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221.
Mitsuru Kitamura Ken Ohmori Toshihisa Kawase Keisuke Suzuki 《Angewandte Chemie (International ed. in English)》1999,38(9):1229-1232
A benzo[ a ]naphthacenequinone core, an amino acid, and a disaccharide are the constituents of pradimicin–benanomicin antibiotics 1 (R1=disaccharide), a class of natural products with significant antifungal and anti-HIV activities. The first total synthesis of pradimicinone (benanomicinone, 1 ; R1=H), the common aglycon of this class of natural products, has now been achieved based on the transmission of chirality during the pinacol cyclization of 2,2′-biaryldicarbaldehydes. 相似文献
222.
Andriy Kovalenko Seiichiro Ten-no Fumio Hirata 《Journal of computational chemistry》1999,20(9):928-936
We proposed a modified procedure of the direct inversion in the iterative subspace (DIIS) method to accelerate convergence in the integral equation theory of liquids. We update the DIIS basis vectors at each iterative step by using the approximate residual obtained in the DIIS extrapolation. The procedure is tested by solving the 3-dimensional (3-D) generalization of the reference interaction site model equation together with the hypernetted chain closure, as well as their 1-D version. We calculated the 3-D site distribution of water, represented by the simple point charge model, around one water molecule considered as a central particle. ©1999 John Wiley & Sons, Inc. J Comput Chem 20: 928–936, 1999 相似文献
223.
The effects of alkyl chain length and of differences in the length of the two alkyl chains on the formation of a monolayer of chemically synthesized corynomycolic acid (2-alkyl-3-hydroxy fatty acid) at the air-water interface were examined. Hydrophobic interactions between the two alkyl chains are required for the formation of a condensed film, which is most stable when the total number of carbon atoms in the two alkyl chains is 25 or more and the difference in their lengths is one. Syn-isomers form condensed films but usually not anti-isomers. However, films may also be formed by the anti-isomer when the alkyl chain at the carboxy group (the 2-position) is longer than the alkyl chain at the hydroxy group (the 3-position). That is, the contribution of anti-isomers to condensed film formation depends on the polar carboxy group which has greater involvement in this formation. The extrapolated area for the condensed film of corynomycolic acid was 40 Å2 per molecule, thus confirming that both the carboxy and hydroxy groups are present on the water surface when a bipolar monolayer is formed. 相似文献
224.
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226.
Kazuyuki Horie Seiichiro Murase Satoshi Takahashi Madoka Teramoto Hidemitsu Furukawa 《Macromolecular Symposia》2003,195(1):201-208
The molecular design for large photo-induced refractive index changes in transparent visible light region was proposed and realized with norbornadiene polymers and poly(vinyl cinnamate). The patterning of pure refractive-index contract on their transparent films was made with near-field scanning optical microscopy (NSOM). Reversible fluorescence patterning on polymer films is also presented by using controlled energy transfer from a fluorescent pyromethene to a photochromic diarylethene. 相似文献
227.
Seiichiro Ten-no Suehiro Iwata Sourav Pal Debashis Mukherjee 《Theoretical chemistry accounts》1999,102(1-6):252-261
Employing separate cluster ansatz in time-independent and time-dependent wave-operators, coupled-cluster (CC) response theory
is generalized to multireference (MR) expansion spaces. For state energies, this corresponds to the MR secular problem with
an arbitrary similarity-transformed effective Hamiltonian, H˜=Ω−1
HΩ. The effective Hamiltonian can be generated via size-extensive CC methods. Thus the states in MR linear response theory
(MRLRT) maintain the usual CC core-extensive properties. We have used the Gelfand unitary group basis of the spin-adapted
configurations to construct the matrix of H˜ in the MR excitation space. As a preliminary application, the CC singles and
doubles effective Hamiltonian is applied to excitation and photoionization energies of the CH+ and N2 molecules, and is compared with experimental results and results from other numerical procedures including conventional CC
linear response theory (CC-LRT), MR and full configuration interaction (MRCI and FCI) methods. The numerical results indicate
that MRLRT reproduces valence and external excited states quantitatively, combining the best features of CC-LRT and MRCI.
Received: 2 July 1998 / Accepted: 28 August 1998 / Published online: 11 November 1998 相似文献
228.
New films of the iron complexes with bis((2-hydroxyphenyl)methylaminosulfonyl)bathophenanthroline(HPBP) and bis((2-aminophenyl)methylaminosulfonyl)bathophenanthroline(APBP) ligands are prepared on the electrode surfaces by electrochemical polymerization. The resulting film-coated electrode shows a well-defined reversible voltammogram corresponding to the redox reaction of the Fe(II/III) complexes and an electrochromic change from red(absorption maximum: 540 nm) to colorless. The response rate of the color change to a potential step was found to be correlated to the apparent diffusion coefficient(Dapp) for the homogeneous charge-transport process within the film. The Dapp values estimated are (3-4) × 10−9cm2s−1 for the [Fe(APBP)3] film and(1-2) × 10−8cm2s−2 for the [Fe(HPBP)3] film, respectively, by potential-step chronoamperometric and chronocoulometric methods. The result of electrochemical quartz crystal microbalance(EQCM) measurements4) and dependence of the formal potential of the metal complex of the Fe(II/III) redox couple with activity of the supporting electrolyte anion in NaClO4 aqueous solution showed that anion, cation, and solvent move simultaneously across the polymer film/solution interface during the redox reaction. A piezoelectric admittance measurement4) of the poly[Fe(APBP)3] coated quartz crystal electrode showed that the viscosity of the film is affected by the oxidation state of iron. 相似文献
229.
Seiichiro OGAWA Shinichi KUNO Tatsushi TOYOKUNI 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2022,98(7):336
For over 50 years, our group has been involved in synthetic studies on biologically active cyclitols including carbasugars. Among a variety of compounds synthesized, this review focuses on carbaglycosylamine glycosidase inhibitors, highlighting the following: (1) the naturally occurring N-linked carbaoligosaccharide α-amylase inhibitor acarbose and related compounds; (2) the novel synthetic β-glycosidase inhibitors, 1′-epi-acarviosin and its 6-hydroxy analogue as well as β-valienaminylceramide and its 4′-epimer; (3) the discovery of the β-glycosidase inhibitors with chaperone activity, N-octyl-β-valienamine (NOV) and its 4-epimer (NOEV); and (4) the recent development of the potential pharmacological chaperone N-alkyl-conduramine F-4 derivatives. 相似文献
230.
Kazuma Shinoda Taisuke Hamasaki Maru Kawase Madoka Hasegawa Shigeo Kato 《Optical Review》2016,23(4):559-570
Multispectral images (MSIs), which consist of more color components than RGB images, can be used in the field of vegetation analysis and medical imaging. A capturing system with multispectral filter array (MSFA) technology has been researched to shorten the capturing time and reduce the cost. In this system, the mosaicked image captured by the MSFA is demosaicked to reconstruct the MSI. We propose a demosaicking method using vectorial total variation (VTV) regularization for an MSI. This process is regarded as inverse problem of the image observation model. The reconstructed image is estimated by minimizing the VTV as a regularization term under the constraint condition. In the experimental results, the reconstructed image quality obtained using the proposed method is better than that of the conventional approaches in terms of both peak signal-to-noise ratio and structural similarity. 相似文献