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41.
Hisao Nakata 《Journal of mass spectrometry : JMS》1992,27(6):686-688
A new parameter, the protonation susceptibility (PS), of functional groups in the chemical ionization mass spectrometry of bifunctional organic compounds is presented. In terms of quasi-equilibrium theory of unimolecular decomposition of the molecular protonated ion of [MH]+, the relative PS corresponds to the relative area under P(E) curves of [MH]+ ions that have a proton at different functional groups. Numerical evaluation of the PS values of pertinent functional groups was made by using particularly selected compounds. The results clearly indicate that PS is independent of proton affinity (PA). 相似文献
42.
Yasushi Koyama Ichiro Takatsuka Munetaka Nakata Mitsuo Tasumi 《Journal of Raman spectroscopy : JRS》1988,19(1):37-49
Raman and infrared spectra in the region of 1800-150 cm−1 were recorded for a set of cis-trans isomers of d̃-carotene, i.e. the all-trans, 7-cis, 9-cis, 13-cis and 15-cis isomers. Spectral comparison revealed Raman and infrared key bands which (1) distinguish stretched or terminal-bent configurations (all-trans, 7-cis and 9-cis) from central-bent configurations (13-cis and 15-cis), and (2) distinguish unmethylated 7-cis and 15-cis configuratios. Keybands (1) include Raman bands at 1160 and 1140 cm−1 and infrared bands at 825 and 775 cm−1 (the intensity varies with the position of the cis-bend) Key bands (2) include Raman bands at 1274 and 962 cm−1 and an infrared band at 741 cm−1 (characteristic of the 7-cis configuration), and also a Raman band at 1247 cm−1 and an infrared band at 775 cm−1 (characteristic of the 15-cis configuration). The normal modes for the key bands were determined by a set of normal coordinate calculations for the isomeric configurations of a simplified model of d̃-carotene. The key bands were mainly related to the C H in-plane bendings, coupled with the CC or C C stretching, or to the C H out-of-plane wagging vibrations, some of which coupled with the CC torsion. 相似文献
43.
Yoshiki Nakata Kunio Tsuchida Noriaki Miyanaga 《Optics and Lasers in Engineering》2009,47(7-8):847-849
Combined periodic structures composed of micron-sized periodic structure and nano-sized quasi periodic structure were generated on Ni–Ti target by multiple shots of interfering femtosecond laser beams. The micron-sized structure was generated by the interference pattern of four beams, and the nano-sized quasi period was generated due to the multiple shot effect of femtosecond laser. The structures were investigated in detail by two-dimensional fast Fourier transform (2D-FFT). The power spectra showed small spots and fuzzy spots due to precise period and quasi period, respectively. The most major size of the quasi periodic structure was 580 nm. 相似文献
44.
Munetaka Nakata Masaaki Sugie Harutoshi Takeo Chi Matsumura Tsutomu Fukuyama Kozo Kuchitsu 《Journal of Molecular Spectroscopy》1981,86(1):241-249
The microwave spectra of four isotopic species of dichlorine monoxide (OCl2) have been observed, and the rotational constants have been obtained. The rm structure for each isotopic species has been determined by Watson's method. The equilibrium structure has been estimated by taking proper averages of rm structures to be and ∠eClOCl = 110.886(6)°. The general applicability and the merit of the present method for estimating the equilibrium structure are pointed out. 相似文献
45.
46.
Munetaka Nakata Tsutomu Fukuyama Kozo Kuchitsu Harutoshi Takeo Chi Matsumura 《Journal of Molecular Spectroscopy》1980,83(1):118-129
The microwave spectra of eight isotopic species of COCl2 have been observed, and the following rotational constants have been obtained: An analysis of the rotational constants has resulted in the rs and rm structures. The equilibrium structure, re, has been estimated by combining the rm parameters derived according to Watson's method and the re bond distances estimated in our recent electron-diffraction and spectroscopic studies to be , , ∠eClCCl = 111.79 ± 0.24°. 相似文献
47.
Inner shell ionization cross sections by low-energy positron impact have been measured. Development of an x-ray detector with thin Si(Li) crystals has enabled the first measurements of the absolute cross sections for the positron impacts in the energy range below 30 keV. Threshold behavior of the measured cross sections for the Cu K shell and Ag L shell are compared with the theoretical results of Gryzinski and Kowalski [Phys. Lett. A 183, 196 (1993)]] and Khare and Wadehra [Can. J. Phys. 74, 376 (1996)]]. Good agreement has been found for the Cu K shell, while the experimental values for the Ag L shell were found to be smaller than the corresponding theoretical results. 相似文献
48.
49.
The effect of temperature perturbation on a single-chain-collapse process was studied for poly(methyl methacrylate) with the molecular weight M(w)=1.05 x 10(7) in the mixed solvent of tert-butyl alcohol+water (2.5 vol %). In the chain-collapse process after a quench from the theta; temperature to a temperature T(1), the temperature was changed from T(1) to T(2) at the time t(1) after the quench and returned to T(1) at the time t(1)+t(2). In the three stages at T(1), T(2), and T(1), measurements of the mean-square radius of gyration of polymer chains were carried out by static light scattering and the chain-collapse process was represented by the expansion factor as a function of time. An effect of chain aggregation on the measurements was negligibly small because of the very slow phase separation. For the negative temperature perturbation (T(1)>T(2)), the chain-collapse processes observed in the first and third stages were connected smoothly and agreed with the collapse process due to a single-stage quench to T(1). A memory of the chain collapse in the first stage at T(1) was found to persist into the third stage at the same temperature T(1) without being affected by the temperature perturbation of T(2) during t(2). The memory effect was observed irrespective of the time period of t(2). The positive temperature perturbation (T(1)相似文献
50.
Long lines of periodic hole structures were produced on a gold film, a glass slide and polystyrene by laser ablation using interfering femtosecond lasers split by a transmission grating. An optical system comprising a cylindrical lens added to an imaging system with a transmission grating was used to obtain the interference of two beams along a long length, and high laser fluence was used to achieve laser ablation. The separation of each hole was 6.25 m, and the total length of the structure produced reached 6 mm, which is longest periodic structure produced by a shot of femtosecond laser. PACS 42.62.-b; 07.60.Ly; 42.40.Eq 相似文献