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41.
Takumi Yokota 《Geometriae Dedicata》2008,133(1):169-179
In this paper, we consider the behavior of the total absolute and the total curvature under the Ricci flow on complete surfaces
with bounded curvature. It is shown that they are monotone non-increasing and constant in time, respectively, if they exist
and are finite at the initial time. As a related result, we prove that the asymptotic volume ratio is constant under the Ricci
flow with non-negative Ricci curvature, at the end of the paper.
相似文献
42.
43.
Tsunetoshi Kobayashi Katsuyuki Yokota Saburo Nagakura 《Journal of Electron Spectroscopy and Related Phenomena》1973,2(5):449-454
The photoelectron spectra of styrene and its methyl derivatives were measured and interpreted. The vinyl group twisted by the steric hindrance of the α- or orthomethyl group was found to play an important role in the interpretation of the photoelectron spectra of these compounds. The dependence of the higher occupied π orbital energies of styrene upon the twist angle of the vinyl group was estimated from the experimental data. 相似文献
44.
45.
Ichirou Yamaguchi Masayuki Yokota Takasi Ida Mizuki Sunaga Koichi Kobayashi 《Optical Review》2007,14(6):362-364
The state of drying paint is monitored from the dynamic behaviors of the speckle pattern arising from laser illumination of
the region inspected. Temporal variation of the peak height of the cross-correlation function between successive frames taken
with a fixed interval is plotted until the peak maintains a stationary maximum value. We used a speckle pattern in the diffraction
field for monitoring of a single region and that in the image field for simultaneous monitoring of various regions. Both the
normal and the phase-only algorithms were compared for cross-correlation computation. The former showed more distinct variation
of peak height. 相似文献
46.
47.
We theoretically investigated laser trimming to adjust grating offset in phase-shifted fiber grating coupler (FGC) for all-optical switching application. It was clarified that the trimming made the extinction ratio higher in all-optical FGC switch. 相似文献
48.
The molecular structure of SR-90 and CR-39 is very similar except that the average length of carbonate linkages in SR-90 is 1.6 times longer than in CR-39. However, the effect of vacuum and carbon dioxide (CO2) on the track registration of these two detectors is very different: 1) the sensitivity of CR-39 becomes very low in vacuum; the sensitivity of SR-90 does not go down to zero even after storage in vacuum for a long time; 2) the sensitivity of SR-90 decreases both in air and in vacuum but the original sensitivity can be restored by storing it in CO2 of 13 atm for several days. We also found that the sensitization of latent tracks by oxygen (O2) is effective only at the time of irradiation but the sensitization by CO2 is effective after irradiation. 相似文献
49.
Tsutomu Kagiya Shizuo Narisawa Taizo Ichida Kenichi Fukui Hisao Yokota Masatsune Kondo 《Journal of polymer science. Part A, Polymer chemistry》1966,4(2):293-299
The copolymerization of carbon monoxide and aziridines such as ethylenimine and propylenimine was carried out by γ-ray irradiation. Aziridines and carbon monoxide were allowed to copolymerize under γ-ray irradiation from a Co60 source and gave a crystalline solid copolymer. The yield of the copolymer increased with reaction temperature. The composition of copolymers obtained did not depend on the feed ratio of monomers and was found to be almost equimolar. The copolymer of ethylenimine and carbon monoxide melted at about 322–335°C. with decomposition and has an infrared spectrum identical with that of poly-β-alanine obtained by the hydrogen-migration polymerization of acrylamide. The hydrolyzed product of the ethylenimine–carbon monoxide copolymer was confirmed to be β-alanine by paper chromatography. These results lead to the conclusion that the copolymerization of aziridines and carbon monoxide took place alternatively by γ-ray irradiation, and produced crystalline poly-β-alanines. 相似文献
50.
When two waves are coupled in Bi12SiO20 crystals, the polarization states of the signal wave are affected by the self-diffraction. We have theoretically studied the influence of the self-diffraction on the polarization of the signal wave. The change of polarization states are strongly affected by the self-diffraction effect when the external field is applied. We present a new method that converts the change of polarization into an intensity signal. 相似文献