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331.
Atsushi Yamaguchi Naoya Nakagawa Taro Sekikawa Hiroyuki Asanuma 《Applied Surface Science》2009,255(24):9864-9868
We performed the transient absorption measurement and the first rate equation (RE) analysis for cis isomer of 4-carboxy-2′,6′-dimethylazobenzene to clarify the quantitative difference between the photoisomerization process and the thermal relaxation process from the excited state. The RE analysis enabled us to determine the cis-to-trans photoisomerization rate per each pump pulse to be 3% under the condition of the 430 nm, 150 fs pump pulse with energy of 200 nJ. Moreover, the signal due to the yielded trans molecules appearing in the transient absorption was assigned from the following observed result: the transient absorbance change at the 380 nm probe mostly decreased within 300 fs after the 430 nm pulse pumping and then slowly decreased to zero, while the absorbance change at the 350 nm probe had a positive constant component in the over one picosecond time region. The RE analysis showed that this constant component is due to the yielded trans molecules, and its positive value is due to the fact that the absorption cross-section of the -to- transition in their trans molecules is larger than that of the -to- transition in the original cis molecules. 相似文献
332.
Masao Kato Taro Ichijo Keizo Ishii Masaki Hasegawa 《Journal of polymer science. Part A, Polymer chemistry》1971,9(8):2109-2128
A new preparative route to photocrosslinkable polymers in which the polymers are produced directly from the polymerization of vinyl monomers having photocrosslinkable groups has been investigated. The photosensitive resins thus produced have higher sensitivity and resolution than conventional photosensitive resins. The monomers were synthesized from the esterification of vinylphenols or vinyl β-chloroethyl ether with cinnamic acid, β-styrylacrylic acid, and their homologs, and from the etherification of vinyl β-chloroethyl ether with hydroxychalcones. Homopolymerizations of these monomers and their copolymerizations with other comonomers were investigated with the use of both radical and ionic initiators. It is shown that radical polymerization of the monomers gave soluble polymers only at low conversion. Anionic initiators did not initiate polymerization. Cationic polymerization imparted soluble polymers in high yield, except for the monomers bearing cyano groups, which generally gave insoluble polymers. Infrared and NMR spectroscopic investigation of the cationically obtained soluble polymers and comparative investigation by cationic polymerization of model compounds indicated that polymerization of the monomers proceeds through the vinyl double bond without affecting the photosensitive unsaturated bond. Thus, linear photocrosslinkable polymers with an intact photoreactive group may be produced by cationic polymerization. In general, these polymers have uniform structure and modifiable physical properties depending on the monomer used. The polymer thus obtained from β-vinyloxyethyl cinnamate has been shown to have excellent properties for use as a photo-resist. 相似文献
333.
Hideshi Nakamura Kazuhiro Fujimaki Osamu Sampei Akio Murai 《Tetrahedron letters》1993,34(52):8481-8484
Gonyol, 3S-5-dimethylsulfonio-3-hydroxylpentanoate, was isolated from a dinoflagellate Gonyaulax polyedra cultured in a medium containing methionine and the structure was elucidated by spectroscopic method and confirmed by chemical synthesis. Gonyol was shown to be biogenetically derived from methionine and acetic acid. 相似文献
334.
Extreme stability and almost periodic solutions of functional-differential equations 总被引:2,自引:0,他引:2
Taro Yoshizawa 《Archive for Rational Mechanics and Analysis》1964,17(2):148-170
335.
An electric field enhanced by a metallic nanoprobe has locally induced coherent anti-Stokes Raman scattering (CARS) of adenine molecules in a nanometric DNA network structure. Owing to the third-order nonlinearity, the excitation of the CARS polarization is extremely confined to the end of the tip apex, resulting in a spatial resolution far beyond the diffraction limit of light. Our tip-enhanced CARS microscope visualized the DNA network structure at a specific vibrational frequency (approximately 1337 cm(-1)) corresponding to the ring-breathing mode of diazole of adenine molecules. 相似文献
336.
Miyamoto N Kamei M Yoshitomi D Kanai T Sekikawa T Nakajima T Watanabe S 《Physical review letters》2004,93(8):083903
We have successfully observed two-photon above-threshold ionization in rare gas atoms (Ar, Xe, and He) by the fifth harmonic (25 eV photon energy) of a KrF laser. Use of the energy-resolved photoelectron counting system together with our laser, providing strong 25 eV radiation at 40-100 Hz, enabled us to detect the very weak single-color two-photon above-threshold ionization signals. Experimental data are in good agreement with our theoretical calculations newly developed along the line of multichannel quantum defect theory. 相似文献
337.
Taro Tsubomura Shigenobu Yano Sadao Yoshikawa Koshiro Toriumi Tasuku Ito 《Polyhedron》1983,2(2):123-124
338.
Tadakatsu Mandai Sadahiro Suzuki Atsushi Ikawa Taro Murakami Mikio Kawada Jiro Tsuji 《Tetrahedron letters》1991,32(52):7687-7688
A new synthetic method for polycyclic compounds via the palladium-catalyzed tandem carbonylation and intramolecular Diels-Alder reaction is described. 相似文献
339.
Low-temperature elastic moduli and internal dilational and shear friction of polymethyl methacrylate
Longitudinal and transverse wave velocity, five kinds of elastic parameters (young, shear and bulk moduli, Lamér; parameter. Poisson's ratio) and dilational and shear internal friction of polymethyl methacrylate were simultaneously measured over a temperature range 68–400K, using the ultrasonic pulse method. All elastic moduli decrease with increasing temperature, suggesting lowering of molecular bonding strength. From dilational and shear internal frictions, the 139, 382, and 385K peaks are interpreted as rotation of x-methyl estel groups, micro Brownian motion of main chains and stress relaxation, and abrupt increases from 242 and 395K are regarded as free motion of side chains and glass transition, respectively. ©1995 John Wiley & Sons, Inc. 相似文献
340.
Taro Nagao 《Journal of statistical physics》2007,129(5-6):1137-1158
It is well known that Pfaffian formulas for eigenvalue correlations are useful in the analysis of real and quaternion random matrices. Moreover the parametric correlations in the crossover to complex random matrices are evaluated in the forms of Pfaffians. In this article, we review the formulations and applications of Pfaffian formulas. For that purpose, we first present the general Pfaffian expressions in terms of the corresponding skew orthogonal polynomials. Then we clarify the relation to Eynard and Mehta’s determinant formula for hermitian matrix models and explain how the evaluation is simplified in the cases related to the classical orthogonal polynomials. Applications of Pfaffian formulas to random matrix theory and other fields are also mentioned. 相似文献