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781.
Masanori Kumagai Kikuko Karube Tomoaki Sato Naganori Ohisa Toshio Amano Ryoei Kikuchi Nobuaki Ogawa 《Analytical sciences》2002,18(10):1145-1150
Using a portable near infrared (NIR) spectrometer, we discriminated flours for making Japanese noodles (Soba), not only relying on a statistical and mathematical approach, but also on a chemical interpretation of the NIR spectra. In original NIR spectra, the particle-size difference, which results in an undesired systematic variation, was extracted and interpreted as the first-principal component factor by a principal-component analysis. The discrimination of flour materials cannot be satisfied by this factor. However, after a standardized treatment for the original spectra, the particle-size effects were eliminated; alternatively, differences in the chemical contents were extracted as principal-component factors. Using these factors, flour material discrimination was achieved much better. This study suggests a novel idea of utilizing the wavelength contribution ratio spectra for interpreting the factors extracted from the principal-component analysis for the NIR spectra. This report also describes the relationship between the NIR spectra and the chemical-analysis data. 相似文献
782.
Y Furukawa S TakadaK Kumagai T KawashimaE Takayama-Muromachi N KobayashiT Fukase K ChibaT Goto 《Journal of Physics and Chemistry of Solids》2002,63(12):2315-2318
We have carried out 99/101Ru and 63/65Cu nuclear magnetic resonance experiments in order to investigate magnetic and electronic properties of the magnetic superconductor RuSr2RECu2O8 (RE=Gd, Eu and Y). The two kinds of 99/101Ru signals were observed in the magnetically ordered state for each system, suggesting a charge segregation of Ru5+ (S=3/2) and Ru4+ (S=1) ions in the RuO2 layers. The internal field at the Cu sites is revealed to be of the order of kilo Oe, indicating weak magnetic interactions between the CuO2 and RuO2 planes. The temperature dependence of nuclear spin-lattice relaxation time T1 of 63Cu in RE=Y shows a ‘spin gap’ like behavior, suggesting the system is under-doped. 相似文献
783.
N-Methylation at the pyrazole ring by sequential treatment of 5-tributylstannyl-4-trifluoromethylpyrazole with LDA and iodomethane regioselectively provided the title compound in high yield. The addition reaction of 5-lithiated-4-trifluoromethylpyrazole with a wide range of electrophiles allowed easy and high-yielding introduction of substituents on position 5. 相似文献
784.
A. Zhang Y. Wei M. Kumagai Y. Koma 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(1):119-128
Summary The Minor Actinides Recovery from HLW by Extraction Chromatography (MAREC) process was used mainly for the separation of minor
actinides (MAs) and some specific fission products (FPs) from highly active liquid waste (HLW) by the composite CMPO/SiO2-P of the macroporous silica based polymeric octyl(phenyl)-N,N-diisobutylcarbamoylmethylphoshine oxide (CMPO) and others.
In this study a cascade of chromatographic separation was performed on a 3.0M HNO3 solution containing 5.0 . 10-3M of 13 elements, at 323 K. The cascade consisted of three columns the first and second ones were packed with CMPO/SiO2-P and the third with SiO2-P particles. The first column was employed to prepare various eluents containing saturated CMPO. The second column was used
for separation into groups. The CMPO of CMPO/SiO2-P was recovered from the effluent by the third column and a CMPO-free effluent containing minor actinides was obtained. The
elements contained in the simulated HLW of 3.0M HNO3 were separated into (1) a non-adsorption group (Sr, Cs, and Ru etc.), (2) a MA-hRE (heavy rare earth)-Mo-Zr group, and (3) a lRE (light rare earth) group by eluting with 3.0M HNO3, 0.05M DTPA (diethylenetriaminepentaacetic acid) (pH 2.0) and HNO3 (pH 3.5), respectively. The resultant MA-hRE-Mo-Zr mixture containing minor actinides was then separated into the groups (1) Pd-Ru, (2) MA-hRE, and (3) Mo-Zr by utilizing 3.0M HNO3, distilled water, and 0.05M DTPA (pH 2.0) as eluents. More than 92% of CMPO in the MA-hRE containing effluent was adsorbed by SiO2-P particles. The effectivity and technical feasibility of MAREC process were demonstrated. 相似文献
785.
The monopole map defines an element in an equivariant stable cohomotopy group refining the Seiberg-Witten invariant. Part I discusses the definition of this stable homotopy invariant and its relation to the integer valued Seiberg-Witten invariants. 相似文献
786.
Nitrogen‐Rich Manganese Oxynitrides with Enhanced Catalytic Activity in the Oxygen Reduction Reaction 下载免费PDF全文
Dr. Akira Miura Dr. Carolina Rosero‐Navarro Dr. Yuji Masubuchi Dr. Mikio Higuchi Prof. Dr. Shinichi Kikkawa Prof. Dr. Kiyoharu Tadanaga 《Angewandte Chemie (International ed. in English)》2016,55(28):7963-7967
The catalytic activity of manganese oxynitrides in the oxygen reduction reaction (ORR) was investigated in alkaline solutions to clarify the effect of the incorporated nitrogen atoms on the ORR activity. These oxynitrides, with rock‐salt‐like structures with different nitrogen contents, were synthesized by reacting MnO, Mn2O3, or MnO2 with molten NaNH2 at 240–280 °C. The anion contents and the Mn valence states were determined by combustion analysis, powder X‐ray diffraction, and X‐ray absorption near‐edge structure analysis. An increase in the nitrogen content of rock‐salt‐based manganese oxynitrides increases the valence of the manganese ions and reinforces the catalytic activity for the ORR in 1 m KOH solution. Nearly single‐electron occupancy of the antibonding eg states and highly covalent Mn?N bonding thus enhance the ORR activity of nitrogen‐rich manganese oxynitrides. 相似文献
787.
Toi Kobayashi Prof. Dr. Naoya Kumagai 《Angewandte Chemie (International ed. in English)》2023,62(32):e202307896
A new 15-membered-macrocyclic molecular entity, oxa-TriQuinoline (o-TQ), was designed and synthesized. In o-TQ, three oxygen atoms were joined onto three quinoline units at the 2- and 8-positions in a head-to-tail fashion by three-fold SNAr reactions, giving rise to the characteristic N3O3 aza-oxa-crown architecture. o-TQ can serve as a new tridentate nitrogen ligand to capture a CuI cation and adopt a bowl shape, before supramolecular complexation with corannulene and [12]cycloparaphenylene (CPP) occurs through π–π and CH–π interactions. In the presence of the CuI cation, the non-emissive o-TQ becomes a highly emissive material in the solid state, whereby the emission wavelengths depend on the ancillary ligand on the CuI cation. The o-TQ/CuI complex is able to promote carbene catalysis to provide a range of enamines with a gem-difluorinated terminus. 相似文献
788.
Daisuke Nagao Mikio Yokoyama Shu Saeki Yoshio Kobayashi Mikio Konno 《Colloid and polymer science》2008,286(8-9):959-964
Dual functions of magnetic and fluorescent properties were created in composite particles that incorporated magnetite (Fe3O4) nanoparticles in particle cores of silica and fluorescent pyrene in particle shells of polystyrene. The Fe3O4 nanoparticles were prepared with a conventional homogeneous precipitation method and surface modified with a coupling agent of carboxyethylsilanetriol. The silica particles incorporating Fe3O4 nanoparticles were synthesized with a modified Stöber method in which the Fe3O4 nanoparticles were added to a system of tetraethylorthosilicate (TEOS)/ammonia/water/ethanol. Then, the magnetite/silica composite particles were coated with the pyrene/polystyrene shell in a soap-free emulsion polymerization, which was conducted in the presence of pyrene in a mixed solvent of water/ethanol. The composite particles prepared in the mixed solvent had both magnetic and fluorescent properties. The fluorescent spectrum of the particles with Fe3O4 was very similar to that without Fe3O4, indicating that the magnetic component within the core particles scarcely interfered with the fluorescent emission from the polymer shell. 相似文献
789.
Naoaki Hayashi Shigetoshi Muranaka Mikio Takano Dong-Feng Zhang Chun-Hua Yan 《Journal of solid state chemistry》2008,181(12):3283-3286
A SnO2/α-Fe2O3 architectural nanocomposite, which was evidenced as SnO2 nanorod arrays assembled on the surface of α-Fe2O3 nanotubes in our previous study, was investigated microscopically by means of Mössbauer spectroscopic and magnetic measurements. It was found for the SnO2 nanorods that Fe3+ ions substituted slightly to Sn0.998Fe0.002O2. Concerning the α-Fe2O3 tubes, the Morin transition, which was completely suppressed in the mother, SnO2-free α-Fe2O3 nanotubes, was found to be recovered locally. We speculate that it takes place in the interface area as a result of structural modification needed for the connection with the SnO2 nanorods. 相似文献
790.
Shintaro Ishiwata Ichiro Terasaki Mikio Takano 《Journal of solid state chemistry》2008,181(5):1273-1278
A new magnetoplumbite-type hexagonal cobalt oxide, SrCo12O19, has been synthesized at a high pressure of 3 GPa and its structural and magnetic properties have been studied using single crystalline samples. Bond-valence calculations for five crystallographically independent Co sites show a rather wide charge distribution from +2.15 to +3.50. Magnetic measurements have revealed anisotropic magnetic behavior below a magnetic ordering temperature of 80 K. Comparative discussions on the structure-property relationship for SrCo12O19 and related compounds suggest the presence of localized spins with a uniaxial anisotropy at the trigonal bipyramidal site. 相似文献