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141.
The electron spin resonance spectra of Mn2+ ions have been studied in GexTe100?x with x = 15, 17.5 and 20, and Ge20?xTe80Six with 0 ?x? 20. All samples are found to exhibit six hyperfine lines centered at g = 4.3 with hyperfine interaction constant A = 56 × 10?4cm?1. The g = 4.3 line is interpreted as being caused by Mn2+ ions incorporated in the amorphous network and surrounded by four Te atoms in an arrangement of orthorhombic symmetry. Some of the samples of GeTe show a g = 2.0 line. This line also appears after heat treatment in air at temperatures above the glass transition temperature. It is concluded that the g = 2.0 line is caused by Mn2+ ions in phase separated microcrystalline or concentrated regions of MnO in the glass. 相似文献
142.
143.
144.
Ichiro Ohba 《Foundations of Physics》1997,27(12):1725-1738
A novel method to quantize systems of damped motion is proposed in the frameworks of canonical quantization and path integral
quantization. It can be afforded by considering a Lagrangian multiplied by a time-dependent function, which may represent
an effective interaction with “environment.” 相似文献
145.
Tsuneo Itoh Ikuko Fujii Yasuo Tomii Ichiro Ishikawa Hamo Ogura Yoshihisa Mizuno Norio Kawahara 《Journal of heterocyclic chemistry》1987,24(5):1453-1455
An improved and efficient synthesis of 1,3-dialkylpyrido[2,3-d]pyrimidine-2,4-(1H,3H)-diones from 6-methylaminouracils and methyl propiolate or diethyl ethoxymethylenemalonate is described. 相似文献
146.
Yasuhasru Kihira Hitoshi Yamamura Ichiro Murakami 《Journal of Polymer Science.Polymer Physics》1986,24(4):867-876
Dielectric and infrared data have been obtained over a wide temperature range on copolymers of ethyl methacrylate with methacrylic and acrylic acid synthesized by radical copolymerization. The dissociation energy ΔH0 for the acid dimer in the copolymer is estimated from the temperature dependence of the relaxation strength Δεα of the α relaxation, which is associated with the glass transition. The value of δH0 obtained by this method is in fair agreement with that determined by infrared (IR) spectroscopy. The strength of the α relaxation and its activation energy are both increased by the incorporation of methacrylic acid units but are decreased by acrylic acid units. This behavior is attributed to the restriction of main-chain motions by hydrogen-bonded acid dimers in the copolymers with methacrylic acid and to the incorporation of more flexible links in the copolymers with acrylic acid. The β relaxation observed below the glass transition temperatures is almost unaffected by the incorporation of methacrylic acid. 相似文献
147.
Ichiro Miyada 《manuscripta mathematica》1995,88(1):535-540
We show that there exist only finitely many imaginary abelian number fields of type (2,2,...,2) with one class in each genus.
Moreover, if the Generalized Riemann Hypothesis is true, we have exactly 301 such fields, whose degrees are less than or equal
to 23. Finally we give the table of those 301 fields. 相似文献
148.
149.
Recently the double-minimum potentials for the pyramidal distortion in the S1(n,π*) state of a number of aliphatic carbonyl compounds like acetaldehyde, acetone and cyclic ketones have been determined using the supersonic nozzle beam technique We have found a good correlation between the barrier height to inversion and the angle between the two bonds adjacent to the carbonyl carbon atom. In order to elucidate the correlation in more detail, we performed ab initio calculations for the S1 state of formaldehyde with the HCH angle as a parameter. The SCFCI calculation verified the observed correlation. It is postulated that the barrier height can be correlated with a single geometric parameter, the HCH angle. 相似文献
150.
Several substituted oxetanes were treated with lithium acetylides in the presence of boron trifluoride etherate to give f-hydroxyacetylenes. The reaction conditions were varied and several synthetic features of the present reaction were revealed. 相似文献