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61.
Toshiro Uchida Tsutomu Furuzono Kazuhiko Ishihara Nobuo Nakabayashi Mitsuru Akashi 《Journal of polymer science. Part A, Polymer chemistry》2000,38(17):3052-3058
Polystyrene core nanosphere particles possessing 2‐methacryloyloxyethyl phosphorylcholine (MPC) polymers on the corona were prepared by the free radical polymerization of hydrophilic polyMPC macromonomer and hydrophobic styrene with AIBN as a radical initiator in ethanol as a polar solvent. The morphology of the nanospheres was observed by transmission electron micrograph (TEM). The nanospheres were spherical in form and have a narrow size distribution. Their sizes could be controlled by varying the molecular weight of the macromonomer and the amount of it in feed. Electron spectroscopy for chemical analysis (ESCA) of the nanosphere surfaces suggested that polyMPC chains were located favorably on the surface of the nanosphere. The nanospheres having the polyMPC chains on their surfaces can be significant and useful materials in technological and medical fields. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3052–3058, 2000 相似文献
62.
Toshikazu Takata Fumio Sanda Toshiro Ariga Hideo Nemoto Takeshi Endo 《Macromolecular rapid communications》1997,18(6):461-469
A variety of cyclic carbonates was shown to undergo volume expansion on polymerization. The degree of volume expansion, which was measured by the density gradient tube method, was ranging from 1.1% to 7.7%. The volume expansion was examined by assuming a change in molecular interaction such as dipole moment between monomer and polymer states. 相似文献
63.
The smallness is proved of étale fundamental groups for arithmetic schemes. This is a higher dimensional analogue of the Hermite-Minkowski theorem. We also refer to the case of varieties over finite fields. As an application, we prove certain finiteness results of representations of the fundamental groups over algebraically closed fields. 相似文献
64.
T Takeguchi T Yamanaka K Asakura EN Muhamad K Uosaki W Ueda 《Journal of the American Chemical Society》2012,134(35):14508-14512
A randomly mixed monodispersed nanosized Pt-Ru catalyst, an ultimate catalyst for CO oxidation reaction, was prepared by the rapid quenching method. The mechanism of CO oxidation reaction on the Pt-Ru anode catalyst was elucidated by investigating the relation between the rate of CO oxidation reaction and the current density. The rate of CO oxidation reaction increased with an increase in unoccupied sites kinetically formed by hydrogen oxidation reaction, and the rate was independent of anode potential. Results of extended X-ray absorption fine structure spectroscopy showed the combination of N(Pt-Ru)/(N(Pt-Ru) + N(Pt-Pt)) ? M(Ru)/(M(Pt) + M(Ru)) and N(Ru-Pt)/(N(Ru-Pt) + N(Ru-Ru)) ? M(Pt)/(M(Ru) + M(Pt)), where N(Pt-Ru)(N(Ru-Pt)), N(Pt-Pt)(N(Ru-Ru)), M(Pt), and M(Ru) are the coordination numbers from Pt(Ru) to Ru(Pt) and Pt (Ru) to Pt (Ru) and the molar ratios of Pt and Ru, respectively. This indicates that Pt and Ru were mixed with a completely random distribution. A high-entropy state of dispersion of Pt and Ru could be maintained by rapid quenching from a high temperature. It is concluded that a nonelectrochemical shift reaction on a randomly mixed Pt-Ru catalyst is important to enhance the efficiency of residential fuel cell systems under operation conditions. 相似文献
65.
Garuda Fujii Toshiro Matsumoto Toru Takahashi Tsuyoshi Ueta 《Applied Physics A: Materials Science & Processing》2012,107(1):35-42
In a random system composed of dielectric materials, laser action is expected to occur from the light localization caused
by multiple scattering and interference effect. The wavelengths at which the laser oscillation occurs in random media depend
on the mean free path of continuous scattering. Since the mean free path of continuous scattering is dependent on the filling
factor, it is important to investigate systematically the effect of the filling factor for the laser action. In the present
study, we calculate the Poynting vectors of the light emitted from two-dimensional random media consisting of dielectric rods
with population inversion modeled by the negative imaginary part of relative permittivity. The spectra of the radiated Poynting
vectors from the two-dimensional random media are shown for several different filling factors and for various values of population
inversion. We try to find laser generation which occurs at low population inversion and discuss about the threshold of laser
action occurring in dielectric structures with different filling factors. We also study the spacial distribution of the electric
field amplitude in several frequency regions where light strongly amplifies. 相似文献
66.
Alekseev PA Mignot JM Nemkovski KS Rybina AV Lazukov VN Ivanov AS Iga F Takabatake T 《J Phys Condens Matter》2012,24(20):205601
Peculiarities in the lattice dynamics of the Kondo insulator Y bB(12) have been studied by inelastic neutron scattering. Selected phonon modes were traced above and below the temperature region (T ~ 50 K) where the gap opens in the electron density of states. The intensities of some low-energy modes exhibit an anomalous temperature dependence for q vectors close to the Brillouin zone boundary, suggesting a renormalization of the phonon eigenvectors. This effect is thought to arise from a coupling with magnetic excitations of the same symmetry, which exist at nearby energies. It is argued that this magnetovibrational coupling may in turn play a role in the steep temperature crossover existing in Y bB(12) between the low-temperature (Kondo insulator) and high-temperature (incoherent spin-fluctuation) regimes, which is rapidly suppressed by lighter Zr substitution. 相似文献
67.
Nobuhiro Innami Katsuhiro Shiohama Toshiro Soga 《Geometric And Functional Analysis》2012,22(5):1400-1406
Let M be a complete Riemannian manifold. We first prove that there exist at least two geodesics connecting p and every point in M if the tangent cut locus of ${p \in M}$ is not empty and does not meet its tangent conjugate locus. It follows from this that if M admits a pole and ${p \in M}$ is not a pole, then the tangent conjugate and tangent cut loci of p have a point in common. Here we say that a point q in M is a pole if the exponential map from the tangent space T q M at q onto M is a diffeomorphism. Using this result, we estimate the size of the set of all poles in M having a pole whose sectional curvature is pinched by those of two von Mangoldt surfaces of revolution, meaning that their Gaussian curvatures are monotone and nonincreasing with respect to the distances to their vertices. 相似文献
68.
ω-(Phenylthio)-ω-chloroalkyl acetates were allowed to react with MeLi (3.2 equiv) to give 2-(phenylthio) cycloalkanols which were produced by the regioselective intramolecular insertion by (phenylthio) carbenes. 相似文献
69.
G.M. Luke K. Kojima M. Larkin J. Merrin B. Nachumi Y.J. Uemura G.M. Kalvius A. Brückl K. Neumaier K. Andres G. Nakamoto M. Sirasi H. Tanaka T. Takabatake H. Fujii M. Ishikawa 《Hyperfine Interactions》1997,104(1-4):199-203
We present zero and longitudinal field μ SR measurements of single crystal and polycrystalline specimens of the heavy fermion
compound CePt2Sn2. Above 1 K the behaviour of the two samples is indistinguishable; the muon 1/T_1 increases with decreasing temperature until
25 K when it plateaus. The 1/T_1 relaxation rate differs strongly for the two cases below \sim\,0.8\ K. At 0.1 K a rate of
about 20 μ s-1 is seen in the polycrystal while in the single crystal it is only about 5 μ s-1. Even more revealing is the fact that longitudinal field decoupling spectra at very low temperatures demonstrate an essentially
static spin system to be present in the polycrystalline material while the single crystal shows definite dynamic spin properties.
We conclude that, in the presence of the distortion, long range magnetic order occurs below 0.9 K while in tetragonal symmetry
long range order is suppressed (probably due to frustration) and spin fluctuations remain for T\rightarrow0.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
70.
A new synthetically useful decarboxylative reduction of γ-carbamoyloxy-α,β-unsaturated esters with lithium dialkylcuprate under mild condition was described. 相似文献