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201.
Ryoichi Hirayama Yoshitaka Matsumoto Yuki Kase Miho Noguchi Koichi Ando Atsushi Ito Ryuichi Okayasu Yoshiya Furusawa 《Radiation Physics and Chemistry》2009,78(12):1175-1178
The contribution of OH radical-mediated indirect action by particle beams under hypoxic irradiation condition was investigated by using a radical scavenger. V79 cells were irradiated with 150 MeV/nucleon helium ions at an LET of 2.2 keV/μm in the presence or absence of DMSO, and their colony survivals were determined. The contribution of indirect action to cell killing under hypoxic condition was estimated to be 52±9%. We conclude that OH radical-mediated indirect action still has a half in total contribution on cell killing under hypoxic condition. 相似文献
202.
Hiroaki Chihaya Masao Kamiko Toru Kuzumaki Ryoichi Yamamoto 《Solid State Communications》2006,139(4):170-175
Effects of Co seed layer on the structural and magnetic properties of Co/Pd multilayers have been studied. Reflection high-energy electron diffraction measurements showed a possible control of the crystal orientation of Pd buffer layer from polycrystalline to face-centered cubic (111) orientation when using Co seed layer. Additionally, atomic force microscopy observations confirmed the ability of Co seed layer to flatten the Pd buffer layer drastically. In fact, the usage of Co seed layer has decreased the root-mean-square roughness from 2.3 to 0.23 nm. As for controlling the structural properties of Pd buffer layer, the effective perpendicular magnetic anisotropy constant was enhanced, mainly by the improvement of surface anisotropy. Electronic states of α-Al2O3(0001)/metal interface obtained by electron energy loss spectroscopy proved that these differences were the fruit of the interaction between the metal layer and oxygen atoms on the Al2O3(0001) surface. 相似文献
203.
The mean and variance of the temperature are analytically obtained in a functionally graded annular disc with spatially random heat transfer coefficients (HTCs) on the upper and lower surfaces. This annular disc has arbitrary variations in the HTCs (i.e., arbitrary thermal interaction with the surroundings) and gradient material composition only along the radial direction and is subjected to deterministic axisymmetrical heating at the lateral surfaces. The stochastic temperature field is analysed by considering the annular disc to be multilayered with spatially constant material properties and spatially constant but random HTCs in each layer. A type of integral transform method and a perturbation method are employed in order to obtain the analytical solutions for the statistics. The correlation coefficients of the random HTCs are expressed in the form of a linear function with respect to the radial distance as a non-homogeneous random field of discrete space. Numerical calculations are performed for functionally graded annular discs composed of stainless steel and ceramic, which comprise two types of material composition distributions. The effects of the magnitude of the means of HTCs, volume fraction distributions of the constitutive materials and correlation strengths of the HTCs on the standard deviation of the temperature are discussed. 相似文献
204.
205.
Ryoichi Kuwano Toshihiko Koga Tsuyoshi Tokunaga Toshitaka Wakayama Yukitoshi Otani Nobuyuki Fujii 《Optical Review》2012,19(2):98-102
In this study, a method for generating ring intensity distribution at a refraction-type lens with an aspheric element was
proposed, and the beam shaping optical element was finished using only ultra-precision cutting. The shape of the optical element
and its irradiance pattern were determined from numerical calculation based on its geometrical and physical optics. An ultra-precision
lathe was employed to fabricate beam shaping optical elements, and acrylic resin was used as the material. The transmittance
of an optical element (a rotationally symmetrical body) with an aspheric surface fabricated using a single-crystal diamond
tool was over 98%, and its surface roughness was 9.6 nm Ra. The method enabled the formation of a circular melting zone on
a piece of stainless steel with a thickness of 300 μm through pulse YAG laser (λ 1:06 μm) processing such that the average radius was 610 μm and the width was 100–200 μm. Circular processing using a ring
beam shaping optical element can be realized by single-pulse beam irradiation without beam scanning. 相似文献
206.
207.
Masahiko Hada Jian Wan Ryoichi Fukuda Hiroshi Nakatsuji 《Journal of computational chemistry》2001,22(13):1502-1508
Calculations for 125Te magnetic shielding constants and chemical shifts were carried out using a quasirelativistic Hamiltonian including the spin‐free relativistic, one‐ and two‐electron spin–orbit, and relativistic magnetic interaction terms. For the tellurium‐containing series Te(CH3)2, TeH2, TeF6, Te(CH3)4, and Te(CH3)2Cl2, the relativistic effects amounted to as much as 1300 ppm and were very important for qualitatively reproducing the absolute value of the 125Te shielding constants obtained experimentally. On the other hand, for the 125Te chemical shifts the relativistic effects were less important, because they cancelled each other between the sample and reference compounds. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 1502–1508, 2001 相似文献
208.
Absolute Measurement of Second-Order Nonlinear Optical Coefficient of LiNbO3 by Parametric Processes
We have redetermined the absolute values of the nonlinear optical coefficient, d31, of LiNbO3 by parametric fluorescence and, for the first time, by difference frequency generation measurements to resolve the considerable discrepancy that existed between the values determined by second-harmonic generation (SHG) and parametric fluorescence. We obtain d31 = 4.8±0.5 and 4.3±0.5 pm/V at the pump wavelengths of 488 and 532 nm, respectively, in reasonable agreement with the SHG data. It appears that the previous parametric fluorescence value, d31=5.8 pm/V, was overestimated.Author to whom correspondence should be addressed. 相似文献
209.
Tsukasa Ikeda Ryoichi Kojin Chul-joong Yoon Hiroshi Ikeda Masao Iijima Fujio Toda 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(1):93-98
We modified cyclodextrin (CD) by a histamine group to make a model of -chymotrypsin. Enzymatic turnover reaction was realized with CD-histamine at around neutral pH value. Compared with amino-CD, it is ascertained that this catalytic activity of CD-histamine is caused by an imidazole group. Using several substrates in the hydrolytic reactions, it shows that CD-histamine has a structural selectivity for substrates which are structurally different to each other. 相似文献
210.
This model is a variant on Baker's lattice model for liquids; it takes certain features of water into account by means of a hydrogen-bond parameter in the Hamiltonian. Solutions for the complete phase diagram are obtained by means of the cluster variation method. The model displays three phases chosen to correspond with the vapor, open ice and liquid state. The isotherms show a density maximum. We discuss the shortcomings of the model and what to do about them. 相似文献