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991.
M. Piiparinen Y. Nagai P. Kleinheinz M. C. Bosca B. Rubio M. Lach J. Blomqvist 《Zeitschrift für Physik A Hadrons and Nuclei》1991,338(4):417-421
In-beamγ-ray and conversion electron measurements with (α, xn) reactions have established the145Sm highspin states up toI π=25/2+ at 3.5 MeV excitation. A shell model analysis using empirical two- and one-body energies from neighbouring nuclei classifies the low-lying odd-parity levels as 3-quasiparticle states formed by the144Sm two-proton-hole excitations and thef 7/2 valence neutron. The higher-lying positive-parity states involve particle-hole core excitations with one proton inh 11/2. 相似文献
992.
993.
Juzo Nakayama Hidetoshi Sugiura Atsuko Shiotsuki Masamatsu Hoshino 《Tetrahedron letters》1985,26(18):2195-2198
A variety of 1,3-oxathiolanes undergo a benzyne-induced fragmentation leading to phenyl vinyl sulfides and carbonyl compounds. The reaction developed here provides a novel method for deprotection of carbonyl compounds from 1,3-oxathiolanes, preparation of phenyl vinyl sulfides, and 1,2-carbonyl transposition. 相似文献
994.
Ken-Ichi Okamoto Kazuhiro Tanaka Osamu Yokoshi Hidetoshi Kita 《Journal of Polymer Science.Polymer Physics》1989,27(3):643-654
Sorption and transport of carbon dioxide were investigated for poly(4,4'-oxydiphenylene-pyromellitimide) films (PI-1, PI-2, and PI-3) imidized at 160, 200, and 400°C, respectively, as well as for a chemically identical commercial polyimide film, Kapton-H. The solubility, permeability, and diffusion coefficients (S, P, and \[ \overline D \] , respectively) at 80°C and 20 atm in PI-3 were 67, 25, and 37%, respectively, as large as those in PI-2. These significant reductions are attributed to a higher degree of segmental aggregation in PI-3 caused by a 1.7% increase in the density (d) as compared with PI-2. The differences in S, P, \[ \overline D \] , and d between PI-3 and Kapton-H were rather small as compared with those between PI-3 and PI-2, suggesting that the in-plane orientation has a minor effect on the sorption and transport in Kapton-H as compared with the aggregation. Influence of the morphology on the dual-mode sorption and transport parameters was also investigated. With increasing density, the Langmuir capacity constant and the diffusion coefficients for the Henry's law and Langmuir populations decreased by higher rates than the Henry's law solubility constant, being contrary to the results reported for a typical semicrystalline glassy polymer, polyethylene terephthalate. This may suggest that the nonaggregated or less-aggregated regions taking an important part in the sorption and transport are denser for the sample having a higher overall density. 相似文献
995.
996.
Keiichi Nagai Chikashi Yamada Yasuki Endo Eizi Hirota 《Journal of Molecular Spectroscopy》1981,90(1):249-272
The ν1 (CO stretching) and ν2 (CF stretching) bands of the FCO radical were observed with Doppler-limited resolution by an infrared diode laser spectrometer with Zeeman and source modulation. The FCO radical was generated by a 60-Hz discharge in one of the following three gas mixtures: O2 + C2F4, CO + SF6, and CO + C2F4, all diluted with He. The observed spectra were analyzed to determine the rotational constants, the centrifugal distortion constants, and the spin-rotation interaction constants. The band origins, 1861.6372(1) and 1026.1283(1) cm?1 [with standard errors in parentheses], which were obtained, were found to agree well with matrix data, 1857 and 1023 cm?1, respectively. The assignment of the observed spectra to the FCO radical was further supported by observing the ν1 band of F13CO, which was obtained from 13CO and SF6. The molecular structure and the force field of FCO are briefly discussed by using molecular constants obtained from the observed spectra. 相似文献
997.
998.
999.
N4-(4-Carboxybutyryl)-1-beta-D-arabinofuranosylcytosine (glu-ara-C), the conjugate of glu-ara-C and poly-L-lysine (PLL), (PLL-glu-ara-C), and the conjugate of glu-ara-C and decylenediamine-dextran T70 (T70-C10), (T70-C10-glu-ara-C), were prepared. Drug regeneration from glu-ara-C and the conjugates was investigated in buffered solutions of pH 4,5,7,7.4 and 8. The character of the drug release from the conjugates was different from that from glu-ara-C. Namely, the release of 1-beta-D-arabinofuranosylcytosine (ara-C) from glu-ara-C was accelerated under both weakly acidic and weakly basic conditions, while it was accelerated only under weakly basic conditions from the conjugates. Overall, the drug release profiles from the conjugates showed similar patterns. However, under neutral and weakly basic conditions, ara-C was regenerated more rapidly from PLL-glu-ara-C than from T70-C10-glu-ara-C. During the incubation of glu-ara-C and the conjugates under weakly acidic conditions, 1-beta-D-arabinofuranosyluracil (ara-U) was detected and its amount increased with time to similar extents. 相似文献
1000.
The chemical reaction between SiO2 and tetragonal zirconia polycrystal (TZP) was directly observed using a TEM in-situ heating technique in order to understand the behavior of SiO2 in TZP at high temperatures. Their dynamic interaction was recorded up to about 1400°C using a CCD camera-video system connected to the TEM. Most of SiO2 phase dissolved into the ZrO2 grains above 1300°C. On the other hand, during cooling from the high temperature to around 400°C, amorphous SiO2 reprecipitated from the surface of ZrO2 grains and formed a thin layer around the ZrO2 grains. This result agrees well with the fact that silicon segregates in the vicinity of grain boundaries in SiO2-doped TZP. In order to confirm the grain boundary segregation at high temperatures, we investigated grain boundaries in quenched specimens by high resolution electron microscopy (HREM), energy dispersive X-ray spectroscopy (EDS) and electron energy-loss spectroscopy (EELS). It was found that no amorphous phase was present between two adjacent grains in the quenched samples. EDS analysis revealed that silicon segregated at the grain boundaries and that the segregation layer was wider than that in as-sintered specimens. The electron energy loss near edge structure (ELNES) of O K-edge was measured from both grain boundary and grain interior in quenched specimen, and their spectra were interpreted by a first principles molecular-orbital (MO) calculation using the discrete-variational (DV)-X method. 相似文献