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1.
Phosphonic acid analogues of acylcarnitine were prepared in an optically active form expecting CPT I inhibitory activities. The synthetic methodology was based on catalytic asymmetric dihydroxylation of β,γ-unsaturated phosphonates and subsequent regioselective amination via the cyclic sulfates. 相似文献
2.
Tsutomu KumagaiMasaaki Tomura Jun-ichi NishidaYoshiro Yamashita 《Tetrahedron letters》2003,44(36):6845-6848
1,3-Dithiol-2-ylidene derivatives containing bis(ethynylpyridine) units were synthesized using a Pd-catalyzed reaction of the corresponding dibromide. X-Ray crystal analysis revealed unique crystal structures depending on the aromatic groups. The absorption spectra and redox properties indicated intramolecular charge-transfer interactions between the 1,3-dithiole unit and the pyridyl parts. 相似文献
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Prof. Dr. K. Ikegami Prof. Dr. T. Sugibayashi Mr. K. Matsuo 《Archive of Applied Mechanics (Ingenieur Archiv)》1994,65(1):44-53
Summary A method of joining two metal cylindrical shafts with adhesive coupling is proposed. Two cylindrical shafts with the same diameter are connected by bonding through a cylindrical coupling with epoxy resin. The strength of the shaft joint under tensile loading and torsional loading is investigated analytically and experimentally. The stress and strain distributions of the shaft joint is analyzed by the finite element method. The analyzed strain distributions in the joint are compared with experimental values. The joint strength is predicted by applying the strength laws of shafts, coupling, adhesive layer and adhesive interface between shaft and adhesive coupling. The effects of the coupling dimension on the joint strength are examined. It is shown that the adhesive shaft joint can transfer the load by which the cylindrical shafts are plastically deformed.This paper was refined by the author, K. Ikegami, during statying at Technische Universität München under the support of Deutscher Akademischer Austauschdients. The author is grateful to Professor Lippmann of Technische Universität München who is the host professor of the support. 相似文献
5.
A. Ikegami Y. Kimura H. Suzuki T. Sato T. Tanigaki O. Kido M. Kurumada Y. Saito C. Kaito 《Surface science》2003,540(2-3):395-400
Titanium carbide formation by the solid–solid reaction on the surface of Ti nanoparticles was studied in situ using a high-resolution transmission electron microscope with a heating stage. The cross-sectional image of the Ti surface was clearly observed. Vacuum-deposited carbon covered the whole the surface of Ti nanoparticles in spite of the partly evaporation on the nanoparticle surface. The diffusion of the carbon atoms inside the Ti nanoparticles depended on the size of the nanoparticles. When the Ti nanoparticle diameter was less than 30 nm, carbon atoms diffused into the Ti nanoparticle and formed TiC. The superstructure of the Ti nanoparticles was observed, which revealed the growth process of TiC to be the diffusion of carbon atoms. For Ti nanoparticles with diameter larger than 30 nm it was observed that diffusion of Ti atoms into the carbon layer was dominant, which resulted in formation of TiC in the carbon layer at the surface of Ti nanoparticles. 相似文献
6.
Tsutomu Nakanishi Hajime Okamoto Maki Kasahara Kyozaburo Takeda 《Journal of Polymer Science.Polymer Physics》2003,41(22):2829-2849
We theoretically investigated the polymorphy of the stereostructures of a periodic polymer. Using the polymer's internal conformation parameters of bond lengths, bond angles, and internal rotation angles, we extended the mathematical treatment for designing polymer backbones. We considered those periodic polymers whose unit cell consists of one (m = 1), two (m = 2), or three (m = 3) kinds of atoms. Moreover, for these three types of polymers, we supposed two catenation types for the skeleton atoms; one is a “homorotatory” sequence and the other is a “heterorotatory” one. To specify the backbone's stereostructure, we introduced several conformation parameters such as the helical pitch number n, the translation distance d, and the inclination angle of the skeleton plane Θ. By combining these parameters, we can systematically understand the variety and the possible polymorphy in the stereostructure of a periodic polymer backbone. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 2829–2849, 2003 相似文献
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Ikegami H 《Physical review letters》1990,64(15):1737-1740
9.
The structure of senecicannabine(), a new mcrocyclic pyrrolizidine alkaloid isolated from , has been established by chemical study and X-ray analysis. 相似文献
10.
Hideki Nishimori Masahiro Tatsumisago Tsutomu Minami 《Journal of Sol-Gel Science and Technology》1997,9(1):25-31
Monodispersed silica particles up to ca. 1.2 μm in diameter were prepared by hydrolysis of tetraethoxysilane in the presence
of sodium dodecyl sulfate (SDS). The particle size was increased with an increase of SDS added. The geometrical standard deviation
of the particles was decreased with an increase of SDS. In the earlier reaction stage, double spherical particles by the coalescence
of the particles were frequently observed when large amounts of SDS were added. Particle size was gradually increased after
the coalescence occurred and spherical particles were finally obtained. The results of Nielsen’s chronomal analysis suggest
that the polynuclear layer growth took place after the coalescence of the particles in the presence of larger amount of SDS. 相似文献