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101.
Keigo Aoi Kaname Tsutsumiuchi Ayami Yamamoto Masahiko Okada 《Macromolecular rapid communications》1998,19(1):5-9
Sugar-substituted α-amino acid N-carboxyanhydrides (glycoNCAs), i.e., O-(tetra-O-acetyl-β-D -glucopyranosyl)-L -serine NCA (2a ) and O-(2-acetamido-3,4,6-tri-O-acetyl-2-deoxy-β-D -glucopyranosyl)-L -serine NCA (2b ), were successfully used for the introduction of a mono(glycopeptide) unit into each terminal primary amino group of a dendrimer. Well-defined dendrimer-based artificial glycoconjugates, O-(β-D -glucopyranosyl)-L -serine-persubstituted poly(amido amine) (PAMAM) dendrimer (3a ) and O-(2-acetamido-2-deoxy-β-D -glucopyranosyl)-L -serine-persubstituted PAMAM dendrimer (3b ), were synthesized by polymer reaction of PAMAM dendrimer with 2a and 2b , respectively, followed by deacetylation with hydrazine monohydrate. 相似文献
102.
Toyoki Matsuyama 《The European Physical Journal C - Particles and Fields》1999,8(1):163-169
We investigate the canonical structure of the (2+1)-dimensional non-linear model in a polynomial formulation. A current density defined in the non-linear model is a vector field, which satisfies a formal flatness (or pure gauge) condition. It is the polynomial formulation in which the vector field is regarded as a dynamic variable
on which the flatness condition is imposed as a constraint condition by introducing a Lagrange multiplier field. The model
so formulated has gauge symmetry under a transformation of the Lagrange multiplier field. We construct the generalized Hamiltonian formalism of the model
explicitly by using the Dirac method for constrained systems. We derive three types of the pre-gauge-fixing Hamiltonian systems:
In the first system the current algebra is realized as the fundamental Dirac Brackets. The second one manifests the similar
canonical structure as the Chern-Simons or BF theories. In the last one there appears an interesting interaction as the dynamic
variables are coupled to their conjugate momenta via the covariant derivative.
Received: 29 September 1998 / Published online: 14 January 1999 相似文献
103.
For the singly charged 53 cations from Li+ to Cs+ and 43 anions from H− to I− in their ground states, spherically averaged electron-pair intracule (relative-motion) density h(u), extracule (center-of-mass-motion) density d(R), and their moments un and Rn are examined, where u and R are the interelectronic distance and the center-of-mass radius of a pair of electrons, respectively. The intracule and extracule densities of all the 96 ions are found to be monotonically decreasing functions, as for neutral atoms. Approximate relations d(R)8h(2R) and un/Rn2n are confirmed to be valid for the charged atoms as well. 相似文献
104.
It is found numerically that the time-bandwidth product (TBP) of optical pulse from a gain-switched semiconductor laser operating under a sufficient gain saturation condition increases monotonously with increasing modulation amplitude. This enhancement of the TBP becomes remarkable for longer-wavelength semiconductor lasers (1.3, 1.55 μm) having large value of the gain compression factor ε (∼ 10−23 m3), making the pulse chirp estimation using the TBP difficult. 相似文献
105.
Tatsushi Matsuyama Hideo Yamamoto Brian Scarlett 《Particle & Particle Systems Characterization》2000,17(2):41-46
If a particle is not spherical, the Fraunhofer diffraction pattern is not circular, however the particle size distribution obtained from conventional particle sizer are made under the assumption of spherical particle. It is, therefore, necessary to discuss or interpret the relationship between the obtained equivalent diameter and the diffraction pattern. In this paper, this transformation problem was discussed principally for the case of ellipsoid particle. A relationship between an original size of ellipsoid and obtained equivalent particle size distribution was given in an analytical expression. The equivalent particle size clearly had double peaks in the size corresponding both to the minor and major diameter of the original ellipsoid. On the other hand, if the original particle had its own size distribution, the double peak was eliminated due to the effect of this original size distribution. In the case of random orientation of the ellipsoid in the sensing zone, the double peak was also eliminated and a rather clear single peak appeared at the minor diameter of the original ellipsoid. 相似文献
106.
Mitsuo Kira Takakazu Hino Yasushi Kubota Naoko Matsuyama Hideki Sakurai 《Tetrahedron letters》1988,29(52):6939-6942
Reduction of 1,1-bis(trimethylsilyl)ethylene by alkali metal led to the facile dimerization to the 1,1,4,4-tetrakis(trimethylsilyl)butane-1,4-diyl dianion which has been found to be utilized as a reagent for the Peterson reaction. 相似文献
107.
108.
109.
Xunyao Fu Tatsuo Maruyama Tomohiro Sotani Hideto Matsuyama 《Journal of membrane science》2008,320(1-2):483-491
A serious problem faced during the application of membrane filtration in water treatment is membrane fouling by natural organic matter (NOM). The hydrophilicity, zeta potential and morphology of membrane surface mainly influence membrane fouling. The aim of the present study is to reveal the correlation between membrane surface morphology and membrane fouling by use of humic acid solution and to investigate the efficiency of backwashing by water, which is applied to restore membrane flux. Cellulose acetate butyrate (CAB) hollow fiber membranes were used in the present study. To obtain the membranes with various surface structures, membranes were prepared via both thermally induced phase separation (TIPS) and nonsolvent-induced phase separation (NIPS) by changing the preparation conditions such as polymer concentration, air gap distance and coagulation bath composition. Since the membrane material is the same, the effects of hydrophilicity and zeta potential on membrane fouling can be ignored. More significant flux decline was observed in the membrane with lower humic acid rejection. For the membranes with similar water permeability, the lower the porosity at the outer surface, the more serious the membrane fouling. Furthermore, the effect of the membrane morphology on backwashing performance was discussed. 相似文献
110.