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991.
Kazunori Matsumura Kikuko Hayamizu Osamu Yamamoto 《Journal of Polymer Science.Polymer Physics》1989,27(12):2407-2418
1H-NMR and 2H-NMR spectra of water (H2O and D2O) absorbed in Visking cellulose tubing have been observed as a function of the angle Θ between the film surface and the magnetic field. 1H-NMR spectra show broad lines, and the chemical shift and the linewidth depend on Θ. From the angular dependence of the chemical shift, the anisotropic volume diamagnetic susceptibilities of the film are determined, i.e., χ∥ in the direction longitudinal to the tubing (stretched direction) is 0.43 ppm, and χ⊥ in the transverse direction is 0.57 ppm. The different values of χ∥ and χ⊥ afford an evidence of the anisotropy of the film. 2H-NMR spectra of D2O absorbed in the film show quadrupole splitting which also depends on Θ. The angular dependences of the linewidth (1H-NMR) and the quadrupole splitting (2H-NMR) indicate that the H? H axes of the water molecules have a tendency to orient in the direction longitudinal to the film surface. 相似文献
992.
Atsushi Yamamoto Mio Kawai Mitsunori Sakamoto Shuji Kodama Kazuichi Hayakawa 《Analytical sciences》2008,24(3):361-364
A sensitive and variable-wavelength optical rotatory (OR) detector for high-performance liquid chromatography is presented. This design is entirely different from that of conventional OR detectors consisting of a crossed polarizer pair. By placing a polarizing prism and a retardation plate into a commercial circular dichroism (CD) detector, the OR signal was obtained. The Mueller matrix approach was used to prove the principle of the OR signal appearance. Sugars and 4-androstene-3,17-dione were chosen as test compounds. The limit of detection was below 0.5 microg of injected sucrose at 260 nm, which was superior to that obtained with a conventional OR detector. For 4-androstene-3,17-dione, which is CD active, and shows a large anomalous OR dispersion curve, our detector gave a large OR signal with approximately half the intensity of the CD signal at 340 nm. 相似文献
993.
Y Yamamoto M.M Gupta P.N Nikiforuk 《Journal of Mathematical Analysis and Applications》1985,111(1):49-64
A method is presented for determining the dynamics of a system so that it will have prescribed hypersurfaces as limit sets with preassigned stability properties. This method is applicable not only to the synthesis of systems, but also to the analysis of nonlinear systems. This is equivalent to determining the approximate analytical solutions for multiple limit sets, or the boundary of the domain of attraction. Examples which verify this method are included. 相似文献
994.
Combination of the dianion of dialky 3-hexenedioate and β-bromopropionate leads directly to a 2,3-disubstituted cyclopentanone, which can be transformed to a variety of primary prostaglandins and sarkomycin. 相似文献
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998.
Mayumi Takasu Hiroaki Wakabayashi Kyoji Furuta Hisashi Yamamoto 《Tetrahedron letters》1988,29(52):6943-6946
Achiral and chiral crowns complexed with potassium bases catalyze the Michael additions of enolates to cycloalkenones. 相似文献
999.
1000.
Kouichi Akahane Naokatsu Yamamoto Shin-ichiro Gozu Akio Ueta Naoki Ohtani 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):81
InGaAsSb strain-reducing layers (SRLs) are applied to cover InAs quantum dots (QDs) grown on GaAs substrates. The compressive strain induced in InAs QDs from the GaAs is reduced due to the tensile strain induced by the InGaAsSb SRL, because the lattice constant of InGaAsSb is closer to InAs lattice constant than that of GaAs, resulting in a significant red shift of photoluminescence peaks of the InAs QDs. The emission wavelength from InAs QDs can be controlled by changing the Sb composition of the InGaAsSb SRL. The 1.5 μm band emissions were achieved in the sample with an InGaAsSb SRL whose Sb compositions were above 0.3. The calculation of the electron and the hole wave functions using the transfer matrix method indicates that the electron and the hole were localized around InAs QDs and InGaAsSb SRL. 相似文献