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91.
Hirotsugu Ogawa Yasunari Harada Yohsuke Kyotani Toshihiro Ueda Satoru Kitazawa Kazuhisa Kandori 《Journal of carbohydrate chemistry》2013,32(4-5):729-738
Abstract Sulfo Lewisx analog containing 1-deoxynojirimycin (13) has been efficiently synthesized. Glycosidation of ethyl 2,3,4-tri-O-benzyl-1-thio-β-D-fucopyranoside (5) with O-2,6-di-O-benzoyl-3,4-isopropylidene-β-D-galactopyranosyl)-(1→4)-2,6-di-O-benzoyl-N-benzyloxycarbonyl-1,5-dideoxy-1,5-imino-D-glucitol (4), prepared from O-β-D-galactopyranosyl-(1→4)-1,5-dideoxy-1,5-imino-D-glucitol (1) via 3 steps, and subsequent acid hydrolysis of the isopropylidene group gave the desired trisaccharide diol derivative (7) in good yield. Compound 7 was easily converted into 3′-O-sulfo Lewisx analog (13) via 6 steps in high yield. 相似文献
92.
A reduced version of the Kogut-Susskind gauge theory is presented for U(∞) gauge theories. The reduced hamiltonian
, where Vij=trUiDiDjDj(UiDj) + (UiDj)+, is obtained by representing the group of space translations in the diagonal part of U(∞) U(∞). The space of states is invariant to the reduced gauge transformation Ui→ωUiDiω+Di+ and the scalar product carries a gauge invariant constraint on Ui The hamiltonian is also expr essed in terms of the string variables of Bars. We present the linear potential between static quarks at strong coupling and sketch the weak coupling expansion. 相似文献
93.
Takeshi Kawasaki Takafumi Kitazawa Tatsuru Nishimura Masami Nakada Masakatsu Saeki 《Hyperfine Interactions》2005,166(1-4):417-423
We now report the 237Np Mössbauer spectra for [NpO2(acac)2py] I. The neptunium(VI) ion in I is coordinated by six oxygen atoms and the one nitrogen atom of pyridine. The isomer shift value obtained for I is ?40 mm/s, which falls in the range for the Np(VI) oxidation state. The relationship between the isomer shift and Np–O bond distance of the neptunyl group for oxygen coordination compounds is in good agreement with the reported structure of I. It is well known that the mean Np–O bond distance of the neptunium compounds is shorter by 0.01 Å than that of analogous uranium compounds. The good agreement in the 237Np–Mössbauer parameters and the Np–O distance has indicated that the reported analogous [UO2(acac)2py] structure may have some inaccuracies. Therefore, we have re-determined the crystal structure of [UO2(acac)2py]. The U–O bond distance we have obtained is reasonable. 相似文献
94.
95.
New particles and new interactions reveal themselves most clearly where standard model contributions are negligibly small. A prominent example with this advantage is the one-lepton inclusive longitudinal structure function (WL) in e+ e? annihilation and Z-decay. We discuss general features of this approach and present structure functions for two types of new particles (heavy charged fermion, e.g. new sequential lepton or top quark; and supersymmetric scalar lepton, i.e. slepton), along with the (small) standard model “background”. The x-dependence of WL provides a distinct signature of the identity of the new particle. Extensions of this approach are discussed. 相似文献
96.
Vertically aligned one-dimensional ZnO nanowire arrays have been synthesized by a hydrothermal method on sol–gel derived ZnO films. Sol–gel derived ZnO films and corresponding ZnO nanowire arrays have been characterized by X-ray diffraction and field-emission scanning electron microscopy. The effect of sol–gel derived ZnO film surface on the morphology of ZnO nanowire arrays has been investigated. The authors suggest from our investigation that sol–gel derived ZnO films affect the growth of one-dimensional ZnO nanostructures. Not only crystalline ZnO films but also amorphous ones can act as a scaffold for ZnO nucleus. Tilted ZnO micro-rods are grown on ZnO gel films, whereas vertically aligned ZnO nanowire arrays are grown on nanometer-sized ZnO grains. The average diameter of ZnO nanowire arrays are correlated strongly with the grain size of sol–gel derived ZnO films. 相似文献
97.
98.
The reflectivity spectra of BaPb1?xBixO3 were measured in near-infrared region in several samples. The effective masses for the metallic samples of compositions from x = 0 to 0.25 were estimated from the observed plasma edges to be 0.5–0.8 me. These values are rather small comparing with those in other typical high Tc superconductors. 相似文献
99.
100.