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81.
Yasuhiro Kubota Toshihiro Shibata Jun Uehara Shinya Matsumoto Masaki Matsui 《Tetrahedron》2009,65(12):2506-296
2,3-Diaminomaleonitrile (DAMN) was allowed to react with 2,6-heptanedione to produce (2Z)-2-amino-3-[(1E)-3-methylcyclohex-2-enylideneamino]but-2-enedinitrile and (2Z)-2-amino-3-[(1Z)-3-methylcyclohex-2-enylideneamino]but-2-enedinitrile. The reaction of DAMN with 2,7-octanedione yielded trans-5,8a-dimethyl-1,5a,6,7,8,8a-hexahydrocyclopenta[e]-1,4-diazepine-2,3-dicarbonitrile. DAMN reacted with 2,8-nonanedione to afford trans- and cis-5,9a-dimethyl-5a,6,7,8,9,9a-hexahydro-1H-benzo[e]-1,4-diazepine-2,3-dicarbonitrile. These compounds were characterized by X-ray crystallography, NMR spectroscopy, and DFT calculations. 相似文献
82.
傅元勇 周书华T. Koike S. Kinoshita Y. Ma Y. Miura K. Miwa Y. Miyagi K. Shirotori T. Suzuki H. Tamura K. Tsukada M. Ukai K. Futatsukawa K. Hosomi M. Kawai M. Mimori N. Terada N. Maruyama K. Aoki H Fujioka Y Kakiguchi T. Nagae D. Nakajima H Noumi T Takahashi T.N. Takahashi A. Toyota M. Dairaku T. Fukuda S. Minami W. Imoto S. Aiimura K. Tanida 《中国物理快报》2007,24(8):2216-2218
From the ^12 C(π^+,K^+)^12 AC reaction the γ -rays of 261.6±0.24 ke V(7/2^+ →5/2^+)and 1481.7±0.7 ke V(1/2^+ →5/2^+) of ^11 A B,and 2667.3±2.8 keV(1^- 2 → 2^- 1)of ^12 A C hypernuclei have been identified using a large germanium detector array Hyperball2 at K6 beam line of KEK. The observed energies of the transitions 1481.7keV and 261.6 keV are significantly different from the values predicted by the shell model using the △ and SN parameters determined from the ^7 △ Li data. 相似文献
83.
Minemura Y Ito S Miyao T Naito S Tomishige K Kunimori K 《Chemical communications (Cambridge, England)》2005,(11):1429-1431
In preferential CO oxidation in H2-rich gas, K-Pt/Al2O3(K/Pt = 10) was very effective in decreasing CO concentration below 10 ppm in the 375-410 K range, and the turnover frequency of the K-Pt/Al2O3 was 20 times as high as that of Pt/Al2O3 at 353 K; furthermore, the activity of CO oxidation was promoted drastically by the presence of H2. 相似文献
84.
Prof. Dr. Yoshinobu Isono Toshihiro Kamohara Atsushi Takano Toshio Kase 《Rheologica Acta》1997,36(3):245-251
Simultaneous measurements of stress relaxation and differential dynamic modulus were made at 268 K over a time scale of 10 to 1045 s for nearly monodisperse polybutadiene (M
w
=2.2x105, 1,2-structure 70%, M
e
=3600) and also one having coarse cross-linking (M
c
=29000). Static shear strain ranged from 0.1 to 2.0. In a long-time region (t>
k
), the relaxation modulus G (; t) could be expressed by the product G (0; t) h (y). The observed h() agreed well with the Doi-Edwards theory without use of IA approximation. Both the cured and uncured samples showed initial drop of the differential storage modulus G (), ; t) followed by gradual recovery, but did not attain the value before shearing G (, ; t) for the uncured sample showed smaller values than that for the cured one in the whole measured time scale at the higher strain, confirming the two origins of nonlinear viscoelasticity of well entangled polymer; induced chain anisotropy and induced decrement in entanglement density. G (, ; t) curves for the cured sample agreed well with the BKZ predictions. But the curves for the uncured sample agreed well with the BKZ prediction only at the time scale of t<
k
. BKZ prediction showed significant upward deviations at t>
k
. Such the differences are discussed in terms of the two origins.Dedicated to Prof. John D. Ferry on the occasion of his 85th birthday. 相似文献
85.
Two new cycloartane glycosides, named aquilegiosides K and L, have been isolated from the dried underground parts of Aquilegia vulgaris. Their structures were determined by two dimensional (2D) NMR spectroscopic analysis and chemical evidence. 相似文献
86.
We investigate the photoluminescence (PL) properties of silver/porous-silicon (Ag/PSi) nanocomposites prepared by metal-assisted etching in solution, on the basis of steady-state and time-resolved PL spectroscopy measurements. The PL intensity and peak position are strongly dependent on the concentration. Time-resolved PL measurements reveal that the nonradiative rate decreases with an increase in the concentration for the Ag/PSi nanocomposites. It is found from x-ray photoelectron spectroscopy measurements that the decrease in the nonradiative rate is caused by the formation of layers on the PSi surfaces. Further, the number of light-emitting Si nanocrystals in the nanocomposites, which is estimated from the PL decay rate and PL intensity, increases with the concentration. From the wavelength dependence of the PL decay rate, it is found that the nonradiative rate is considerably dispersive, i.e., the shorter the wavelength, the higher the nonradiative rate. 相似文献
87.
Two novel aromatic glycosides were obtained from Puerariae Radix and their chemical structures were characterized. 相似文献
88.
N. Kawamura I. Higashino Y. Kimura M. Fujioka S. Hayashibe 《Zeitschrift für Physik A Hadrons and Nuclei》1994,348(3):173-176
Nuclearg-factors of the 1229 keV 13+/2 and 2911 keV 21+/2 level and the half-life of the 1229 keV level have been measured to beg(1229)=0.058(5),g(2911)=0.69(12) andT
1/2 (1229)=6.79(2) ns. The experimental g-factors show that the 1229 keV level has a dominant configuration of (f
7/23–), and the 2911 keV level has an almost pure (f
7/27–), configuration.The authors would like to thank the crew of CYRIC for the operation of the cyclotron. 相似文献
89.
Akemi Umeyama Chihiro Ohta Yukari Shino Minori Okada Yukari Nakamura Tatsuya Hamagaki Hiroshi Imagawa Masami Tanaka Aki Ishiyama Masato Iwatsuki Kazuhiko Otoguro Satoshi Ōmura Toshihiro Hashimoto 《Tetrahedron》2014
During the search for new antitrypanosomal drug leads, three new antitrypanosomal compounds, hexatenuins A–C (1–3), were isolated from the fruiting body of Hexagonia tenuis. 1 and 3 possessed an unusual malonate half-ester functional group at C-3 position, and 1 and 2 had a spirostructure in the side-chain. Their structures were elucidated using MS analyses, extensive 2D-heteronuclear NMR data interpretation. Compounds 1–3 showed in vitro antitrypanosomal activity against Trypanosoma brucei brucei with IC50 values of 0.57, 8.60 and 5.62 μg/ml, respectively. 相似文献
90.
Masahiro Manabe Toshihiro Ochi Hideo Kawamura Hajime Katsu-ura Masaki Shiomi Mandeep Singh Bakshi 《Colloid and polymer science》2005,283(7):738-746
The partial molar volumes (Va) of 1-alkanols (carbon number, m=5, 6, 7) in - and -cyclodextrin (CD) solutions at 5.00 mmol kg–1 have been determined as a function of alkanol concentration (Ca) between 293.2 and 308.2 K by using a dilatometer. It has been observed that with an increase in Ca, Va increased in -CD solution but decreased in -CD solution, asymptotically to a value of Va in CD-free water. The dependence of Va on Ca provided the binding constant (K) of 1:1 complex, the volume change in complex formation, and the partial molar volume of complex itself. The complex formation mechanism has been discussed on the basis of these values and their carbon number dependences in the respect of geometric behavior, hydrophobic interaction, and van der Waals interaction. It is concluded that the CD cavity in water is not rigid but flexible for fitting in nicely with guest molecule. 相似文献