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81.
M. Matoba M. Hyakutake S. Nakamura T. Katayama T. Tonai K. Yagi K. Sato Y. Aoki 《Physics letters. [Part B]》1973,44(2):159-160
In the (p,p′) reaction on 130Te, strong excitation of the second 3? state was found at 3.36±0.01 MeV excitation energy. No strong second 3? state was observed in the (p,p′) reaction on 126Te. 相似文献
82.
Charged particle activation analysis of phosphorus in biological materials using the31P (α,n)34mCl reaction has been studied. Since34mCl is also produced by the32S (α,pn) and the35Cl (α, α′ n) reactions, the thick-target yield curves on phosphorus, sulfur and chlorine were determined in order to choose
the optimum irradiation conditions. As a result, it was found that the activation analysis for phosphorus without interferences
from surfur and chlorine is possible by bombarding with less than 17 MeV alphas. The applicability of this method to biological
samples was then examined by irradiating several standard reference materals. It was confirmed that phosphorus can readily
be determined at the detection limit of 1 μg free from interferences due to the matrix elements. 相似文献
83.
A. A. Kaminskii K. Ueda A. F. Konstantinova H. Yagi T. Yanagitani A. V. Butashin V. P. Orekhova J. Lu K. Takaichi T. Uematsu M. Musha A. Shirokava 《Crystallography Reports》2003,48(5):868-871
Refractive indices of the nanocrystalline Y3Al5O12 ceramic and a garnet single crystal of the same composition have been measured. In the visible and near IR range (0.4–1.064 μm), the prism method was used; in the medium IR range (2–6.2 μm), the interference method with the use of thin plates was applied. The refractive indices of these crystalline materials are practically the same over the entire spectral range studied and are described by the approximate formula proposed earlier for a single crystal. The parameters of the continuos-wave lasing in the nanocrystalline Y3Al5O12 ceramic doped with Nd3+ and Yb3+ ions measured recently are presented. 相似文献
84.
An ITO electrode was coated by a Nafion film incorporating Ru(bpy)32+ complex as redox centers either by mixture casting method, adsorption method, or swelling method and the electrochemical reactivity of the modified electrode was determined by the in-situ spectrocyclic voltammogram (SCV) in a sodium perchlorate aqueous solution at pH 1.2. A modified Poisson statistics equation was used to estimate the charge transfer distance (Ro) between the Ru(bpy)32+ complexes. The estimated charge transfer distances for the electrodes prepared by swelling method (Ro = 1.63 nm for the electrode modified in M/W 1:10, and 1.69 nm in M/W 1:2) and adsorption method (Ro = 1.61 nm) were longer than that for mixture casting method (Ro = 1.5 nm). Based on the different procedure of Ru(bpy)32+ complex incorporation in the Nafion film, the reasons that affect the apparent charge transfer distance were discussed. 相似文献
85.
Heat capacities of MnxFe3?xO4 with the composition x = 1.0, 1.5, and 2.0 were measured from 200 to 740 K. λ-type heat capacity anomalies due to the ferri-paramagnetic transition were observed for all the compositions. The transition temperatures were 577, 471, and 385 K for the composition x = 1.0, 1.5 and 2.0, respectively, which are in good agreement with the results of magnetic measurements. The difference in heat capacities between the different samples was small except for the temperature range of the transition. The magnetic contribution to the observed heat capacity was obtained by assuming that the heat capacity can be expressed by the sum of the lattice heat capacity Cv (l), the dilation contribution C(d), and the magnetic contribution C(m). Entropy changes due to the transition were obtained from C(m) as 55.5, 50.7 and 49.2 J K?1 mole?1 for the composition x = 1.0, 1.5, and 2.0, respectively. The entropy changes were also calculated by assuming the randomization of unpaired electron spins on each ion, but they were from 6 to 10 J K?1 mole?1 smaller than the observed ones. The difference between the experimental and the calculated values is roughly explained by taking into account the cation exchange reaction between the tetrahedral and the octahedral sites in the spinel structure. 相似文献
86.
Fujita K Nakaguma H Hamada T Yamaguchi R 《Journal of the American Chemical Society》2003,125(41):12368-12369
Reactions of [(Cp*Ir)2(mu-dmpm)(mu-H)2]2+ (1) with NaOtBu in aromatic solvent at room temperature give [(Cp*Ir)(H)(mu-dmpm)(mu-H)(Cp*Ir)(Ar)]+ [Ar = Ph (3), p-Tol (4a), m-Tol (4b), 2-furanyl (5a), 3-furanyl (5b)] via intermolecular aromatic C-H activation. Treatment of [(Cp*Ir)2(mu-dppm)(mu-H)2]2+ (2) with base (Et2NH) results in intramolecular C-H activation of the phenyl group in the dppm ligand to give [(Cp*Ir)(H){mu-PPh(C6H4)CH2PPh2}(mu-H)(Cp*Ir)]+ (6). The structures of 3, 5a, and 6 have been determined by X-ray diffraction methods. 相似文献
87.
88.
Yoshitaka Nakano Yoshihiro Irokawa Yasunobu Sumida Shuichi Yagi Hiroji Kawai 《固体物理学:研究快报》2010,4(12):374-376
We have investigated electronic deep levels in two AlGaN/GaN hetero‐structures with different current collapses grown at 1150 and 1100 °C by a photo‐capacitance spectroscopy technique, using Schottky barrier diodes. Three specific deep levels located at ~2.07, ~2.80, and ~3.23 eV below the conduction band were found to be significantly enhanced for severe current collapse, being in reasonable agreement with photoluminescence and capacitance–voltage characteristics. These levels probably originate in Ga vacancies and residual C impurities and are probably responsible for the current collapse phenomena of the AlGaN/GaN hetero‐structures. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
89.
Jean-Francois Bisson Hideki Yagi Takakimi Yanagitani Alexander Kaminskii Yuri N. Barabanenkov Ken-Ichi Ueda 《Optical Review》2007,14(1):1-13
Grain boundaries play a key role in determining several key properties of polycrystalline laser ceramics. Heat transfer measurements
at low temperature constitute a good tool to probe grain boundaries. We review the results of heat transfer measurements in
polycrystalline Y3Al5O12 garnets as well as Y2O3 and Lu2O3 sesquioxide materials obtained by self-energy-driven sintering of nano-particles. The average phonon mean free path in Y3Al5O12 was found to be significantly larger than the average grain size and to scale with temperature as T
−2 at low temperature. Existing models describing the interaction between phonons and grain boundaries are reviewed. Correct
temperature dependence of the mean free path and order of magnitude of scattering rates were found by assuming the existence
of a grain boundary layer having acoustic properties different from those of the bulk. A different temperature dependence
of phonon mean free path was found for the sesquioxides and was ascribed to the stronger elastic anisotropy of these materials.
The thermal resistance associated to the grain boundaries of laser ceramics was found to be lower than in other dense polycrystalline
ceramic materials reported in the literature. 相似文献
90.
The directional energy transport, i.e. exciton migration, in nanostar dendritic systems composed of two-state monomer units is studied using a quantum master equation approach. We examine the effects of the variation in the excitation energy of the monomer in the core region (core monomer) on the multistep exciton migration from the periphery to the core based on the relaxation factors among exciton states originating in weak exciton-phonon coupling. It turns out that when the core monomer possesses both an excitation energy slightly lower than that of the first generation and a partial exciton overlap with the first generation, more efficient and rapid exciton migration to the core is expected as compared with other core monomer cases with the energy level closer to or much lower than that of the first generation. 相似文献