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891.
K. Asahi H. Okuno H. Ueno H. Sato J. Kura T. Kubo T. Nakamura N. Inabe A. Yoshida Y. Ohkubo M. Adachi T. Ichihara M. Ishihara T. Shimoda H. Miyatake N. Takahashi D. Beaumel D. J. Morrissey W. -D. Schmidt-Ott 《Hyperfine Interactions》1992,75(1-4):101-108
Ejectile nuclei in the fragmentation of intermediate-energy heavy-ion projectiles were found to be largely spin polarized.
The observed polarization as a function of the outgoing momentum was nicely explained by a simple kinematical argument based
on the participant-spectator model of projectile fragmentation. The measurements extended to cover several different targets,
incident energies, exit channels, and emission angles revealed that substantial polarization shows up widely in projectile
fragmentation reactions. Furthermore, this polarization exhibits an interesting behavior which may be interpreted as a manifestation
of a gradual change in the deflection angle from positive to negative values as the energy increases and/or the target-Z decreases. The present polarization results also suggests various applications of spin polarized radioactive beams. As the
first example of such an application, we present a recent result on theg-factor measurements on neutron-rich nuclei. 相似文献
892.
Nobumoto?NagasawaEmail author Shugo?Ikeda Aiko?Shimoda Takeshi?Waki Yoshikazu?Tabata Hiroyuki?Nakamura Hisao?Kobayashi 《Hyperfine Interactions》2016,237(1):39
The 57Fe Mössbauer spectra of the single crystalline and the finely ground Sr1?x La x Fe12?y Co y O19 (x = 0 : y = 0, x = 0.192 : y = 0.152 and x = 0.456 : y = 0.225) samples have been measured to investigate the La-Co substitution effects. All observed spectra at 150 K were well fitted using the five subspectra which correspond to the five crystallographical nonequivalent Fe sites in the M-type hexaferrite, indicating that the valence changes to Fe2+ ions in the Fe3+ ions were not observed in our Sr1?x La x Fe12?y Co y O19 samples. In SrFe12O19, the relative absorption intensities in the five subspectra show the large anisotropies in the recoilless fractions at the five Fe sites whereas these anisotropies were not observed in Sr0.544La0.456Fe11.775Co0.225O19. These results indicate the chemical compositional dependence on the anisotropies of the recoilless fractions at the five Fe sites. The substitution of a Co2+ ion for the Fe3+ ion changes the center shifts of the Fe3+ ions near the Co2+ ion by the perturbation of the Fe-O-Co hybridizations. Therefore, the Co2+ ions occupy the 4f 1 and the 4f 2 sites due to the chemical compositional dependences of the refined magnetic hyperfine field and center shifts of the Fe3+ ions. 相似文献
893.
Nakamura H Ishikura M Sugiishi T Kamakura T Biellmann JF 《Organic & biomolecular chemistry》2008,6(8):1471-1477
Mono- and 1,3-disubstituted allenes were synthesized from the corresponding propargylamines via palladium-catalysed hydride-transfer reaction. In the current transformation, propargylic amines can be handled as allenyl anion equivalents and introduced into various electrophiles to be transformed into allenes under palladium-catalyzed conditions. 相似文献
894.
Organometallic polymers containing tricarbonyl(η4-diene)-ruthenium(0) and -iron(0) as pendant groups
Hajime Yasuda Yoshitsugu Morita Ippei Noda Kyoko Sugi Akira Nakamura 《Journal of organometallic chemistry》1981,205(2):C9-C13
Vinyl ethers containing tricarbonyl(14-η4-1,3-pentadiene)-ruthenium(0) and -iron(0) species were prepared utilizing selective dienylation with penta-dienylpotassium and were polymerized with cationic initiators to give high molecular weight polymers. The diene-metal moieties were converted into tricarbonyl(13-η3-allyl)metal species by protonation with dry HCl. Tricarbonyl(3-allyl-14-η4-1,3-pentadiene)iron(0) also undergoes cationic polymerization but the presence of its isomer, tricarbonyl(3-propenyl-14-η4-1,3-pentadiene)iron(0) inhibits the polymerization. 相似文献
895.
Mikita K Nakamura M Hoshi N 《Langmuir : the ACS journal of surfaces and colloids》2007,23(17):9092-9097
Structural effects on the adsorption of CO have been studied using infrared reflection absorption spectroscopy (IRAS) on Pt(S)-[n(100)x(110)] surfaces (n = 2, 5, 9) that have densely packed kink atoms in the step. Coverage and potential dependence of the IRAS spectra are scrutinized. On-top and bridge-bonded CO are found on all of the surfaces examined. CO is adsorbed on only kink at low coverage (thetaCO < or = 0.2). Adsorbed CO on kink gives an IR band at lower frequency than that on step. CO is adsorbed on both kink and terrace at 0.3 < or = thetaCO. Water is adsorbed on the terrace of Pt(510) n = 5 and Pt(910) n = 9 at low CO coverage, but water is not found on Pt(210) n = 2 of which the first layer is composed of only kink atoms. It is suggested that coadsorbed water on the terrace enhances the activity for the oxidation of adsorbed CO on the kink remarkably. 相似文献
896.
Tadashi Nakamura Per B. Zetterlund Masayoshi Okubo 《Macromolecular rapid communications》2006,27(23):2014-2018
Summary: 2,2,6,6‐Tetramethylpiperidinyl‐1‐oxy (TEMPO)‐mediated radical polymerization of styrene in aqueous miniemulsion at 125 °C using sodium dodecylbenzenesulfonate and poly(vinyl alcohol), respectively, as colloidal stabilizers has been investigated. The particle size had a dramatic effect on the polymerization process. Decreasing particle size led to a markedly higher polymerization rate, but less control and a lower degree of livingness. For particles with diameters greater than approximately 170 nm, the polymerization behavior was essentially the same as in the corresponding bulk system. By varying the particle size within an appropriate range, it is possible to tune the polymerization such that the polymerization rate is increased while still maintaining reasonable control and livingness.
897.
Core-shell nanoparticles of Au@silica with a diameter of approximate 45–60 nm and wall thickness in range of 3–10 nm were synthesized by using 40 and 50 nm gold nanoparticles as the templates. The mesoporous particles are regulated by 3-aminopropyltrimethoxysilane addition. Hollow mesoporous silica nanocapsules (HMSNs) were prepared by using sodium cyanide to dissolve the gold cores. The characterization of Au@silica and HMSNs by transmission electronic microscope indicated that the silica shells were uniform and smooth, and also the porosity was proved by fluorescein isothiocyanate (FITC) release experiments. The ratio of hollow core to HMSNs is more than 70%. HMSNs were subsequently used as drug carrier to investigate FITC (as a model drug) release behaviors in vitro. Fluorescent spectrometry was performed to determine the release kinetics from the HMSNs. The release profiles are significantly different as compared with the control (free FITC), which show that HMSNs are good drug carriers to control drug release, and have high potential in therapeutic drugs delivery in future applications. 相似文献
898.
899.
900.
Saori Ichinose Mayumi Nakamura Mayu Maeda Rie Ikeda Mitsuhiro Wada Mio Nakazato Yoshihito Ohba Noboru Takamura Takahiro Maeda Kiyoshi Aoyagi Kenichiro Nakashima 《Biomedical chromatography : BMC》2009,23(9):935-939
A semi‐micro column HPLC‐fluorescence method for routine determination of thiol derivatives such as homocysteine (Hcy), cysteine (Cys) and cysteamine (CA) is described. The thiol derivatives labeled with ammonium‐7‐fluorobenzo‐2‐oxa‐1,3‐diazole‐4‐sulfonate (SBD‐F) were isocratically separated within 12 min on a semi‐micro ODS column (Daisopak‐SP‐120‐5‐ODS‐BP) with a mixture of 25 mm acetate buffer (pH 2.00) and CH3CN as a mobile phase. The purity and similarity of SBD‐thiols by a multi‐wavelength fluorescence detector were more than 92.3 and 96.7%. The detection limits of Hcy, Cys and CA at a signal‐to‐noise ratio of 3 were 0.16, 0.47 and 0.03 µm , respectively. Furthermore validation parameters such as accuracy, precision and robustness of the proposed method showed satisfactory results. Almost 850 plasma sample injections (range 572–1076, n = 3) for a column could be performed without differences in retention time and peak heights of labels. As an application of the proposed method, the determination of thiol derivatives in normal human plasma (n = 103) was demonstrated. The correlation coefficients between Hcy vs Cys and Hcy vs CA were 0.38 and −0.35, respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献