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Shigeru Yabumoto Kiyoshi Ishii Masakiyo Kawamori Koichiro Arita Hiroshi Yano 《Journal of polymer science. Part A, Polymer chemistry》1969,7(7):1683-1696
The properties of the acrylonitrile–styrene copolymer prepared in the presence of zinc chloride were investigated in comparison with those of a copolymer having the same overall composition and prepared by the ordinary radical procedure. The characteristics of the polymer prepared with ZnCl2 were as follows: (1) less coloration by alkali treatment, (2) less coloration by thermal treatment and (3) higher glass transition temperature. These features may be attributed principally to the structure of the copolymer, which has more unlike bonds and less long sequences as described in the first article of this series. The effects of residual salt in the copolymer on the properties were also investigated. 相似文献
96.
Toshihiko Omote Syun'ichi Hayashi Kazuhisa Ishii Kazuhiko Naitoh Tsuguo Yamaoka 《先进技术聚合物》1993,4(4):277-287
A polyimide (6F-THP) with a tetrahydropyranyl group (THP) in its side chain has been synthesized. The THP group exhibits a high acidolysis rate in this polymer's film. This rate was faster than that of a tertbutoxycarbonyl group (t-BOC), which has been previously reported [1]. Furthermore, the deprotected fluorinated polyimide (6FDA-AHHFP) became soluble in an aqueous base due to the presence of a hydroxyl group attached to the phenyl group of the diamine segment. The polyimide thus provides high performance as a photopolymer when used in conjunction with a photoacid generator after the post-exposure baking process (PEB). The photoacid generators used in this study were p-nitrobenzyl-9,10-dimethoxyanthoracene-2-sulfonate (NBAS) and diphenyliodonium-9,10-dimethoxyanthoracene-2-sulfonate (DIAS). The quantum yields of photodissociation and photoacid generation were also measured. The photoacid-generating quantum yields closely corresponded to the photosensitivities of the photoreactive polyimide system. It was confirmed that the THP group was easily deprotected even in the 6F-THP film with p-toluenesulfonic acid as a model acid catalyst. The activation energy of the THP deprotection reaction was determined to be 12.8 kcal/mol (19.5 kcal/mol in the case of t-BOC). The relationships between the THP deprotecting rate constant (kd) and acid molecular size and between kd and polyimide structure were further investigated. 相似文献
97.
Maeyama T Yagi I Murota Y Fujii A Mikami N 《The journal of physical chemistry. A》2006,110(51):13712-13716
Vibrational spectra of microsolvated benzonitrile radical anions (C6H5CN- -S; S = H2O and CH3OH) were measured by probing the electron detachment efficiency in the 3 microm region, representing resonance bands of autodetachment via OH stretching vibrations of the solvent molecules. The hydrogen-bonded OH band for both the cluster anions exhibited a large shift to the lower energy side with approximately 300 cm-1 compared to those for the corresponding neutral clusters. The solvent molecules are bound collinearly to the edge of the CN group of the benzonitrile anion in the cluster structures optimized with the density functional theory, in which the simulated vibrational energies are in good agreement with the observed band positions. Natural population analyses were performed for a qualitative implication in changes of solvent orientation upon electron attachment. Asymmetric band shapes depending on the vibrational modes are discussed with respect to dynamics of the autodetachment process from a theoretical aspect incorporated with density functional calculations. 相似文献
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99.
H. Iwasawa J.F. Douglas K. Sato T. Masui Y. Yoshida Z. Sun H. Eisaki H. Bando A. Ino M. Arita K. Shimada H. Namatame M. Taniguchi S. Tajima S. Uchida T. Saitoh D.S. Dessau Y. Aiura 《Physica C: Superconductivity and its Applications》2010
Using angle-resolved photoemission spectroscopy (ARPES) with low-energy tunable photons, we studied the oxygen isotope effect in optimally doped Bi2Sr2CaCu2O8+δ (Bi2212). We found the oxygen isotope shift in the real part of the electron self-energies [ReΣ(ω)s] along the nodal direction derived not only from the momentum distribution curves (MDCs) but also from the energy distribution curves (EDCs). Present results indicate straightforwardly the coupling between the nodal electrons and the phonons. 相似文献
100.
Multi-mode absorption spectroscopy, MUMAS, using wavelength modulation and cavity enhancement techniques 总被引:1,自引:0,他引:1
M. L. Hamilton G. A. D. Ritchie Y. Arita P. Ewart 《Applied physics. B, Lasers and optics》2010,100(3):665-673
Multi-mode absorption spectroscopy, MUMAS, has been combined with the techniques of wavelength modulation spectroscopy, WMS, and cavity enhanced absorption spectroscopy, CEAS, to record multiple molecular transitions using a single laser and a single detector. MUMAS signals were recorded using a multi-mode diode laser of the A-band $b^{1}\varSigma _{g}^{+}\leftarrow X^{3}\varSigma _{g}^{-}Multi-mode absorption spectroscopy, MUMAS, has been combined with the techniques of wavelength modulation spectroscopy, WMS,
and cavity enhanced absorption spectroscopy, CEAS, to record multiple molecular transitions using a single laser and a single
detector. MUMAS signals were recorded using a multi-mode diode laser of the A-band
b1\varSigma g+? X3\varSigma g-b^{1}\varSigma _{g}^{+}\leftarrow X^{3}\varSigma _{g}^{-} of molecular oxygen at 760 nm. Direct MUMAS and WMS-MUMAS signals were recorded using a White cell for air and pure oxygen
for pressures in the range 0 to 1 bar. CEAS-MUMAS signals were recorded with and without WMS in an open enhancement cavity
containing laboratory air. Enhancement of the signal-to-noise ratio has been obtained demonstrating the potential for increased
detection sensitivity for gas-sensing applications of MUMAS. 相似文献