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101.
Mitiko Miura Hitoshi Arimori Hiromu Murata Akiko Kida Kazuaki Iishi 《Journal of Physics and Chemistry of Solids》1983,44(7):627-631
The effect of the electronic extension on the electrostatic potential was first taken into account functionally by Birman. We have applied his model to the lattice dynamics of CaO, where the degree of the electronic extension w was defined and determined with the use of the electronic charge density distribution obtained from analysis of X-ray data. Our treatment shown here not only gives a physically meaningful model including the feature of the electronic extension, but also involves essentially the same very simple process as the conventional point-charge model but with fewer adjustable parameters. Good reproduction of calculated phonon dispersion curves was obtained by taking into account the electronic extension, although the degree of the electronic extension, w, used to fit the curve was a little larger than that derived from the observed data owing to the first rough approximation for the potential energy arising from the electronic extension. 相似文献
102.
A convenient synthesis of peripherally substituted or unsubstituted phthalocyanines having a variety of metals is described. Phthalocyanines can be obtained by heating phthalimides or phthalic anhydride with metal salts, hexamethyldisilazane, a catalytic amount of p-TsOH, and DMF at 150 degrees C. 相似文献
103.
Hitoshi Tanaka Takayuki Otsu 《Journal of polymer science. Part A, Polymer chemistry》1977,15(11):2613-2621
Photodegradation behavior of atactic and isotactic polymers of tert-butyl vinyl ketone (t-BVK) and its copolymers with styrene and α-methylstyrene was studied in dioxane as a solvent at room temperature. The quantum yield of main-chain scission of atactic poly(t-BVK) was found to be larger than that of isotactic poly(t-BVK) and atactic poly(methyl vinyl ketone). From the Stern-Volmer plots on the quenching study of atactic poly(t-BVK) with naphthalene and 2,5-dimethyl-2,4-hexadiene, it was found that 60–70% of its photochemical reaction underwent main-chain scission from the triplet state. It was also found that the increase in t-BVK contents of both copolymers accelerated the photodegradation, and the copolymer with styrene was more photodegradable than that with α-methylstyrene. These results seemed to suggest that the main-chain scission of these vinyl ketone polymers and copolymers proceeded through a Norrish type II photoelimination mechanism. 相似文献
104.
Matthew R. Buckley Seong Youl Choi Kentarou Mawatari Hitoshi Murayama 《Physics letters. [Part B]》2009
Determining the spin of new particles is critical in identifying the true theory among various extensions of the Standard Model at the next generation of colliders. Quantum interference between different helicity amplitudes was shown to be effective when the final state is fully reconstructible. However, many interesting new physics processes allow only for partial reconstruction. In this Letter, we show how the interference effect can be unambiguously extracted even in processes that have two-fold ambiguity, by considering the correlation between two decay planes in e+e− collisions. 相似文献
105.
Michio Jimbo Hitoshi Konno Satoru Odake Yaroslav Pugai Jun'ichi Shiraishi 《Journal of statistical physics》2001,102(3-4):883-921
The Wakimoto construction for the quantum affine algebra U $_q$ ( $(\widehat{\mathfrak{s}\mathfrak{l}_2 })$ ) admits a reduction to the q-deformed parafermion algebras. We interpret the latter theory as a free field realization of the Andrews–Baxter–Forrester models in regime II. We give multi-particle form factors of some local operators on the lattice and compute their scaling limit, where the models are described by a massive field theory with $\mathbb{Z}$ $_k$ symmetric minimal scattering matrices. 相似文献
106.
Moyoko Tomiyasu Noriko Aida Yoshihiro Watanabe Kana Mori Kazuo Endo Kouki Kusakiri Jeff Kershaw Takayuki Obata Hitoshi Osaka 《Magnetic resonance imaging》2012
Background and Purpose
Influenza viral infection, which results in central nervous system dysfunction, is a major cause of acute encephalopathy (AE). The purpose of this study was to investigate the changes in the concentrations of brain metabolites in children with AE using single-voxel magnetic resonance spectroscopy (MRS) and to provide diagnostic information about the relationship between the symptoms of AE and metabolite concentrations.Materials and Methods
The subjects were 10 children (mean age: 6.2 years; range: 1–13) with AE caused by the novel influenza A virus responsible for the 2009 influenza pandemic. The serial MRS data (TE/TR=30/5000 ms, 3 T) acquired from the basal ganglia (BG) and centrum semiovale (CS) of each patient were categorized into three periods: (1) initial neurological symptom presentation and the start of treatment (n= 10), (2) short-term follow-up (n= 9) and (3) long-term follow-up (n= 3). As controls, the magnetic resonance (MR) spectra of eight age-matched children were also investigated.Results
In both regions, the concentrations of the major metabolites (N-acetylaspartate, creatine, choline, myo-inositol, glutamate/glutamine complex and glutamate) only showed minor fluctuations between the three periods. On the other hand, higher levels of taurine (Tau) were observed in the BG during the second period (P=.005), and increased levels of glucose were observed in the CS during the first (P=.005) and second (P=.036) periods.Conclusions
Serial monitoring of brain metabolite changes was carried out with a clinical MR system. The concentrations of major metabolites only displayed very minor fluctuations in response to mild H1N1-related AE. However, a higher Tau concentration was found to be associated with neurological symptoms. Further studies are required to improve our understanding of the detailed activity of Tau in AE. 相似文献107.
Masami Sawada Yasuo Okumura Hitoshi Yamada Yoshio Takai Shigetoshi Takahashi Takahiro Kaneda Keiji Hirose Soichi Misumi 《Journal of mass spectrometry : JMS》1993,28(12):1525-1528
Using fast atom bombardment (FAB) mass spectrometry (MS), cross-chiral relationships were confirmed for the first time for the diasteromeric host-guest complexations between the chiral crown ether host (1) and the chiral organic ammonium ion guest (2) on the basis of the relative peak intensities (RPI). Both host–guest combinations (R, R, R, R) – 1, (R) – 2 and (S, S, S, S) – 1, (S) – 2 obviously provided larger RPI values than the combination of both (R, R, R, R) – 1, (S) – 2 and (S, S, S, S) – 1, (R) – 2 by a factor of 1.6 as an averaged value: 1.87 (n = 4)/1.16 (n = 4) = 1.6. These results are consistent with the expected stabilities of the host-guest complexations by CPK model examinations. Successfully observed cross-chiral examinations strongly suggest a potentially useful FABMS/RPI methodology for rapidly searching newly designed and synthesized crown ether-like host compounds with a higher degree of enantioselectivity. 相似文献
108.
Kohji Tashiro Hitoshi Asanaga Kiyotaka Ishino Ryoko Tazaki Masamichi Kobayashi 《Journal of Polymer Science.Polymer Physics》1997,35(11):1677-1700
A software and some useful tools have been developed for identifying individual x-ray reflectional peaks recorded with an x-ray imaging plate system. These techniques were applied to analyze the crystal structure of uniaxially oriented polymer samples. Characteristic features of the present method may be summarized as follows. (1) The indexing of the observed reflections and the determination of the unit cell parameters can be made easily on the display of the computer. (2) The integrated intensity of the individual component of the overlapped reflections can be evaluated quantitatively through the curve separation technique. The Rmerge's for the equivalent reflections were 5–6%, indicating the exact evaluation of the integrated intensities. (3) The thus obtained reflectional data were successfully utilized for the extraction of the initial structural models by the direct method. The actual applications have been made for orthorhombic polyethylene, trigonal polyoxymethylene, and isotactic polybutene-1, giving the refined crystal structures including even the positions of hydrogen atoms in some cases. The reliability factors were 12, 5, and 15%, respectively, for these three polymer cyrstals. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1677–1700, 1997 相似文献
109.
Norihiro?SadatoEmail author Hiroki?Yamada Tomohisa?Okada Masaki?Yoshida Takehiro?Hasegawa Ken-Ichi?Matsuki Yoshiharu?Yonekura Harumi?Itoh 《BMC neuroscience》2004,5(1):56
Background
Sign-language comprehension activates the auditory cortex in deaf subjects. It is not known whether this functional plasticity in the temporal cortex is age dependent. We conducted functional magnetic-resonance imaging in six deaf signers who lost their hearing before the age of 2 years, five deaf signers who were >5 years of age at the time of hearing loss and six signers with normal hearing. The task was sentence comprehension in Japanese sign language. 相似文献110.
Yoshitaka Ogiwara Kikuji Igeta Hitoshi Kubota 《Journal of polymer science. Part A, Polymer chemistry》1972,10(3):845-853
It was noted in a graft copolymerization reaction involving a system of poly(vinyl alcohol) fibers (PVA fibers), methyl methacrylate, and water that fibers oxidized with hydrogen peroxide or sodium hypochlorite or ferric ion-adsorbing fibers effectively initiate the reaction as in the case of cellulose fibers. The initiation reaction of the sample was markedly activated by the presence of a pretreatment with an oxidizing agent at a concentration on the order of 10?9 mole/l., but the oxidized samples were sharply deactivated by such means as reduction and oximation. Since model initiators for the present system, such as iron(III) acetylacetonate-adsorbing PVA fibers or ferric ion-adsorbing fibres, with the co-existence of acetylacetone were observed to initiate graft copolymerization effectively, it is believed that carbonyl groups in modified PVA fibers could be a major factor for initiating copolymerization through interaction with metallic ions. 相似文献