · (2CHCl
3
) are also described. Each of the metal atoms in 4 has a distorted octahedral coordination, while in 5a · (2CHCl
3
) one metal atom takes a distorted octahedral geometry and the other pseudooctahedral, which is completed by presenting a Ru ··· Br secondary bonding interaction. 相似文献