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121.
Keisuke Araki 《Optical Review》2000,7(3):221-229
We have established a new method of aberration analysis for off-axial optical systems which are generalized concepts of co-axial optical systems, by introducing two kinds of newly defined 4-element vectors and expanding these vectors with the help of tensor algebra. In this method, since aberration properties are represented in tensor form, we can easily formulate the aberration relations between different azimuths. We can then evaluate the azimuth dependence of aberration properties in greater detail by separating them into inherent optical properties parts, which are independent of azimuths, and the paraxial ray-tracing part, which includes the expression of the evaluation azimuth. 相似文献
122.
Angelo Sassaroli Fabrizio Martelli Yukari Tanikawa Kenji Tanaka Ryuichiro Araki Yoichi Onodera Yukio Yamada 《Optical Review》2000,7(5):420-425
The in vivo optical properties of a piglet brain were measured using a time-resolved system at three different wavelengths (759, 794, 824 nm). To separate the contribution of different head layers to the detected signals, the measurements were acquired from the surfaces of skin, skull, dura mater and brain. The source detector distance was chosen to assure a mean penetration depth within each layer. Measurements were analyzed and compared with the results of other in vivo measurements reported in literature. 相似文献
123.
A. Yokoyama S. Morimoto T. Inoue J. Sanada H. Araki T. Saito H. Baba S. Shibata A. Shinohara T. Muroyama Y. Ohkubo 《Journal of Radioanalytical and Nuclear Chemistry》1999,239(1):143-149
Target-like products, that is,191–200Au,185–200Pt, and183–195Ir, from197Au target bombarded with12C ions at the energies of 180, 230, and 400 MeV/u were measured by using off-line gamma-ray spectrometry combined with chemical
separation procedures. Spallation systematics by Rudstam reproduces well the measured cross sections for formation of platinum
and iridium isotopes. It was found that the cross sections of gold nuclides increase with increase of the incident energy
in the range studied and they are enhanced if compared with the reported proton-induced reaction of gold at a similar incident
energy. It is suggested that the electromagnetic dissociation process plays a role for production of such gold nuclides. 相似文献
124.
Shigeo Sato Koji Omori Sawa Araki Yohei Takahashi Kazuaki Wagatsuma 《Surface and interface analysis : SIA》2009,41(6):496-501
Nitriding phenomena that occur on the surfaces of pure Fe and Fe? Cr alloy (16 wt% Cr) samples were investigated. An Ar + N2 mixture‐gas glow‐discharge plasma was used so that surface nitriding could occur on a clean surface etched by Ar+ ion sputtering. In addition, the metal substrates were kept at a low temperature to suppress the diffusion of nitrogen. These plasma‐nitriding conditions enabled us to characterize the surface reaction between nitrogen radicals and the metal substrates. The emission characteristics of the band heads of the nitrogen molecule ion (N2+) and nitrogen molecule from the glow‐discharge plasma suggest that the active nitrogen molecule is probably the major nitriding reactant. AES and angle‐resolved XPS were used to characterize the thickness of the nitride layer and the concentration of elements and chemical species in the nitride layer. The thickness of the nitride layer did not depend on the metal substrate type. An oxide layer with a thickness of a few nanometers was formed on the top of the nitride layer during the nitriding process. The oxide layer consisted of several species of Nx‐Fey‐O, NO+, and NO2?. In the Fe? Cr alloy sample, these oxide species could be reduced because chromium is preferentially nitrided. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
125.
126.
Jai Han Seok Mohamed E. El-Khouly Yasuyuki Araki Kwang-Yol Kay 《Journal of organometallic chemistry》2009,694(12):1818-3862
Photoinduced electron transfer processes of two newly synthesized tetrads with a triphenylamine (TPA) as central building block, to which bisfullerenes (C60) and bisferrocenes (Fc) are covalently connected, have been studied. One of them has a TPA linked with one C60 moiety and two ferrocene moieties C60-TPA-(Fc)2 and another tetrad has a TPA linked with two C60 moieties and one ferrocene unit (C60)2-TPA-Fc. The photophysical properties of (C60)m-TPA-(Fc)n have been investigated by applying the picosecond time-resolved fluorescence and nanosecond transient absorption techniques in both polar and nonpolar solvents. The charge separation process via the excited singlet state of the C60 moiety of the C60-TPA-(Fc)2 is more efficient than that of the (C60)2-TPA-Fc. It is found that the ratio of Fc-donor to C60-acceptor affects charge separation efficiency via the excited singlet state of the C60 moiety. 相似文献
127.
Reactions of electron-deficient alkenes with dibromomethylene compounds activated by cyano and ester groups were promoted by LiI or tetrabutylammonium bromide to afford the corresponding cyclopropanes in high yields. 相似文献
128.
Abe M Hattori M Takegami A Masuyama A Hayashi T Seki S Tagawa S 《Journal of the American Chemical Society》2006,128(24):8008-8014
A detailed study of the regioselectivity of 1,2-oxygen migration was conducted using the unsymmetrically substituted singlet 2,2-dialkoxy-1,3-diarylcyclopentane-1,3-diyls 5. The alkoxy group selectively migrates to the electron-donating p-methoxyphenyl-substituted carbon. The regioselective migration of oxygen clearly indicates a hyperconjugative resonance structure, that is, zwitterionic characteristics, in singlet 2,2-dialkoxy-1,3-diyls. This represents the first attempt to experimentally probe the contribution of hyperconjugation to stabilizing the singlet state. 相似文献
129.
Molecular dynamics (MD) simulation using the reference potential spatial warping algorithm (REPSWA) is a promising method for computing the conformational equilibrium of a system with a rugged energy surface. Its effectiveness has previously been demonstrated using only a simplified model system of a hydrocarbon chain omitting nonbonded interaction terms from the potential energy function. To evaluate the applicability of REPSWA MD simulation to more realistic problems, we applied it to small peptide systems in an aqueous environment. Difficulties were encountered, however, forcing us to devise several modifications. We investigated their effectiveness in comparison to conventional constant-temperature and multicanonical MD simulations. We found that the sampling efficiency of the modified REPSWA MD after a careful optimization of its parameters was better than that of the constant-temperature MD and comparable to that of the multicanonical MD in several cases. 相似文献
130.
A series of zinc porphyrinic receptors for a viologen substrate (hexyl viologen, HV2+) were synthesized, in which varying numbers of diarylurea moieties, from one to four, were appended at the porphyrin's meso positions. The increase in the number of the diarylurea moiety led to the increase in stability of the receptor-HV2+ complex, showing that the convergent dipoles set up on the porphyrin platform played an essential role in the complexation. In this system, formation of the stable electron donor-acceptor complex resulted in the effective electron transfer from the singlet excited state of the zinc porphyrin to HV2+. 相似文献