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71.
Keigo Kobayashi Prof. Hirokazu Kobayashi Prof. Mitsuhiko Maesato Dr. Mikihiro Hayashi Tomokazu Yamamoto Dr. Satoru Yoshioka Prof. Syo Matsumura Prof. Takeharu Sugiyama Dr. Shogo Kawaguchi Prof. Yoshiki Kubota Prof. Hiroshi Nakanishi Prof. Hiroshi Kitagawa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(23):6678-6682
We report on hexagonal close-packed (hcp) palladium (Pd)–boron (B) nanocrystals (NCs) by heavy B doping into face-centered cubic (fcc) Pd NCs. Scanning transmission electron microscopy–electron energy loss spectroscopy and synchrotron powder X-ray diffraction measurements demonstrated that the B atoms are homogeneously distributed inside the hcp Pd lattice. The large paramagnetic susceptibility of Pd is significantly suppressed in Pd–B NCs in good agreement with the reduction of density of states at Fermi energy suggested by X-ray absorption near-edge structure and theoretical calculations. 相似文献
72.
Harada T Ikeda S Hashimoto F Sakata T Ikeue K Torimoto T Matsumura M 《Langmuir : the ACS journal of surfaces and colloids》2010,26(22):17720-17725
A core-shell composite consisting of a palladium (Pd) nanoparticle and a hollow carbon shell (Pd@hmC) was employed as a catalyst for aerobic oxidation of various alcohols. The core-shell structure was synthesized by consecutive coatings of Pd nanoparticles with siliceous and carbon layers followed by removal of the intermediate siliceous layer. Structural characterizations using TEM and N(2) adsorption-desorption measurements revealed that Pd@hmC thus-obtained was composed of a Pd nanoparticle core of 3-6 nm in diameter and a hollow carbon shell with well-developed mesopore (ca. 2.5 nm in diameter) and micropore (ca. 0.4-0.8 nm in diameter) systems. When compared to some Pd-supported carbons, Pd@hmC showed a high level of catalytic activity for oxidation of benzyl alcohol into benzaldehyde using atmospheric pressure of O(2) as an oxidant. The Pd@hmC composite also exhibited a high level of catalytic activity for aerobic oxidations of other primary benzylic and allylic alcohols into corresponding aldehydes. The presence of a well-developed pore system in the lateral carbon shell enabled efficient diffusion of both substrates and products to reach the central Pd nanoparticles, leading to such high catalytic activities. This core-shell structure also provided high thermal stability of Pd nanoparticles toward coalescence and/or aggregation due to the physical isolation of each Pd nanoparticle from neighboring particles by the carbon shell: this specific property of Pd@hmC resulted in possible regeneration of catalytic activity for these aerobic oxidations by a high-temperature heat treatment of the sample recovered after catalytic reactions. 相似文献
73.
74.
Shin-ichi Matsumura 《Mathematische Annalen》2014,359(3-4):785-802
The purpose of this paper is to establish Nadel type vanishing theorems with multiplier ideal sheaves of singular metrics admitting an analytic Zariski decomposition (such as, metrics with minimal singularities and Siu’s metrics). For this purpose, we generalize Kollár’s injectivity theorem to an injectivity theorem for line bundles equipped with singular metrics, by making use of the theory of harmonic integrals. Moreover we give asymptotic cohomology vanishing theorems for high tensor powers of line bundles. 相似文献
75.
The resistivity of a hydrogenated sputtered amorphous-silicon is controlled by using room temperature implantation of P+. It is found that the defects produced by implantation can be minimized by annealing at 300°C in an H2 atmosphere, and also found that there is a threshold implanted dose, beyond which the resistivity begins to be controlled by changing the dose. 相似文献
76.
Hisatoshi Kura Kan Fujihara Akira Kimura Teruhisa Ohno Michio Matsumura Yoshinori Hirata Tadashi Okada 《Journal of Polymer Science.Polymer Physics》2001,39(23):2937-2946
The anthracene‐sensitized photodecomposition of diphenyliodonium hexafluorophosphate was studied in an epoxy matrix. From steady‐state photolysis, the generation of protons, which are considered to be the actual initiators of the polymerization of epoxides, was confirmed. In addition, 9‐phenylanthracene was detected as a main product from anthracene. From time‐resolved laser‐flash photolysis, a broad absorption band with a peak at about 500 nm was observed that was thought to be due to the precursor of 9‐phenylanthracene. On the basis of these results, we propose electron transfer from anthracene in the excited singlet state to the diphenyliodonium cation as the initial step of photoacid generation. This process is followed by fast chemical reactions, which generate 9‐phenylanthracene and protons, and back electron transfer from the diphenyliodine radical to the anthracene cation radical. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2937–2946, 2001 相似文献
77.
H. Matsumura T. Miura S. Ishihama N. Matsuda T. Aze K. Masumoto T. Suzuki 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(2):423-428
Gold activation detectors were placed at nine positions on the inner wall of the KEK neutrino target station, and were exposed
to secondary particles during approximately one month of machine operation. After exposure, the production rates of 19 spallation
nuclides, which were produced in the Au activation detectors by nuclear reactions with different threshold energies, were
determined by γ-ray spectrometry. Thus, it was indicated that the Au activation detector is a novel tool for obtaining the
distribution of various secondary particles with high intensity and high energy. 相似文献
78.
79.
Daisuke Nagae Koichiro Asahi Hisanori Miyoshi Kenzi Shimada Akihiro Yoshimi Hideki Ueno Jiro Murata Makoto Uchida Daisuke Kameda Go Kato Shoken Emori Go Kijima Sachiko Oshima Makoto Takemura Takemasa Arai Yoshio Kobayashi Tomohito Haseyama W.D. Schmidt-Ott 《Physica E: Low-dimensional Systems and Nanostructures》2005,29(3-4):580
A device that produces a low-energy and largely spin polarized RI beam based on the atomic beam resonance method (RIABR) has been developed. We have performed measurements of stopping and drifting an incoming RI ion beam in a gas chamber, extraction of the ions into a vacuum region, and neutralization of the extracted low-energy ion beam. The drift efficiency of RI ions in a gas and the extraction efficiency at a Laval-type glass nozzle were found to be 0.72±0.04 and 0.033, respectively. The result of the experiment for the neutralization is also discussed. 相似文献
80.
The influence of cell density of cells cryopreserved inside a collagen matrix at various cooling rates was investigated. Human fibroblasts were three-dimensionally cultured for 2 days in a collagen sponge (20 mm in diameter and 1 mm in thickness) as an extracellular matrix to imitate biological tissue (artificial tissue). Different cell densities for the artificial tissue were used, from 10(5) to 10(7) cells/cm(3). Four artificial tissues were first stacked in a test chamber, frozen at a cooling rate of 0.3 to 50 degrees C/min in a solution of Dulbecco's Modified Eagle Medium, 20% fetal bovine serum and 10% dimethylsulfoxide, kept frozen below -185 degrees C for 2 hours, and then finally thawed. Membrane integrity of fibroblasts using a trypan blue exclusion assay was evaluated as an index for post-thaw cellular viability. Results show that with increasing cell density, the post-thaw membrane integrity decreased. Therefore, in the cryopreservation of biological tissue, it seems high cell density is one factor which causes a decline in viability. 相似文献