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31.
Koichi Itoh Takeji Takui 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2004,80(2):29
This review paper deals with an overview of molecule-based magnetism as a rapidly developing interdisciplinary field, topological symmetry rule as the first principle of spin alignment in organic open-shell systems in the ground state, the proposal of organic through-bond 1D and 2D ferro- and superparamagnets and the detection of the first organic high-spin molecule, m-phenylenebis(phenylmethylene) in the quintet ground state (S = 2), followed by extended organic high-spin systems with π-conjugation such as aromatic hydrocarbons having S = 3, 4, 5. The paper also describes a theoretical approach to the understanding of electronic spin structures of organic high-spin molecules by invoking both Heisenberg and Hubbard model Hamiltonians, weakly interacting intramolecular high-spin systems from both experimental and theoretical sides, the spin density distribution of the first organic high-spin molecule in terms of electron- nuclear multiple resonance spectroscopy and the detection and characterization of ionic high-spin hydrocarbons, emphasizing the establishment of high spin chemistry underlying organic molecular magnetism. 相似文献
32.
Koichi Omori Hisayoshi Kojima Rajesh Kakani David H. Slavit Stanley M. Blaugrund 《Journal of voice》1997,11(1):40-47
This study investigates the relationship between rough voice and the presence of Subharmonics, which correspond to smaller yet distinct peaks located between two consecutive harmonic peaks in the power spectrum. Spectrum analysis was undertaken in 389 pathologic voices, of which 20 had subharmonics. Although all 20 voices had roughness perceptually, 8 had normal jitter and/or shimmer. The degree of roughness had a significant inverse relationship with the frequency of subharmonics. By digital signal processing, sound samples with various types of subharmonics were synthesized and perceptually analyzed. Power and frequency of subharmonics in the synthesized sound also had significant relationships with the degree of roughness. Rough voice is acoustically characterized not only by jitter and shimmer but also by the presence of subharmonics in the power spectrum. Subharmonics are important acoustic properties for objective evaluation of rough voices. 相似文献
33.
A diode-pumped chirped-pulse regenerative amplifier with a cooled Yb:YLF crystal has been developed. The output pulse energy is 30 mJ at 20-Hz repetition rate. A high effective extraction efficiency of 68% is obtained, which is attributed to reduced saturation fluence at low temperature and to a high effective pulse energy fluence during regenerative amplification. After pulse compression by use of a parallel grating pair, 18-mJ pulse energy and 795-fs pulse duration are obtained. 相似文献
34.
Kazuya Itsuki Yoshitaka Michihiro Shigeki Endou Koichi Nakamura Takashi Ohno 《Solid State Ionics》2009,180(14-16):917-921
Under the harmonic approximation, the contributions from the indirect ionic interactions to the elastic constants are calculated for the alkali halide and silver halide crystals with the rock-salt structure. The coupling constants of the indirect ionic interactions are calculated by the self-consistent field treatment of the local density approximation and the spherical solid model. The calculated values of the coupling constants are large for the silver ion. The indirect ionic interaction significantly affects the elastic constants. It quantitatively explains the deviation from the Cauchy relation in alkali halide crystals. Moreover, it provides a clear account for the large values of the deviation from the Cauchy relation in AgCl and AgBr. 相似文献
35.
36.
Tomohiro Suetsuna Seiichi SuenagaShinya Sakurada Koichi HaradaMaki Tomimatsu Toshihide Takahashi 《Journal of magnetism and magnetic materials》2011,323(13):1793-1798
Self-forming core/shell nanoparticles of magnetic metal/oxide with crystalline grain size of less than 40 nm were synthesized. The nanoparticles were highly concentrated in an insulating matrix to fabricate a nanocomposite, whose magnetic properties were investigated. The crystalline grain size of the nanoparticles strongly influenced the magnetic anisotropy field, magnetic coercivity, relative permeability, and loss factor (tan δ=μ″/μ′) at high frequency. The packing ratio of the magnetic metallic phase in the nanocomposite also influenced those properties. High permeability with low tan δ of less than 1.5% at up to 1 GHz was obtained in the case of the nanoparticles with crystalline grain size of around 15 nm with large packing ratio of the nanoparticles. 相似文献
37.
In order to determine the copper content x of copper Chevrel compound CuxMo6S8?y(0?y?0.4) as a function of copper activity aCu and sulfur deficit y, a solid state electrochemical cell, Cu/Rb4Cu16I7Cl13/CuxMo6S8?y/Pt, was constructed and coulometric titration studies were made at 400 K. For the evaluation of the coulometric titration data, measurements were made on the electronic conductivity of copper-ion conductor Rb4Cu16I7Cl13. Also, a brief investigation was made on the condition of formation of single phase Chevrel CuxMo6S8?y with varying x and y at 1000°C. The structural change of CuxMo6S8?y with a change in x and y was studied by the X-ray diffraction method. It was found that x for constant aCu decreases with increasing y. The maximum value xmax of x in CuxMo6S8?y in equilibrium with metallic copper was found to be expressed by . In the region of y<0.3, xmax exceeded 4, contrary to a presupposition that xmax is less than 4. X-ray analysis revealed that most of the copper Chevrel compounds denoted by CuxMo6S8 so far were sulfur deficient ones with y?0.4. The importance of sulfur deficit on the properties of the copper Chevrel compound was emphasized. 相似文献
38.
We discuss the scenario with TeV-scale right-handed neutrinos, which are accessible at future colliders, while holding down tiny seesaw-induced masses and sizable couplings to the standard-model particles. The signal with tri-lepton final states and large missing transverse energy is appropriate for studying collider signatures of the scenario with extra spatial dimensions. We show that the LHC experiment generally has a potential to discover the signs of extra dimensions and the origin of small neutrino masses. 相似文献
39.
40.
The electrochemical reduction of nitric oxide in the presence of the excess oxygen was reviewed. It was shown that the selectivity
and activity of the cathodes is strongly dependent on the composition and on the microstructure of the cathode material. A
concept of electrochemical reactor with multilayer electro-catalytic electrode was proposed and successfully designed in Advanced
Manufacturing Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Nagoya, Japan.
The typical values of current efficiency in such electrochemical reactors are of the order of 10–20% at gas composition: 1,000 ppm
NO and 2% O2 balanced in He and at gas flow rate 50 ml/min. The value of current efficiency depends on the functional multi-layer electrode
composition, structure, and operating temperature. Such electrochemical reactors show the value of NO/O2 selectivity (ν
sel) higher than 5 (ν
sel > 5) at intermediate temperature and up to ν
sel = 25 at low temperature operation. It was shown that multilayer electro-catalytic electrode should consist at list from three
main functional layers: cathode, electro-catalytic electrode, covering layer, in order to operate as an electrode with high
selectivity. 相似文献