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61.
Muto R Chiba J En'yo H Fukao Y Funahashi H Hamagaki H Ieiri M Ishino M Kanda H Kitaguchi M Mihara S Miwa K Miyashita T Murakami T Nakura T Naruki M Ozawa K Sakuma F Sasaki O Sekimoto M Tabaru T Tanaka KH Togawa M Yamada S Yokkaichi S Yoshimura Y 《Physical review letters》2007,98(4):042501
Invariant mass spectra of e(+) e(-) pairs have been measured in 12 GeV p + A reactions to detect possible in-medium modification of vector mesons. Copper and carbon targets are used to study the nuclear-size dependence of e(+) e(-) invariant mass distributions. A significant excess on the low-mass side of the phi meson peak is observed in the low betagamma(= beta/square root(1-beta(2))) region of phi mesons (betagamma < 1.25) with copper targets. However, in the high betagamma region (betagamma > 1.25), spectral shapes of phi mesons are well described by the Breit-Wigner shape when experimental effects are considered. Thus, in addition to our earlier publications on rho/omega modification, this study has experimentally verified vector meson mass modification at normal nuclear density. 相似文献
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63.
Y. Fujii H. Kakihana M. Okamoto T. Oi Y. Sakuma 《Isotopes in environmental and health studies》2013,49(7):203-208
Isotope separation by chromatographic electromigration has been studied for lithium (6Li and 7Li) and uranium (235U and 238U), using cation-exchange membranes as migration media. The membranes were pulled back against the direction of the movement of isotopic cations in a countercurrent manner. In both cases of the elements the lighter isotope, 6Li or 235U, was concentrated at the frontal part of a migration zone; at the extreme front the 6Li atom % increased to 16.8% from the original value of 7.5% after 386 cm migration, and the 235 U atom % rose to 0.743% from the original value of 0.723% after 200 cm migration. Isotope separation coefficients were experimentally determined: ε = (3.7 ± 0.4) μ 10?3 for lithium isotopes, and two slightly different values ε = (4.9 ± 1.0) μ 10?5 and (5.4 ± 1.1) μ 10?5 for uranium isotopes. The steep isotope accumulation was observed in a narrow boundary region. A mathematical expression for the isotope accumulation curve was derived, and the slope of the curve was assessed for each experimental result. 相似文献
64.
Chiral Lewis base-assisted Br?nsted acids (Chiral LBBAs) have been designed as new organocatalysts for biomimetic enantioselective cyclization. A salt of a chiral phosphonous acid diester with FSO(3)H catalyzes the enantioselective cyclization of 2-geranylphenols to give the desired trans-fused cyclized products with high diastereo- and enantioselectivities (up to 98:2 dr and 93% ee). 相似文献
65.
A protein A affinity chromatographic medium based on porous silica modified with phosphorylcholine (PC) groups and amino groups (PNSP) was synthesized. The PC groups functioned as suppressors of non-specific protein adsorption. Recombinant protein A was bound to the amino groups on PNSP with a glutaraldehyde used as a spacer (PNSP-PA). The PC groups and amino groups were immobilized on porous-silica particles using two silane coupling reagents, PC-bound silane, and 3-aminopropyltrimethoxysilane. After optimizing various factors in the synthetic process, the resultant protein A medium showed improvements in non-specific protein adsorption, dynamic binding capacity, and chemical stability under basic conditions compared with conventional protein A affinity media. 相似文献
66.
Khairul Basar Xianglian Takashi Sakuma Masao Yonemura Toru Ishigaki 《Physica B: Condensed Matter》2008,403(17):2557-2560
The oscillatory profile of diffuse scattering of ordered crystal PbF2 is observed by time-of-flight (TOF) neutron scattering measurement. The theoretical expression of diffuse scattering intensity including the correlation effects among the thermal displacements of atoms is used to analyze the diffuse scattering profile of PbF2. The theoretical expression is effective for the analysis of the diffuse scattering data by the TOF measurement. 相似文献
67.
Makoto Toba Tetsuya Sakuma Shu-Ichi Niwa Hiromichi Shimada Fujio Mizukami 《Journal of Sol-Gel Science and Technology》2000,19(1-3):695-699
Titania containing catalysts were prepared by conventional procedures (coprecipitation, hydrogel kneading and titania precipitation) and a complexing-agent assisted sol-gel method. The effect of preparation methods on their properties and catalytic activities in the oxidation of olefins and decomposition of cumene hydroperoxide were examined. The sol-gel method gave the best dispersion of titania. In contrast, with the kneading and titania precipitation method, titania formed crystalline particles. The sol-gel catalysts are more effective for epoxydation of olefins because of the high dispersibility of Ti in them. However, the most active catalysts in the decomposition of cumene hydroperoxide are kneading ones. 相似文献
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The vibrational spectrum for a fine particle is obtained by exactly solving the wave equation for a homogeneous elastic sphere with free surface. In terms of this frequency spectrum, enhancements in the specific heat of fine particles are calculated and compared with the experiments at low temperatures. Qualitative features of the experimental results are consistently explained in our theory. 相似文献
70.
Dedicated to Professor Yoko Tao for her 60th birthday 相似文献