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811.
Yukio Yamada 《Optical Review》2000,7(5):366-374
This paper reviews the studies of photon migration in biological tissues and its application to optical tomography which were conducted in the Mechanical Engineering Laboratory of Japan’s Ministry of International Trade and Industry. The research subjects range from theoretical and experimental studies of photon migration in random media to the development of image reconstruction algorithms and experiments for optical tomography. The most fundamental theoretical study of the photon diffusion equation has proved that the photon diffusion coefficient is independent of the absorption coefficient while the conventional one is dependent on the absorption coefficient. Experimental studies included the time-resolved spectroscopy and the fabrication of realistic human head phantoms which have five tissue types with different optical properties. Several types of reconstruction algorithms have been developed and verified experimentally. These investigations are pioneering work in the field of biomedical optics in Japan. 相似文献
812.
Ionic distributions of three sorts of oxygens in glasses in the systems Na2OSiO2K2OSiO2 and PbOSiO2 were determined from molar refractivity. The distribution of these oxygen ions in PbOSiO2 glasses was compared with that determined by the XPS method and with the theoretical calculation based on the athermal mixture model. The present result showed good agreement with that by the XPS method when the PbO content was 70 mol % or over, and showed a discrepancy when the PbO content was less than 70 mol %. It was indicated that a theoretical treatment based on a higher approximation that the athermal mixture model is required in order to enable the comparison with experiments for silica contents higher than 50 mol %. 相似文献
813.
Journal of Nanoparticle Research - 相似文献
814.
Wataru Takahashi Yukio Takeuchi 《Journal of Mathematical Analysis and Applications》2008,341(1):276-286
In this paper, we prove a strong convergence theorem by the hybrid method for a family of nonexpansive mappings which generalizes Nakajo and Takahashi's theorems [K. Nakajo, W. Takahashi, Strong convergence theorems for nonexpansive mappings and nonexpansive semigroups, J. Math. Anal. Appl. 279 (2003) 372-379], simultaneously. Furthermore, we obtain another strong convergence theorem for the family of nonexpansive mappings by a hybrid method which is different from Nakajo and Takahashi. Using this theorem, we get some new results for a single nonexpansive mapping or a family of nonexpansive mappings in a Hilbert space. 相似文献
815.
The liquid structures of As2Se3 and GeSe2 have been investigated using the neutron diffraction patterns. In both cases the structure factor showed a low first peak maximum which follows a weak but apparent pre-peak at very low momentum transfer. It was also observed that the radial distribution function of both materials are characterized by the well-defined first neighbor shell because of the deep minimum on its right-hand side although in the liquid state. These results indicate that strong covalent bondings between unlike atoms in the solid state still remain when melting. Both the structure factor and the distribution curves of these alloys are, on the whole, similar to those in the amorphous phase which have already been examined. A slight difference in the coordination number, however, is found between amorphous and liquid phases of these materials. 相似文献
816.
Budi Purnama Masashi Koga Yukio Nozaki Kimihide Matsuyama 《Journal of magnetism and magnetic materials》2009,321(9):1325-1330
Thermally assisted magnetization reversal of sub-100 nm dots with perpendicular anisotropy has been investigated using a micromagnetic Langevin model. The performance of the two different reversal modes of (i) a reduced barrier writing scheme and (ii) a Curie point writing scheme are compared. For the reduced barrier writing scheme, the switching field Hswt decreases with an increase in writing temperature but is still larger than that of the Curie point writing scheme. For the Curie point writing scheme, the required threshold field Hth, evaluated from 50 simulation results, saturates at a value, which is not simply related to the energy barrier height. The value of Hth increases with a decrease in cooling time owing to the dynamic aspects of the magnetic ordering process. Dependence of Hth on material parameters and dot sizes has been systematically studied. 相似文献
817.
Keitaro Yoshimoto Takumi Hirase Jeppe Madsen Steven P. Armes Yukio Nagasaki 《Macromolecular rapid communications》2009,30(24):2136-2140
Poly[2‐(methacryloyloxy)ethyl phosphorylcholine] ‐modified gold surfaces, which have been newly prepared by a ‘grafting to’ method using a series of monosulfanyl‐terminated PMPC, are characterized by protein adsorption experiments based on surface plasmon resonance spectroscopy and ellipsometry measurements. The extent of BSA adsorption on PMPC‐modified surfaces was systematically reduced for thicker PMPC layers, thus the number of MPC units on the gold surface appears to be an important factor for the excellent protein resistance offered by PMPC‐modified gold surfaces fabricated by the ‘grafting to’ method, which is sharp contrast to that of PEG tethered chains.
818.
Yukio Kawashima Keisuke Sawada Takahito Nakajima Masanori Tachikawa 《Journal of computational chemistry》2019,40(1):172-180
We apply ab initio path integral molecular dynamics simulation employing ωB97XD as the quantum chemical calculation method to acetic acid–arsenic acid anion and acetic acid–phosphoric acid anion clusters to investigate the difference of the hydrogen bond structure and its fluctuation such as proton transfer. We found that the nuclear quantum effect enhanced the fluctuation of the hydrogen bond structure and proton transfer, which shows treatment of the nuclear quantum effect was essential to investigate these systems. The hydrogen bond in acetic acid–arsenic acid anion cluster showed characters related to low-barrier hydrogen bonds, while acetic acid–phosphoric acid anion cluster did not. We found non-negligible distinction between these two systems, which could not be found in conventional calculations. We suggest that the difference in amount of atomic charge of the atoms consisting the hydrogen bond is the origin of the difference between acetic acid–arsenic acid and acetic acid–phosphoric acid anion cluster. © 2018 Wiley Periodicals, Inc. 相似文献
819.
Ono M Takara Y Egami M Uranaka K Yoshimitsu H Matsushita S Fujiwara Y Ikeda T Nohara T 《Chemical & pharmaceutical bulletin》2006,54(2):237-239
Two new steroidal alkaloid glycosides, esculeosides C and D, have been isolated from the ripe fruit of Cherry tomato [Lycopersicon esculentum var. cerasiforme (DUNAL) ALEF.], along with three known steroidal alkaloid glycosides, esculeoside A, esculeoiside B, and lycoperoside G. Their chemical structures were determined on the basis of spectroscopic data. 相似文献
820.
A new kind of cyclic olefin polymer COP-E48R has been selected as the dielectric material for a silver hollow glass tube. Owing to its lower extinction coefficient at the wavelength of 10.6 μm, transmission losses for the CO2 laser light has been reduced significantly in the COP-E48R-coated silver (COP-E48R/Ag) hollow glass waveguide. By properly selecting the film thickness of COP, Er:YAG and CO2 laser light are shown to be transmitted with low loss simultaneously or independently. Delivery properties of red and green pilot beams were also evaluated. 相似文献