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991.
Counter‐Anion‐Regulated Mixed‐Valency of Cobalt(II/III) Centers in a Metallosupramolecular Framework
A diamagnetic AuI4CoIII2 hexanuclear complex, [Au4Co2(dppe)2(l ‐nmc)4]2+ ([ 1L ‐ nmc ]2+; dppe=1,2‐bis(diphenylphosphino)ethane, l ‐H2nmc=N‐methyl‐l ‐cysteine), was newly synthesized by the reaction of [Co(l ‐nmc)2]? with [Au2Cl2(dppe)] and crystallized with different inorganic anions (X=ClO4?, NO3?, Cl?, SO42?) to produce ionic solids ([ 1L ‐ nmc ]Xn). Single‐crystal X‐ray analysis revealed that all the solids crystallize in the chiral space group F432 with a face‐centered‐cubic lattice structure consisting of supramolecular octahedra of complex cations. The paramagnetic nature of all the solids was evidenced by magnetic susceptibility measurements, showing the variation of the oxidation states of two cobalt centers in [ 1L ‐ nmc ]n+ from CoII1.00CoIII1.00 for X=ClO4? or NO3? to CoII0.67CoIII1.33 for X=Cl?, via CoII0.83CoIII1.17 for X=SO42?. The difference in the CoII/III mixed‐valences was explained by the difference in sizes and charges of counter anions accommodated in lattice interstices with a fixed volume. 相似文献
992.
Shoji Kobayashi Tomoki Tamura Saki Yoshimoto Takashi Kawakami Araki Masuyama 《化学:亚洲杂志》2019,14(21):3921-3937
4‐Methyltetrahydropyran (4‐MeTHP) is a hydrophobic cyclic ether with potential for industrial applications. We herein report, for the first time, a comprehensive study on the performance of 4‐MeTHP as an organic reaction solvent. Its broad application to organic reactions includes radical, Grignard, Wittig, organometallic, halogen‐metal exchange, reduction, oxidation, epoxidation, amidation, esterification, metathesis, and other miscellaneous organic reactions. This breadth suggests 4‐MeTHP can serve as a substitute for conventional ethers and harmful halogenated solvents. However, 4‐MeTHP was found incompatible with strong Lewis acids, and the C?O bond was readily cleaved by treatment with BBr3. Moreover, the radical‐based degradation pathways of 4‐MeTHP, THP and 2‐MeTHF were elucidated on the basis of GC‐MS analyses. The data reported herein is anticipated to be useful for a broad range of synthetic chemists, especially industrial process chemists, when selecting the reaction solvent with green chemistry perspectives. 相似文献
993.
Shigeki Matsuo Haruki Sumi Satoshi Kiyama Takuro Tomita Shuichi Hashimoto 《Applied Surface Science》2009,255(24):9758-9760
A femtosecond laser-assisted etching technique was applied to Pyrex glass, a kind of borosilicate glass, to perform removal processing with three-dimensional arbitrarity in design and micrometer-order spatial resolution. An aqueous solution of potassium hydroxide (KOH) was adopted as a highly selective etchant. The rate and selectivity of etching were evaluated from in situ images, and fabrication of three-dimensional microchannels was demonstrated. 相似文献
994.
Takayuki Kumada Yohei Noda Takeji Hashimoto Satoshi Koizumi 《Physica B: Condensed Matter》2009,404(17):2637-2639
We have developed a dynamic nuclear polarization (DNP) system for the SANS-J-II spectrometer at the JRR-3 atomic research reactor of Japan Atomic Energy Agency (JAEA). The DNP system is composed of a split-type horizontal superconducting magnet (3.3 T), a Gunn oscillator as a microwave source (94 GHz), and a cryostat (1.2 K). In particular, a sample cell with 40 in inner diameter and the magnet with a field homogeneity of 5×10−5 in a volume of 25 mm×8 mm were employed to polarize samples with a diameter of 20 mm for the ultra small-angle scattering experiment using the magnetic lens installed at the SANS-J-II spectrometer [S. Koizumi, H. Iwase, J. Suzuki, T. Oku, R. Motokawa, H. Sasao, H. Tanaka, D. Yamaguchi, H.M. Shimizu, T. Hashimoto, J. Appl. Crystallogr. 40 (2007) s474]. We obtained the proton polarization |P|=32% in the polyethylene doped with 2,2,6,6-tetra-methyl-piperidine-1-oxyl (TEMPO). 相似文献
995.
A. Murakami H. Miyata R. Hashimoto K. Otaka K. Katagiri A. Iwamoto 《Physica C: Superconductivity and its Applications》2009,469(15-20):1207-1210
Mechanical properties of low porosity Dy123 (DyBa2Cu3Ox) bulks with different Dy211 (Dy2BaCuO5) content were evaluated through bending tests and Vickers indentation tests of specimens cut from the bulks. The bending strength and the Young’s modulus of the low porosity bulks were higher than those of porous Dy123 bulks evaluated in the previous study. The bending strength of the low porosity bulks, which was decreased by the oxygen annealing, increased with increase of the Dy211 content. The fracture toughness of the area with uniform dispersion of the Dy211 particles was superior to that with low density of the Dy211 particles. 相似文献
996.
Takaaki Sakai Hiroshige Matsumoto Reiri Yamamoto Takao Kudo Sachio Okada Masato Watanabe Shin-ichi Hashimoto Hitoshi Takamura Tatsumi Ishihara 《Ionics》2009,15(6):665-670
An electrode design with no use of three-phase boundary was investigated using palladium electrode. The hydrogen evolution
rate of the palladium electrode cell using SrZr0.9Y0.1O3 − α
electrolyte followed Faraday’s law up to 180 mA cm−2, and the anode and cathode overpotentials were significantly lower than those of a platinum electrode cell, suggesting that
the palladium electrode is effective to improve the performance of the hydrogen-pumping cell using SrZrO3-based electrolyte. The rate-determining step (RDS) for electrode reaction was also investigated by changing the electrode
morphology and hydrogen partial pressure, and it was suggested that the RDS of the anode is a reaction at electrode/electrolyte
interface. 相似文献
997.
Mitsuhiro Okuda Masaki Takeguchi Motohiro Tagaya Toru Tonegawa Ayako Hashimoto Nobutaka Hanagata Toshiyuki Ikoma 《Micron (Oxford, England : 1993)》2009,40(5-6):665-668
Elemental distribution of calcium, phosphorus, oxygen, and carbon in a single collagen fibril obtained from tilapia fish scales was identified with an electron energy-loss spectroscopy and an energy-filtered transmission electron microscopy, for the first time. The carbon intensity profile of the single collagen fibril showed the specific D-periodic pattern at 67 nm of type I collagen fibrils. The calcium L2,3-edge and oxygen K-edge peak positions were detected at 347/350 eV and 137 eV, respectively, and these positions were identical to those of hydroxyapatite. Calcium, phosphorus, and oxygen were present in the hole zones as the amorphous phase, while carbon was present in the overlap zone. Our results indicated that the hole zones preferentially attract calcium and phosphate ions and thus serve as possible nucleation sites for mineralization. 相似文献
998.
HAN Yun-cheng N.Chiga Y.Fujii K.Futatsukawa O.Hashimoto K.Hirose T.Ishikawa H.Kanda M.Kaneta D.Kawama Konno MA Yue K.Maeda T.Maruta N.Maruyama A.Matsumura Y.Miyagi K.Miwa S.N.Nakamura A.Sasaki H.Shimizu K.Shirotori K.Suzuki T.Tamae H.Tamura K.Tsukada WANG Tie-shan H.Yarnazaki 《原子核物理评论》2009,26(Z1)
The reactions γd→π~- pp and γd→npπ~+π~- have been studied in an energy range from 0.8 to 1.1 GeV at the tagged photon facility of Laboratory of Nuclear Science,T ohoku University.Charged pions and protons in the final state were measured by using the Neutral Kaon Spectrometer (NKS2).The analysis of the γd→π~- pp was mainly used to check the acceptance of the NKS2 and to calibrate the tagged photon energy.The photoproduction of the Δ~(++)Δ~- was identified in the γd→npπ~+π~- reaction.Since the data analyses are still in progress,we issue an interim report and preliminary results. 相似文献
999.
D.Kawama A.Acha I.Albayrak D.Androic O.Ates P.Baturin B.Beckford W.Boeglin A.Bruell C.Chen M.Christy R.Ent H.Fenker Y.Fujii M.Furic D.Gaskell S.Gogami O.Hashimoto T.Horn V.Hungerford Ed M.Jones H.Kanda C.Keppel M.Kohl L.Kramer Y.Li A.Liyanage P.Markowitz T.Maruta A.Matsumura S.N.Nakamura T.Petkovic B.Raue J.Reinhold T.Seva A.Shichijo G.Smith L.Tang N.Taniya W.Vulcan T.Walton S.A.Wood T.Yamamoto Z.Ye K.Yokota L.Yuan L.Zhu 《原子核物理评论》2009,26(Z1)
We are now preparing for the third generation (e,e′K~+) A hypernuclear spectroscopic experiment at Hall C,Jefferson Lab (USA).The goal of the experiment is the precise spectroscopy of hypernuclei in wide mass region.We have constructed a new high resolution electron spectrometer "HES" dedicated to (e,e′K~+) hypernuclear study in Japan and it was shipped to JLab in February,2008.We will discuss about the physics of the (e,e′K~+) hypernuclear study at JLab and report the current preparation status of the third generatrion experiment. 相似文献
1000.
Mori N Miki Y Fushimi Y Kikuta K Urayama S Okada T Fukuyama H Hashimoto N Togashi K 《Magnetic resonance imaging》2008,26(6):835-840
Moyamoya disease (MMD) is a rare disorder of unknown etiology in which terminal portions of the internal carotid arteries become steno-occlusive, with fine collateral "moyamoya vessels" formed secondarily, resulting in serial ischemic strokes throughout its clinical course. Whole-brain histogram (WBH) of diffusion tensor imaging (WBH-DTI) is an analytical tool whose feasibility has been ascertained in various pathologies. To elucidate whether WBH-DTI could detect any difference between ischemic MMD and normal controls, we examined 27 consecutive MMD patients without hemorrhage and 48 normal controls in this prospective study using a 3.0-T magnetic resonance scanner. WBHs of fractional anisotropy (FA) (WBH-FA) and mean diffusivity (MD) (WBH-MD) were compared among three groups: Group 1, MMD patients with infarct (n=15); Group 2, MMD patients without infarct (n=12); and Group 3, normal controls (n=48). Group 1 showed significantly higher peak height and significantly lower mean value on WBH-FA, as well as significantly lower peak height and significantly higher mean value on WBH-MD, compared with Groups 2 and 3. No significant difference was seen in parameters at either WBH-FA or WBH-MD between Groups 2 and 3. These results might reflect the pathological severity of each group, and WBH-DTI could feasibly detect differences between ischemic MMD with infarction and MMD without infarction and normal controls. 相似文献