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31.
Allylgallation of cyclopropenes with allylgallium sesquibromide has been investigated; a novel cyclopropylgallium compound was isolated via allylgallation of hydroxy-bearing cyclopropene, and its structure was fully characterized by X-ray crystallography. 相似文献
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Jun-ichiro Sugisaka Noritsugu Yamamoto Kazuhiro Komori Masahide Itoh 《Optics Communications》2008,281(23):5788-5792
A two-dimensional photonic crystal waveguide with a novel geometry is introduced. The center line of this waveguide is bent along a free-curve such that the direction of the propagating light can be changed without scattering or reflection losses. The design method is described for a triangular lattice, its optical properties such as transmission spectrum and dispersion relation are calculated, and actual devices are then fabricated and demonstrated that they worked as optical waveguides. 相似文献
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Dr. Yoshihiro Ishimaru Naoyuki Shimoyama Dr. Takashi Fujihara Keigo Watanabe Prof. Dr. Jun‐ichiro Setsune 《化学:亚洲杂志》2015,10(2):329-333
2,5‐Bis(4‐propyl‐2‐pyrrolyl)thiophene was reacted with aryl aldehydes to afford large porphyrinoids; [24]dithiaamethyrin(1.0.0.1.0.0) and [36]trithianonaphyrin(1.0.0.1.0.0.1.0.0). X‐ray crystallography of the dithiaamethyrin revealed a highly planar ring structure with mean plane deviation (MPD) value of 0.053 Å. A large positive NICS(0) value (+13.9 ppm) calculated for this planar 24π system unambiguously indicates an antiaromatic character that is consistent with a remarkably low field 1H chemical shift of the inner NH proton at 24.0 ppm. The magnitude of the paratropic ring current effect in the 24π amethyrin framework in the free base form and the diprotonated form was discussed on the basis of the MPD value and the NICS value. The present dithiaamethyrin is much more strongly antiaromatic than the dodecaalkylamethyrin in their free base forms, but the order inversed in their diprotonated forms. 相似文献
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Condensation reaction of gem-dimethyldipyrrylmethane-5,5′-dicarbinol and 4,4′-dimethyl-3,3′-di-iso-butyl-2,2′-bipyrrole under the catalysis by trifluoroacetic acid gave a hexapyrrolic macrocycle 6 in 15% yield after DDQ oxidation. X-ray crystallography of 6 shows that three parts of highly planar dipyrrylmethene unit are assembled by two sp3 hybridized gem-dimethyl carbon bridges and one direct linking at the pyrrole α-positions, leading to C2 molecular symmetry. The complexation of 6 with (S)-(+)- and (R)-(−)-mandelic acid induced a CD Cotton effect at 461 and 650 nm. 相似文献
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Jun-ichiro KishineA.S. Ovchinnikov 《Physics letters. A》2011,375(17):1824-1830
We revisit a long-standing problem concerning the inertial mass of a magnetic domain wall (DW) motion. Using constrained Hamiltonian formalism, we set up the macroscopic physical Hamiltonian describing the free-particle-like motion of the DW starting with the micromagnetic Lagrangian density. 相似文献
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Takehito Yokoyama Yukio Tanaka Alexander Golubov Jun-ichiro Inoue Yasuhiro Asano 《Physica E: Low-dimensional Systems and Nanostructures》2005,29(3-4):520
Charge transport in the normal metal/insulator/diffusive ferromagnet/insulator/s-wave superconductor (N/I/DF/I/S) junctions is studied for various situations solving the Usadel equation under the Nazarov's generalized boundary condition. Conductance of the junction is calculated by changing the magnitude of the resistance in DF, Thouless energy in DF, the exchange field in DF, the transparencies of the insulating barriers. We have found a new broad peak around zero voltage as well as zero bias conductance peak splitting and dip splitting. 相似文献
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S. Kohiki S. Hatta T. Kamada A. Enokihara T. Satoh K. Setsune K. Wasa Y. Higashi S. Fukushima Y. Gohshi 《Applied Physics A: Materials Science & Processing》1990,50(5):509-514
An enhancement of the critical current density (to more than 106 A/cm2 below 65 K) of Gd1Ba2Cu3O7–x superconducting thin films was achieved by X-ray irradiation with oxygen annealing. This process of X-ray irradiation with oxygen annealing introduced stable pinning centers into the crystal and also increased the activation energy from 0.1 eV to 0.25 eV. 相似文献
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Jun-ichiro Ohe Yoshihiro Tomoda Nejat Bulut Ryotaro Arita Kazuma Nakamura Sadamichi Maekawa 《Journal of magnetism and magnetic materials》2010,322(9-12):1192-1194
The magnetic correlation between magnetic impurities in semiconductors is investigated by performing the quantum Monte Carlo (QMC) simulation. The Anderson Hamiltonian with the realistic parameters obtained by the local density approximation (LDA) calculation is employed. The LDA calculation gives a dispersion of the host (GaAs) electron and the mixing energy between host and magnetic impurity (Mn). The mixing between host and impurity electrons generates the impurity bound state in the energy gap of semiconductors. The long range ferromagnetic coupling is observed when the Fermi energy locates between the band edge and the impurity bound state. The ferromagnetic coupling is enhanced by decreasing temperature. 相似文献