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171.
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
172.
173.
Yoshio Nishi Yasuo Horiuchi Akira Murai 《International Journal of Infrared and Millimeter Waves》1988,9(1):71-86
We have developed the resonance system which is able to operate a TE-CO2 discharge tube in two color emission source. The two color source is excellent in pumping efficiency, spacial overlap and time synchronization of the two emission CO2 lines.We indicate that the competitive operation of the two emissions is well explained by a simple model.When a TE-CO2 laser operates at the total pressure of below half atmospheric pressure, we make clear in this work that the operation of a TE-CO2 laser forms depression like hole burning, with regards to the J of the upper laser level by J-J collisional relaxation during the laser emission.As an example of the two-photon source, two-photon pumping of NH3 and FIR emissions are given in this paper. 相似文献
174.
Shuji Watanabe 《Proceedings of the American Mathematical Society》1997,125(3):839-848
We discuss spaces of Sobolev type which are defined by the operator with singularity: , where and . This operator appears in a one-dimensional harmonic oscillator governed by Wigner's commutation relations. We study smoothness of and continuity of () where is in each space of Sobolev type, and obtain a generalization of the Sobolev embedding theorem. On the basis of a generalization of the Fourier transform, the proof is carried out. We apply the result to the Cauchy problems for partial differential equations with singular coefficients.
175.
176.
H. Nakahara M. Tsukada A. Moriizumi K. Horiuchi Y. Murakami 《Journal of Radioanalytical and Nuclear Chemistry》1982,72(1-2):377-391
The improvement obtained by epithermal neutron activation analysis was studied in terms of the detection sensitivity and precision
in the γ-ray spectrometry for geological and biological reference samples. For geological samples, small improvement was observed
only for the elements As, Ba, Sb, Se and U. For biological samples, however, large improvement was observed for As, Br, Sb
and U. The ratio of the resonance integral to the effective thermal-neutron capture cross section was observed for 19 nuclides.
The effect of the (n, p) reaction to the determination of Al and Mg by the ordinary reaktor-neutron activation analysis was
estimated. 相似文献
177.
Katsutoshi Nagai Shuji Machida 《Journal of polymer science. Part A, Polymer chemistry》1981,19(2):571-582
The reaction of 1,3-cycloheptadiene (1,3-CHpD) with acrylonitrile (AN) in the presence of ZnCl2 leads spontaneously to the simultaneous formation of an alternating copolymer and a small amount of cycloadduct. The copolymer has a predominantly cis-1,4-structure. The formation of the charge—transfer complex between 1,3-CHpD and (AN)c (AN coordinated to ZnCl2) in AN was detected by ultraviolet (UV) spectroscopy. The activation energies for the cycloaddition and for the copolymerization under the conditions used were determined to be 17.6 (in the presence of 1,1-diphenyl-2-picrylhydrazyl) and 16.3 kcal/mole, respectively. The rate of copolymerization in AN was found to depend on the 1.5th power of the concentrations of (AN)c and of 1,3-CHpD. Oxygen and UV irradiation causes an acceleration of the copolymerization only. On the basis of these results the mechanism of the spontaneous copolymerization is discussed and its relation to the cycloaddition in systems of 1,3-cyclodienes and AN in the presence of ZnCl2 is mentioned. 相似文献
178.
Shuji Kondo Yasuhito Inagaki Masashi Ozeki Kazuichi Tsuda 《Journal of polymer science. Part A, Polymer chemistry》1989,27(10):3383-3391
Polymeric formamides were prepared by free radical polymerization of N-methyl-N-vinyl-formamide or N-methyl-N-(4-vinylbenzyl)formamide, and copolymerization of these monomers with styrene. These soluble polymers serve as phase transfer catalysts for several reactions under liquid–liquid biphase conditions. The catalytic activity of copolymers containing styrene unit is affected remarkably by composition, and there are maxima at certain composition in both polymers. However, copolymers with an acrylonitrile co-unit scarcely exhibit catalytic activity. Furthermore, it was found that these polymers can extract all alkali metal ions employed here, and that the extraction ability increases with increasing the density of active sites. From these results, it is demonstrated that catalytic activity strongly depends on both cation extraction ability of polymers and lipophilicity around the active sites in the polymer. 相似文献
179.
180.
Sakurai R Suzuki S Hashimoto J Baba M Itoh O Uchida A Hattori T Miyano S Yamaura M 《Organic letters》2004,6(13):2241-2244
[reaction: see text] A diastereomeric mixture of the alpha-amino nitrile prepared by the Strecker reaction of benzaldehyde, (1S,2R)-1-aminoindan-2-ol, and cyanotrimethylsilane thermally epimerizes in the solid state to give a single diastereomer with an (S)-configuration at the alpha position to the nitrile moiety. This shows a sharp contrast to the reaction conducted in DMSO at room temperature, which gives a 1:1 mixture of (S)- and (R)-isomers. Several other alpha-amino nitriles also epimerize in the solid-state toward single diastereomers. 相似文献