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111.
Toru Doi Akira Akimoto Akikazu Matsumoto Takayuki Otsu 《Journal of polymer science. Part A, Polymer chemistry》1996,34(3):367-373
Radical copolymerization of N-methylmaleimide (MeMI) as well as other N-alkylmaleimides (RMI) and isobutene (IB) was carried out with 2,2′-azobis(isobutyronitrile) as an initiator at 60°C. The initial rate of the copolymerization (Rp) was dependent on the monomer composition and was maximum at the 40 mol % of MeMI in the feed. A solvent effect on the Rp and the monomer reactivity ratio was observed in this copolymerization system, i.e., copolymerization in chloroform produced a higher Rp and an alternating tendency compared with those in dioxane (rMeMI = 0.14, r1B = 0 in chloroform and rMeMI = 0.47, r1B = 0 in dioxane). The alternating copolymer of RMI and IB shows a high glass transition temperature (Tg) and excellent thermal stability, e.g., the Tg and the thermal decomposition temperature (Td) were 152 and 363°C, respectively, for the alternating copolymer of MeMI and IB. Both the Tg and Td increased as the concentration of the MeMI unit in the copolymers increased. Colorless transparent sheets were obtained from press molding the alternating copolymers. They showed excellent mechanical and optical properties. © 1996 John Wiley & Sons, Inc. 相似文献
112.
113.
The radical polymerization kinetics and mechanism of sterically hindered dialkyl fumarates (DRF) bearing various ester alkyl groups are described comprehensively. The overall polymerization reactivity of DRF, the initiation mechanism and the reactivity of the primary radicals in the polymerizations with azo initiators, the determination of the propagation and termination rate constants by means of electron spin resonance spectroscopy, the propagation mechanism and the microstructure of the polymers, and the chain rigidity of poly(DRF) and bimolecular termination process are discussed. 相似文献
114.
115.
In relation to a colloid stability, the adsorption structure of the Stern layer on a sessile mercury electrode in a thin liquid film of nonionic surfactant was investigated by measuring the double layer capacitance. The Stern capacitance on the electrode in the film could be detected when the measuring frequency used was low, for the resistance of the film was not extremely high but of the order of several thousand ohm. It was found that the adsorption structure of nonionic surfactant in the thin liquid film shows a stratification different from that of bulk. 相似文献
116.
Dr. Kyohei Otsuka Naozumi Matsumoto Dr. Shintaro Ishida Prof. Dr. Soichiro Kyushin 《Angewandte Chemie (International ed. in English)》2015,54(27):7833-7836
The radical anion of octa‐tert‐butyloctasilacubane was generated and isolated. The EPR spectrum showed the satellites due to the tertiary 13C nuclei of the eight tert‐butyl groups. The X‐ray crystallographic analysis showed that the Si? Si bonds are shortened and the Si? C bonds are elongated compared with those of octa‐tert‐butyloctasilacubane. These results are well explained by the distribution of an unpaired electron in the singly occupied molecular orbital (SOMO). 相似文献
117.
Y. Watanabe H. Yamaguchi M. Hashinokuchi K. Sawabe S. Maruyama Y. Matsumoto K. Shobatake 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(1):103-109
The scattering of a hyperthermal Xe from a graphite (0001) surface
has been studied using a molecular beam-surface scattering technique
and molecular dynamics (MD) simulations.
The angular and velocity distributions of scattered Xe atoms
were measured at incidence energies from 0.45 to 3.5 eV,
three incidence angles of 15°, 35° and 60°
and the surface temperatures of 300 K and 550 K.
The observed time-of-flight spectra exhibit a sharp velocity distribution
with only one velocity component, which is ascribed
to the direct inelastic scattering process.
The angle-resolved energy ratios of the mean final translational energy
over the mean incidence energy Ef/Ei agree well
with those predicted based on the assumption of the conservation
of the momentum parallel to the surface.
The Hard-Cube model, where the mass of the cube is approximately 310 u,
has reproduced the angle-resolved flux distributions of scattered Xe atoms.
In the Hard-Cube model
almost 80% of the normal component of the incidence translational energy is found
to be lost in collision.
The MD simulations reproduce well the experimental results
by using the Brenner potential for intralayer C atoms
and a Lennard-Jones potential for interlayer C–C pair interactions. 相似文献
118.
Taketoshi Matsumoto Patricia Nickut Kazuya Watanabe Tatsuya Tsukuda Katharina Al-Shamery 《Surface science》2007,601(22):5226-5231
Reduction of oxidized gold nanoclusters by exposures to foreign gases and irradiation of UV photons has been investigated using X-ray photoelectron spectroscopy. Gold nanoclusters with narrow size distributions protected by alkanethiolate ligands were deposited on a TiO2(1 1 0) surface with dip coating. Oxygen plasma etching was used for removal of alkanethiolate ligands and oxidization of gold clusters. The oxidized gold clusters were exposed to CO, C2H2, C2H4, H2, and hydrogen atoms. Although, C2H4 and H2 did not show any indications of reduction of oxidized gold clusters, CO, C2H2, and hydrogen atoms reduced the oxides on gold cluster surfaces. Among them, hydrogen atoms were most effective for reduction. Irradiation of UV photons around 400 nm could also reduce the oxidized gold clusters. The photochemical reduction mechanism was proposed as follows. The photo-reduction was initiated by electronic excitation of gold clusters and oxygen atoms activated reacted with carbon atoms at the surfaces of gold clusters. Carbon species were likely absorbed in gold clusters or remained at the boundaries between gold clusters when gold clusters agglomerated during oxygen plasma exposures. As the photochemical reduction progressed, carbon atoms segregated to the surfaces of gold clusters. 相似文献
119.
Laguerre-Gaussian (LG) beams of various higher-order radial modes are generated by using a reflective phase-only liquid crystal on silicon (LCOS) spatial light modulator (SLM). Because of the LCOS SLM's phase-modulation characteristic of a wide spatial bandwidth, a phase modulation scheme effectively generates higher-order LG beams of up to the fifth-order radial mode. We also perform correlation analyses between the observed and the theoretical two-dimensional mode profiles to universally obtain correlation coefficients of more than 0.946, which suggest mode generations of high quality. 相似文献
120.
A new imaging method using an incoherent-type pupil filter: SFINCS (Spatial Filter for INCoherent Stream) is presented. The new filter divides the imaging beam into several incoherent beams at the pupil plane thereby enlarging the depth-of-focus (DOF). The capabilities of SFINCS are studied by simulations and several ways to realize the method are also discussed. The experimental results show that SFINCS has excellent DOF expanding capabilities for a point-image such as a hole pattern in VLSI lithography, and that 1.7 μm DOF is obtained with a 0.30 μm hole pattern by an i-line projection lens with 0.57 NA (numerical aperture).Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994. 相似文献