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51.
YiKai Zhou Mohamed Almokhtar Hitoshi Kubo Nobuya Mori Shuichi Emura Shigehiko Hasegawa Hajime Asahi 《Solid State Communications》2012,152(14):1270-1273
Symmetric GaGdN/AlGaN (Gd concentration: 2%) and GaN/AlGaN double quantum well superlattices (DQW-SLs) were grown by radio-frequency plasma-assisted molecular-beam epitaxy on GaN (0001) templates. Atomic steps were observed on all the sample surfaces by atomic force microscope. X-ray diffraction θ/2θ scan curves exhibited well-defined satellite structures. Room temperature ferromagnetism was confirmed for the GaGdN/AlGaN DQW-SL samples by using alternating gradient magnetometer. Strong photoluminescence was observed from both GaGdN and GaN QWs at higher energy side of GaN excitonic peak. Magneto-photoluminescence spectra for GaGdN/AlGaN DQW-SL samples showed a large magnetic field dependence of the excitonic energy by applying a magnetic field up to 7 T. The observed strong redshift of excitonic PL indicated an enhancement of Zeeman splitting of the free carrier energy levels in magnetic GaGdN/AlGaN DQW-SL. Enhanced g-factor was estimated to be about 60 for GaGdN/AlGaN DQW-SL sample with QW thickness of 1 nm. 相似文献
52.
53.
Hiyoshizo Kotsuki Yoshikatsu Ichikawa Mitsuhiro Iwasaki Masanori Kataoka Hitoshi Nishizawa 《高压研究》2013,33(1-3):107-118
Abstract A variety of cyclic and acyclic ethers are efficiently reacted with acyl chlorides or acyl bromides to afford the ether-cleaved compounds of ω-chloro-or ω-bromoesters under high pressure conditions. The reactivity of ethers is found to be roughly depend on the basicity of the ether oxygen atom. 相似文献
54.
Ko-Ki Kunimoto Kouji Kimura Takatomo Takai Hitoshi Senda Motoo Shiro Akio Kuwae 《光谱学快报》2013,46(4):509-522
Two polymorphic forms (I and II) of 4-fluorophenylpyruvic acid (F-PPA) were obtained by crystallization from different solvents, showing a melting point at 163.2 and 171.0 °C. Crystal structures of polymorphs I and II were determined by X-ray crystallography. IR and Raman spectra of the two polymorphs were measured and the spectral characteristics were compared with those of phenylpyruvic acid. the two polymorphs show similar molecular and crystal structures to each other, except for the molecular geometries of the enol and the carboxylic acid moieties. Distinct IR spectral differences which result from the crystal field splitting were observed between the two polymorphs. 相似文献
55.
Transient response of thickness mode piezoelectric plates is theoretically analyzed using a transmission line type equivalent circuit. From the analysis, a method for measuring the electromechanical coupling factor is proposed called the “Transient Response Method”. Experiments showed good agreement with the theory. The feature of this transient response method depends upon the fact that the electromechanical coupling factor of the thickness mode can be measured, when samples have a smaller ratio of diameter to thickness than the usual ratio required in the resonance-antiresonance method. 相似文献
56.
Hitoshi Fujii Toshimitsu Asakura 《Applied Physics A: Materials Science & Processing》1974,3(2):121-129
The general formula for multiple-beam interference due to regular slit arrays illuminated with partially coherent quasi-monochromatic
light is derived. The correlation functions chosen for partially coherent light assume Gaussian, sinc and besinc forms of
correlation. The intensity distribution in the interference patterns is presented and discussed as a function of the spatial
coherence condition. It is shown that spatial coherence of the illumination largely affects the features of multiple-beam
interference patterns. 相似文献
57.
58.
The (132R)-methoxycarbonyl group of methyl pheophorbide a, one of the chlorophyll-a derivatives, was converted to a methyl group through methylation at the C132 position followed by removal of the methoxycarbonyl group. The methylation of the C132 carboanion gave a 4:1 mixture of methyl 132-methyl-pheophorbide a and its 132-epimer. The successive pyrolysis of the major methylated product afforded methyl (132R)-methyl-pyropheophorbide a with a small amount of its (132S)-epimer. The substitution effects at the C132 position including stereochemistry were discussed on the basis of 1D/2D NMR, UV–vis absorption, and circular dichroism spectroscopic analyses as well as molecular modeling simulation. 相似文献
59.
Systematic Tuning and Switching of Neutral and Ionic Phases in a Donor–Acceptor Chain Compound by Doping with Less‐Active Donors and by Pressure Application 下载免费PDF全文
Keita Nakabayashi Prof. Dr. Hitoshi Miyasaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):5121-5131
The temperature‐induced stepwise neutral–ionic (N–I) phase transition in the covalently bonded donor–acceptor chain compound [Ru2(2,3,5,6‐F4PhCO2)4DMDCNQI] ? 2(p‐xylene) (2,3,5,6‐F4PhCO2?=2,3,5,6‐tetrafluorobenzoate; DMDCNQI=2,5‐dimethyl‐N,N′‐dicyanoquinodiimine) was systematically tuned over a wide temperature range using two techniques: 1) A chemical technique based on doping with a less‐active donor unit [Ru2II,II(F5PhCO2)4] (F5PhCO2?=pentafluorobenzoate), thereby providing an isostructural doped series [{Ru2II,II(2,3,5,6‐F4PhCO2)4}1?x{Ru2II,II(F5PhCO2)4}xDMDCNQI] ? 2(p‐xylene), with x=0.06, 0.10, 0.21, and 0.24; and 2) a physical technique, which was the application of hydrostatic pressure to the doped compounds. The stepwise N–I transition observed in the original compound was systematically varied in terms of the viewpoints of both transition temperature and transition features (stepwise or monotonic) dependent on the amount of dopants x. Application of pressure efficiently tuned the N–I transitions, with the oxidation phases being dramatically modified by applying only weak pressure up to 4 kbar. Even in cases that led to N–I transitions in small domains of the chains at ambient pressure, the application of pressure caused an expansion of the domains that enabled N–I transitions, finally leading to a complete change in the oxidation state of the chains, from neutral to ionic, accompanied by a change from a paramagnetic state to a ferrimagnetically ordered state. 相似文献
60.
Hitoshi Tanaka 《Macromolecular Symposia》1994,84(1):137-143
Magnetism of hydroanilino ladder polymer and indigo polymer which were prepared by the oxidative polyrecombination of captodative substituted methane and indoxyl, respectively, was studied by ESR spectroscopy and magnetic susceptibility measurement. It was found that both spin polymers contained domains with high spin state in their structures and their spins were much more ordered with decreasing temperature. 相似文献